Medical fluid cassette leak detection methods and devices.
Abstract
A method is provided for detecting leaks in a disposable medical fluid cassette that includes a base and a flexible membrane attached to the base such that the base and the flexible membrane cooperate to at least partially form a fluid passage. In method it includes applying a first force to the flexible membrane, measuring a first physical property of a system that includes the medical fluid cassette, a medical fluid pumping machine, removing the first force from the flexible membrane, applying a second force to the flexible membrane, measure a second physical property of the system, and determine if the medical fluid cassette is filtered based on a comparison of the first physical property and the second physical property.

Term
7.4 yearsleft in the term
Expires 28 February 2034.
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- Today
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17 claims: 1 independent, 16 dependent
- 1Un método para detectar filtraciones en un casete de fluido médico desechable, el casete de fluido médico comprende una base y una membrana flexible fijada a la base de tal forma que la base y la membrana flexible cooperan para formar al menos parcialmente un pasaje de fluido, el método caracterizado porque comprende:aplicar una primera fuerza a la membrana flexible con un pistón configurado para avanzar contra y retraerse de la membrana flexible;medir una primera propiedad física de un sistema que incluye el casete de fluido médico y una máquina de bombeo de fluido mecánico mientras la primera fuerza es aplicada a la membrana flexible;remover la primera fuerza de la membrana flexible;separar el pistón de la membrana flexible después de remover la primera fuerza;hacer avanzar el pistón contra la membrana flexible después de separar el pistón de la membrana flexible;aplicar una segunda fuerza a la membrana flexible después de hacer avanzar el pistón contra la membrana flexible;medir una segunda propiedad física del sistema que incluye el casete de fluido médico y la máquina de bombeo de fluido médico mientras la segunda fuerza es aplicada a la membrana flexible;y determinar si el casete de fluido médico se filtra con base en una comparación con la primera propiedad física y la segunda propiedad física. puertos de entrada de fluido y puertos de salida de fluido que proporcionan comunicación entre el pasaje de fluido y un exterior del casete de fluido médico, y la aplicación de la primera fuerza se realiza con los puertos de entrada de fluido y puertos de salida de fluido cerrados.
- 24. El método de acuerdo con la reivindicación 1, caracterizado porque la aplicación de la primera fuerza a la membrana flexible comprende aplicar la primera fuerza hasta que al menos una porción de la membrana flexible contacte la base.
- 35. El método de acuerdo con la reivindicación 1, caracterizado porque el método incluye aplicar un vacío a una superficie exterior de la membrana flexible entre remover la primera fuerza de la membrana y aplicar la segunda fuerza a la membrana.
- 46. El método de acuerdo con la reivindicación 1, caracterizado porque:la aplicación de la primera fuerza a la membrana flexible comprende hacer avanzar el pistón contra la membrana flexible hasta que se logra una presión dada dentro del casete de fluido médico, la aplicación de la segunda fuerza a la membrana flexible comprende hacer avanzar el pistón contra la membrana flexible hasta que se logra la presión dada dentro del casete de fluido médico, la primera propiedad física comprende una primera posición del pistón correspondiente a la posición del pistón cuando se logra la presión dada mientras se aplica la primera fuerza, y la segunda propiedad física comprende una segunda posición del pistón correspondiente a la posición de pistón cuando se logra la presión dada mientras se aplica la segunda fuerza.
- 57. El método de acuerdo con la reivindicación 6, caracterizado porque la comparación de la primera propiedad física y la segunda propiedad física comprende calcular una diferencia entre la primera posición y la segunda posición.
- 68. El método de acuerdo con la reivindicación 1, caracterizado porque el casete de fluido médico incluye puertos de entrada de fluido y puertos de salida de fluido que proporcionan comunicación entre el pasaje de fluido y un exterior del casete de fluido médico, y aplicar la primera fuerza se realiza con los puertos de entrada de fluido y puertos de salida de fluido abiertos.
- 79. El método de acuerