Dialysis fluid heating systems

(Cross-reference of related applications) This application claims priority and benefit as a partial continuation application to US Provisional Patent Application No. 10 / 982,170 (named "High Convection Home Hemodialysis / Hemofiltration and Sorbent System", filed November 4, 2004). The application then claims priority and its interests in US Provisional Patent Application No. 60 / 517,730 (named "High Convection Home Hemodialysis / Hemofiltration And Sorbent System", filed November 5, 2003).

(Field of invention) The present disclosure relates generally to medical fluid systems, and more specifically to fluid heating for dialysis systems.

Due to a variety of causes, an individual's renal system can fail. Renal failure causes some physiological abnormalities. It is no longer possible to balance water and minerals or to shed daily metabolic loads. Also, toxic end products of nitrogen metabolism (urea, creatinine, uric acid, and others) can accumulate in blood and tissues.

Renal failure and impaired renal function have been treated with dialysis. Dialysis removes waste products, toxins, and excess water from the body, which the otherwise normally functioning kidneys remove. Dialysis treatment for renal function replacement is important for many because the treatment can save lives.

One type of renal failure therapy is peritoneal dialysis, in which a dialysis solution, also called dialysate, is injected into the patient's abdominal cavity via a catheter. The dialysate contacts the peritoneum of the abdominal cavity. Waste products, toxins, and excess water pass through the patient's bloodstream through the peritoneum into the dialysate by diffusion and penetration, i.e., an osmotic gradient is generated across the membrane. The used dialysate is drained from the patient and removes waste products, toxins, and excess water from the patient. This cycle is repeated.

There are various types of peritoneal dialysis therapy, including automatic peritoneal dialysis (APD), periodic flow dialysis, and continuous flow peritoneal dialysis (CFPD).

Automatic peritoneal dialysis (APD) is generally a batch therapy that involves drainage, filling, and retention cycles. However, the APD machine or "cycle" typically cycles automatically while the patient is asleep. The APD machine frees the patient from having to perform the treatment cycle manually and from having to carry supplies during the day. The APD machine fluidly connects to an implantable catheter, to an unused dialysate source or bag, and to a fluid drainage tube. The APD machine delivers unused dialysate from the dialysate source through the catheter into the patient's abdominal cavity, causing dialysate to accumulate in the abdominal cavity and transferring waste products, toxins, and excess water. Allows what is done. The dialysate source can be multiple sterile dialysate bags.

The APD machine delivers used dialysate from the abdominal cavity through a catheter to the drainage tube. Similar to the manual process, several drainage, filling, and retention cycles occur during dialysis. The "final filling" occurs at the end of CAPD and APD and remains in the patient's abdominal cavity until the next treatment.

Periodic flow removes a portion of the fluid and replaces it after a smaller time increment, instead of removing all of the fluid from the patient over a longer period of time.

Continuous flow or CFPD systems clean or regenerate used dialysate instead of discarding it. The system pumps fluid inside and outside the patient through a loop. The dialysate exits one catheter cavity through another and flows into the abdominal cavity. The fluid exiting the patient passes through a reconstitution device that removes waste products from the dialysate, for example, via a urea removal column that employs urease that enzymatically converts urea to ammonia. Ammonia is then removed from the dialysate by absorption before reintroducing the dialysate into the abdominal cavity. Additional sensors are employed to monitor the removal of ammonia. CFPD systems are typically more complex than batch systems.

<p num="0011"> All of the above systems require the dialysate to be heated to the desired temperature, eg body temperature. Known systems for heating dialysis fluids are not ideal for a number of reasons. Some systems require more energy and higher temperature, which can overheat the dialysate if the dialysate flow is stopped. Also, some heating systems force the dialysate pump to be located upstream of the heater. This can be detrimental to some pumps that measure fluid volume and generate volume measurement errors related to fluid temperature. In addition, measuring the temperature of dialysate in some heating systems is difficult due to the high thermal resistance of the plastic film through which the fluid temperature is measured.</p>

<p num="0012"> The heating systems and methods described herein are described in the context of dialysis, specifically peritoneal dialysis. However, systems and methods include any type of dialysis, such as hemodialysis (HD), hemofiltration (HF), hemodiafiltration (HDF), continuous renal replacement therapy (CRRT), and It is also applicable to other medical fluid heating systems.</p><p num="0013"> In one major embodiment, the heating system is an induction heating system. The induction systems and methods described herein generally use relatively small disposable heating modules that, due to their improved efficiency, can be heated to temperatures lower than previous heaters. Guidance systems and methods can use one metal tube or baffle (eg, straight or cylindrical), or multiple tubes or baffles that are relatively rigid and do not collapse under negative fluid pressure, for related medical purposes. Allows the fluid pump to be located either upstream or downstream from the heating section.</p><p num="0014"> Also, the heating element is in direct thermal contact with the fluid, allowing the outlet temperature of the fluid to be very closely approximated through the measurement of the tube temperature near the fluid outlet. This measurement, along with the inlet fluid temperature and fluid flow rate, allows the power delivered to the heater to be controlled to produce the desired temperature as described below.</p><p num="0015"> In addition, the inductive heating system transfers energy from the transformer's primary coil to the transformer's secondary coil by magnetic field, eliminating the need for the transformer's primary coil to contact the transformer's secondary coil, thus eliminating the secondary coil. Is placed inside the disposable and can come into direct contact with the heated dialysis fluid. Here, the secondary coil is referred to as a susceptor because it is part of what is heated and then the fluid. The susceptor is in direct thermal contact with the fluid. The susceptor does not have to be heated to as high a temperature as the resistance plate in contact with the outside of the disposable heating path sheet, which has high thermal resistance, for example. This type of plate heating requires a higher temperature difference to drive the same energy across materials with higher thermal resistance. The temperature gradient over the metal is lower than the temperature gradient for driving the same amount of power into the fluid.</p><p num="0016"> In the induction system described herein, an electrical circuit is used to generate the magnetic field. The magnetic field is directed to a metal structure (called a susceptor) contained in the disposable fluid path of the dialysis system. The magnetic field creates an electric field in the metal structure, which in turn creates an electric current in the metal structure. Current is i in metal equipment²Due to the R power loss, it is resisted by the bulk resistance of the metal structure, which produces heat in the metal structure. In one embodiment, the alternating current is generated by the metal device, so that the current flows mostly on the surface of the metal device. Higher frequencies and the use of magnetic metal devices tend to force the flow of current towards the surface of the metal part. Some of the induction heating modules discussed herein are configured to seek to maximize surface area contact between the susceptor and the fluid.</p><p num="0017"> In the various embodiments discussed below, the primary coil is a spiral coil wound around a secondary coil, referred to herein as a susceptor. This configuration can have a coil length to coil diameter ratio of about 2.5: 3, which has been found to result in efficient coils. The spiral coil in one embodiment is wound with no space between windings so as to minimize unchained magnetic flux. Coils with smaller length-to-diameter ratios should be avoided to avoid end losses and low overall power efficiency. The coils shown below are also wound as close to the susceptor as possible to maximize the area inside the coil filled by the susceptor and to reduce the flux gap.</p><p num="0018"> In one embodiment, the coil wire is a litz wire that optimizes the AC resistance of the coil, especially in the relatively high frequency electrical circuits used herein. Litz wire contains multiple wire chains wound in parallel to reduce the increased resistance of a single (larger) diameter conductor coil due to the skin effect. In essence, a multi-wire coil wire increases the surface area of the wire used to produce the coil without increasing the outer diameter of the wire coil and reduces the amount of coil that conducts very little current. ..</p><p num="0019"> The various embodiments discussed herein also provide a structure (eg, a magnetic core) that contains a magnetic field and is configured to direct the magnetic field towards the susceptor, which also provides the performance of the heating subsystem. Also improves. The directional structure can be a ferrite material that exhibits low magnetic field loss at high frequencies where induction heating typically operates. The helical coil is wound in a ferrite-oriented structure in various embodiments discussed below, providing load flexibility for disposable heating modules, as detailed and discussed below.</p><p num="0020"> In most of the embodiments discussed herein, the secondary coil is in direct contact with the dialysis fluid (where the secondary coil is part of the susceptor and disposable item). In one alternative embodiment, the secondary coil does not come into direct contact with the fluid (where the secondary coil is not part of the susceptor or instrument). Instead, a current is induced in the secondary coil on the outside of the fluid heating module. The secondary coil is then electrically connected to the conductive module in contact with the fluid. The current from the secondary coil is i in a separate module²R Heats separate modules due to power loss. This embodiment is classified below as resistance type heating, which uses the secondary coil of the transformer to resistance heat the conductive structure in the fluid heating path.</p><p num="0021"> In a further alternative embodiment, a separate metal heating module, eg, a tube, is placed in direct contact with an appliance heater, such as a resistance heater, and is heated primarily through conduction.</p><p num="0022"> The tubing is modified in various embodiments to enhance the overall heat transfer efficiency of the system. For example, a tube can have a pattern on its surface, which increases the surface area of the tube in contact with the fluid. Alternatively, the tubing is flattened or bent, for example, from round to oval so that the fluid travels through the wider and thinner cross section of the tubing and increases the surface area to fluid volume ratio of the tubing. .. The fluid path of a flat tube is made thinner so that the distance of the fluid and the corresponding temperature gradient difference between the inner wall of the tube and the middle of the tube (the fluid is the coldest) are reduced.</p><p num="0023"> The heating system can also form a high surface area relative to the fluid volume section of the tubing and can be sintered with each other and on the inner surface of the tubing to increase the surface area to fluid ratio, eg, conductive particles. Also consider the step of filling the cross section of the tube with a metal ball. For example, an estimate of a tube section with an inner diameter of 4 mm multiplied by 8.1 cm, carrying a 0.4 mm sphere, produces a contact surface area of about 100 mm square and provides a fluid volume of only about 0.345 ml. Advantages of metal filler heating systems include heating of smaller tube sections, formation of smaller disposable heating sections, and ease of providing heating sections that are easy to assemble into other parts of the disposable part of the dialysis system.</p><p num="0024"> In an induction system that induces current through the susceptor, the system can determine the electrical resistance of the susceptor by measuring the voltage drop across the susceptor and the current flowing through the susceptor. Knowing the initial resistance, temperature, and temperature coefficient of a metal susceptor, the system measures its resistance by measuring its resistance using this method, which is faster than measuring its temperature through a contact temperature sensor, which is typically slow to respond. , The average temperature of the susceptor can be calculated. This temperature measurement method can also be used in the resistance heating system described above, which uses a secondary coil to drive an electric current through a metal heater located within a disposable item.</p><p num="0025"> The initial susceptor temperature is, in one embodiment, another calibrated temperature sensor (a diode, thermistor, integrated circuit sensor, infrared sensor, or resistance temperature device (RTD) that is in thermal contact with the susceptor (possibly a susceptor). It is determined by measuring the thermistor temperature using a fluid in the system)) to ensure thermal contact between the and the calibrated temperature sensor. Initial susceptor resistance occurs when the fluid is not heated. The initial resistance depends on the susceptor configuration, eg, the thickness of the tube wall, which can vary slightly from module to module. Therefore, the set calibration procedure is performed at the beginning of each treatment so that the temperature matches the resistance of a given disposable item.</p><p num="0026"> The temperature coefficient of the metal susceptor is a function of the metal, not the composition of the metal. For example, the coefficient for certain types of stainless steel can be 0.001 ohm / ° C, regardless of the configuration of the module using metal. Knowing one data point and temperature coefficient provides sufficient information to determine different susceptor temperatures for different measured resistors.</p><p num="0027"> The system can use the average temperature as a reference point to (i) prevent overheating of the tubing or (ii) to calculate the average temperature of the fluid in contact with the tubing. The system can use the average temperature of the tube in the safety control of the heating system, even if the average temperature of the tube does not provide an accurate or instantaneous outlet temperature for the dialysis fluid temperature. For example, if the temperature of the susceptor or tube rises dramatically, it can be assumed that air has entered the heating module or that the fluid flow has stopped. The heating system reacts in such cases, bypassing the normal control of the module, removing power from the coil and, for example, performing an air release or flow blockage routine, whereby (i) air flows to the patient or flow. It can be programmed to prevent the occlusion from being reached and (ii) the module from overheating.</p><p num="0028"> The teachings discussed herein are not limited to the use of tubes. For example, i²An electric current can be induced into the metal baffle or plate to cause R heating. Such a structure is created, for example, by folding a single metal plate into a proposed shape similar to the cross section of an accordion or bellows. The baffle can, as an alternative, be a separate structure with openings formed in separate plates to allow fluid to flow from one baffle section to the next. The metal baffle is coupled to a plastic enclosure in one embodiment.</p><p num="0029"> As a further alternative, a cylindrical susceptor is provided. Other susceptors are shown below. Any of the embodiments discussed herein can provide a plastic enclosure, eg, an outer coating around a metal plate portion forming a fluid path.</p><p num="0030"> In one embodiment, a tube, baffle, or cylinder type susceptor is provided for the heating module. The heating module can be connected to a disposable cassette, as shown in many of the examples below. Alternatively, the module is connected to different parts of the system's disposable parts, in series, for example in a tube such as a patient tube or supply tube. As a further alternative, the susceptor is integrated directly into the cassette, for example, and is provided as a conductive baffle within the cassette.</p><p num="0031"> As discussed above, the average tube or surface temperature can be used for safety control, for example, to prevent overheating. Due to the close thermal contact of the metal heating surface of the tubing or baffle with the fluid, the instantaneous fluid temperature can also be closely monitored and controlled. The outer surface temperature of the metal heating plate or tube allows an accurate determination of the actual fluid temperature, which is then used to efficiently control the heater, eg, as discussed in detail below. In addition, it reduces overshoot.</p><p num="0032"> Although induced fluid heating has been highlighted in the present application, many concepts disclosed herein fall under other types of fluid heating, such as resistance heating. In either case, the heating subsystem of the dialysis instrument is intended to be efficient. The heating subsystem is insulated to prevent heat from being transferred from the heater to the dialysis machine. This lowers the temperature of the ambient air inside the appliance and reduces the amount of heat that the appliance must remove from inside the appliance. Lowering the inside of an instrument increases its reliability and reduces the operating temperature of the components housed in the instrument. Such configurations also result in lower energy costs for the user and more environmentally friendly appliances.</p><p num="0033"> The above advantages of increasing energy efficiency of the heater subsystem include induction, resistance using a transformer, and pure resistance using direct contact between the resistance heater and the heating path sheet of all types. Corresponds to fluid heating. The heating system is capable of heating the dialysis fluid from about 22 ° C to about 37 ° C at a flow rate of about 250 ml / min, regardless of type. Applicants strive to make the heating subsystem more energy efficient by more than 80% and limit wasted power to less than 100 watts.</p><p num="0034"> Also discussed herein are systems for applying negative or positive pressure between the heating path or portion of a disposable dialysis fluid set and the corresponding heater to achieve the desired effect. .. For example, negative pressure can be applied during heating to help increase surface contact between the fluid heating path and one or more heating plates. When it is desirable to discharge the fluid from the fluid heating path, for example, when air is detected in the fluid and the fluid needs to be discarded, or when a new type of fluid is to be introduced into the system, the old fluid Positive pressure can be applied if the fluid needs to be washed away as much as possible. While a pressurized heating system may be assisted by resistance plate heating, the system may have, for example, a fluid heating module that houses the susceptor of the induction system, eg, a flexible sheet. , Or when having flexible components, can be used in induction heating.</p><p num="0035"> In addition, control schemes or algorithms that are applicable to any of the fluid heater types described herein are discussed herein. The control method has a feedforward part and a feedback part. The feedforward portion results in the path determination of the power set point (the heater is controlled in one embodiment via adjusting the power to the heater). The course setting of the feedforward portion of the control scheme seeks to allow the outlet fluid temperature of the fluid to reach the desired temperature without the use of feedback. This in turn makes it possible to minimize conventional feedback loop limitations such as temperature overshoot and delay in reaching the desired temperature. Feedforward determination can be made using a table that correlates power setting points with initial fluid temperature, final fluid temperature, and flow velocity. Alternatively, feedforward decisions are made using the underlying equations used to generate the table.</p><p num="0036"> After the set point is first determined through the feedforward portion of the heating control scheme, the initial power set point is fine-tuned to eliminate the error between the desired fluid outlet temperature and the actual fluid outlet temperature. Therefore, a feedback loop is adopted. The feedback loop can adjust the power set point by applying one or more gains, such as proportional gain, integral gain, or differential gain (PID), to the power set point. Alternatively, the feedback loop modifies the feedforward decision, for example, if the actual outlet fluid temperature is too low, it increases the difference T used in the feedforward decision at the power set point, or the actual outlet fluid temperature If it is too high, the difference T will be reduced.</p><p num="0037"> Therefore, it is an advantage of the present disclosure to provide an improved medical fluid heating system and method based on the embodiments discussed herein.</p><p num="0038"> Another advantage of the present disclosure is to provide a fluid heating system that can use less energy and lower temperature to achieve the desired fluid temperature.</p><p num="0039"> It is a further advantage of the present disclosure to provide a fluid heating system that can be located upstream or downstream of one or more related medical fluid pumps.</p><p num="0040"> It is yet another advantage of the present disclosure to provide a fluid heating system capable of accurately detecting the outlet fluid temperature.</p><p num="0041"> Moreover, a further advantage of the present disclosure is to provide a fluid heating system that reduces overheating.</p><p num="0042"> Still, a further advantage of the present disclosure is to provide a fluid heating system with efficient heating control.</p><p num="0043"> A still further advantage of the present disclosure is to provide a fluid heating system having a pressurized joint surface between the heating energy supply (resistance or induction) and the dialysis fluid carrier in contact with the supply. ..</p><p num="0044"> It is also an advantage of the present disclosure to provide a fluid heating system that can be used in any type of dialysis or renal failure therapy system, such as a peritoneal dialysis system or a hemodialysis system.</p><p num="0045"> Additional features and benefits will be described herein and will become apparent from the detailed description and figures below.</p>

<figref num="1">FIG. 1 is a perspective view illustrating an embodiment of the induction dialysis fluid heating system of the present disclosure.</figref><figref num="2">FIG. 2 is a side sectional view illustrating an embodiment for meshing a conductive inductor coil with an electrically insulating housing.</figref><figref num="3">FIG. 3 is a perspective view illustrating another embodiment for meshing a conductive inductor coil with a thermally insulating enclosure.</figref><figref num="4">FIG. 4 is a perspective view illustrating another embodiment of the inductive dialysis fluid heating system of the present disclosure, which uses at least one pancake primary coil and a baffled secondary coil.</figref><figref num="5">FIG. 5 is a perspective view illustrating a further embodiment of the inductive dialysis fluid heating system of the present disclosure, which uses at least one built-in secondary coil.</figref><figref num="6">FIG. 6 shows another embodiment of the inductive dialysis fluid heating system of the present disclosure, which uses at least one embedded secondary coil inside an insulating enclosure, which can be provided for the purpose of preserving the coil during storage. It is a cross-sectional elevation view which illustrates.</figref><figref num="7">FIG. 7 is a perspective view illustrating an embodiment of an inductive dialysis fluid heating system of the present disclosure using a spiral or spiral primary coil, a flux directional core including first and second components, and a secondary coil tube. Is.</figref><figref num="8">FIG. 8 is a perspective view illustrating an embodiment of the inductive dialysis fluid heating system of the present disclosure using a spiral or spiral primary coil, a magnetic flux directional core, and a secondary coil tube.</figref><figref num="9">FIG. 9 is a perspective view illustrating an embodiment of the inductive dialysis fluid heating system of the present disclosure using a pancake-type primary coil and secondary coil plate.</figref><figref num="10">FIG. 10 is a perspective view illustrating an embodiment of an inductive dialysis fluid heating system of the present disclosure using a spiral or spiral primary coil, a magnetic flux directional core, and a plurality of secondary coil plates.</figref><figref num="11">FIG. 11 is a perspective view illustrating another embodiment of the inductive dialysis fluid heating system of the present disclosure, which uses a spiral or spiral primary coil and a plurality of secondary coil plates.</figref><figref num="12">FIG. 12 is a plan view illustrating an embodiment of a secondary coil using a single metal sheet folded to produce windings with multiple baffles or intervening insulating baffles.</figref><figref num="13A">FIG. 13A is a schematic diagram illustrating an embodiment of the induction dialysis fluid heating system of the present disclosure using a split magnetic core.</figref><figref num="13B">FIG. 13B is a schematic diagram showing another embodiment of the inductive dialysis fluid heating system of the present disclosure using a split magnetic core.</figref><figref num="14A">FIG. 14A is an exploded perspective view of the various components of the secondary coil fluid heating module of the present disclosure using multiple separate baffle plates.</figref><figref num="14B">FIG. 14B is a plan view of the heating module of FIG. 14A.</figref><figref num="14C">FIG. 14C is an end sectional view of the heating module obtained along line XIVC-XIVC of FIG. 14B.</figref><figref num="14D">FIG. 14D is a side view of the heating module of FIG. 14A during assembly.</figref><figref num="14E">FIG. 14E is a side view of an embodiment of the baffle plate of the module of FIG. 14A.</figref><figref num="15A">FIG. 15A is an exploded perspective view of various components of another secondary coil fluid heating module of the present disclosure using multiple separate baffle plates.</figref><figref num="15B">FIG. 15B is a plan view of the heating module of FIG. 15A.</figref><figref num="15C">FIG. 15C is an end sectional view of the heating module obtained along line XVC-XVC of FIG. 15B.</figref><figref num="15D">FIG. 15D is a side view of the heating module of FIG. 15A during assembly.</figref><figref num="15E">FIG. 15E is a side view of an embodiment of the baffle plate of the module of FIG. 15A.</figref><figref num="16A">FIG. 16A is an exploded perspective view of various components of another secondary coil fluid heating module of the present disclosure using multiple separate baffle plates.</figref><figref num="16B">FIG. 16B is a plan view of the heating module of FIG. 16A.</figref><figref num="16C">FIG. 16C is an end sectional view of the heating module of FIG. 16A obtained along line XVIC-XVIC of FIG. 16B.</figref><figref num="16D">FIG. 16D is a side view of the heating module of FIG. 16A during assembly.</figref><figref num="16E">FIG. 16E is a side view of an embodiment of the baffle plate of the module of FIG. 16A.</figref><figref num="17A">FIG. 17A is a side view of yet another secondary coil fluid heating module of the present disclosure using multiple separate baffle plates.</figref><figref num="17B">FIG. 17B is a front sectional view of the heating module of FIG. 17A obtained along the lines XVIIB-XVIIB of FIG. 17A.</figref><figref num="17C">FIG. 17C is a cross-sectional view of the detailed XVIIC of FIG. 17B.</figref><figref num="17D">FIG. 17D is a front view of the heating module of FIG. 17A.</figref><figref num="17E">FIG. 17E is a bottom sectional view of the heating module of FIG. 17A obtained along the lines XVIIE-XVIIE of FIG. 17D.</figref><figref num="17F">FIG. 17F is a side view of an embodiment of the baffle plate of the module of FIG. 17A.</figref><figref num="18A">FIG. 18A-18C is a perspective view of various components of another secondary coil fluid heating module of the present disclosure, using multiple baffle plates or folds from a single metal plate.</figref><figref num="18B">FIG. 18A-18C is a perspective view of various components of another secondary coil fluid heating module of the present disclosure, using multiple baffle plates or folds from a single metal plate.</figref><figref num="18C">FIG. 18A-18C is a perspective view of various components of another secondary coil fluid heating module of the present disclosure, using multiple baffle plates or folds from a single metal plate.</figref><figref num="19A">FIG. 19A is an exploded perspective view of various parts of an embodiment of the induction cylindrical fluid heating module.</figref><figref num="19B">FIG. 19B is an elevational view of the induction cylindrical fluid heating module of FIG. 19A.</figref><figref num="19C">FIG. 19C is a plan view of the induction cylindrical fluid heating module of FIG. 19A.</figref><figref num="19D">FIG. 19D is an elevation sectional view obtained along the line XIXD-XIXD of FIG. 19C.</figref><figref num="20A">FIG. 20A is an exploded perspective view of various parts of another embodiment of the induction cylindrical fluid heating module.</figref><figref num="20B">FIG. 20B is an elevational view of the induction cylindrical fluid heating module of FIG. 20A.</figref><figref num="20C">FIG. 20C is an upper sectional view of the induction cylindrical fluid heating module of FIG. 20A obtained along the lines XXC-XXC of FIG. 20B.</figref><figref num="20D">FIG. 20D is a plan view of the induction cylindrical fluid heating module of FIG. 20A.</figref><figref num="20E">FIG. 20E is an elevation sectional view obtained along the lines XXE-XXE of FIG. 20D.</figref><figref num="21">FIG. 21 is a perspective view of a further embodiment of the induction cylindrical fluid heating module.</figref><figref num="22">FIG. 22 is an elevational view of yet another embodiment of the induction cylindrical fluid heating module.</figref><figref num="23">FIG. 23 is a perspective view of a further embodiment of the induction cylindrical fluid heating module.</figref><figref num="24">FIG. 24 is a perspective view of yet another embodiment of the induction cylindrical fluid heating module.</figref><figref num="25A">FIG. 25A illustrates various components of an embodiment of the secondary coil fluid heating module of the present disclosure, which uses a plurality of heating tubes.</figref><figref num="25B">25B hHA Figure 25A is a side view of the assembled fluid heating module.</figref><figref num="25C">It is a plan sectional view of the base and the installed pipe obtained along the line XXVC-XXVC of FIG. 25B.</figref><figref num="25D">FIG. 25D is a plan view of the assembled fluid heating module of FIG. 25A.</figref><figref num="25E">FIG. 25E is an elevational cross-sectional view of the base and installed pipes obtained along line XXVE-XXVE of FIG. 25D.</figref><figref num="26A">FIG. 26A illustrates various components of another embodiment of the secondary coil fluid heating module of the present disclosure, which uses multiple heating tubes.</figref><figref num="26B">26B and 26C are side views of the assembled fluid heating module of FIG. 26A.</figref><figref num="26C">26B and 26C are side views of the assembled fluid heating module of FIG. 26A.</figref><figref num="26D">FIG. 26D is an end view of the assembled fluid heating module of FIG. 26A.</figref><figref num="26E">FIG. 26E is a side sectional view of the assembled fluid heating module of FIG. 26A obtained along line XXVIE-XXVIE of FIG. 26D.</figref><figref num="27A">FIG. 27A illustrates various components of a further embodiment of the secondary coil fluid heating module of the present disclosure, which uses multiple heating tubes.</figref><figref num="27B">FIG. 27B is a bottom end view of the assembled fluid heating module of FIG. 27A.</figref><figref num="27C">FIG. 27C is a side view of the assembled fluid heating module of FIG. 27A.</figref><figref num="27D">FIG. 27D is a side sectional view of the assembled fluid heating module of FIG. 27A obtained along line XXVIID-XXVIID of FIG. 27C.</figref><figref num="28A">FIG. 28A is a side view of yet another embodiment of the secondary coil fluid heater of the present disclosure, which uses a plurality of heating tubes and wound primary coils.</figref><figref num="28B">FIG. 28B is a front sectional view of the heater of FIG. 28A obtained along the line XXVIIIB-XXVIIIB of FIG. 28A.</figref><figref num="28C">FIG. 28C is a cross-sectional view of the detailed XXVIIIC of FIG. 28B.</figref><figref num="28D">FIG. 28D is a front view of the heater module of FIG. 28A showing a wound primary coil.</figref><figref num="28E">FIG. 28E is a bottom sectional view of the heater of FIG. 28A obtained along the lines XXVIIIE-XXVIIIE of FIG. 28D.</figref><figref num="28F">FIG. 28F is a side view of an embodiment of the heating tube of the heater of FIG. 28A.</figref><figref num="28G">FIG. 28G is a perspective view of the heating module used with the heater of FIG. 28A.</figref><figref num="28H">FIG. 28H is very similar to that of FIGS. 28A-28G, but instead employs a rectangular tube divided into first and second tube sections, a front view of an alternative fluid heating module. Is.</figref><figref num="28I">FIG. 28I is a side sectional view of the heating module of FIG. 28H obtained along line XXVIIII-XXVIIII of FIG. 28H.</figref><figref num="28J">FIG. 28J is a bottom sectional view of the heating module of FIG. 28H obtained along the line XXVIIIJ-XXVIIIJ of FIG. 28H.</figref><figref num="28K">FIG. 28K is an upper sectional view of the heating module of FIG. 28H obtained along the line XXVIIIK-XXVIIIK of FIG. 28H.</figref><figref num="28L">28L and 28M are perspective views and side views of an embodiment of a static mixer used in any of the tube fluid heating modules described herein.</figref><figref num="28M">28L and 28M are perspective views and side views of an embodiment of a static mixer used in any of the tube fluid heating modules described herein.</figref><figref num="28N">28N and 28O are perspective views and side views of a second embodiment of the static mixer used in any of the tube fluid heating modules described herein.</figref><figref num="28O">28N and 28O are perspective views and side views of a second embodiment of the static mixer used in any of the tube fluid heating modules described herein.</figref><figref num="28P">28P and 28Q are perspective views and side views of a third embodiment of the static mixer used in any of the tube fluid heating modules described herein.</figref><figref num="28Q">28P and 28Q are perspective views and side views of a third embodiment of the static mixer used in any of the tube fluid heating modules described herein.</figref><figref num="29A">FIG. 29A is a front view of an embodiment of a secondary coil fluid heating module of the present disclosure using a single tube and a twisted conductive baffle.</figref><figref num="29B">FIG. 29B is a side view of the secondary coil fluid heating module of FIG. 29A.</figref><figref num="29C">FIG. 29C is a plan view of the secondary coil fluid heating module of FIG. 29A.</figref><figref num="29D">FIG. 29D is a rear view of the secondary coil fluid heating module of FIG. 29A showing a hidden line twisted baffle.</figref><figref num="29E">FIG. 29E is a perspective view of the twisted baffle assembly of the fluid heating module of FIG. 29A.</figref><figref num="30A">FIG. 30A is a plan view of an embodiment of the secondary coil fluid heating module of the present disclosure using a conductive washer.</figref><figref num="30B">FIG. 30B is a front view of the secondary coil fluid heating module of FIG. 30A.</figref><figref num="30C">FIG. 30C is a perspective view of the secondary coil fluid heating module obtained along the lines XXXC-XXXC of FIG. 30A.</figref><figref num="30D">FIG. 30D is a perspective view of the detailed XXXD of FIG. 30C.</figref><figref num="30E">FIG. 30E is a plan view of an embodiment of a washer heating plate used with the secondary coil fluid heating module of FIG. 30A.</figref><figref num="30F">FIG. 30F is a perspective view of an embodiment of the insulated housing portion of the secondary coil of FIG. 30A.</figref><figref num="31A">FIG. 31A is a cross-sectional perspective view of an embodiment of the dual chamber fluid heating module.</figref><figref num="31B">FIG. 31B is a perspective view of an embodiment of the susceptor of the dual chamber fluid heating module of FIG. 31A.</figref><figref num="32">FIG. 32 is a perspective view of an embodiment of a fluid heating module integrated into a disposable pump cassette.</figref><figref num="33">FIG. 33 is a cross-sectional perspective view of another embodiment of a fluid heating module integrated into a disposable pump cassette.</figref><figref num="34">FIG. 34 is a cross-sectional perspective view of a further embodiment of a fluid heating module integrated into a disposable pump cassette.</figref><figref num="35">FIG. 35 is a cross-sectional elevation view of an embodiment of a fluid heating module having a stainless steel ball trapped in a fluid heating path, eg, a path of a disposable pump cassette.</figref><figref num="36">FIG. 36 is a cross-sectional elevation view of an embodiment of a fluid heating module having stainless steel electrodeposited on a fluid heating path, eg, a path of a disposable pump cassette.</figref><figref num="37">FIG. 37 is a plan view of an embodiment of a disposable pump cassette having a port connection for connecting to the fluid heating module described herein.</figref><figref num="38">FIG. 38 is a perspective view of the disposable cassette of FIG. 37 showing an additional alternative fluid heating module connected to the cassette.</figref><figref num="39">FIG. 39 is a perspective view of the disposable cassette and alternative fluid heating module of FIG. 38 showing an operable position cassette and heating module having a dialysis instrument magnetic core and primary coil.</figref><figref num="40">FIG. 40 is a plan view of another embodiment of a disposable pump cassette having a built-in port connection for connecting to the fluid heating module described herein.</figref><figref num="41">FIG. 41 is a perspective view of the disposable cassette of FIG. 40 showing an additional alternative fluid heating module connected to the cassette.</figref><figref num="42">FIG. 42 is a plan view of a further alternative embodiment of a disposable pump cassette with a single built-in port connection for connecting to a single tube fluid heating module.</figref><figref num="43">FIG. 43 is a perspective view of the disposable cassette of FIG. 42 showing an additional alternative single tube fluid heating module connected to the cassette.</figref><figref num="44">FIG. 44 is a perspective view of yet another alternative embodiment of the single tube fluid heating module that can operate with the disposable cassette of FIG. 43.</figref><figref num="45">FIG. 45 is a cross-sectional perspective view of the built-in reinforced fluid port, similar to that shown in connection with FIGS. 42-44.</figref><figref num="46">FIG. 46 is a plan view of the built-in reinforced fluid port of FIG. 45, which is connectably spaced, for example, to the conductive washer fluid module of FIGS. 30A to 30F.</figref><figref num="47">FIG. 47 is a cross-sectional perspective view of one of the built-in reinforced fluid ports of FIG.</figref><figref num="48">FIG. 48 is a plan view of a further alternative embodiment of a disposable pump cassette connected to an alternative looped tube fluid heating module.</figref><figref num="49">FIG. 49 is a perspective view of a disposable warmer bag or pouch containing a metal ball or metal bristles susceptor.</figref><figref num="50">FIG. 50 is a perspective view of a fluid heating system capable of pressurizing positive or negative pressure between the heater and the disposable heating interface.</figref><figref num="51A">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51B">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51C">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51D">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51E">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51F">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51G">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51H">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="51I">51A-51I show multiple embodiments for sealing a disposable heating path in a frame or in an inlet or outlet tube to create a pressurized environment for the system of FIG. 50.</figref><figref num="52">FIG. 53 is a schematic diagram illustrating an embodiment of a control scheme capable of controlling the heating system discussed herein.</figref><figref num="53">FIG. 53 is a graph showing data from the temperature sensor response time improvement method and algorithm.</figref>

As shown in many of the examples below, the heating system comprises any type of renal failure therapy system, eg, any type of peritoneal dialysis (PD), or hemodialysis (HD), Fluid heating pathways for disposable units for use with medical fluid systems that require heating, such as any type of hemotherapy, including hemofiltration (HF), and hemodiafiltration (HDF). Can work with.

(Resistance system using a transformer) Here, with reference to the drawings, in particular FIG. 1, the system 10 illustrates another possible resistor embodiment using a transformer. Here, a piece of metal 20a is placed inside the disposable item, which is heated by passing an electric current. The current supplied by the secondary winding of the transformer is electrically isolated from the AC mains connected to the primary winding. The appliance makes electrical contact with the disposable item, allowing the current from the transformer to pass through the metal contained in the disposable item. The primary coil 12 and the secondary coil 14 are located in the appliance. The secondary coil of the transformer is connected to the disposable item via electrical contact, and the heated metal part is located inside the disposable item.

In system 10, the primary coil 12 of the transformer creates a magnetic field directed towards the secondary coil 14 of the transformer and induces a current in the secondary coil 14. The current in the secondary coil 14 has higher electrical resistance compared to the secondary coil of the transformer, which can be part of a disposable set, eg, a disposable dialysis set, and is in thermal contact with the fluid being heated. , Transmitted to the metal structure 20c.

The heater housing 22 can be connected to pipes (not shown) via, for example, a luer joint, a hamate joint, a press fit on the portion 22, and a press fit portion 22 on a rigid tube section. The heater housing 22 can be connected to, or become part of, a portion of loose tubing (eg, tubing connected to a disposable cassette) or incorporated directly into the disposable cassette. The heating enclosure 22 and the metal structure 20a can have a cross-sectional shape suitable for their application, for example, a square or rectangle for the rigid path of the disposable cassette, or a circle for the tube connection. Suitable materials for the heater housing 22 include polycarbonate, polysulfone, urethane, or potentially other hot plastics.

It is advantageous that the primary and secondary coils 12 and 14 are made of wires for the metal structure 20a that do not generate excessive heat due to i2R power loss. Suitable materials for the primary and secondary coils 12 and 14 are (i) Cooner Wire (coonerwire.com) litz wire, P / N = 1650 / 44SPSN, 1650 chains of 44 AWG litz wire with each chain insulated. A bundle wrapped in nylon, which is considered well suited for higher coil currents, and (ii) New England Wire Technologies, P / N = NELD1050 / 44, SPSD Type2 litz wire, which is lower. Includes wires, which are considered well suited for coil currents and allow for more turns in a given space.

In system 10, the electronic device for supplying power to the primary coil 12 can be a printed circuit, an application specific integrated circuit (ASIC), and a circuit 24 such as an equivalent. The circuit 24 shown in FIG. 1 includes a logical implementer 16 that includes processing and memory storage. The logic implementer receives input 18a (eg, analog or digital input from sensors and other logical devices) and outputs 18b (eg, analog or digital output to a heater power supply or other instrument device). Generate. The circuit 24 in the illustrated embodiment operates a power supply 26 and a transistor such as an insulated gate bipolar transistor (IGBT) type switching device 28 or a metal oxide field effect transistor (MOSFET). Including equipment. The switching device 28 in one embodiment between the on and off states so as to reduce the power loss in the transistor switching element 28 when transitioning from the on state to the off state or from the off state to the on state. It is an IGBT, 60 amp, 1 kV device that has a zero voltage across the associated transistors, or a zero voltage through the transistors when transitioned.

The switching device 28 then controls a quasi-resonant LC circuit 30 that activates the primary coil 12 of the system 10. The primary coil 12 can have an inductance of about 0.5 to about 50 uH. The coil 12 can be activated to 10 amperes or more to deliver maximum power, depending on the power loss in the wire. The LC circuit 30 can have a resonance frequency of about 20-1000 kHz. The required power from the power source 26 is from about 300 W to about 1000 W for maximum power delivery into the fluid, depending on, for example, the inlet fluid temperature, the outlet fluid temperature, and the flow rate. A bridge rectifier (not shown) can also be connected between the power supply 26 and the quasi-resonant LC circuit 30.

Typical operating frequencies of System 10 and the systems described herein are from about 20 kHz to about 1 MHz, which are generally considered high frequencies. The audible noise limits the low frequency endpoints of the frequency range radiated by the electronics, the primary coil 12, and the secondary coil 14. The power loss in the switching circuit used to drive the induction coil limits the high end points of the frequency range. Faster electronic components may increase the above designated high endpoints in the future.

In the illustrated embodiment, the circuit 24, the primary coil 12, and the secondary coil 14 are part of an instrument and are not disposable. The heated fluid in contact with the metal structure 20a and the housing 22 is part of the disposable set. Therefore, the patient or caregiver needs to mount the metal structure 20a / housing 22 on the secondary coil 14 for operation. In the illustrated embodiment, the metal structure 20a is configured to be spaced apart and accept secondary coil leads 14a and 14b, respectively, for example hollow, conductive legs and extensions (integrally formed or connected). Includes parts 21 and 21. The conductive leg or extension 21 can be formed with an inner diameter that seals around the outer diameter of the coil leads 14a and 14b. The inner diameter forms a blind bore that prevents the coil leads 14a and 14b from actually touching the sterile medical fluid in contact with the structure 20a. However, the conductive leg or extension 21 allows the coil leads 14a and 14b to make electrical contact with the metal structure 20a. The insulating housing 22 is sealed around the leg or extension 21 to prevent dialysis fluid from leaking between the leg 21 and the housing 22.

To capture the magnetic flux and direct it towards the secondary coil 14, the system 10 surrounds the windings of the primary and secondary coils 14, the magnetic core (here, the inner solid cylinder 34a and the outer). A hollow cylinder 34b) is provided. System 10 indicates that coils 12 and 14 each contain a single winding, with the primary coil 12 wound around the inner portion 34a of the magnetic core and the secondary coil 14 wound around the primary coil 12. This pattern can be repeated, i.e. add as many primary / secondary coil layers as desired, such as the second primary coil winding is around the first secondary coil winding, etc. Or it should be understood that the order of the primary and secondary coils is reversed. The outer portion 34b of the magnetic core is fitted around the outermost secondary coil layer.

In FIG. 1, the disposable metal structure 20a is a structure of a cylindrical sintered metal, such as stainless steel, which can be solid if ease of manufacture and cost are so determined. The current guided to the secondary coil 14 and flowing through the primary coil 12 to the structure 20a tends to flow around the surface of the substantially cylindrical structure 20a, due to what is known in the art as the skin effect. .. A solid, cylindrical sintered metal tube is formed or hollowed into a cylinder 20a made of porous metal or sintered metal spheres to optimize energy for a given amount of metal. To. The insulating member 32 can be filled into the opening formed by the hollow cylinder 20a. Alternatively, the sintered cylinder 20a can be formed around the insulating member 32, for example, pressed together. In any case, the resulting structure forces the fluid flowing through the heating portion 22 towards the outer wall structure where most of the current is present.

Instead, the system 10 instead wraps the primary coil 12 around the insulating housing 22 of the disposable set, eliminating the secondary coil 14 and related contacts, with the metal structure 20a as the secondary coil or susceptor of the induction heating system. By allowing it to operate, it can be transformed into an induction system. The circuit 24 operates in the transformed guidance system as described above. It is also suitable for powering the induction system described below.

(General guidance system) With induction heating, the heating system passes an electric current through a metal susceptor that is in thermal contact with the fluid. To do so, the heating system in one embodiment places the metal susceptor in magnetic contact with the primary coil of the transformer that drives the power into the secondary coil of the transformer known as the susceptor. This configuration electrically insulates the metal susceptor structure in the disposable from the primary coil of the transformer. The heating system uses the metal structure in the disposable as the secondary coil of the electric transformer. The system directs the changing magnetic field of the transformer's primary coil towards the metal structure in the disposable, then the changing magnetic field induces a changing electric field in the metal structure, which in turn is a conductive metal structure. Induce the current to flow through. The transformer primary coil can be thermally coupled to the heating area of the disposable set to direct the heat from the power loss generated by the transformer primary coil through the outside of the disposable item and improve efficiency. ..

The induction heating system can operate at high frequencies. The high frequency current used to guide the magnetic field into the susceptor has the ability to generate electromagnetic interference outside the heater subsystem. The medical industry imposes strict limits on the amount of radiation that medical devices can emit as a whole. The heating system uses ferrite or other magnetic material to (i) configure the susceptor to completely (or almost completely) absorb the magnetic field from the coil, and (ii) direct the magnetic field to the susceptor. , And (iii) one or a combination of methods such as providing shielding to limit the emitted electromagnetic field, are configured to contain the amount of emitted radiation.

Therefore, the system described herein can surround the heating subsystem as much as possible with a lightweight and inexpensive aluminum sheet to contain the magnetic field. The thickness of the sheet needs to be sufficient so that the magnetic field generated by the coil of the induction heater does not leak from the sheet. Other potentially suitable shielding materials include lossy ferrite materials and magnetic steel.

FIG. 2 illustrates an alternative metal structure 20b, including a metal, eg, stainless steel tube, or a susceptor for an induction system, which is bent and then fitted inside the insulating tube 22. The curved tube 20b expands and contracts the insulating tube 22 so that the tube 22 matches the shape of the curved tube 20b. FIG. 3 illustrates an alternative metal structure 20c or susceptor, in which the conduction tube is bent along its vertical axis and fitted inside the insulating tube 22 to shape the tube 22 into the shape of a curved tube 20c. Match. The insulating tube 22 is, as an alternative, vacuum sealed to a metal tube or surface, and vice versa. In yet another alternative embodiment, the insulating tube 22 is heat-shrinked around the metal structure.

With reference to FIG. 4, system 40 illustrates an alternative induction heater, and the secondary coil 44 of the transformer is made of any of the materials discussed above for the heating portion 22 of system 10. Insulation, eg, placed in a plastic housing 46. The plastic enclosure 46 is also incorporated into the disposable set, for example as part of a disposable cassette for dialysis applications. The primary coil 42, shown here as a pancake coil, is located above and / or below the housing 46. The primary coil 42 in the embodiment can be connected to the same circuit shown above with the system 10 of FIG.

The housing 46 includes a dialysis fluid (eg, dialysate or dialysate component) inlet 48a and a dialysis fluid outlet 48b. The housing 46 further directs the dialysis fluid above the secondary coil 44, which bends back and forth through the baffle 38, from baffles 38a to 38d (collectively referred to herein, or baffle 38). Generally individually referred to as baffle 38). The coils 44 in one embodiment are dense enough so that the baffle 38 is not needed. The secondary coil 44 is, as an alternative, a pancake coil-like coil 42, which also serves a buffing function so that a separate baffle 38 is not required.

The secondary coil 44 can be made of stainless steel, an induced fit metal such as copper coated with a medical grade compatible material such as stainless steel type 316. The secondary coil 44 is, as an alternative, a stainless steel pipe that is bent into a coil form and filled with an induced fit metal such as copper rods, copper particles, or copper cuts. The secondary coil 44 is, as an alternative, pure stainless steel.

Here, with reference to FIG. 5, the system 50 illustrates a further alternative induction heating embodiment. Here, the secondary coil 54, eg, a pancake coil made of an induced fit material, eg copper, is incorporated into one or more walls, eg, the bottom wall 52 of the housing 56. The housing 56 may include, for example, a baffle 38 made of stainless steel, as described above, or may be filled with a stainless steel net or other metal filler. In the secondary coil, located below the wall 52, the primary coil (eg, the pancake coil 42 of system 40) is heated and then the baffle or filler and the fluid in the housing 56 is heated. , Induces current. The housing 56 further includes an inlet 58a for receiving the unheated dialysis fluid and an outlet 58b for clearing the heated fluid.

With reference to FIG. 6, system 60 illustrates yet another alternative induction heating embodiment. Here, the primary coil, such as the pancake coil 42, induces an electric current into one or more secondary coils 54, eg, a pancake coil made of an induced fit material, eg copper. One or more coils 54 are incorporated into one or more insulating sleeves 62 that are injection or insert molded. The one or more sleeves 62 are then placed within the housing 66. One or more sleeves 62 can additionally serve a buffing function, directing the dialysis fluid from inlet 68a to outlet 68b. The housing 66 can additionally be filled with a stainless steel mesh or other medically compatible metal filler.

In any of the embodiments described herein, induction heating of the dialysis fluid is a conductive heated element (eg, sintered metal 20a, tubes 20b and 20c, coil 44, FIG. 5). It provides good heat transfer of energy from the metal filler, the metal-filled plastic 62 of FIG. 6, each of which can generally be referred to as a "sinter") to the fluid. The low thermal mass of the susceptor causes little overheating of the fluid due to the latent heat stored in the susceptor when the flow begins and stops, eg, is stagnant. In combination with a fast-responsive fluid temperature sensor such as an infrared sensor as described below, the rapid response susceptor 20 achieves efficient control of the output fluid temperature.

The disclosure also considers the step of using the dialysis fluid itself as a susceptor or, more precisely, instead of the susceptor 20. In general, a physical configuration that creates a magnetic field in a conductive material creates an electric current in the material. Because the dialysis fluid is conductive, it can be used in place of the susceptor, the heat itself. One drawback of doing this is that the relatively low conductivity of the dialysis fluid requires a relatively high voltage on the primary coil to provide proper heating.

As shown above, one possible primary coil design is a pancake design. However, according to one study, the most efficient primary coil design is a coil with a metal structure similar to a solenoid winding or wound around a susceptor 20, which may limit the use of "pancake" designs. Therefore, in FIG. 1, the primary coil 12a can be wound around the insulator 22, and the metal device 20a is the secondary coil to provide a more efficient heater. For FIGS. 4 and 6 above, the coil 42 is, as an alternative, wound around each housing, and in FIG. 5, the coil 54 is, as an alternative, spirally wound through the housing 56.

Here, with reference to FIG. 7, the system 70 illustrates an embodiment of a further solenoid coil. Here, the coil 72 encloses the metal core 76, which includes arms 78a and 78b that work with the second core body 82 to direct the magnetic flux Φ through the secondary coil, which is here the tube 80. .. The magnetic flux Φ travels above the arms 78a and 78b and below the tube 80, as indicated by the arrows. The coil 72 in any of the embodiments shown herein can be powered via the electronic circuit 24 shown in FIG. The tube 80 can be stainless steel, for example magnetically sensitive stainless steel 430. Magnetic heating tubes or susceptors improve the energy efficiency of fluid heating systems. The metal cores 76 and 82 in any of the embodiments herein can be magnetic materials that tend to be stable even at high frequencies.

In the illustrated embodiment, the dialysis fluid flows through the inside of the tube 80. The tube 80 can be a single wide tube as shown below, or similarly multiple narrow tubes as shown below. Here, the inside of the tube 80 can be connected to a temperature sensor that measures the temperature of the susceptor tube 80 and detects, for example, air or low fluidity in the system, the system reacts and the air It makes it possible to prevent reaching the patient, remove line obstruction, and / or prevent overheating of tube 80.

Here, with reference to FIG. 8, the system 90 illustrates yet another solenoid coil embodiment. Here, the coil 72 encloses the metal core 76, which includes the arms 78a and 78b, which direct the magnetic flux Φ through the secondary coil, which is here the tube 92a. The fluid flows through tube 92a, as indicated by the associated arrow. The tube 92a can be stainless steel, for example magnetically sensitive stainless steel 430. The temperature sensor 94 is located at the downstream end of the tube 90 and indicates one preferred arrangement of temperature sensors for providing feedback to the heating system 90. The wick 76 and the arms 78a and 78b operate as described above.

Here, with reference to FIG. 9, system 100 illustrates an embodiment of a pancake coil. Here, the pancake coil 42 directs the magnetic flux Φ through the secondary coil and the heater plates 102 and 104 perpendicular to the plane of the coil. The coil 42 in any of the embodiments shown herein can be powered via the electronic device 24 shown in FIG. The heater plates 102 and 104 can be stainless steel, for example magnetically sensitive stainless steel 430. The fluid can flow above and / or below the plates 102 and 104 in the direction of the associated arrow, perpendicular to the arrow, or diagonally to the arrow. Here, and in other flat plate embodiments discussed herein, the plate can be roughened or sintered to increase turbulence in the dialysis fluid flow.

With reference to FIG. 10, system 110a illustrates yet another solenoid coil embodiment. Here, the coil 72 encloses the metal core 76, which directs the magnetic flux Φ through the plurality of secondary coils and the heater plates 112, 114, 116, and 118, the longer arm 78a and the shorter. Includes arm 78b. The heater plates 112, 114, 116, and 118 can be stainless steel, such as magnetically sensitive stainless steel 430. The sheet can be roughened or sintered to increase the turbulence of the dialysis fluid flow. Fluid flow can bend up and down around plates 112, 114, 116, and 118, or left and right around plates 112, 114, 116, and 118. The arms 78a and 78b are also of the same length to accommodate the susceptor plates 112, 114, 116, and 118, and may be either both long or both short.

With reference to FIG. 11, system 110b illustrates yet another solenoid-like or spiral coil embodiment. As in system 110a of FIG. 10A, system 130 includes a plurality of heater plates 112, 114, and 116. Here, the coil 72 wraps the plurality of heater plates 112, 114, 116, etc. The heater plates 112, 114, and 116 can be stainless steel, such as magnetically sensitive stainless steel 430. Fluid flow can bend up and down around plates 112, 114, and 116, or left and right around plates 112, 114, and 116. Plates 112, 114, and 116 can be separate metal sheets or can be formed from a single sheet. The sheet can be roughened or sintered to increase the turbulence of the dialysis fluid flow.

With reference to FIG. 12, the susceptor or secondary coil 120 illustrates an embodiment of a baffled susceptor. In contrast to the separate baffles 38a-38d discussed above, the coil 120 is bent multiple times to form a meandering or baffled path, a single piece of stainless steel, eg, magnetically sensitive stainless steel. Formed at 430. The plurality of insulating baffles 124a to 124d (collectively referred to herein as baffles 124 or individually referred to as baffles 124) are inward from the wall of the housing 122 and the folds of one sheet 120. It extends between. The baffle 124 classifies the flow of dialysis fluid around the folds of the heated sheet 120. The flow of dialysis fluid can be top-to-bottom, bottom-to-top, page-in, and page-out with respect to the housing 120, as oriented in FIG.

The primary coil that can work with the secondary coil 120 can be a pancake coil that is located adjacent to any one or more sides of the housing 122. Alternatively, the primary coil is spirally or spirally wound around the housing 122 and the susceptor 120 in the solenoid mode shown above. Any metal core 76 or body 82 and associated arms shown herein can be magnetic. In each of the above systems, the coil 72, core 76, body 82 are each part of the dialyzer, while the secondary coil or susceptor is part of the sterile dialysis fluid disposable.

With reference to FIGS. 13A and 13B here, the systems 130a and 130b employ induction heating, which employs split magnetic cores 76a / 76b and facilitates insertion and removal of disposable heating tubes 132 (FIG. 13A) and 134 (FIG. 13B), respectively. The system is illustrated. The primary coil 72 connects to the induction circuit 24 described above and encloses a magnetic core 76a / 76b, which can be a magnetically sensitive material stainless steel 430. The tubes 132 and 134 are stainless steel, for example, magnetically sensitive stainless steel 430 is one embodiment.

The magnetic cores 76a / 76b direct the magnetic flux to the heating tube or susceptors 132 and 134. The susceptors 132 and 134 in the illustrated embodiment are a single loop of metal tubing. When passed through the magnetic core 76a / 76b, the magnetic core directs the magnetic field through the center of the loop of the magnetic core 76a / 76b.

Disposables for systems 130a and 130b include conductive metal tubes 132 and 134, along with fluid inlets and outlets for tubes that make electrical contact with each other. The coil 72 and the magnetic core 76a / 76b are arranged so that the disposable tubes 132 and 134 can be easily mounted and removed from the magnetic core. In system 130b, the shape of tubes 134 is simpler so that a single continuous bend is produced with overlapping tube ends.

The metal tubes 132 and 134 are shown facing the primary coil 72 with a magnetic core 76 in between, but the tubes 132 and 134 are, as an alternative, closer to the primary coil 72 and still mounted on each system 130a and 130b. be able to. For example, the core portion 76b can be placed along the primary coil 72 within the main body of the system appliance, while the core portion 76a is provided inside the door of the system appliance. One of the metal tubes 132 and 134 is then fitted into the appliance so that when the door is closed and the cores 76a and 76b are meshed to form the core 76, they loop around the seam 136. Can be mounted (eg with a disposable cassette). Such mounting of cassettes and susceptors places either metal tubes 132 or 134 closer to the coil 72, increasing the efficiency of the heater.

(Heating module with baffle) With reference to FIGS. 14A-14E here, the heating module 150 illustrates one possible secondary coil and housing embodiment. The housing of the heating module 150 includes a base 152 and a lid 162. The base 152 and lid 162 are made of suitable medical grade plastics such as polycarbonate, polysulfone, urethane, or potentially other hot plastics. The base 152 includes the longer side walls 154a and 154b, the shorter end walls 156a and 156b, and the bottom 158. At the end wall 156a, the base 152 includes or defines a dialysis fluid inlet 160a and a dialysis fluid outlet 160b.

The dialysis fluid inlet 160a and the dialysis fluid outlet 160b can be suitable medical tubing port connectors, such as lure connectors or hose hook connectors. The dialysis fluid inlet 160a and the dialysis fluid outlet 160b can connect the heating module 150 directly to, for example, a disposable pump and / or cassette. The dialysis fluid inlet 160a and dialysis fluid outlet 160b are alternative parts of the disposable dialysis set, such as those for peritoneal dialysis or hemodialysis, where the heating module 150 is in series with the supply or patient line. Connect to. It is understood that any of the fluid heating embodiments described herein can be used to heat the already mixed dialysate, or the fluid components or concentrates used in making the dialysate. I want to.

The lid 162 includes the longer side walls 164a and 164b, the shorter side walls 166a and 166b, and the top 168. At the end wall 166a, the lid 162 includes or defines inlet and outlet covers 170a and 170b, respectively.

14A-14C show, in one embodiment, the heating module 150, as its secondary coil, seven conductive baffle plates 172a to 172g (collectively referred to herein as heater baffle plates 172). And generally individually referred to as baffles or plates 172). The baffle plate 172 can be stainless steel, for example magnetically sensitive stainless steel 430. The baffle 172 can be roughened or sintered to increase the turbulence of the dialysis fluid flow.

As can be seen in FIGS. 14B and 14C, the dialysis fluid flow bends back and forth along the length of plates 172a to 172g. Plates 172a-172g in the illustrated embodiment define corresponding openings 174 (FIG. 14E), respectively, which alternate to be located at either end 156a or 156b of the base 152 of the adjacent plate. Forces fluid to flow back and forth along alternating plates from one end to the other. This allows the plates or baffles 172 to be all identical and then fitted in alternating arrangements for assembly. This also allows each plate 172 to be fixed and supported at each of its ends, as shown in FIG. 14C, in which case the bottom of the plate 172 is provided by the bottom 158 of the base 152. Friction fit into the defined grooves 176a to 176g, and the top of the plate 172 is friction fit into the grooves 178a to 178g defined by the top 168 of the lid 162. The ends of the plate 172 are similarly friction-fitted into the grooves (not shown) defined by the ends 156a and 156b of the base 152.

In the illustrated embodiment, the height of the module 150 from bottom 158 to top 168 (best seen in FIG. 14D) is about 0.47 inches (11.9 mm). The height of the module 150 from the tip of the inlet / exit 160a / 160b to the top 168 (best seen in Figure 14D) is about 0.80 inches (20.3 mm). In the illustrated embodiment, the width of the module 150 from side 164a to side 164b (best seen in FIG. 14B) is about 0.84 inches (21.3 mm). The width of the module 150 from the exit cover 170a to the exit cover 170b (best seen in Figure 14B) is about 0.99 inches (25.1 mm). The plate 172 can have dimensions of about 3.25 inches (8.26 cm) in length and 0.38 inches (9.7 mm) in height (as best seen in Figure 14E), which can be about 0.036 inches (9.1 mm). Separated by approximately the thickness of the baffle 172.

Bonds may not be used to support the plate 172 robustly using the grooves discussed above, but medically safe high temperature adhesive bonds can be used. Also, in one embodiment, the lid 162 snaps into the base 152 to prevent fluid from leaking out of the heating module 150. A gasket, or soft, flexible material, can be squeezed between the lid 162 and the base 152 to help provide a fluid seal. Again, medically safe adhesive bonds or ultrasonic welding can be used to seal the lid 162 to the base 152.

In one embodiment, the fluid heating system using the heating module 150 winds the primary transformer coil 72 around the assembled base 152 and lid 162 in a spiral or spiral, eg, solenoid. The spiral coil 72 can be spiral along any desired portion or proportion of the assembled base 152 and lid 162, exposing inlet 160a and outlet 160b for connection to a disposable cassette or set. Leave it as it is. The primary coil is powered, for example, via the electronic device 24 shown in FIG.

A fluid heating module very similar to the heating module 150 was tested using an electronic circuit from the Sunpentown hot plate P / N: SR-1881 as the power supply. The primary coil 72 used was spirally wound 17 times around the housing of the heating module so that the axis of the spiral coil was at least substantially parallel to the length of the blade 172 shown in FIG. 14A. did. Coil 72 was a small diameter wire of about 22 AWG. With water passing through the disposable at a rate of about 335 ml / min, the heating module heated the water from about 22.3 ° C to about 56.2 ° C, which showed the power input of the heating module to about 789 watts into the water. .. The power, mainly from the AC mains into the hot plate, was measured at 888 watts. This showed an overall efficiency of about 89%.

The heating module 150 is efficient in terms of magnetism and heat. The metal susceptor blade 172 can be manufactured at a relatively low cost and has a minimum number of parts. By thinning the blades and lowering the induction frequency, the effect of current cancellation is increased and the heating module 150 becomes less efficient. On the other hand, the thinner blade 172 can increase the responsiveness of the heating module 150 and make the dialysis fluid less likely to overheat. Each of these factors contributes to the final dimensions selected for the heating module 150.

By operating the plate at a higher temperature, the number of metal blades 172 can be reduced and the same amount of power into the fluid can be achieved (same fluid temperature rise and flow rate). For example, using two of the same metal plates 172 operating at 75 ° C, in contrast to the seven shown above for the heating module 150 heated to 55 ° C, the same fluid outlet for the same fluid flow velocity. Achieve temperature.

Here, referring to FIGS. 15A to 15E, an alternative heating module 180 is illustrated. The heating module 180 is very similar to the heating module 150 described above and includes many similar element numbers of the heating module 150 and incorporates all disclosures and alternatives relating to these numbers by reference. In the illustrated embodiment, the heating module 180 has six plates 172a-172f, as opposed to the seven shown in FIGS. 14A-14E. The plates 172a-172f are mechanically supported via grooves 176a-176f and 178a-178f as described above and, if necessary, via suitable adhesive bonds. The fluid, as an alternative, travels between the plates through the opening 174, as described above.

The main difference between the heating module 180 and the heating module 150 is to provide inlets 160a and 160b and inlet and outlet covers 170a and 170b along the same longer side 154b of the base 182, respectively. , The base 182 and the lid 184 are modified from the above. An initial flow path 157 is added to the end 156b of the base 182 so that the baffle flow begins at the side surface 154a of the base 182 and ends at the side surface 154b of the base 182.

Seen in FIG. 15A, by placing both the inlet 160a and the outlet 160b on the same long side 154b of the base 182, the primary winding extends at least substantially parallel to the longer length of the plate 172. The winding of the primary coil 72 in the vertical direction is promoted. That is, the axis of the coil, as seen in FIG. 15A, is at least substantially perpendicular to the plane of plate 172. The heating module 180 is substantially the same as the heating module 150 from the point of view of heat transfer, but different from the point of view of magnetic coupling. Here, the current in the blade flows along the edge of the blade and therefore there is no current cancellation at any realistic frequency. The disadvantage of this concept is poor coil efficiency due to the short coil length (see Figure 15A, length caused by stacking turns) compared to the cross-sectional area formed inside a single turn of the coil. Is.

The coil 72 can also be wound vertically and rotated 90 degrees so that its axis is at least substantially perpendicular to the top 168 of the lid 184 and the bottom 158 of the base 182. This configuration can also result in poor coil efficiency due to the resulting short coil (low turns) and current cancellation at low frequencies.

In the illustrated embodiment, the height of the module 180 from the bottom 158 to the top 168 (best seen in FIG. 15D) is about 0.47 inches (11.9 mm). The height of the module 180 from the tip of the inlet / exit 160a / 160b to the top 168 (best seen in Figure 15D) is about 0.80 inches (20.3 mm). The maximum width of Module 180 (best seen in Figure 15B) is about 1.11 inches (2.82 cm). The plate 172 can have dimensions of about 3.25 inches (8.26 cm) in length and 0.38 inches (9.7 mm) in height (as best seen in Figure 15E), and as best seen in Figure 15C, about. Separated by a thickness of approximately baffle 172, which can be 0.036 inches (9.1 mm).

Here, referring to FIGS. 16A to 16E, an alternative heating module 210 is illustrated. The heating module 210 is very similar to the heating modules 150 and 180 described above and includes many similar element numbers for the heating modules 150 and 180, and by reference all disclosures and alternatives relating to these numbers. Incorporate. The main difference between the heating modules 210 and the heating modules 150 and 180 is that the alternative base 186 and lid 188 are modified from the above to provide only two baffle plates 172a and 172b. By operating the plate 172 at a higher temperature, as discussed above, the number of baffles can be reduced and the same amount of power into the fluid can be achieved (same fluid temperature rise). And flow velocity).

The plates 172a and 172b are mechanically supported through the grooves 176a, 176b, and 178a, 178b as described above, and, if necessary, via a suitable adhesive bond. The fluid travels between the plates through the opening 174, as described above.

In the illustrated embodiment, the height of the module 210 from bottom 158 to top 168 (best seen in FIG. 16D) is about 0.47 inches (11.9 mm). The height of the module 210 from the tip of the inlet / exit 160a / 160b to the top 168 (best seen in Figure 16D) is about 0.80 inches (20.3 mm). The longest length of the module (as best seen in Figures 16B and 16D) is about 3.87 inches (9.83 cm). The maximum width of Module 210 (best seen in Figure 16B) is about 1.11 inches (2.82 cm). The plate 172 can have dimensions of about 3.25 inches (8.26 cm) in length and 0.38 inches (9.7 mm) in height (as best seen in Figure 16E), and as best seen in Figure 16C, about. Separated by a thickness of approximately baffle 172, which can be 0.036 inches (9.1 mm).

Here, referring to FIGS. 17A-17F, an alternative baffled heating module 220 is illustrated. The heating module 220 is a three-plate module, very similar to the heating modules 150, 180, and 210 described above, and includes and by reference many similar element numbers of the heating modules 150, 180, and 210. , Incorporate all disclosures and alternatives for these numbers.

The main difference between the heating modules 220 and the heating modules 150, 180, and 210 is that the alternative base 212 and cap 214 have been modified from the above to provide the three baffle plates 172a-172c. is there. As discussed above, the number of baffles can be optimized by the operating temperature of the plate 172, which inputs the desired amount of power and frequency to the fluid.

Another difference is that the inlet 216 and outlet 218 are placed adjacent to each other on a substantially cylindrical cap 214. The dialysis fluid inlet 216 and dialysis fluid outlet 218 can be (i) any suitable medical tubing port connector, such as a luer connector or hose hook connector, (ii) direct the heating module 220 to, for example, a disposable pump cassette. Connect the heating module 220 to another part of the disposable dialysis set so that it can be connected, or (iii) as an alternative, in series with the supply line or patient line.

FIG. 17C shows one suitable joint surface between the cap 214 and the base 212. The base 212 includes an ultrasonic welding energy waveguide 222 extending from the top of the base 212 at an angle Θ. The angle Θ in one embodiment is about 45 degrees. The cap 214 includes a mesh recess that receives the ultrasonic welding energy waveguide 222 of the base 212. In the embodiment, the cap 214 and the base 212 are both ultrasonically welded. The angled energy waveguide 222 helps to focus the ultrasonic energy at that point (annular ridge), so that the waveguide 222 and the meshing recess combine to form a cap 214 and a base 212. It provides a tight seal around the entire joint surface between them. It should be understood that the joint area that needs to be sealed is smaller for module 220 than for modules 150, 180, and 210 shown above. The cap 214 and the base 212 (as the mating plastic parts discussed herein are possible) can be secured as an alternative or in addition, mechanically and / or by an adhesive bond.

Plates 172a, 172b, and 172c can be sintered or roughened as described herein, through grooves 176a, 176b, and 176c on the base 212 as described above. It is mechanically supported through the grooves 178a, 178b, and 178c of the cap 214 as described above, and if necessary via a suitable adhesive bond. Grooves 176a, 176b, and 176c also extend into the sides of the base 212, as seen in FIG. 17F.

The fluid flows between the plates through the opening 174, as described above and shown in FIG. 17F. By the heating module 220, the fluid flows into the inlet 216, below the base 212, along the outside of the baffle 172a, through the opening 174 at the bottom of the baffle 172a, between the baffles 172a and 172b. Flows above the base 212, flows through the top opening 174 of the baffle 172b, flows below the base 212 between the baffles 172b and 172c, flows through the bottom opening 174 of the baffle 172c, and is outside the baffle 172c. Flows above the base 212 along and out from the exit 218.

In the illustrated embodiment, the height of the module 220 from the bottom of the base 212 to the top of the cap 214 is slightly greater than 3 inches (7.62 mm). The height of the ultrasonic energy director 222 above the top of the base 212 is approximately 0.015 inches (0.381 mm). The total width x1 from the outside of the inlet 216 to the outside of the exit 218 (as you can see in Figure 17D) is about 0.540 inches (1.37 cm). The width x2 between the centers of inlet 216 and exit 218 (as can be seen in Figure 17D) is approximately 0.300 inches (7.62 mm). The plate 172 can have dimensions of about 3.00 inches (7.62 cm) in length and 0.300 inches (7.62 mm) in height (as can be seen in Figure 17F) and is about 0.020 inches (0.508 mm) thick. It has an opening diameter of about 0.125 inches (3.18 mm) and is separated by a gap of about 0.050 inches (1.27 mm). The baffle 172a can be separated from the baffle 172c at a distance x3 of about 0.160 inches (4.06 mm).

In one embodiment, as seen in connection with FIG. 17B, the fluid heating system using the heating module 220 is a spiral or spiral, eg, solenoid-shaped, assembled base 212 and optionally a cap 214. The primary transformer coil 72 is wound around a part of. The spiral coil 72 can be spiral along any desired portion or proportion of the assembled base 212 and cap 214, exposing the inlet 216 and outlet 218 for connection to a disposable cassette or set. Leave it as it is. The primary coil is powered, for example, via the electronic device 24 shown in FIG.

Here, with reference to FIGS. 18A-18C, an alternative heating module 190, similar to the heating module 150, is illustrated. Here, the meandering path susceptor 212, made of a single metal plate, replaces the plate 172 above, reducing the number of susceptor sections and keeping the average temperature of the susceptor more constant throughout the fluid path. Allows you to become.

The housing of the heating module 190 includes a base 192 and a lid 202. The base 192 and lid 202 are made of any suitable insulating material described herein. The base 192 includes the longer side walls 194a and 194b, the shorter end walls 196a and 196b, and the bottom 198. The base also includes an intervening insulating baffle 199a-199g that separates the different folds of the bent metal susceptor 212.

At the end wall 196b, the base 192 includes or defines a dialysis fluid inlet 200a and a dialysis fluid outlet 200b. The dialysis fluid inlet 200a and the dialysis fluid outlet 200b allow the heating module 190 to connect the heating module 190 directly to a disposable pump and / or valve cassette or other part of the disposable set, suitable medical tubing as described above. Can be a port connector.

The lid 202 is substantially flat and snaps into the base 192. A gasket, or soft, flexible material, can be squeezed between the lid 202 and the base 192 to help provide a fluid seal. Again, medically safe high temperature adhesive bonds or ultrasonic welding can be used to seal the lid 202 to the base 192.

In the illustrated embodiment, the heating module 190 employs six conductive baffle folds 212a-212f from the meandering path susceptor 212 as its secondary coil. The meandering path susceptor 212 can be stainless steel, eg, magnetically sensitive stainless steel type 430. The folds 212a-212f can be roughened or sintered to increase the turbulence of the dialysis fluid flow. The illustrated embodiment shows that the folds 212a-212f have steps (eg, stamped) to increase turbulence and heat transfer from the susceptor 212 to the dialysis fluid.

As seen by the arrows in FIG. 18A, the dialysis fluid flow bends back and forth along the length of the insulating baffles 199a-199e and along both sides of the conductive folds 212a-212f. In particular, cold fluid enters module 190 at port 200a. The fluid path forces the fluid to flow along the outside of the conductive folds 212f until it reaches the end wall 196b of the base 192, until the fluid reaches the bend between the folds 212e and 212d. The fluid is forced to pass along the inside of the conductive fold 212e. The fluid runs along the outside of the conductive folds 212d until the fluid reaches the end wall 196a of the base 192, which is the outside of the conductive folds 212c until the fluid reaches the bend between the folds 212c and 212b. Force the fluid to pass along. The fluid then passes along the inside of the conductive folds 212b until the fluid reaches the end wall 196a of the base 192. The fluid further passes along the outside of the conductive folds 212a until the fluid reaches the end wall 196a of the base 192. The fluid continues to pass along the inside of the conductive folds 212a until the fluid reaches the bend between the folds 212a and 212b, which is the conductive folds 212b until the fluid reaches the end wall 196b of the base 192. Force the fluid to pass along the outside. Eventually, the fluid runs along the inside of the conductive folds 212c until the fluid reaches the bend between the folds 212c and 212d, which is conductive until the fluid reaches the end wall 196b of the base 192. Forces the fluid to pass along the inside of the folds 212d, which forces the fluid to pass along the outside of the conductive folds 212f until the fluid reaches the bend between the folds 212e and 212f. Force the fluid to pass along the inside of the conductive folds 212f until the fluid reaches the end wall 196b of the base 192 and the fluid outlet 200b of the lid 202.

The above path is a backflow arrangement that forces the warmest fluid (out of outlet 200b) into contact with the coldest fluid (entering inlet 200a). Such an arrangement tends to equalize the temperature throughout the susceptor 212 and to minimize the hot spots.

The plate 212 is bent and supported between the base 192 and the lid 202. The bottom of the folds 212a-212f of the plate 212 can be friction-fitted into a groove (not shown) defined by the bottom 198 of the base 192, in which case the top of the folds 212a-212f of the plate 212 is a lid. Friction fit into the groove (not shown) defined by 202. The free end of the baffle 212 can also be friction-fitted into a groove (not shown) defined by the end 196b of the base 192. The groove can negate the need for an adhesive bond to support the plate 212 robustly, but medically safe high temperature adhesive bonds can be used.

The steps of the baffle folds 212a to 212f of the susceptor 212 in one embodiment are embossed to a height that alternates from one side to the other and maintains a constant spacing between the insulating baffles 199a and 199g. .. The need for binding to the groove or base 192 should be eliminated by interposing the folds 212a to 212f between the baffles 199a and 199g.

The heating modules 190 and the baffles 212a-212f can have similar dimensions to the modules 150 in FIGS. 14A-14E and the modules 180 in FIGS. 15A-15E. Figure 18C shows one meandering flow path, where baffles 199a-199e force dialysis fluid to flow along both sides of folds 212a-212f, starting outside the folds 212f and ending inside the folds 212f. To do.

In one embodiment, as shown in FIGS. 18A and 18B, a fluid heating system using the heating module 190 has a primary transformer coil 72 on a base 192 and lid 202 assembled in a spiral or spiral, eg, solenoid. The axis of the coil, as seen in FIGS. 18A and 18B, is at least substantially parallel to the direction of the longer flat path of the baffles 212a-212f. Alternatively, the coil 72 is wound in any direction as described herein in connection with the baffle module. The spiral coil 72 can be spiral along any desired portion or proportion of the assembled base 192 and cap 202, exposing inlets 200a and outlets 200b for connection to disposable cassettes or sets. Leave it as it is. The primary coil 72 is powered, for example, via the electronic device shown in FIG.

The heating module 190 is efficient in terms of magnetism and heat. The metal susceptor blade 212 can be manufactured at a relatively low cost and has a minimum number of parts. By reducing the thickness of the susceptor 212 and lowering the induction frequency, the effect of current cancellation is increased and the heating module 150 becomes less efficient. On the other hand, the thinner susceptor 212 enhances the responsiveness of the heating module 150 and makes the dialysis fluid less likely to overheat. By operating the folds at a higher temperature, the number of folding baffles can be reduced and the same amount of power into the fluid can be achieved (same fluid temperature rise and flow velocity). Each of these factors is related to the final dimensions selected for the heating module 190.

(Cylindrical heating module) Here, referring to FIGS. 19A to 19D, the heating module 230 illustrates an embodiment of an induction cylinder heating module. The heating module 230 is configured to be integrated into a disposable cassette, connected to a cassette via a tube, or otherwise connected to a disposable set as discussed above.

The heating module 230 includes a base 232 made of any of the insulating materials discussed herein. The base 232 includes an inner cylindrical wall 234, an outer cylindrical wall 236, and an annular bottom 238 connecting the cylindrical walls 234 and 236. Cylindrical walls 234 and 236, as seen in FIG. 19B, at their top, open their mouths outward and inward, respectively, to define or include inlets 242 and outlets 244, spaces for caps 240. Tolerate. The cap 240 can also be made of any of the insulating materials discussed herein. The inlet 242 and the outlet 244 can also be one of the types of tube port connectors discussed herein.

The cap 240 is substantially flat and snaps into the base 232 via, for example, the outer peripheral edge 246. A gasket, or soft, flexible material, can be squeezed between the cap 240 and the base 232 to help provide a fluid seal. Again, or as an alternative, medically safe high temperature adhesive bonds or ultrasonic welding can be used to seal the cap 240 to the base 232.

The cap 240 snaps into the groove and / or forms a groove between the edges to carry the top of the susceptor or secondary coil 250 that can be glued to any contact surface of the cap 240. Includes 248 concentric margins. A portion 252 of the bottom 238 of the base 232 is filled with an insulating material to additionally support the secondary coil 250. The dialysis fluid flows around the bottom of the secondary coil 250 in that the bottom 238 of the base 232 is not filled with insulating material (see, eg, the left side of the heating module 230 in FIG. 19B).

The cylindrical secondary coil 250 can be stainless steel, for example magnetically sensitive stainless steel 430. The coil can be roughened or sintered on its surface to increase the turbulence of the dialysis fluid flow. The coil can also have a step (eg, stamped) to increase the turbulence of the fluid flow.

When using a sintered metal filter material, the sintered secondary coil can extend to the bottom 238 of the cylindrical walls 234 and 236, so that the fluid flows around the bottom of the susceptor instead of the sintered metal susceptor. Must flow through the thickness of the wall. A sufficient proportion of the sintered material can be left open so that at least most of the dialysis fluid flows through the thickness of the cylinder, such as the air flow through the filter. Sintered metal filters provide high surface area, high turbulence, and low fluid volume to secondary surface area ratio, resulting in good heat transfer.

The heating module 230 creates a double annular fluid flow path, through which the fluid flows from the inlet 242 and vertically downwards outside the secondary coil 250 before exiting the heating module 230 through the outlet 244. It flows, flows around the bottom of the secondary coil 250, and flows upward inside the secondary coil 250. The inlet 242 and outlet 244 can be reversed so that the fluid flows inside the secondary coil 250 before exiting the heating module 230 along the outside of the secondary coil 250.

In embodiments, the disposable set or cassette containing the heating module 230 is on the dialysis instrument such that the heating module 230 is located directly above or inside the primary coil, eg, the outer coil 72 is located within the instrument. Will be inserted. When activated, the primary coil 72 magnetically directs an electric current into the short-circuited susceptor 250, heating the susceptor 250 and surrounding fluids. Thus, the primary coil 72 (in many embodiments disclosed herein) serves the secondary purpose of centralizing and stabilizing at least the heated portion of the cassette or disposable item in a position where it can operate with the dialysis instrument. ..

The heating module 230 is considered to have a good configuration from an electromagnetic point of view. Allows the susceptor 250 to become very thin, at least with virtually no current cancellation, minimizing the heat stored in the susceptor and thus overheating the fluid if the flow stops before the susceptor 250 cools. Reduce or eliminate the possibility.

In the illustrated embodiment, the base 232 has an outer diameter of approximately 1.99 inches (5.1 cm). The susceptor 250 has an outer diameter of about 1.75 inches (4.45 cm) and can be about 0.049 inches (1.2 mm) thick. The length y1 from the bottom of the susceptor 250 to the overhangs of the walls 234 and 236 (the length of the heating path, which forces the fluid to approach the susceptor 250) is approximately 1.93 inches (4.9 cm). The length y2 (the length of the return path beneath the susceptor 250) from the bottom of the susceptor 250 to the top of the U-shape at the bottom 238 is approximately 0.24 inches (6.1 mm). The length y3 from the top of the susceptor 250 to the bottom of the susceptor 250 is approximately 2.25 inches (5.72 cm).

Here, with reference to FIGS. 20A-20E, the heating module 260 illustrates another embodiment of the induction cylinder heating module. The heating module 260 is configured to be integrated into a disposable cassette, connected to a cassette via a tube, or otherwise connected to a disposable set as discussed above.

The heating module 260 includes a base 262 made of any of the insulating materials discussed herein. The base 262 includes an inner cylindrical wall 264, an outer cylindrical wall 266, and an annular bottom 268 connecting the cylindrical walls 264 and 266. The outer wall 236 allows room for the cap 270 to open outwards to define or include the inlet 272 and exit 274, as seen in FIGS. 20A and 20C. The cap 270 can also be made of any of the insulating materials discussed herein. The inlet 272 and the outlet 274 can further similarly be any of the types of tube port connectors discussed herein.

The cap 270 is substantially flat and snap-fits or press-fits into the cylindrical wall of the base 262 via the outer peripheral edge 278 (Fig. 20E). A gasket, or soft, flexible material, can be squeezed between the cap 270 and the base 262 to help provide a fluid seal. Again, or as an alternative, medically safe high temperature adhesive bonds or ultrasonic welding can be used to seal the cap 270 to the base 262.

The concentric fringe 278 also forms a groove between the rims for carrying the top of the susceptor or secondary coil 250 as described above. The susceptor 250 can also be glued to any contact surface of the cap 270. The susceptor 250 also is centered, the base 262 or is carried between the walls 264 and 266 via the projecting divider 276 that extends et outwardly and inwardly.

The cylindrical secondary coil 250 can be stainless steel, for example magnetically sensitive stainless steel 430. The coil can be roughened or sintered on its surface to increase the turbulence of the dialysis fluid flow. The coil can also have a step (eg, stamped) to increase the turbulence of the fluid flow. Again, if the susceptor 250 is made of sintered metal filter type material, a significant proportion of the material should be such that at least most of the dialysis fluid flows through the thickness of the cylinder, such as airflow through the filter. Can be kept open.

The main difference of the heating module 260 compared to the heating module 230 is that the divider 276 forces the fluid to flow above and below the different segments and on both sides of the susceptor 250. Due to the staggered shape of the divider 276 as seen in FIG. 20E, the fluid entering the inlet 272 is pushed downward along the first outer path outside the susceptor 250 and around the bottom of the susceptor 250. It is pushed up, above the first inner path inside the susceptor 250 (in line with the first outer path), and pushed over the top of the divider 276 inside the susceptor 250. The fluid travels down the second adjacent inner path, around the bottom of the susceptor 250, and the second outer path outside the susceptor 250 (in line with the second inner path and the first outer path). Proceed above (adjacent to) and continue past the top of the divider 276 on the outside of the susceptor 250 (as seen in Figure 20E). The fluid can further travel below the third outer path (adjacent to the second outer path) and continue around the susceptor 250 through outlet 274 until exiting module 260. The divider 276 increases the contact time between the fluid and the susceptor 250, creating a more uniform flow around the susceptor and reducing the hot spots.

The coil 72 in the illustrated embodiment is wound around the heating module 260 as illustrated in FIG. 20E. Alternatively, the coil 72 resides inside the inner insulating wall of the heating modules 230 and 260.

In the illustrated embodiment, the base 262 has an outer diameter of approximately 2.00 inches (5.08 cm). The susceptor 250 has an outer diameter of about 1.75 inches (4.4 cm) and can be about 0.049 inches (1.3 mm) thick. The top-to-bottom height y1 of the susceptor 250 is approximately 2.25 inches (5.71 cm). The height y2 from the top of the cap 270 to the bottom of the base 262 is approximately 2.61 inches (6.63 cm). The height y3 from the top of the inlet / exit 272/274 to the bottom of the base 262 is about 2.94 inches (7.5 cm).

With reference to FIG. 21, the heating module 280 illustrates one resistance heating system of the present disclosure. The heating module 280 includes a cylindrical insulated housing 282 made of any of the materials discussed herein. The housing includes a fluid inlet 284 and a fluid outlet 286. Fluid flow is generally indicated via the arrow associated with element 288. The housing 282 is configured to be integrated into a disposable cassette, connected to a cassette via a tube, or otherwise connected to a disposable set as discussed above.

In this resistance system, elements 288 and the corresponding baffles 290a-290d are part of a thin plastic disposable part, such as a cassette or disposable set, which transfers heat to the fluid and is itself and one of the dialysis instruments. A fluid flow path is defined between the part and the meshing resistance heater 292. Heater 292 includes circular angled thermal fins 294a-294d that mesh with thin plastic baffles 290a-290d of a cassette or disposable set and again provide a large surface contact area in a relatively small package. ..

In order to increase the heat transfer between the resistance heater 292 and the electrically insulating element 288, conductive fats and oils can be used to increase the heat transferred from the resistance heater 292 to the fluid through the insulator 288. it can. Alternatively, use a silicone rubber-based thermally conductive Sil-Pad (R) material from Berguist Company or a thermally conductive, submissive, low modulus polymer Gap-Pad (R) material instead of fats and oils. Can be done. As a further alternative, element 288 can be made of electrically insulating heat conductive material such as Kapton (R) material. As a further alternative, element 288 can be made of metal to efficiently transfer thermal energy to the fluid. In this case, the electrical insulation that insulates the main power source from element 288 is located elsewhere in the heating subsystem.

With reference to FIG. 22, the heating module 300 illustrates yet another alternative embodiment of the induction cylinder heating module. The heating module 300 includes an outer cylindrical insulating shell 302, an inner cylindrical insulating shell 304, and a downwardly spiral insulating baffle 306 sealed between the shells 302 and 304. The disc-shaped top 308 and bottom 310 are also sealed in shells 302 and 304. The top 308 contains the entrance 312a. The bottom 310 includes the exit 312b. The inlet 312a and outlet 312b can be of any connection type described herein. All of the above items are made of electrically insulating material, for example one of the plastics mentioned above. The heating module 300 is configured to be integrated into a disposable cassette, connected to a cassette via a tube, or otherwise connected to a disposable set as discussed above.

The primary coil 314 can be a metal cylinder on which the heating module 300 is placed. Alternatively, a solid cylindrical primary coil is wound around the outside of the heating module 300. As a further alternative, the wire coil 72 (shown as an alternative in FIG. 22) is wound around the heating module 300 in the manner shown. In either case, the primary coil can be arranged to cover part or all of the heating module 300.

The fluid flows through the inlet 312a into the heating module 300, below and around the spiral baffle 306, and out of the outlet 312b. In this embodiment, the heating module 300 does not include a conductive susceptor. Instead, the heating system relies on the conductivity of the dialysis fluid to be induced by the current from the primary coil. Such a configuration is advantageous in terms of cost because it does not use metal. The configuration is practical because an input voltage of perhaps 140 volts / cm may be required to heat the fluid according to the parameters identified in connection with the tests of embodiments 14A-14E. It is disadvantageous from the viewpoint.

In an alternative embodiment, the shell 304 is a metal, eg, one of the types discussed herein, while the shell 302 and the spiral baffle 306 are plastics. As a further alternative, while the outer shell 302 is plastic, one or both of the inner shell 304 and the spiral baffle 306 are metal or metallized, eg, of the metals discussed herein. Is one of. The metal part provides a susceptor, which is guided via the primary coil 314 or 72 discussed above.

With reference to FIG. 23, the heating module 320 illustrates yet another alternative embodiment of the induction cylinder heating module. The heating module 320 includes an outer cylindrical insulating shell 302 and a susceptor 316 that fits tightly within the shell 302. The susceptor 316 can be any of the metals discussed herein. The susceptor 316 has an inner spiral flow path portion 318 and an outer spiral machine screw type baffle 322. The pitch, frequency, and relative width w1 of the path 318 as opposed to the width w2 of the baffle 322 are chosen to maximize performance. Path 318 can have agitation features such as stainless steel net or wool.

The disc-shaped end 324 (one shown) connects to the shell 302 and has an inlet / exit 326 (one shown). Route 318 communicates with inlet 326 and exit 326. The inlet / outlet 326 can be of any type described herein and can be made of an electrically insulating material, such as any of the plastics described above. The heating module 300 is configured to be integrated into a disposable cassette, connected to a cassette via a tube, or otherwise connected to a disposable set as discussed above.

In an alternative embodiment, the baffle 322 is replaced with stainless steel, eg, type 316 or 430, wool or net (not shown) that can extend between the ends 324. Here, the inner portion 318 is plastic. Further alternative modules (not shown), for example, have no insulator, fill the insulation tube with metal wool or net, and place an end cap at the end of the tube. Metal wool or net acts as a susceptor. In either case, the spiral primary coil 72 can be wound around the outer tube 302 as shown.

With reference to FIG. 24 here, the susceptor 328 illustrates another possible susceptor for the induction cylinder fluid heating module. The susceptor 328 fits inside the insulating housing 302 as shown. The susceptor 328 is a piece of metal wound in a spiral as shown. The susceptor 328 can have a step or other agitation device, or can be sintered. The fluid flows parallel between the different spiral layers. The housing 302 can be wound by the primary coil 72, as shown herein.

(Tube heating module) With reference to FIGS. 25A-25E here, the heating module 330 illustrates one possible secondary coil and housing embodiment using a conductive heating tube. The heating module 330 allows fluid to flow on both sides of the tube to maximize heat transfer from the susceptor to the fluid. The housing of the heating module 330 includes a base 332, an end cap 340, and a lid 350. The base 332, end cap 340, and lid 350 are made of suitable medical grade and at least relatively high melting temperature plastics such as polycarbonate, polysulfone, urethane, or potentially other hot plastics.

The base 332 includes a bottom 334 and a semi-circular wall 336a-336e extending from the bottom 334 and having a diameter slightly larger than the tubes 338a-338e located within the base 332.

The lid 350 includes or defines a dialysis fluid inlet 352 and a dialysis fluid outlet 354. The dialysis fluid inlet 352 and the dialysis fluid outlet 354 can be any suitable medical tube port connector, such as a luer connector or a hose hook connector. The dialysis fluid inlet 352 and the dialysis fluid outlet 354 can connect the heating module 330 directly to, for example, a disposable pump and / or valve cassette. The dialysis fluid inlet 352 and dialysis fluid outlet 354 are alternatives to another disposable dialysis set, such as for peritoneal dialysis or hemodialysis, where the heating module 330 is in series with the supply or patient line. Connect to the part. It is understood that any of the fluid heating embodiments described herein can be used to heat the already mixed dialysate, or the fluid components or concentrates used in making the dialysate. I want to.

In FIG. 25A, the heating module 330 employs five conduction tubes 338a to 338e (collectively referred to herein, and generally individually referred to as tubes 338) as its secondary coils. It is illustrated. The conduction tube 338 can be stainless steel, for example magnetic sensitive stainless steel 430, or non-magnetic sensitive stainless steel 304. The tubes can be roughened or sintered to increase the turbulence of the dialysis fluid flow. The tubes 338 are all the same in the illustrated embodiments.

At its upper end, each tube 338 is secured to the circular collar 342 (FIGS. 25A and 25E) of the end cap 340. The end of the tube 338 is frictionally fitted into the collar 342. A suitable adhesive bond can also be used to support the tube 338 within the collar 342. The bottom end of tube 338 is supported by support material 344 (see Figures 25C and 25E), which provides support but allows dialysis fluid to flow out of the bottom of tube 338 and into the bottom of base 332. To.

The upper part of the end cap 340 defines a multi-tube region 346 that is filled with fluid after entering the heating module 330 from the inlet 352. The collar 342 defines the opening leading from the multi-tube region 346 into the tube 338, as best seen in Figure 25E. The end cap 340 also includes an outlet port 348, which is operably located in communication with the outlet 354, as best seen in FIG. 25E.

In the illustrated embodiment, the combined base 332 and lid 350 are about 3.47 inches (8.81 cm) long (total length to the inlet / exit end is about 3.80 inches, 9.65 cm). The base 332 is approximately 0.74 inches (19 mm) in diameter at its maximum width point. The tubes 338 are all the same in the illustrated embodiments. In the illustrated embodiment, the tube 338 is 3 inches (7.62 cm) long, has an outer diameter of about 0.156 inches (4 mm), and is about 0.010 inches (0.25 mm thick) thick. Tube 338 is equally spaced along the central circle and has a diameter of approximately 0.34 inches (8.6 cm), as seen in Figure 25C.

Through the heating module 330, the dialysis fluid flow enters through the inlet 352 and fills the diversified tubing region 346, while simultaneously flowing down each of the tubing 338s, exiting the bottom of the tubing and returning along the outer surface of the tubing. Exit the heating module 330 through outlet ports 348 and 354. In this way, the fluid flows in parallel through all of the pipe 338 and returns in parallel on the outer surface of the pipe.

The meshing semicircles 336a-336e force a return flow closer to the outer surface of tube 338, as seen in Figure 25C. Alternatively, the base 332 has a round cross-sectional shape, i.e. does not provide the semicircles 336a-336e.

In one embodiment, the fluid heating system using the heating module 330 winds the primary transformer coil 72 around the base 332 in a spiral or spiral, eg, solenoid. The spiral coil 72 can be spiral along any desired portion or proportion of the base 332, leaving the inlet 352 and outlet 354 exposed for connection to a disposable cassette or set. The induction coil 72 is wound so that the axis of the coil 72 is at least substantially parallel to the axis of the tube 338 in the illustrated embodiment. The primary coil 72 can be powered, for example, via the electronic device 24 shown in FIG.

The heating module 330 is efficient in terms of magnetism and heat. The metal tube 338 can be manufactured at a relatively low cost and has a minimum number of multi-layered parts. The relatively thin tube allows the heating module 330 to be responsive to fluid inlet temperature and flow rate fluctuations. Each of these factors is related to the final dimensions, operating temperature, and number of tubes selected for the heating module 330.

By operating the tubes 338 at a higher temperature, the number of tubes 338 can be reduced and the same amount of power into the fluid can be achieved (same fluid temperature rise and flow velocity). The number of tubes can be increased as an alternative (see, for example, Figures 27A-27D below). The dimensions of the tube can also be changed. The fluid flow can be reversed so that the feedback path passes through the center of the tube, which may be beneficial if the outer surface of the tube carries most of the current. Here, the hottest portion (outer surface) of the tube contacts the coldest dialysis fluid in the backflow arrangement.

In a further alternative embodiment, fluid flow is restricted to the outside of the tube 338, leaving the inside of the tube dry. This allows the temperature probe to come into contact with the inside of the tube and measure the tube temperature. Alternatively, as discussed below, the resistance of a tube can be determined by applying a voltage or current to the tube and measuring the current or the other of the voltages. The resistance of a tube fluctuates with temperature, allowing the tube temperature to be correlated and determined.

With reference to FIGS. 26A-26E, the heating module 360 illustrates another possible secondary coil and housing embodiment using a conductive heating tube. The heating module 360 allows fluid to flow only on the inside of tubes 338a through 338f. The instrument uses a sensor (eg, infrared temperature sensor, diode, thermistor, integrated circuit sensor, or resistance temperature device (RTD)) or through resistance correlation as discussed herein. The temperature of the tubes can be measured in the dry outer portion of the tube 338. Since the tubing is metal and therefore highly thermally conductive, the appliance can determine the fluid temperature from the tubing temperature relatively accurately.

The heating module 360 includes an inlet / outlet multi-tube 362, an end cap 370 fixed to the multi-tube 362, a return multi-tube 380, and an end cap 390 fixed to the return multi-tube 380. Each of these components can be made of a suitable medical grade, at least relatively high melting temperature plastic, such as that described above.

The cap 370 comprises or defines a dialysis fluid inlet 372 and a dialysis fluid outlet 374 which can be reversed from the order shown in FIGS. 26A-26E. The dialysis fluid inlet 372 and the dialysis fluid outlet 374 can be any suitable medical tube port connector, such as a luer connector or a hose hook connector. The dialysis fluid inlet 372 and the dialysis fluid outlet 374 can connect the heating module 360 directly to, for example, a disposable pump and / or valve cassette. The dialysis fluid inlet 372 and dialysis fluid outlet 374, as an alternative, connect the heating module 360 to another part of the disposable dialysis set, such as for peritoneal dialysis or hemodialysis. For example, the dialysis fluid inlet 372 and outlet 374 can connect the module 360 in series with the supply line or patient line. It is understood that any of the fluid heating embodiments described herein can be used to heat the already mixed dialysate, or the fluid components or concentrates used in making the dialysate. I want to.

Caps 370 and 390 can be snap-fitted and / or adhesively bonded or ultrasonically welded to the diversified tubes 362 and 380, respectively. Alternatively, the caps 370 and 390 are formed integrally with the diversified tubes 362 and 380, respectively.

In FIG. 26A, the heating module 360 employs six conduction tubes 338a to 338f as its secondary coils (collectively referred to herein as conduction tubes 338, and generally individually referred to as tubes 338). It is illustrated. The conduction tube 338 can be stainless steel, for example magnetic sensitive stainless steel 430, or non-magnetic sensitive stainless steel 304. Tube 338 can be roughened or sintered to increase the turbulence of the dialysis fluid flow. The tubes 338 are all the same in the illustrated embodiments.

At the upper end of each pipe 338, it is fixed to the diversified pipe 362. The end of tube 338 is frictionally fitted into collar 364 of diversified tube 362, as shown in FIG. 26E. A suitable adhesive bond can also be used to support the tube 338 within the collar 364. The bottom end of the tube 338 is similarly friction-fitted into the return diversified tube 380. The end of the tube 338 is frictionally fitted into the collar 382 of the multi-purpose tube 380. A suitable adhesive bond can also be used to support the tube 338 within the collar 382.

As seen in FIG. 26A, the inlet / outlet diversified pipe 362 defines an inlet opening 366a that communicates with the inlet 372 and the inlet pipe 338a of the cap 370. The divergent pipe 362 defines an outlet opening 366b that communicates with the outlet 374 and the outlet pipe 338f of the cap 370. The divergent pipe 362 further defines a diagonal slot 368a communicating with the pipes 338b and 338d and a diagonal slot 368b communicating with the pipes 338c and 338e.

As further seen in Figure 26E, the return diversified tube 380 defines three right angle openings 384 (only one is visible in Figure 26E), which is the front row of three tubes and the back row of three tubes. Allows fluid communication with the corresponding pipe, in other words, the right angle opening 384 allows pipe 338a to fluidly communicate with pipe 338d, pipe 338b to fluidly communicate with pipe 338e, and pipe 338c to fluidize with pipe 338f. Make it possible.

In the illustrated embodiment, the distance between the outer diversified tubes is about 5.52 inches (14 cm). The divergent tubes 362 and 380 are about 0.45 inches (1.1 cm) in length, and in the illustrated embodiment, the tubes 338 are about 5 inches (12.7 cm) long and have an outer diameter of about 0.156 inches (4 mm). It has a thickness of about 0.010 inch (0.25 mm). The outer tubes 338a and 338c (338d and 338f) have a center-to-center distance of approximately 0.39 inches (1.0 cm). The tubes 338a and 338d (338b and 338e, 338c and 338f) have a center-to-center distance of approximately 0.20 inches (0.5 cm).

Through the heating module 360, the dialysis fluid flow enters through the inlet 372, through the opening 366a, through the tube 338a, through the right angled diversified tube 384 and into the tube 338d. The fluid continues through pipe 338d, through diagonal slot 368a, into pipe 338b, through pipe 338b, through right-angled diversified pipe 384, and into pipe 338e. The fluid then continues through pipe 338e, through diagonal slot 368b, into pipe 338c, through pipe 338c, through right-angled diversified pipe 384, and into pipe 338f. The fluid continues through tube 338f, through opening 366b, and out of outlet 374. Thus, the fluid then flows through tube 338.

In one embodiment, the fluid heating system using the heating module 360 is a primary transformer coil, spiral or spiral, eg, solenoid-like, via an insulating jacket (shown below as an example in FIGS. 28A-28D). Wind 72. The spiral coil 72 can be spiral along any desired portion or proportion of tube 338, leaving the inlet 372 and outlet 374 exposed for connection to a disposable cassette or set. The induction coil is wound so that the axis of the coil 72 is at least substantially parallel to the axis of the tube 338. The primary coil 72 is powered, for example, via the electronic device shown in FIG.

The heating module 360 is efficient in terms of magnetism and heat. The metal tube 338 can be made relatively inexpensively and has a minimum overall part count. The module 360 can have a relatively thin wall, which enhances the reactivity of the heating module 360. Thin tubes do not store too much energy and allow the module to better cope with fluid stoppages or bubbles.

By operating the tubes 338 at a higher temperature, the number of tubes 338 can be reduced and the same amount of power into the fluid can be achieved (same fluid temperature rise and flow rate) (eg, below. See Figures 27A-27D in. The number of tubes can be increased as an alternative or in addition. The dimensions of tube 338 can also be changed.

In a further alternative embodiment (not shown), composite parallel and series modules are provided, for example, the fluid first flows from the diversified tubing 362 through the divergent tubes 338a and 338d to the diversified tubing 380 and then the tubing. It returns to the multi-purpose tube 362 through 338b and 338e, and then again flows down the multi-purpose tube 380 through the tubes 338c and 338f and flows out of the multi-purpose tube 380. This arrangement can simplify the structure of the diversified tubes 362 and 380. Thus, it is expressly provided that the inlet 372 is provided above one end and the module 360, in fact, the exit 374 above the second end of any of the modules described herein. Will be considered. The inlet and outlet of any of the modules can be in series with the module 360, as shown, or at right angles to the module 420 of FIGS. 28A-28G, for example, as shown below.

With reference to FIGS. 27A-27D, the heating module 400 illustrates a further possible secondary coil and housing embodiment using a conductive heating tube. The heating module 400 is a two-tube version of the heating module 360, which also allows fluid to flow only inside tubes 338a and 338b. The instrument uses a sensor (eg, infrared temperature sensor, diode, thermistor, integrated circuit sensor, or resistance temperature device (RTD)) or through resistance correlation as discussed herein. The temperature of the tubes can be measured in the dry outer portion of the tube 338. Since the tubing is metal and therefore highly thermally conductive, the appliance can determine the fluid temperature from the tubing temperature relatively accurately.

The heating module 400 includes an inlet / outlet multi-tube 402 having an integral end cap, a return multi-tube 410, and an end cap 390 fixed to the return multi-tube 410. Each of these components can be made of a suitable medical grade, at least relatively high melting temperature plastic, such as that described above.

The diversified tube 402 includes or defines a dialysis fluid inlet 404 and a dialysis fluid outlet 406, which can be reversed from the order shown in FIGS. 27A-27D. The dialysis fluid inlet 404 and the dialysis fluid outlet 406 can be any suitable medical tubing port connector, such as a luer connector or a hose hook connector. The dialysis fluid inlet 404 and the dialysis fluid outlet 406 can connect the heating module 400 directly to, for example, a disposable pump and / or cassette. The dialysis fluid inlet 404 and dialysis fluid outlet 406, as an alternative, connect the heating module 400 to another part of the disposable dialysis set, such as for peritoneal dialysis or hemodialysis. For example, the dialysis fluid inlet 404 and outlet 406 can connect the module 400 in series with the supply or patient line. It is understood that any of the fluid heating embodiments described herein can be used to heat the already mixed dialysate, or the fluid components or concentrates used in making the dialysate. I want to.

The cap 390 can be snap-fitted and / or coupled to the diversified tube 410 or ultrasonically welded. Alternatively, the cap 390 is formed with the diversified tube 410. In FIG. 27A, the heating module 400 employs two conduction tubes 338a and 338b (collectively referred to herein, and generally individually referred to as tube 338) as its secondary coils. It is illustrated. The conduction tube 338 can be stainless steel, for example magnetic sensitive stainless steel 430, or non-magnetic sensitive stainless steel 304. Tube 338 can be roughened or sintered to increase the turbulence of the dialysis fluid flow. The tubes 338 are all the same in the illustrated embodiments.

Each tube 338 is fixed to the multi-purpose tube 402 at its upper end. The end of the tube 338 is frictionally fitted into the collar 408 of the multi-purpose tube 402. A suitable adhesive bond can also be used to support the tube 338 within the collar 408. The bottom end of tube 338 is similarly friction-fitted into the return diversified tube 410. The end of the tube 338 is frictionally fitted into the collar 412 of the multi-purpose tube 410. A suitable adhesive bond can also be used to support the tube 338 within the collar 412.

As seen in FIG. 27C, the return diversified tube 410 defines a right angle diversified tube 384 that allows the tube 338a to communicate fluidly with the tube 338b. In the illustrated embodiment, the overall length l of the heating module 400 is about 2.64 inches (6.7 cm), the overall width w is about 0.71 inches (1.80 cm), and in the illustrated embodiment, the tube 338 is of length. It is 2 inches (5.1 cm), has an outer diameter of 0.156 inches (4 mm), and is 0.010 inches (0.25 mm) thick.

With the heating module 400, the dialysis fluid flow enters through the inlet 404, flows through the tube 338a, through the right angled diversified tube 384 to the tube 338b, and through the tube 338b to the outside of the outlet 406. Here again, the fluid sequentially flows through the tube 338.

In one embodiment, the fluid heating system using the heating module 400 is primary to tube 338 in a spiral or spiral, eg, solenoid, via an insulating jacket (shown below as an example in FIGS. 28A-28D). Wind the transformer coil 72. The spiral coil 72 can be spiral along any desired portion or proportion of tube 338, leaving the inlet 404 and outlet 406 exposed for connection to a disposable cassette or set. In one embodiment, the induction coil is wound so that the axis of the coil 72 is at least substantially parallel to the axis of the tube 338. The primary coil 72 is powered, for example, via the electronic device shown in FIG. The 6-tube module 360 can be operated at a constant tube temperature of about 55 ° C, while the 2-tube module 400 can be operated at a constant tube temperature of about 75 ° C, both. It causes the same fluid temperature rise at a constant rate.

A fluid heating module very similar to the heating module 400 was tested using an electronic circuit from a custom Ameritherm Hot Shot® power supply. The primary coil 72 used was spirally wound 13.5 times around the housing of the heating module so that the axis of the spiral coil was at least substantially parallel to the length of the tube. Coil 72 was a 1050 chain of 42 AWG litz wire. With water passing through the disposable at a rate of about 250 ml / min, the heating module 400 heats the water from 24.2 ° C to 46.7 ° C, which means that the heating module 400 powers the water at about 393 watts. Shown. The power input to the hot plate, mainly by the AC mains, was measured at about 440.2 watts. This shows an efficiency of about 89%.

The heating module 400 is efficient in terms of magnetism and heat. The metal tube 338 can be manufactured at a relatively low cost, and the overall number of parts is minimal. Again, the module 400 can have a relatively thin wall, increasing the reactivity of the heating module 400. The thin tube does not store too much energy and allows the module 400 to better cope with fluid stoppages or bubbles. Module 400 can be changed to a single tube that bends in a U shape, eliminating the multi-purpose tube 410. Module 360 can also be modified to be a single tube that is bent multiple times.

With reference to FIGS. 28A-28F, the heater 420 illustrates a further possible secondary coil and housing embodiment using a conductive heating tube. The heater 400 is a two-tube version of the heating module 360, which also allows fluid to flow only inside tubes 338a and 338b. The instrument uses a sensor (eg, infrared temperature sensor, diode, thermistor, integrated circuit sensor, or resistance temperature device (RTD)) or through resistance correlation as discussed herein. The temperature of the tubes can be measured in the dry outer portion of the tube 338. Since the tubing is metal and therefore highly thermally conductive, the appliance can determine the fluid temperature from the tubing temperature relatively accurately.

The heater 420 includes the fluid heating module 430 most clearly shown in FIG. 28G. The heating module 430 includes an inlet / outlet multi-tube 432 with an integral end cap 434, a return multi-tube 440, and a return multi-tube 440 with an end cap 442 fixed to the return multi-tube 440. Cap 442 can be ultrasonically welded to the diversified tube 440 as seen in FIG. 28C via at least one ultrasonic energy concentrator, as described above. Each of these components can be made of a suitable medical grade, at least relatively high melting temperature plastic, such as that described above.

The end cap 434 of the divergent tube 432 comprises or defines a dialysis fluid inlet 436 and a dialysis fluid outlet 438, which can be reversed from the order shown in FIGS. 28A-28G. The dialysis fluid inlet 436 and dialysis fluid outlet 438 can be any suitable medical tube port connector, such as (i) luer connector or hose hook connector, (ii) heating module 430, disposable pump and / or valve cassette. The heating module 430 can be directly connected to, or (iii) as an alternative, to another part of the disposable dialysis set, such as for peritoneal dialysis or hemodialysis, in series with the supply line or patient line. You can connect. In the illustrated embodiment, the inlet 436 and outlet 438 are oriented at right angles to the tube 338, which may be advantageous for mounting the heater 420 as shown below.

In FIGS. 28B, 28C, and 28G, the heating module 430 has two conduction tubes 338a and 338b as its secondary coils (collectively referred to herein as conduction tube 338, and generally separately with tube 338. (Called) is illustrated. The conduction tube 338 can be stainless steel, for example magnetic sensitive stainless steel 430, or non-magnetic sensitive stainless steel 304 or 316. Tube 338 can be roughened or sintered to increase the turbulence of the dialysis fluid flow. The tubes 338 are all the same in the illustrated embodiments.

At the upper end of each pipe 338, it is fixed to the diversified pipe 432. The uppermost end of the pipe 338 is frictionally fitted into the collar 444 of the multi-purpose pipe 432. A suitable adhesive bond can also be used to support the tube 338 within the collar 444. The bottom end of the tube 338 is similarly friction-fitted into the collar 446 of the return diversified tube 440. A suitable adhesive bond can also be used to support the tube 338 within the collar 446.

As seen in FIG. 28C, the return diversified pipe 440 allows the pipe 338a to communicate fluidly with the pipe 338b. Tubes 338 are angled at their ends, eg, at 45 degrees, to direct the flow towards the desired destination or to accept the flow from a particular direction (Figures 28B, 28C, and 28F). ).

By the heating module 430, the dialysis fluid flow enters through the inlet 436, enters the tube 338a through the inlet of the angled tube, flows through the tube 338a and out of the angled outlet of the tube 338a. It flows. The fluid continues to travel through the diversified pipe 440 to the angled inlet of pipe 338b, exits through pipe 338b and exits at the angled outlet of pipe 338b, and exits outlet 436. Here again, the fluid sequentially flows through the tube 338.

As can be seen in FIGS. 28A-28D, the fluid heater 420 using the heating module 430 spirals or spirals, eg, solenoids, to wind the primary transformer coil 72 around the tube 338 around the insulating jacket 450. Dress up. The insulating jacket 450 is best visible in FIGS. 28B and 28C and is located between the tube 338 and the coil 72. The jacket 450 includes a flanged end that helps support the coil 72 in place. The jacket is provided with a dialysis instrument, in one embodiment, such as coil 72. The spiral coil 72 can be spiral between the flanges of the jacket 450 along any desired part or proportion of tube 338, inlet 436 and outlet for connection to a disposable cassette or set. Leave the 438 exposed. As shown, the induction coil 72 is wound so that the axis of the coil 72 is at least substantially parallel to the axis of the tube 338.

In any embodiment herein having a substantially extended susceptor and coil 72, the coil 72 can extend beyond the susceptor at one or both ends. For example, tube 338 can be 3 inches (7.62 cm) long, as shown. The coil 72 extends, for example, 1/4 inch (6.35 mm) beyond each end of the susceptor 72, and the total length of the coil 72 can be approximately 3.5 inches (8.89 cm). The extension induction heating module may tend to heat the center of tube 338 rather than the ends of the tube. That is, they may tend to produce "hot spots" in the center of the susceptor. By extending the coil 72 beyond the susceptor, the "high temperature point" is controlled and the heat generated along the overall length of the susceptor is equalized.

Another method for countering the "high temperature point", which is applicable to any of the extension induction heating modules herein, is to change the pitch of the coil at the "high temperature point". The coil 72 in one embodiment is wound as tightly as possible so that there is no or substantially no space between the windings of the coil 72. However, it is considered to separate the windings at a known susceptor "high temperature point" to prevent a "high temperature point". The windings can be separated by a small portion of the wire diameter of the coil 72, or by a distance greater than the wire diameter. The spacing can vary or can be substantially the same between the windings of the coil 72. The windings in the cooler part of the susceptor remain tightly wound, for example, with little or no spacing between the windings. The coil 72, which has a winding section that is tightly wound at a non- "high temperature point" and a winding that is separated at a "high temperature point", attempts to generate uniform heating along the entire length of the susceptor.

It is considered that the coil 72 is attached or mechanically fixed to the outer cover 450 located in the instrument in a partially separated state. It is also considered to place the coil 72 in the instrument and structure the instrument with spacers to support the windings in place at desired intervals. In addition, (i) the extension of the coil 72 beyond one or both ends of the susceptor, and (ii) the "high temperature point" to counter the "high temperature point" in an attempt to produce uniform heating along the length of the susceptor. It is considered to provide both changes in the pitch of the susceptor at the "hot point".

The primary coil is powered, for example, via the electronic device 24 shown in FIG. The heater 420 can be powered so that the two tubes 338 of the module 430 can be operated at a higher constant tube temperature to produce the desired flow velocity, operating power, and frequency.

In the illustrated embodiment, the flange length and width of the jacket 450 is about 1.00 inches (2.54 cm) x about 1.00 inches. The inner diameter of the outer cover 450 is about 0.500 inches (1.27 cm). In the illustrated embodiment, the tube 338 is about 3.00 inches (7.62 cm) long, has an outer diameter of about 0.159 inches (4 mm), and is about 0.010 inches (0.25) thick, including an angled tip. mm). The center-to-center distance between the tubes is approximately 0.21 inches (5.33 mm). The nominal flux gap G1 between the inner diameter of the coil 72 and the outside of the tube 338 is approximately 0.126 inches (3.2 mm). The maximum flux gap G2 between the inner diameter of the coil 72 and the outside of the tube 338 is approximately 0.231 inches (5.9 mm). The height y1 of the multi-purpose pipe 440 is about 0.500 inches (1.27 cm). The adhesive well or wrinkle y2 extends approximately 0.200 inches (5.1 mm) downward between the top of the diversified tube 440 and the outside of the tubing 338, allowing the adhesive to penetrate between the diversified tubing and the tubing. To enable. Wells also extend between tubes 338.

A fluid heating module very similar to the heating module 420 was tested using an electronic circuit from a custom Ameritherm Hot Shot® power supply. The primary coil 72 used was spirally wound 13.5 times around the housing of the heating module so that the axis of the spiral coil was at least substantially parallel to the length of the tube. Coil 72 was a 1050 chain of 42 AWG litz wire. With water passing through the disposable at a rate of about 250 ml / min, the heating module heats the water from 9.8 ° C to 34.2 ° C, which indicates that the heating module powers the water at about 363 watts. The AC main power supply mainly inputs power to the hot plate at about 416 watts. This shows an efficiency of about 87%.

The heating module 420 is efficient in terms of magnetism and heat. The metal tube 338 can be manufactured at a relatively low cost, and the overall number of parts is minimal. Again, the module 430 can have a relatively thin wall, increasing the reactivity of the heating module 430. The thin tube does not store too much energy and allows the module to better cope with fluid stoppage. Module 430 can be changed to a single tube that bends in a U shape, eliminating the diversified tube 440.

Figures 28H-28K illustrate an alternative fluid heating module 430 that can work with the fluid heater 420, including all alternatives. The fluid heating module 430 of FIGS. 28H-28K can have similar dimensions and materials as those of FIGS. 28A-28G. The fluid heating module 430 of FIGS. 28H-28K also includes end caps 432 and 440 similar to the fluid heating module 430 of FIGS. 28A-28G, including right angle inlets 436 and outlets 438. The fluid heating module 430 of FIGS. 28H-28K can also operate with the insulating jacket 450 and coil 72 as described above with the module 430 of FIGS. 28A-28G.

The main difference between the two heating modules is that the fluid heating module 430 in Figures 28H-28K includes a single rectangular susceptor tube 338, which is divided into tube sections 338a and 338b, eg square or rectangular sections. That is. Figures 28I-28K show a common wall or split wall 452 that separates sections 338a and 338b of tube 338, respectively. Such configurations improve manufacturability and module stiffness, minimize module width, and potentially improve overall cost. In the illustrated embodiment, the pipe section 338a is the inlet pipe section that communicates with the inlet 436, while the pipe section 338b is the outlet pipe section that communicates with the outlet 438. It is considered to replace the adjacent tubes of modules 360 and 400 shown above with a single rectangular susceptor tube 338 divided into tube sections 338a and 338b. As a further alternative, any of modules 360, 400, and 430 can be made with separate square tubes.

Figures 28L and 28M illustrate a first static mixer 454a suitable for insertion into any of the tube heating modules described herein. The illustrated static mixer 454a is sized for 3 inch (7.62 cm) tubes, but can be sized differently for tubes of different dimensions. The dimensions shown are merely examples and offer a variety of suitable spacing and orientations. In one embodiment, each tube of the heating module is fitted with a mixer, eg, mixer 454a. Alternatively, fewer than all tubes are fitted with the static mixer.

The mixer 454a can be plastic or metal, for example stainless steel. The mixer mixes the fluid and heats it more uniformly without making the fluid flow more turbulent and creating an unnecessarily pressure drop. The mixer 454a in the illustrated embodiment includes a round handle 456 and an extension peg 458 for smooth contact with the fluid. Alternatively, the handles 456 and pegs 458 are flat and can be oriented approximately perpendicular to the fluid flow or perpendicular to the fluid flow.

The mixer 454a contains three pegs 458 in each peg set, radiating and equidistant at about 120 °. More or less pegs 458 can be provided per peg set and can be extended equidistant or non-equidistant, if desired. Different peg sets can have different peg configurations, eg, the number and spacing of pegs. The peg 458 in one embodiment extends so as to contact or be very close to the inner wall of the tube into which the mixer 454a is inserted. The three pegs 458 are oriented on the handle 456 in some cases (eg, in the center) for the illustrated mixer 458a in a manner different from the next set of pegs. The three pegs 458 are otherwise (eg, at the edges) oriented on the handle 456, similar to the next set of pegs, for the illustrated mixer 458a. Alternatively, the three pegs 458 are, in all cases, oriented on the handle 456 in the same or different manner as the next set of pegs.

The mixer 454a represents a set of pegs 458, evenly spaced (eg, 0.177 inches (4.5 mm)) along the handle 456. The mixer 454b is at a greater distance along the handle 456 at the edges of the handle 456 (eg, at 0.354 inches (9.0 mm)) and at a shorter distance along the handle at the center of the handle 456 (eg, 0.177 inches). Shows a set of pegs 458 separated (at (4.5 mm)). The mixer 454c is also at a greater distance along the handle 456 at the edges of the handle 456 (eg, at 0.472 inches (12.0 mm)), and at the center of the handle 456 at a shorter distance along the handle (eg 0.118). Bundle a set of pegs 458 separated (in inches (3.0 mm)). The mixer 454c also contains two different spacing reductions per side of the handle 456, while the mixer 454b exhibits one spacing reduction per side of the handle 456.

Bundling the pegs in the center of the handle 456 (and orienting the set differently from the next set) also tends to mix the temperature of the fluid in the center of the susceptor to make it more uniform, where it is. , Generally may be most needed due to the "hot spot" located in the center of the susceptor. Again, the spacing dimensions are just an example. It should be understood that the number, spacing, radial orientation, orientation with respect to the next peg set, peg and peg set shape and dimensions can be modified and optimized to produce the desired mixing and pressure drop results, respectively.

In an alternative embodiment, a plastic or metal spring is inserted into the tube as a static mixer. The spring can be a known compression spring whose outer diameter is sized to be the same as or slightly smaller than the inner diameter of the tube into which the spring is inserted. The spring (or a plurality of springs) can extend at least substantially the entire length of the tube. A spring mixer is advantageous because its windings tend to push the fluid inward from the wall of the tube, in which case the fluid is heated more than the center of the tube. The spring also promotes fluid mixing, providing a more uniformly heated fluid for both reasons. Springes are also economical and are likely to be found as off-the-shelf components. The diameter of the spring coil and the number of coil pitches are selected to optimize uniform fluid heating and pressure drop.

Mixing of fluids when heated, for example through baffle steps or inconsistencies, additional stainless steel wool or beads, sintering, etc., is discussed elsewhere herein. Therefore, it is considered to add a mixing element in any of the baffles, cylinders, tubes, cassettes, pouches, or bag heating modules discussed herein.

(Twisted baffle) With reference to FIGS. 29A-29E here, the fluid heating module 460 further illustrates an alternative secondary coil or susceptor, including a capped metal tube 470. Module 460 includes an inlet / outlet diversified tube 462 with a dialysis fluid inlet 464 and a dialysis fluid outlet 466. The dialysis fluid inlet 464 and the dialysis fluid outlet 466 can be (i) any suitable medical tube port connector, such as a luer connector or a hose hook connector, (ii) a heating module 460, eg, a disposable pump and / or Separate disposable dialysis sets, such as those for peritoneal dialysis or hemodialysis, which can be directly connected to the valve cassette, or (iii) as an alternative, via a heating module 460 in series with the supply line or patient line. Can be connected to the part of. In the illustrated embodiment, the inlet 464 and the outlet 466 are oriented substantially in series with the twisted susceptor 480. In an alternative embodiment, the inlet 464 and the outlet 466 are arranged at right angles to the axis of the susceptor 470.

The divergent tube 462 is mechanically connected to the conductive susceptor 470 via an adhesive and / or an adhesive bond. The susceptor 470 includes a substantially hemispherical end 472, which provides a suitable shape for the dialysis fluid so that the fluid turns 180 degrees upon reaching the bottom end 482 of the twisted baffle 480.

The divergent tube 462 can be made of any of the insulating materials described herein. The susceptor 470 can also be made of stainless steel, such as magnetically sensitive stainless steel 430, or non-magnetic stainless steel 304 or 316. The twisted baffle 480 can be plastic.

The divergent tube 462 mechanically and / or adheres at the top 484 of the baffle to support the baffle 480. To that end, the divergent tube 462 accepts the top 484 of the baffle 480, mechanically tightens the top 484, and / or allows the top 484 to be adhesively bonded to the crimp structure 468. Alternatively, other types of crimping structures can be provided.

As best seen in FIG. 29E, the dialysis fluid flows into the fluid heating module 460 through inlet 464. The dialysis fluid generally flows along the first surface 486a of the baffle 480, around the end 482 of the baffle 480, along the second twisted surface 486b of the baffle 480, and through the outlet 466 the fluid heating module. It flows out of the 460. The twisted baffle 480 is generally illustrated as having two twists, but can provide a single twist or three or more twists.

In one implementation, the overall length L1 of the fluid heating module 460 is about 4.361 inches (11.1 cm). The length L2 of the multi-purpose pipe 462 is about 0.96 inches (2.44 cm). The outer diameter of the housing 470 is approximately 0.281 inches (0.714 cm). Inlet 464 and exit 466 are separated from the center by about 0.300 inches (7.62 mm).

As discussed above, the housing 470 in one embodiment is a metal susceptor such as stainless steel, and the dialysis instrument is an insulated jacket such as the jacket 450 shown above in connection with the heater 420. including. The coil 72 is wound around the jacket in the manner shown with the heater 420. The stainless steel housing 470 is then firmly slid into the outer cover 450. Here, the outer surface of the stainless steel housing 470 is brought closer to the coil 72 by eliminating the bottom diversified pipe, for example, reducing the magnetic flux gap.

In an alternative embodiment, the susceptor 470 is a straight tube with an end cap fitted to the bottom 472 of the housing 470. The alternative end cap can be suitably fixed to the housing 470 by adhesive bonding or mechanically and / or adhesive.

In a further alternative embodiment, the housing 470 is made of an insulating material. The coil 72 of the dialysis instrument is wound so that the plastic housing 470 fits tightly within the coil. Here, the twisted baffle 480 forms a conductive susceptor. The susceptor baffle 480 can be roughened or sintered, or can include a stirring step, or can be sintered as described herein. The susceptor baffle 480 can be replaced with a stainless steel mesh or wool material as an alternative.

(Sim module) Referring here to FIGS. 30A-30F, the heating module 490 includes yet another type of inner and outer cylindrical linked enclosure 492, which carries a pair of conductive washers or shims 500a and 500b. A susceptor or inductive fluid heater is illustrated. The housing 492 of the embodiment is made of an insulating material such as any insulating material described herein. Conductive shims or washers 500 (collectively referred to as washers 500a and 500b) are made of conductive materials such as magnetically sensitive or non-magnetic stainless steel as described herein.

FIG. 30F shows a housing 492 with an inner ring 494 and an outer ring 496, both of which can be bowed slightly away from the flow path between the rings if desired. FIG. 30F illustrates that the stirring baffles 498a through 498h are equidistant on the circumference of the housing 492. The baffle 498 (collectively referred to as the baffle 498a through baffle 498h) can be oriented at the same or different pitches with respect to the horizontal plane passing through both the inner ring 494 and the outer ring 496. In the illustrated embodiment, the pitch of the baffle 498 alternates to allow fluid to flow up and down around the baffle, increasing contact with the metal inner surface of the washer 500.

The outer ring 496 includes a dialysis fluid inlet 502 and a dialysis fluid outlet 504 that approaches and separates the dialysis fluid inlet 502. The detail XXXD shown in FIG. 30D is an inner tube in which each of the inlet 502 and the exit 504 reinforces the connection between the tubes located above the inner port 506b, as discussed in detail below. Illustrated to include port 506b and outer collar 506a.

As seen in FIG. 30F, the dialysis fluid flows into the housing 492 through the inlet 502, is carried either below or above the baffle 498a, and then baffles 498b, 498c until it reaches the exit 504. , And 498d, etc., alternating above or below. In the embodiment, a rigid stop is provided instead of the baffle 498h so that the dialysis fluid is pushed out of the outlet 504 after making one round of the housing 492. Alternatively, a portion of the dialysis fluid can potentially circulate the housing 492 more than once before exiting through outlet 504.

It is possible to provide a volume between washers 500, which is larger than the volume of the tubing inlet port, to slow down the fluid velocity and increase the resident heating time of the dialysis fluid in the chamber of the housing 492. Will be considered. The baffle 498 tends to interrupt laminar flow and create turbulence to improve contact between the actual fluid volume and the heated surfaces of the washers 500a and 500b. The contact surface of the washer 500 can be roughened, for example bead blasted, to improve surface contact.

Reinforcing the collar 506a reduces the moment arm of the tube located above the port 506b when bent relative to the heating module 490. This feature improves the robustness of the 490.

The primary coil operating with the susceptor plate 500 of the heating module 490 can be a pancake-type coil, such as the coil 42 shown in FIGS. 4, 6, and 9. The pancake coil 42 can be placed adjacent to the upper and / or lower washers 500a and 500b. Alternatively, the heating module 490 is placed in an insulating jacket wound by a wire coil 72, as shown and described herein. Here, the jacket is sized slightly wider than the width of the rings 494 and 496 so that the flux gap between the winding and the flat washer surface is preferably small. In a preferred embodiment, the primary coil is a cylindrical coil similar to that of FIG. 7, which can be fitted inside the inner ring 494, for example. In an embodiment, the primary coil touches the inner ring 494. Alternatively, there is a small gap between the primary coil and the inner ring 494.

In one implementation, the inner diameter of the inner ring 494 is approximately 1.38 inches (3.5 cm). The outer diameter of the outer ring 496 is approximately 2.245 inches (5.70 cm). The height h of the inner ring 494 and the outer ring 496 is approximately 0.360 inches (9.14 mm). The outer diameter of the tube port 506b is approximately 0.12 inches (3.05 mm). The center-to-center distance between the inlet 502 and the exit 504 is approximately 0.50 inches (1.27 cm). The washers 500a and 500b in one implementation have an outer diameter of about 2.125 inches (5.40 cm) and an inner diameter of about 1.5 inches (3.81 cm) and are about 0.025 inches (0.635 mm) thick.

(Saddle bag) With reference to FIGS. 31A and 31B here, the fluid heating module 510 illustrates a further alternative, having a saddle bag or a two-chamber enclosure. The fluid heating module 510 includes a first housing 512a and a second housing 512b that are connected at their top ends via a bridge 526. Each chamber 512a and 512b includes an outer wall 528a and an inner wall 528b separated by a longer insulating baffle 514 and a shorter insulating baffle 516. Although not shown in FIG. 31A, chambers 512a and 512b are encapsulated on the bottom (the bottom is not shown to better illustrate the flow pattern). The longer insulating baffle 514 terminates at the bottom of the susceptor 530a 530b and so that the dialysate fluid can flow under the lower edge of the longer insulating baffle 514, as seen by the arrows in FIG. 31A. On the other hand, the shorter insulating baffle 516 extends to the bottom of chambers 512a and 512b to force the dialysis fluid upwards towards the top of the shorter baffle 516, as seen by the arrows in FIG. 31A. Exists.

The longer insulating baffle 514 and the shorter insulating baffle 516 separate each chamber 512a and 512b into eight compartments, generally as shown by the flow arrows in FIG. 31A. The metal susceptor 530a is inserted into chamber 512a so as to further separate the eight compartments into 16 subchambers. Similarly, the metal susceptor 530b is inserted into chamber 512b so as to separate into 16 different subchambers of eight compartments. Thus, when chambers 512a and 512b are connected via bridge 526, fluid module 510 includes 32 separate subchambers. The dialysis fluid flows sequentially through 32 chambers, as indicated by the arrows.

As seen in FIG. 31B, in one embodiment, the susceptor plate 530a fits into the chamber 512a so that the groove 518a of the plate 530a that opens at the lower end of the plate fits over the insulating baffle 516 in the chamber 512a. Will be inserted. The longer insulating baffle 514 is then slid downward into slot 518b of plate 530a, which opens at the top of plate 530a. The same procedure is followed for chamber 512b and plate 530b, where plate 530b also includes grooves 518a and 518b. The outer conductive baffles 532 of the plates 530a and 530b are bonded, ultrasonically welded, and / or snapped to the fluid flow above the top edge of the outer baffle 532 and to the chambers 512a, 512b, and bridge 526. Shortened as shown to allow flow under and under the cap 520.

The susceptor plates 530a and 530b can be made of stainless steel such as magnetically sensitive or non-magnetic stainless steel. The primary coil that works with the susceptors 530a and 530b in the embodiment is a pancake coil that slides between chambers 512a and 512b. The coil can be placed on top of the outer portions of chambers 512a and 512b, either as an alternative or in addition. As a further alternative, the chamber is wound with a litzwire coil 72. The coil is, in any case, part of the instrument in one embodiment.

(Heating module integrated in pump cassette) With reference to FIG. 32, the fluid heating module 540 illustrates one possible module for incorporation into a disposable dialysis fluid pump cassette 550. The disposable pump cassette 550 in the illustrated embodiment includes a rigid body structure 552 that is sealed on the first and second sides via first and second flexible membranes (not shown). The rigid structure 552 can be made of polycarbonate, polysulfone, urethane, or potentially other hot plastics. Rigid structure 552 provides first and second pump chambers 554a and 554b, which operate with pneumatic pump actuators, located in a dialysis instrument (not shown) into which the cassette 550 and integrated fluid heating module 540 are inserted. Including. Pneumatic pump actuators can be used in one embodiment, but the pumping of systems that employ the integrated fluid heating module 540 is not limited to pneumatic pumping, but instead peristaltic pumping or mechanically activated membrane pumping. Understand what you get.

The rigid structure 552 also includes a plurality of valve ports 556a to 556j (collectively referred to herein as valve ports 556 or generally individually referred to as valve ports 556). The flexible membrane seals around the edges of the rigid structure 552 and also extends from the base wall 559 of the structure defining the pump chambers 554 (collectively referred to as the pump chambers 554a and 554b) and the valve ports 556. It also seals on the ridges. A description of the operation of flexible membranes in combination with pump port 554 and valve port 556 is described in connection with US Pat. No. 4,826,482, the relevant parts of which are expressly herein by reference. Be incorporated.

The valve port 556 leads to a flow path located on the opposite side of the base wall 559 of the rigid body structure 552. The cassette 550 also includes a plurality of tube ports 558a to 558 g (collectively, or generally individually referred to as port 558). Port 558 connects to a tube that extends to the supply bag, and potentially connects to or from the patient. One preferred port 560 is discussed in detail below. The heating module 540 also includes a plurality of baffle plates 562a to 562i (collectively referred to herein as baffle plates 562 and generally individually referred to as baffle plates 562).

In one embodiment, the heater module 540 is resistance heated. Here, the baffle plate 562 is part of the cassette 550, is made with it, and is electrically insulating. The heating plate 568 extends from the outside of the cassette 550, through the outer wall of the rigid body structure 552 of the cassette 550, and through each of the baffles 562. The ends 568a and 568b of the heating plate 568 can be operably connected to a resistance heater supply contact (not shown) or directly connected to a current source.

The insulating baffle forces fluid before and after the superheat plate 568. The baffle plate 562 is staggered as illustrated, generally producing a curved path as indicated by the arrow in FIG. The base wall 559, in one embodiment, provides a wall 559 as an alternative that does not extend into the heating path region of the baffle 562, the baffle 562 extending to the invisible side of the rigid housing 552. The holes in the wall 559 allow fluid to flow into the heating path on each side of the wall 559.

In an alternative resistor embodiment, the baffle plate 562 is conductive and is made of stainless steel, such as, for example, non-magnetic stainless steel 304 or 316, or magnetically sensitive stainless steel 430. The baffle 562 can be roughened or sintered for more turbulent flow by interrupting fluid flow. The rigid body structure 552 can carry the conductive baffle 562 mechanically and / or via an adhesive bond. As mentioned above, the plate 559 is not needed in the heating region. Alternatively, the plate 559 can be metal and can be formed with a baffle 562. As an alternative, the plate 559 is made of an insulating material. Here, the baffle 562 can extend through the plate 559 or can be provided as a separate set of baffles on either side of the plate 559.

In an alternative resistance embodiment, the plates 564 and 566 formed on the outside of the baffle 562 are also made of a conductive material, eg, the material of the baffle 562, to provide an electrical path from the plates 568a and 568b. There is. Here, the plate 568 does not extend across the cassette 550 and the baffle 562, but instead is separated into two plates 568a and 568b as shown, terminating at the outer plates 564 and 566, respectively. Plates 564 and 566 communicate electrically with baffle 562.

In a further alternative embodiment, the fluid heating module 540 is located on one or two sides of the cassette 550 when the cassette is mounted on a dialysis instrument, via a single pancake coil or double pancake coil. Induction heating. Alternatively, the cassette 550 can slide inside the winding coil 72 described herein, which is present within the dialysis instrument. The cassette 550 when mounted on the appliance is slid into the coil 72 so that the fluid heating module 540 is aligned with the coil 72. In an embodiment of this induction, the rigid walls 564 and 566 formed on the outside of the baffle 552 can be made of plastic or other insulating material, along with the rest of the rigid housing 552.

In the induction embodiment, the baffle plate 562 is also conductive and forms a susceptor. Here, the plate 562 can be made of stainless steel, such as non-magnetic stainless steel 304 or 316, or magnetically sensitive stainless steel 430. The baffle 562 can be roughened or sintered for more turbulent flow by interrupting fluid flow. The rigid body structure 552 can carry the conductive baffle 562 mechanically and / or via an adhesive bond. In the induction heating embodiment, the plates 568 or plates 568a and 568b described above are not required. All alternatives for not providing the plate 559 or for providing the plate 559 for the embodiment of the resistor in which the baffle 562 is conductive are also applicable here.

Each of the alternative integrated cassette fluid heating modules using induction heating is shown below. However, it should be understood that, like the heating module 540, alternative modules can be made to act as a resistor instead of an induction.

Here, with reference to FIG. 33, an alternative integrated cassette fluid heating module 570 is illustrated. Module 570 works with the disposable cassette 550, which includes each of the components described above. The alternative fluid heating module 570 includes a pair of baffle compartments 572 and 574 extending through the base wall 559 of the rigid body structure 552 of the cassette 550. Baffle compartments 572 and 574 each contain a plurality of staggered baffles that can be any of the materials discussed above for baffle 562. The baffle compartments 572 and 574 in the embodiment are adhesively coupled to the base wall 559 of the cassette 550 in the area marked X in FIG. 33.

The flexible membrane welded to the rigid plastic structure 552 by both the heating modules 540 and 570 can be coupled to the baffle 562 of the module 540, or the baffle of the compartments 572 and 574, or the module 570. Alternatively, the top and bottom of the rigid plastic are sealed in a plastic film, which is then adhesively bonded to a conductive baffle. As an alternative, the top and bottom of the plastic are snap-fitted to the baffle. The top and bottom are then welded or bonded to the flexible sheet. Yet still an alternative, the conductive baffle comprises a top and bottom of conductivity to produce an enclosed conductive shell that is adherently bonded to the rigid body portion 552 of the cassette 550. Here, since the conductive heating baffle portion is enclosed, the portion does not have to be sealed in the cassette sheet.

The heating module 570 is shown operably communicated with the winding primary coil 72. Here, the baffles of compartments 572 and 574 act as susceptors. However, as described above, the baffle compartments 572 and 574 can be modified to operate in resistance heating mode.

Here, with reference to the integrated fluid heating module 580 of FIG. 34, an alternative integrated cassette-based heating module is illustrated. The heater module 580 can work with the disposable cassette 550 as described herein. For convenience, the cutting section of the heater module 580 is illustrated.

In the heating module 580, the rigid body structure 552 is molded to include an upper insulating side wall 582 and a matched lower extension side wall 584. The rigid body portion 552 is further molded to include an upper insulating baffle plate 586 and a matched lower insulating baffle plate 588. The conductive insert 590, made of any of the medically safe conductive materials discussed herein, snaps onto the sidewalls 582 and 584 and the insulating baffle plates 586 and 588. Fitted with and / or adhesively bonded.

The base wall 559 includes an opening (not shown) that allows fluid to bend through a pair of baffles on one side of the base wall 559 and then through the opening to the other of the base wall 559. It flows to the sides of the fluid and allows it to bend through a second set of conductive baffles. It should be understood that the flow in the fluid heating module 580 is very similar to the flow in the saddlebag fluid heating module 510 discussed above in connection with FIGS. 31A and 31B.

In embodiments, the upper and lower flexible sheets are adhesively bonded or welded to the ridges of the insulating sidewalls 582 and 584 and the insulating baffles 586 and 588 to form an enclosed fluid path on both sides of the cassette 550. The induction coil 72 is shown in an operable relationship with the conductive baffle 590, which acts as a secondary coil or susceptor to the primary coil 72. Alternatively, the baffle 590 is extended to the outside of the cassette 550 for the operation of the resistance heater.

Here, with reference to FIG. 35, the heating module 600 illustrates a further alternative integrated cassette embodiment. Here, stainless steel, magnetically sensitive, or non-magnetic spheres or pellets 602 fill the heating path defined by the insulating baffle plate 604. The insulating baffle 604 in the embodiment forms a meandering channel. The insulating baffle plate 604 is coupled or welded to the flexible sheet 606 of the cassette 550. The heating module 600 in one embodiment uses one or more pancake coils 42, or winding coils 72, which are wound to form an axis that is either parallel or perpendicular to, for example, the baffle 604. It is heated via induction heating. The stainless steel ball 602 helps to interrupt the dialysis fluid flow so that it is more turbulent. The stainless steel ball 602 is replaced with stainless steel net wool as an alternative.

With reference to FIG. 36, the fluid heating module 610 illustrates another possible integrated cassette type fluid heating module. Like Module 600, Module 610 includes a rigid plastic construction 552 of a disposable pump cassette 550. The rigid plastic portion 552 defines a plurality of insulating baffles 604. The baffle 604, in the embodiment, defines a meandering pathway as described herein. The top of the baffle 604 is ultrasonically welded or adhesively bonded to the cassette sheet 606.

With module 610, a layer of metal or metal ink 608 on the sides of the baffle 604 and the bottom of the channel defined by the baffle 604, electrolessly, for example, via a spray technique, ink ejection technique, or photographic imaging process. Is deposited. The metal layer 608 can be applied in multiple coats and cured in multiple steps so as to build the layer 608 to the desired thickness. In the embodiment, the metal layer 608 is a stainless steel layer. In one embodiment, the heating module 610 operates inductively with the conductive coil, for example, via one or more pancake coils 42 or spiral coils 72.

In an alternative embodiment, the conductive layer 608 is not provided. Instead, at least the heating module portion 610 of the rigid portion 552 of the pump cassette 550, including the insulating baffle 604, is formed from injection molded parts filled with metal powder or carbon. This modified portion is heated during powering of the associated primary coil, such as one or more pancake coils 42 or wire coils 72, wound around a conductively filled heating portion 610 of the cassette.

In a further alternative embodiment, the metal layer 608 is removed. Instead, at least the heating module portion 610 of the disposable cassette 550 is metal and is made from a metal injection molding (MIM) or powder metal (PM) process. The metal portion 610 is composed of a baffle 604 that is induced and heated via an induction coil and a base that connects the baffle 604. This embodiment also helps with resistance heating, in which the exposed metal portion 610 is placed in contact with the electrical heating contacts.

The conductive portion 610 produced via the MIM or PM process is, in one embodiment, hermetically connected to the rigid plastic portion 552 of the disposable cassette 550 via a tight mating arrangement and an adhesive bond. Alternatively, a metal cover (not shown) is formed at the top of the baffle 604 to provide a fully enclosed metal heated meandering fluid path region.

In yet another alternative integrated cassette heater embodiment, a twisted conductive baffle, such as the baffle 480 of the heating module 460, is formed between the insulating baffles 604. Still in a further alternative embodiment, the insulating baffle 604 is removed and replaced with a twisted susceptor plate 480. The twisted susceptor plate 480 can contain as many turns as desired to create a turbulent flow path. Plate 480 is provided in sufficient quantity to conduct sufficient current to be heated to the required level. The twisted baffle 480 can be crimped to the side of the plastic portion 552 at one end so that the baffle 480 is firmly supported within the cassette 550.

(Heating module attached to pump cassette) With reference to FIG. 37 here, the disposable cassette 550a shows one possible cassette for connecting to the various fluid heating modules discussed above. The cassette 550a includes a rigid body portion 552 defining the pump chamber 554, a valve chamber or valve seat 556, and a tubing port 558 as discussed above. The cassette 550a further includes a port 558h to the heater and a port 558i from the heater. The rigid body portion 552 also includes a path 560a to the heater, which is arranged in fluid communication with the port 558h to the heater. The rigid body portion 552 of the cassette 550a further includes a passage 560b from the heater, which is arranged in fluid communication with the port 558i from the heater. The flexible sheet is applied to the front and back surfaces of the cassette 558a to seal the pump chamber 554, the valve chamber 556, and the fluid heating paths 560a and 560b. The fluid heating paths 560a and 560b communicate with other paths through the valve 556, for example, to one of or from one of the pump chambers 554, or to one or more of ports 558a to 558g. Communicate with the connecting route.

The heating ports 558h and 558i have cassettes 550a with 5 tubes of multiple baffle plate modules 150 from Figures 14A to 14E, 3-plate modules 220 from Figures 17A to 17F, serpentine baffle modules 190 from Figures 18A to 18C, and 5 tubes from Figures 25A to 25E. Allows communication with many of the fluid heating modules, such as Module 330, 6-tube module 360 in Figures 26A-26E, 2-tube module 400 in Figures 27A-27D, and 2-tube module 430 in Figures 28A-28G. To do. Each of the above modules includes an inlet and an outlet that are both close and separated, which is useful for immediate connection to the close and separated ports 558h and 558i. Applicants do not intend to limit the cassette 550a to the modules described below. However, other modules may require additional length of tubing between the cassette 550a and the heating module. The single port cassette of the single tube module 460 of Figures 29A-29E is also shown below.

In one implementation, the cassette 550a has an footprint of about 5.75 inches (14.6 cm) high x about 5.25 inches (13.3 cm) (maximum width) x about 0.50 inches (1.27 cm) thick. Cassette 550a includes two pneumatic pump chambers 554 (although a peristaltic or mechanically actuated capacitive pump chamber can be used instead). The illustrated cassette 550a includes 17 square pneumatic valve ports 565. As an alternative, the valve port is removed from the cassette 550a and a clamp is used instead.

FIG. 38 illustrates the connection of the cassette 550a to a further alternative fluid heating module 620. The fluid heating module 620 includes a tube 632 that is bent to form an inlet 622 and an outlet 624 that are close and separated. As seen in FIG. 38, with close and spaced inlet and outlet pipes 622 and 624, module 620 has short pipe joints 626a and 626b entering (i) port 558h to the heater, respectively. Connect to 622 and (ii) allow port 558i from the heater to be connected to outlet 624. Short distances between joints 626a and 626b tend to prevent heat loss and increase overall system efficiency.

The cassette 550a includes a plurality of metal contacts 630. Metal contacts 630 are used to sense fluid temperatures upstream and downstream from module 620. One suitable metal contact is described in a co-pending patent application, patent application No. 11 / 773,661, filed July 5, 2007, entitled "Dialysis Fluid Measurement Method And MFP Using Conductive Contacts." , The entire contents of which are expressly incorporated herein by reference.

Alternatively, non-invasive, eg, infrared temperature sensors, non-invasive temperature sensing can be used to eliminate contacts 630 and associated electronics. A patent application entitled "Dialysis System Having Non-Invasive Temperature Sensing" filed on July 5, 2007, which is a co-pending patent application expressly incorporated herein by reference thereof. 11 / 773,746 discloses one system and method for non-invasive temperature sensing using an infrared temperature sensor.

Module 620 of FIG. 38 includes a cage 634 that firmly supports the end of tube 632. The end of tube 632 is fed into the diversified tube 621, including inlet 622 and outlet 624. The inlet 622 and the outlet 624 each have a port that fits into one end of one of the tubing joints 626a and 626b. The other end of the tubing junction connects to port 558h to the heater and port 558i from the heater.

FIG. 39 illustrates a module 630 operating with an alternatively configured pump cassette. FIG. 39 shows the fluid heating module 630 working with a primary spiral coil 72 wound around a magnetic core 76 including flux directional arms 78a and 78b, as discussed above in connection with, for example, FIGS. 7-9. It is illustrated that it is a secondary coil. The magnetic flux directional arms 78a and 78b of the magnetic core 76, in one embodiment, are located in the dialysis instrument and induce current in the module 630. As shown, the coil 72 can be wound around the directional coil arm 78b between the arm and the tube of the module 630.

With reference to FIGS. 40 and 41 here, cassette 550b illustrates an alternative pump cassette for connecting to the fluid heating module discussed above. The cassette 550b is largely the same as the cassette 550a and also provides fluid heating paths 560a and 560b. The main differences between cassettes 550b and 550a are the built-in / reinforced port 650a to the heater and the built-in / reinforced port 650b from the heater (collectively referred to herein as port 650, or (Generally individually referred to as port 650). Port 650 is discussed in detail below in relation to Figures 45-47. The port 650a to the heater communicates with the fluid path 560a to the heater. Port 650b from the heater communicates fluidly with path 560b from the heater.

In Figure 41, a cassette 550b with built-in ports 650a and 650b excludes the upper multi-tube of any of the two-tube fluid heating modules discussed above (eg, modules 360, 400, and 420). Illustrates what makes it possible. Instead, the inlet tube of the two-tube heater module is sealed and directly connected to port 650a to the heater, while the outlet tube of the two-tube module is sealed and directly connected to port 650b from the heater. Will be done.

FIG. 41 illustrates an example in which the upper multi-tube 402 is removed from the fluid heating module 400 shown above in relation to FIGS. 27A-27D. Here, the pipe 330a is sealed and directly meshed with the built-in port 650a, while the outlet pipe 338b is sealed and directly meshed with the built-in port 650b. The pipes 338a and 338b are connected at the bottom by the return diversified pipe 410. Alternatively, the tubing 338a and 338b are bent from a single tubing and the U-shaped tubing is hermetically meshed into the built-in ports 650a and 650b. For example, instead of the diversified tube 621 providing inlet and outlet ports 622 and 624, a single curved tube 632 of the fluid heating module 620 shown above in connection with FIG. 38 can be used. Here, the diversified tube 621 is removed and the tube is placed directly into the built-in ports 650a and 650b. The built-in port allows the cassette 550b to be slightly smaller than the cassette 550a. For example, the maximum width along the top of the cassette 550b can be reduced to about 5.055 inches (12.8 cm).

FIG. 40 also illustrates an alternative magnetic core 76 made of any of the materials described herein for the magnetic core 76. The magnetic core 76 has five faces and has an opening top to accommodate the tubes 338a and 338b shown in FIG. The magnetic core 76 also houses the coil 72 shown in the cross section. The magnetic core 76 and coil 72 are part of the instrument and are reused. Cassettes 550b and tubes 338a and 338b are discarded after treatment. The magnetic core 76 may also be used with the single tube version of the cassette 550c discussed below, and with a susceptor having any of three or more tubes or the baffle plate configuration shown herein. Good.

The magnetic core 76 can be structured within the instrument to fit around other modules discussed herein and is not limited to tube modules. For example, a magnetic core 76 similar to FIG. 40 can be fitted around coil 72 of any of the baffle plate modules. The magnetic core 76 can also be configured to fit around the washer module 490 and the canister modules 230 and 260.

The magnetic core 76 provides an additional benefit in that it tends to shield the outside world from the electromagnetic interference (EMI) emitted by the coil 72. Because each of the modules discussed herein, whether provided via a magnetic core 76 or via an additional shield, eg, an aluminum sheet discussed above, contains EMI radiation. Shielded to meet international guidelines.

With reference to FIGS. 42 and 43, an alternative cassette 550c is provided through the provision of a single built-in port 650c that works with a single tube fluid heating module such as the fluid heating module 460 of FIGS. 29A-29E. , Made even smaller. Here, the inlet and outlet diversified pipes 462 of the module 460 shown above are excluded.

Built-in port 650c splits the inlet flow to the bottom 472 of the tube 470 and the flow back to the top of the single tube 470, for example to accommodate a larger tube 470 carrying a twisted baffle 480. In addition, it is wider than the built-in ports 650a and 650b in Figures 40 and 41. Built-in port 650c includes inlet path 652, which allows port 650c to communicate with inlet fluid path 560a. Port 650c also has an outlet path communicating with the outlet fluid path 560b of the cassette 550c, as opposed to port paths 652 and 654 in FIG. 40, which are dedicated to port 650a to the heater and port 650b from the heater, respectively. Includes 654. The provision of a single tube built-in port 650c allows the maximum width of the cassette 550c to be reduced to about 5 inches (12.7 cm) in one implementation.

FIG. 44 illustrates an alternative version of a single tube fluid heating module, which here includes an end cap 474 instead of the rounded end 472 as shown in FIG. 43. The end cap 474 can be plastic or metal and can be secured as described herein. FIG. 44 also illustrates that the twisted baffle 480 can be loosely fitted into the tube 470. In addition, the baffle 480 extends beyond the upper edge 476 of the tube 470. The exposed edge 476 of the baffle 480 extends into the well of the single built-in tube port 650c so that the baffle is firmly supported in place via the adjacency to the inner wall 656 of the port 650c. To enable. The configuration also directs flow from inlet path 652 down the inlet side of the twisted baffle 480 into the wells of single port 650c. The configuration also directs flow from the outlet side of the twisted baffle 480 at edge 476 into the outlet path 654 of cassette 550c.

Here, with reference to FIGS. 45-47, the built-in reinforcing pipe port 650 is illustrated in detail. Non-embedded reinforcement port 502 is shown above in connection with FIG. 30D and the double washer fluid heater module 490. The torque and shear stress associated with the non-embedded reinforcement port 502 is also shared by the embedded reinforcement port 650. The spacing of the built-in ports 650 shown in Figure 46 is appropriate for connecting the dual washer module 490 to the more alternative disposable pump cassette 550d shown in the relevant sections of Figures 45 and 46. I want you to understand. Looking at the heater module 490 in FIG. 30A and the cassette section in FIG. 46, the unheated fluid follows the path 560a to the heater, exits the first port 650 and goes to the heater module inlet 502 (FIG. 30A). A second set that flows around the path between the washer 500a and 500b, exits the fluid heater module outlet 504, and fluidly communicates the path 560b from the heater to the appropriate region of the cassette 550d. It flows into the built-in port 650.

FIG. 47 illustrates that the inner port 656 is formed integrally with the side wall 658 of the rigid body portion 552 of the cassette 550d. Further, the outer holding collar 660 is integrally formed with the wall 658 of the rigid body portion 552. The collar 660 provides the tubing port 656 with the same kind of reinforcement protection that the collar 506a provides to the inner port 506b, shown in connection with the reinforcing inlet and outlet ports 502 and 504 of FIG. 30d. In both cases, it is embedded in the cup feature or additional collar 660 or 506a, respectively, to shift the lever arm axis forward, reducing shear stress on the associated inner port 656 or 506b. Therefore, a person who pivots the flexible tube in the direction indicated by the arrow in FIG. 47 will start with the dotted line on the outside of FIG. 47, as opposed to the dotted line on the inside shown in FIG. 47. A torque having a moment arm as a starting point is applied.

The spacing between the dotted lines indicated by the horizontal arrows indicates how the moment arm and torque applied on the tubing port 656 is reduced. This reduction enhances the durability of ports 502, 504, and 560. Reinforcement ports are shown in connection with the heating modules discussed herein, but, for example, as a supply line port, a port to or from a patient, or a port as another tubing port. It should be understood that the can be used elsewhere on the dialysis cassette 550.

Referring here to FIG. 48, the alternative pump cassette 550e includes modules 180 from FIGS. 15A to 15E, modules 210 from FIGS. 16A to 16E, and the alternative fluid heating module 670 shown in FIG. , An embodiment for connecting to an in-line fluid heating module is illustrated. The cassette 550e is a port to the heater, separated from the port 558i from the heater, at a distance sufficient to allow one of the in-line fluid heating modules to be placed between the ports 558h and 558i. Including 558h. It should be understood that the port can be an alternative built-in and / or augmented type discussed above.

The fluid heating module 670 includes a tube 672, which is wound once and contains an inlet end 674 and an outlet end 676 for connecting to ports 558h and 558i, respectively. The loop of tube 672 fits over the magnetic flux directional extension 78 of the magnetic core 76, as shown, for example, in FIG. 39. The tubing 672 is, in one embodiment, stainless steel such as magnetic or non-magnetic stainless steel, such as the tubing 632 of the fluid heating module 630. The rigid body portion 552 of the cassette 550e extends around the fluid heating module 670 to mount the cassette 550e for the pump and valve actuators and the fluid heating module 670 for the coil 76 operating with the inductive fluid heating module 670. It is extended to provide a handle 662, which is useful for.

(Sphere in the bag) With reference to FIG. 49 here, the fluid heating bag or pouch 680 illustrates yet another alternative fluid heating module of the present disclosure. As discussed herein, the fluid heating modules of the present disclosure are connected elsewhere in a disposable cassette or set, eg, in series with a patient line or solution line. , Can be a separate or stand-alone module. The bag or pouch 680 illustrates that it is also possible to place the conductive susceptor material in a fluid bag or pouch, such as a feed bag or warmer bag. In the illustrated embodiment, the bag 680 provides a fluid inlet 682 and a fluid outlet 684 that are ultrasonically welded or adhesively bonded to one or more sheets 686 and 688 forming the pouch or bag 680. Sheets 686 and 688 can be made of polyvinyl chloride (PVC), or other high temperature flexible medical grade plastics.

The pouch or bag 680 carries a plurality of stainless steel balls 690 in the illustrated embodiment. The stainless steel ball 690 acts as a susceptor or secondary coil for the primary induction coil located inside the dialysis instrument. The primary coil can be a pancake coil 42 or a spiral coil 72. In an alternative embodiment, the stainless steel ball 690 is replaced with another type of stainless steel medium, such as stainless steel net, sintered metal, or wool, which allows fluid to flow through it.

(Plate heater that applies positive and negative pressure) With reference to FIG. 50 here, the heating system 700 illustrates an alternative heating system that uses pressure and vacuum to enhance heat transfer efficiency and provides the additional benefits described herein. To do. The heating system 700 includes an upper heater 702, a lower heater 704, and a fluid heating path assembly 706. The upper heater 702 and the lower heater 704 include a heating plate 708, a heating plate or surface 710, and an outer cover 712, respectively. Heating plates 708 for both upper and lower heaters 702 and 704 include or define openings or ports 714 that provide connections to one or more air pressure sources, including negative and positive pressure sources.

The heated surface or heating plate 710 comprises or defines one or more openings 716, which provides a positive or negative pressure applied through port 714 and a plenum between the cover 712 and the plate 710. , Transfer to the flexible heating section 720 of assembly 706. The openings as described herein are configured to maximize the distribution of positive or negative pressure throughout the flexible heating section 720.

In one embodiment, a pipe (not shown) is connected to the pneumatic port 714. These tubes extend to the valved portion of the disposable, such as those located on a disposable cassette as illustrated above, or to a series of clamps (not shown). The disposable cassette valve can be operated electrically or pneumatically. The clamp can be electrically actuated, for example, in the form of a solenoid.

FIG. 1 illustrates an electronic device for induction heating. System 700 is primarily an embodiment of resistance heating. The electronic device, like the electronic device of circuit 24, includes a processor such as a microprocessor and memory, including, for example, random access memory (RAM) and read-only memory (ROM). It can contain logical implementers such as implementer 16. Memory and processing can be software-based, as is known in the art. As an alternative, one or more application-specific integrated circuits (ASIC) can be used. A logic implementer for a resistor system 700, such as the logic implementer 16, also includes the ability to accept the input signal 18a and the output signal 18d. The input signal 18a can be a signal from a sensor such as a temperature sensor, a flow rate sensor, an air detection sensor, or another type of sensor used in connection with dialysis instruments.

A resistor circuit, such as circuit 24, transmits an output signal 18b to components within the dialysis instrument, such as a power supply that powers one of the primary coils discussed herein for an induction heating module. .. Alternatively, the power supply controls the load cycle output to the resistance plate heater. The output signal 18b can also be connected to a solenoid valve or clamp that can tighten or open the fluid line. A logic implementer of the resistor circuit 24, such as the logic implementer 16, can receive input from an air detection sensor that senses air in a disposable unit, for example, and is connected to port 714 of system 700. A pinch clamp that closes one of the tubes. When an input to the solenoid is received, it can be programmed to send an output.

The upper and lower heaters 702 and 704 form a pneumatic plenum that allows positive or negative pressure to be formed internally and thus redistributed through the opening 716 into the flexible fluid heating path 720. Three openings 716 are shown, but any number, pattern, and dimensions of openings can be provided. For example, a perforated metal with many small holes can be provided to evenly distribute positive or negative pressure on the surface of the flexible heating path 720.

Assembly 706 illustrates that the fluid heating path 720 is sealed between assembly frames 722 and 724. The frames 722 and 724 are then sealed to the heating plates 708 of the upper and lower heaters 702 and 704 to form a sealed environment that carries the positive or negative pressure of the system 700.

Alternatively, the flexible sheet of path 720 is sealed together to (i) form the fluid heating path 720 and (ii) around the inlet and outlet tubes 728, which allows the fluid to be fluid heated. Allows it to be sent and sent to route 720. The upper and lower heating plates 708 are then tightened together around the sealed fluid path 720 to provide a sealed environment. For example, the heating plate 708 can have a soft gasket material or O-ring 718 that provides compression directly on the frame 722/724 or on the sheet of flexible fluid path 720. In a pneumatic system, it expands against one of the heaters 702 and 704 to squeeze the sections together and squeeze the seal 718, thereby opening or closing the enclosed environment of the system 700. The formula sac (not shown) can be pressurized.

In one embodiment, the heating surface 710 is a resistance heating surface. The heated surface 710 can be heated by a resistance heating element (not shown) that is placed between the surface and the cover 712 in thermal contact with the unexposed side of the heated surface 710. Electrical insulation is provided between the AC mains that power the resistance heating element (not shown) and the disposable fluid heating path 720.

In an alternative embodiment, an electric current is inductively applied to the surface 710, which is heated by the resistance material of the heater plate. The lack of direct contact between the induction heating surface 710 meets the requirements for electrical insulation between the AC mains and the disposable fluid heating path 720.

The ability to apply positive or negative pressure provides many benefits for fluid heating. For example, the application of positive or negative air pressure to the surface of the fluid heating path 720 causes the amount of film or sheet in the path 720 to contact the heater plate 720 to vary with ambient air pressure and fluid pressure. to enable. One important pressure to monitor or control is the pressure difference across the sheets forming the fluid heating path 720 (which can be considered as the fluid pressure as opposed to the air pressure). In one case, the negative pressure of air applied between the path 720 and the surface 710 forces the disposable surface to match the plate 710, maximizing the surface area contact between the film and the plate 710 in the path 720. Limit. This allows for better heat transfer between the plate and the fluid.

Applying negative pressure between plate 710 and path 720, this ability also prevents the relative negative pressure of the fluid from destroying the disposable, does it prevent the flow of dialysis fluid through the heater? , Or can be severely restricted. Such a situation can occur when the solution source is below the fluid pump and the fluid pump is located downstream from the heating system 700. In addition, when the fluid path 720 is located downstream from the pump and the fluid destination (patient, etc.) is lower than the fluid path 720, the disposable heating section can also collapse or partially collapse. These conditions still allow the fluid to flow through the heater, but such flow occurs with a loss of contact between the film and the heater plate and between the plate and the fluid. Reduce heat transfer.

As discussed above, the system 700 also allows positive pressure to be applied between the plate 710 and the fluid heating path 720. The application of positive pressure allows the dialysis system 700 to expel fluid from the dialysis fluid path 720 and, potentially, from other areas of the disposable set connected to the fluid path 720. In essence, the application of positive pressure causes the fluid heating path 720 to act as a membrane pump into the inlet line 726, eg, upstream into the supply bag, or outlet line 728 for drainage. Push the fluid out of the fluid heating path through.

One reason the system 700 applies positive pressure to the heating path 720 is to prevent overheating when fluid flow ceases for whatever reason. Positive pressure removes fluid from the heating path 720 so that section 700 is not overheated. Another reason for applying positive pressure is to release one type of dialysis fluid from the fluid heating path 720 so that another type of dialysis fluid may be used. For example, different dialysis fluids can have different glucose concentrations. When switching to a new concentration, the system 700 can release the first concentration of dialysate from the fluid pathway, with the first concentration of solution still remaining in the fluid pathway 720 or perhaps other parts of the disposable set. Allows the second solution to be used without mixing with a portion of the second solution.

The fluid heating path 720 is defined by a heat-bonded, ultrasonic welded, or adhesively bonded seal 730 that spirals inward from the inlet 726 and then forms an outward seam back to the outlet 728. In one embodiment, the opening 716 allows the vacuum or positive pressure to start from a portion of the seam 730 in line with the seam 730 so that the vacuum or positive pressure can travel along the seam. .. This allows vacuum or positive pressure to be easily applied around the entire surface area on either side of the fluid heating path 720.

One or both of the outer surface of the fluid path 720 and the contact surface of the plate 710 can be embossed to allow positive pressure or vacuum to be applied through the gaps in the pattern. Thus, the pattern also helps to spread positive or negative pressure throughout the surface of the fluid heating path 720. The pattern also acts to prevent the formation of a cavity between the film on path 720 and the heater plate 710.

In an embodiment, a sheet of sheet that forms a fluid heating path so that when the system 700 applies positive pressure to the outside of the heating path 720, the embossed surface helps drain all fluid from the inside of the heating path 720. The inner surface is also embossed. The inner embossed surface also prevents fluid from being trapped in path 720.

A more thermally conductive material, such as stainless steel foil, may replace or be applied to one or both films used to make the fluid heating path 720. The stainless steel foil increases heat transfer between the heater plate 710 and the fluid in path 720. Applying a vacuum between the surface of the foil and the heater plate 710 allows a harder foil surface to better fit the heater plate, further increasing heat transfer.

Here, with reference to FIG. 51A, an embodiment for sealing the upper and lower heaters 702 and 704 in the heating path 720 is illustrated, and in this figure and subsequent figures, the individual sheets of the fluid heating path 720 are , Marked as sheets 720a and 720b. The frames 722 and 724 in the illustrated embodiment provide a relatively large area 734 that can accept relatively large forces, for example, from the heating plates 708 of the upper and lower heaters 702 and 704. Forces are applied to the tightening members 738a and 738b, which in turn apply relatively significant sealing forces to the sheets 720a and 720b.

In FIG. 51A, the frame member 732 of the frame 722 includes an energy waveguide 736, which directs ultrasonic energy to the frame member 732 of the frame 724 and around the frame and the sheets 720a and 720b. Illustrated to help generate ultrasonic waves that are welded.

Detail A of FIG. 51A shows that, in one embodiment, the edges of the tightening members 738a and 738b are configured to have a meshing relationship, such as outward and inward meshing protruding triangles. Alternatively, detail B in FIG. 51A shows that the tightening members 738a and 738b have adjacent, eg, square, rounded joint surfaces.

FIG. 51B illustrates an embodiment for applying frames 722 and 724 to sheets 720a and 720b. Here, the fastening mechanism 740 of the frame 722 is formed in the frame 722 with respect to the meshing ridge 744a of the frame 724 so as to be fastened to the frame 724 and seal the seat 720a in the seat 720b. Pull 742a. The mooring mechanism 740 is a thermal caulking that places and captures the flexible sheets 720a and 720b within the frames 722 and 724. FIG. 51B also includes the energy waveguide 736 described above in connection with FIG. 51A.

FIG. 51C illustrates another embodiment of frames 722 and 724 shown in FIG. Here, again, the fastening mechanism 740 functions as a heat crimp that anchors the frame 722 to the frame 724 and positions and captures the flexible sheets 720a and 720b within the frames 722 and 724. The frame 722 provides an alternative undulation 742b and the frame 724 provides an alternative meshing ridge 744b. The heating plates 708 of the upper and lower heaters 702 and 704 are pressed against the heating path frames 722 and 724, for example, at the joint surface where the undulations 742b mesh with the step 744b.

FIG. 51D illustrates an embodiment for sealing the joint surfaces of sheets 720a and 720b, along with inlet or outlet pipes 726 or 728. Here, tubes 726 and 728 (or parts thereof) are rigid tube components. Sheets 720a and 720b are bonded, heat fused or welded to tubing 726 or 728. The frame member 732 of the frames 722 and 724 presses the gasket 746 against the rigid tubing portions 726, 728.

FIG. 51E is an alternative embodiment in which each frame member 732 includes a stepped portion 748 that presses on the sage portion 750 of the tubes 726, 728. The swage portion 750 in the illustrated embodiment is a bundled or crimped section of the tubing 726, 728 that helps to create a compression seal between the tubing and the stepped portion 748 of the frame member 732.

Here, with reference to FIG. 51F, a further alternative embodiment of the joint surface between the sheet and the inlet and outlet pipes is illustrated. Here, the frame members 732 of the frames 722 and 724 are bent around the tube 726/728 to compress the O-ring 752. The frame member 732 also encloses the bushing 754, which helps to create a compression seal between the tubing and the O-ring 752.

With reference to FIG. 51G here, in a further alternative embodiment, tubes 726, 728 are compressible. Here, as the rounded tip 756 of the frame member 732 presses the tubes 726 and 728 slightly inward to create a seal, but so that the tubes remain open for fluid flow. The frame members 732 of the frames 722 and 724 are separated.

With reference to FIG. 51H here, in a further alternative embodiment, the tubes 726 and 728 are separated into tube sections 726a and 726b and tube sections 728a and 728b. The two sets of sections are meshed with a bulkhead joint 758, which is then sealed to the stepped frame members 732 of the upper and lower frames 722 and 724, respectively.

In FIG. 51I, the frame member 732 of the frames 722 and 724 has a female connector portion 760 for hermetically receiving tube sections 726b or 728b and a male port 762 for hermetically receiving tube sections 726a or 728a. To form.

(Heating control structure) The control of the fluid heating embodiments described herein, in particular the induction embodiments, can be accompanied by a separate control regimen, one that controls fluid temperature (FIG. 52), one that controls safety. That is, for example, it prevents the module from overheating due to the air passing through the heater. Safety controls are configured to take precedence over normal control of fluid temperature whenever air is detected in the system. Following additional safety controls, the usual fluid heating algorithms are discussed next.

(Fluid heating control) With reference to FIG. 52, the control scheme 770 illustrates an embodiment of the control algorithm, which (even in FIG. 52, the conductive coil is shown with a cold fluid input and a warm fluid input). Also) fluid heating can be controlled for any of the fluid heating embodiments described herein, including all induction and resistance embodiments. The control scheme 770 is described above and is operated on or by a logical implementer such as the logical implementer 16 shown in FIG. The circuit 24 working with the logical implementer 16 of FIG. 1 is modified from what is shown to work with an embodiment of resistive fluid heating rather than the illustrated induction. The control scheme 770 includes a feedforward portion 772 and a feedback portion 774, which are described in detail below.

In one embodiment, the heating system uses control scheme 770 to control the power input to the heater. The control scheme 770 correlates the flow rate of the dialysis fluid 776 (eg, the instantaneously measured or calculated flow rate as described herein) with the difference T (ΔT) to the heater power supply and heater. Includes feedforward portion 772, using Table 780 to generate 784 power setpoints 790. The power supply and heater 784 heats the cold fluid at the inlet temperature 778 to a warm fluid with the outlet fluid temperature 782.

The control method 770 is also an additive portion of the control method 770 (Σ).₁) Also includes a feedback loop 774 with a feedback control 788 discussed below. Addition part of control method 770 (Σ)₁) Outputs the difference T (ΔT) in Table 780. Addition part of control method 770 (Σ)₁) Includes a desired outlet fluid temperature of 786, which is a constant value in one embodiment, and a dialysis fluid inlet temperature of 778 (eg, measured as described below). Therefore, the difference T (ΔT) is as follows.

ΔT = T_desired786+ Feedback Output 788-Measured T_in778 Table 780 in one embodiment contains values derived from the correlation of the fluid flow rate 776 and the power setting point 790 with the differential fluid temperature. The correlations are shown in the table shown below.

<tables num="1"><img id="000002" he="41" wi="158" file="JP5259708B2_D0001.tif" img-format="tif" img-content="drawing" /></tables> The basis of the table is derived from the specific heat calculation Q = m * c * ΔT, in which Q is required to heat the mass m of the fluid, which has the specific heat c for ΔT from one temperature to another. It is the energy that is said to be. Since the fluid is flowing, P_fYou can write a similar expression = Q / t = (m / t) * c * ΔT, and in the expression, P_fIs the power (per unit time t) required to heat a fluid flowing at a flow rate of m / t (mass per unit time), which has a specific heat c for ΔT from one temperature to another. Energy Q). The table describes the desired changes ΔT of the measured fluid flow velocity and fluid temperature. The flow velocity is assumed using a flow meter, from known pump speed settings, or from calculations as discussed below. ΔT is calculated as shown in FIG. Constants, including the specific heats of the fluid being heated (the constants of water and dialysate, which have approximately the same specific heat constants), are incorporated when the table is created. Therefore, the specific heat of the dialysis fluid is assumed to be a constant when formulating Table 780 for a particular dialysis fluid.

Fluid P_fThe power to is the desired power input, independent of the heating module used. Power supply set point for a specific one of the heaters (P)_setpoint) Determines the efficiency of the heater and the non-linearity of the power supply, and other relationships such as the heat transfer ratio between the susceptor and the fluid at various flow velocities that relate the power setting point to the power delivered to the fluid. Take into consideration. Therefore, for any desired flow velocity and temperature change ΔT, the power supply setting point P_setpointExists and is recorded in the table.

To produce Table 780, the heating system in one embodiment is experimentally tested at various flow rates, differential fluid temperatures, and power supply setting points. The data collected will be used to complete the table. After the table is created, there is a combination of measured flow velocity and desired differential temperature. The corresponding power supply set points are then applied to the power supply section and the fluid is heated by approximately the same temperature difference as when the table was created. In one embodiment, the power setting point to the power supply of the heater is adjusted using an electronically controlled input. The setpoint input can be an analog setpoint (eg, 4-20mA or 0-5VDC) or a digital setpoint (eg, pulse width modulation (PWM) setpoint).

As an example, in order to generate a table, at a specific flow velocity of 1 as shown in the table above, along with the applied power supply setting points 1 and 1 that generate the differential temperature ΔT1. , Operate system 770. Record the corresponding points in the table. Complete each row and column of the table in the same way. In the example using the completed table, the system 770 measures a flow velocity of 776, such as a flow velocity of 2, and T._inWhen measuring the inlet fluid temperature of 778 etc., the system T_{out out}The outlet fluid temperature of 782 is desired, for example, ΔT3 Δcalculation = T_{out out}-T_inBring. The power supply setting points, setting points 3 and 2, are shown in the table. The set points are applied to the power supply unit, which produces a heating system response according to the time the table was generated, T_{out out}Should give rise to the outlet fluid temperature of. If the measured flow velocity or differential temperature ΔT is not exactly present in the table, the algorithm can be applied to the data in the table to interpolate the required power setting points. Alternatively, the closest intersection data point can be selected.

In an alternative embodiment, the logical implementer 16 uses an equation created from the experimental measurements used to create the table, the measured flow velocity 776, the measured inlet temperature 778, and the desired temperature 786. to,NecessaryP in accordance with the requirements_setpointTo calculate. In such cases, Table 780 is not needed. The table or algorithm is the power setting point of feedforward portion 772 used by the heating system in an attempt to bring the outlet fluid temperature to the desired temperature without the traditional overshoot or delay inherent in traditional feedback-only PID temperature control systems. Bring or calculate.

For certain types of fluid pumping, such as turbine pumping, the flow velocity is relatively continuous, making the flow velocity portion of the feedforward calculation relatively easy to carry out. When the flow velocity is discontinuous, such as in a diaphragm pump, the flow velocity portion of the feedforward calculation becomes more difficult.

For intermittent or pulsatile flows, one approach to implementing the feedforward portion 772 of the heating system 770 is to measure or calculate the flow velocity over a short period of time (milliseconds, etc.), and the flow velocity is being measured. The power setting point is adjusted at the same rate as. This approach seeks to produce a constant fluid temperature at the outlet of the heater by adjusting the power input throughout the pump stroke. For example, two diaphragm pumps are used out of phase with each other (one pumps out but the other fills), and neither pump pumps into or out of the heater. If present at the end of the pump stroke, the flow velocity in the heater is zero during that period. With this approach, the power input to the heater is also zero during that period. This system helps prevent overheating of the heating module and, for example, a no-flow condition, which is a more concern for inductive overheating systems.

A patent application entitled "Medical Fluid Pumping System Having Real Time Volume Determination" filed on July 5, 2007, which is a co-pending patent application expressly incorporated herein by reference thereof. No. 11 / 773,773 discloses a real-time method for determining the instantaneous flow velocity, which is one method of providing flow velocity information to the feedforward portion 772 of the system 770. The built-in flow velocity teachings can work with pneumatic control pump systems as described in the application.

Another approach for delivering flow velocity data for the feedforward portion 772 of the system 770 is to measure the flow velocity over several pump strokes of the diaphragm pump and calculate the average flow velocity over the period from the measured flow velocity. It involves a step and a step of finding the power setting point 790 from Table 780 based on the average flow velocity. The measurement and calculation of the average flow velocity can be repeated after a certain time interval, for example, every few seconds. In this second approach, the fluid delivered through the heater during peak flow rates is heated to a temperature slightly below average, while it is delivered through the fluid heated by the heater during periods of lower flow rates. The resulting fluid is heated to a temperature slightly warmer than average. When overheated or underheated fluids are mixed (eg, through contact with a piece of disposable material leading to the patient), the average fluid temperature balances with the desired temperature. This flow velocity method approach may require a larger heater surface mass and may be applicable by a resistance heating system.

The feedback portion 774 of the system 770 attempts to eliminate the error caused by the feedforward setpoint 790 at the actual fluid outlet temperature 782. Feedback portion 774 subtracts the measured outlet fluid temperature 782 from the desired outlet fluid temperature 786, the second sum Σ₂To use. Second sum Σ₂The output of is input to the feedback expression or algorithm 788. In one embodiment, before initiating feedback control 774, system 770 waits for the measured outlet temperature 782 to reach steady state. Here, the output of the feedback control 788 is Σ until the outlet temperature 782 reaches the steady state.₁Can be set to zero.

In one embodiment, the feedback portion 774 is updated each time the feedforward portion 772 is updated. That is, each time the feedforward setting point 790 of the feedforward portion 772 is updated, the setting is updated by one or more of the feedback portion 774, regardless of whether the update period is about a few milliseconds or a few seconds. Take into account the gain (explained below) potentially. Alternatively, for example, if the feedforward setting point is updated frequently, once for every one update of the feedforward setting point 790, for example, 1 for every 10 or 100 updates of the feedforward power setting point 790. Times, one or more gains of feedback portion 774 can be updated instead.

The heating modules and corresponding heating systems described herein may vary from system to system, as shown in Table 780, with different (albeit minor) different results in different systems using the same type of heating module. It is thought that it can occur. That is, in one embodiment, Table 780 is generated once for each type of module and heater (eg, averaging the results for different ones of the modules) and the table has a particular heater. , Used in each instrument to operate that particular module. Common tables may produce different results for different things in the same module. Feedback portion 774 compensates for this potential variation.

It should be understood that an instrument can store multiple tables for different modules that can work with the instrument. It is also possible that the instrument can store multiple tables for different types of fluids, such as different viscosities or specific heats of the same module, or for different temperature ranges of the same module and the same fluid.

Feedback loop 774 outputs ΔT in Table 780, sum Σ₁Produces output to. Feedback part 774 is the sum Σ₂In T_desiredMeasured temperature 782 from 786 (eg, measured via the downstream conductive contact 630 illustrated above), and sum Σ₁Sum Σ to determine the updated output to₂Use one of the proportional gain, integral gain, or derivative gain (PID) in the feedback algorithm 788 that applies to the output of.

The proportional gain is influenced by how far the measured outlet temperature is from the desired temperature. The differential gain is influenced by how fast the measured temperature is approaching (or moving away from) the desired outlet temperature. The integrated gain is influenced by historical data, such as the difference in desired temperature from the measured outlet fluid temperature, which has been integrated over a recent period such as a few seconds.

System 770 uses a temperature sensor that inputs a signal to the logical implementer 16 indicating an outlet temperature of 778 (eg, measured at the outlet contact 630). Due to the fast response of the heaters described herein, especially the thin wall induction heaters, the temperature sensor in one preferred embodiment is a fast response temperature sensor.

One suitable temperature sensor is an infrared sensor commercially available from Exergen as an IRt / c Heat Balance system infrared thermocouple (eg, part number IRt / c.01HB). This sensor responds quickly to changing fluid temperatures. However, the following systems and methods improve the response time of other slow response types of temperature sensors.

Systems and methods use the fact that temperature measurements are changing to predict what the actual fluid temperature might be at a given point in time. The system and method then use the adjusted measured fluid outlet temperature 786'instead of the actual measured fluid outlet temperature 786. The logical implementer 16 is a mathematical derivative of the measured outlet temperature 786 of the past time compared to the actual measured outlet temperature 786 of the current time to predict the current temperature of the fluid 786'. To use.

The inlet and outlet temperature sensors respond almost immediately to changes in fluid temperature, but the actual response is too slow, that is, the sensor is at the right time so that the sensor output lags behind the actual fluid temperature. It is known that it does not respond sufficiently. Therefore, the system and method are such that when the measured fluid temperature changes, eg, increases, the actual fluid temperature changes above the temperature derived from the sensor output, eg, actually derived. It is assumed that the temperature is higher than the above temperature.

As an example, in one test, the fluid outlet temperature 786 is sampled at regular intervals of 0.250 seconds. Current measurement temperature sample 786 for the following equation_nT_nSet to previous temperature sample 786_n-1T_n-1Set to. Current fluid temperature T to compensate for rapidly changing measured temperature_fluidAdjust (786') as follows.

T_fluid= T_n+ K * (T_n-T_n-1) In the equation, K is provided by the physical constants of the system. K is a system constant that can be determined experimentally and is determined to make the above equation accurate. Alternatively, K is determined via a differential equation that takes into account the thermal resistance and capacitance of the system. The thermal system can be modeled as, for example, an electrical system with resistance R and capacitance C in the corresponding electrical circuit, where V (t) = VI * e (-t / RC). Where t is time and VI is similar to the measured starting temperature. V (t) is similar to the measured temperature at time t.

According to the above equation, slight temperature fluctuations between temperature samples are essentially T._nT equal to (786)_fluidBrings (786'). When large temperature fluctuations between temperature samples are measured, the factor K is correspondingly the current measured temperature T._nModify (786) (adjust the measured fluid temperature by the amount of temperature change in the last two samples multiplied by K) and use different adjusted Ts in the heating system 770._fluidProduces (786').

If the temperature change ΔT between n and n-1 is below a certain threshold, the resulting factor K may be determined to be unreliable due to the noise of the heating system 770. Here, (T_n-T_n-1) Is set to zero and T_fluid(786') is T_nIt is said to be (786).

It should be understood that actual time samples may be taken at time intervals different from 0.250 seconds. As an alternative, the method takes many samples very quickly in a short time interval, averages the samples together, and averages T._nCan be assigned to to reduce noise or increase resolution.

FIG. 53 illustrates test data for the above methods and algorithms. The line connecting the diamond-shaped data points represents the actual fluid temperature. The line connecting the square data points represents the predicted fluid temperature based on the above equation, as performed by a microcontroller that reads and reports the measured fluid temperature. The line connecting the triangular data points represents the result of the same equation with different constants on the reported data.

(Heating safety control) As discussed herein, one primary heating system of the present disclosure is an induction heating system that uses a primary coil and a susceptor. The system uses a relatively small amount of metal to heat the fluid, which means that the system does not store too much energy and can quickly dissipate energy when needed. However, the temperature of the susceptor can also rise fairly rapidly, for example due to the cessation of dialysis fluid flow in the heater, or the presence of air bubbles. The heating control structure adds heating safety control to the fluid heating control to counter the potential overheating problem. The heating safety control takes precedence over the fluid heating control in situations where the fluid heating control may not be sufficient to avoid overheating of the fluid and potential overheating of the heating module.

System 770 provides one means of combating overheating due to stagnant or stopped fluid flow. As discussed above, the system 770 inputs the power setting based on the flow rate of the dialysis fluid. In one embodiment, the system 770 knows the instantaneous flow velocity, and if a period of no flow is calculated or known, the system 770 sets the power setting to zero for that period.

Safety controls provide another means of combating overheating due to stagnant or stopped fluid flow. Here, the susceptor temperature is measured. If the susceptor temperature rises excessively dramatically or over an excessively long period of time, flow outages or air problems are expected. Here, safety control takes precedence over system 770 and takes workarounds, for example, setting the power setting to zero.

The susceptor can be (i) fluid, (ii) a mixture of fluid and air, or (iii) directly with pure air before the disposable set is prepared or if large bubbles are drawn into the disposable item of the heater. Can be in thermal contact. The dialysis fluid draws more heat from the susceptor than pure air, and more heat from the susceptor than the combination of fluid and air. Thus, air or partial air can also cause overheating in heating modules, especially in induction heating modules discussed herein.

Safety controls employ several means of coping with air overheating. One way is to look for air upstream of the fluid heating module. If air is detected or sufficient air is detected upstream of the heating module, safety controls can be configured to determine if an overheating problem is about to occur and to take preventive override procedures. .. Here, using one or more known historical flow velocities, safety controls can predict when and how long air bubbles or slags will be present in the heating module, at the appropriate time, or. The power setting point can be reduced or reduced to zero over a suitable length of time. The goal here is to prevent the susceptor temperature from rising due to the air in the module.

One suitable air sensor for prophylactic control is believed to be the LifeGuard® Air Bubble Detector provided by Zevex® Inc. (Salt Lake City, Utah). Model numbers ZLG130 or ZLG200 are considered relevant at this time as they appear to be specifications that detect bubbles of dimensions that can cause overheating of the susceptor. It should be understood that the detection of air in the dialysis system, and therefore the output of the air detector, is useful for purposes other than fluid heating.

Another means provided by safety controls to deal with overheating by air is to measure the susceptor temperature again. Here, if the susceptor temperature rises excessively dramatically or over an excessively long period of time, flow outages or air problems are assumed and safety controls take precedence over System 770 and take workarounds, eg, Set the power setting to zero.

The advantage of using the susceptor temperature in safety control is that it is believed that the susceptor temperature can be determined electrically at least sufficiently accurately for safety control without additional sensors. The susceptors described herein have electrical resistance that varies as a function of the temperature of the susceptors discussed herein. As discussed above, in one embodiment the susceptor is made of stainless steel. Stainless steel resistance is a function of stainless steel temperature. The system and method consider using susceptor resistance measurements to determine the average temperature of the susceptor.

The average temperature of a susceptor may be determined by measuring the susceptor resistance and knowing the relationship between the susceptor resistance and temperature and at least one calibration point that takes into account variations due to susceptor mass.

In one embodiment, the calibration point is determined after mounting the heating module on the dialysis instrument. The calibration points may vary from module to module due to, for example, slight variations in susceptor length, width, wall thickness, etc., i.e., variations due to susceptor mass. Safety control measures resistance when the susceptor is at a known temperature, such as when the susceptor is not actively heated. The temperature of the susceptor can be assumed to be the temperature or average of one of both conductive contacts 630 when the fluid is unheated as it is delivered across the susceptor and temperature sensor. Alternatively, at the beginning of treatment, a temperature sensor (eg, infrared temperature sensor, diode, thermistor, integrated circuit sensor, or resistance temperature device) to measure the temperature of one or more of the susceptors at one or more measured resistors. ("RTD")) can be used.

Safety controls know the temperature coefficient (ohm / ° C) or the relationship between resistance changes and temperature changes (ΔR / ΔT) for certain types of metals used in susceptors. In knowing one or more calibration point resistors Rc, susceptor temperature Tc, and temperature coefficient of the susceptor metal, the safety system resists R at a given time t during treatment._tMeasure and average susceptor temperature T₁The value of can be obtained. Average susceptor temperature T_tIf is too high or is rising too fast, safety controls will take workarounds as described above.

Safety control can measure resistance by at least the following methods.

(i) A heating element (eg, a heating element) that applies a current through a lead from a current source to the resistor of the susceptor 14 and the metal part 20a, measures the corresponding voltage, and calculates the resistance from the applied current and the measured voltage. Direct contact between the leads 14a and 14b) in Figure 1 and the electrical circuit.

(ii) A heating element (eg, a heating element) that applies a voltage through a lead from a voltage source to the resistor of the susceptor 14 and the metal part 20a, measures the corresponding current, and calculates the resistance from the applied voltage and the measured current. Direct contact between the leads 14a and 14b) in Figure 1 and the electrical circuit.

(iii) To measure the voltage and current applied to the primary coil, the known turns ratio of the circuit 24 and any of the resistors described herein, and the known measured voltage and current. Steps to calculate the resistance of the susceptor using and.

(iv) Circuit 24 was used to apply a resonant or damped signal that attenuated as a function of the susceptor's resistance, the damping of the vibration was measured, and the susceptor's resistance was measured to correlate with the susceptor's temperature. Steps to correlate damping. As discussed above, in some fluid control schemes described herein, the power setting point is set to zero when the instantaneous flow velocity is also zero. This provides a good time to measure signal attenuation. The faster the signal decays, the higher the resistance and the corresponding average susceptor temperature. In the embodiment, the amplitude peak is monitored to determine the envelope of attenuation. Different envelopes correlate with different resistances. Detecting a particular envelope results in some resistance, leading to an average temperature.

It should be understood that the various changes and modifications of the currently preferred embodiments described herein will be apparent to the interrogator. Such changes and modifications can be made without departing from the spirit and scope of the subject and without diminishing its intended benefits. Therefore, such changes and amendments are intended to be covered by the appended claims.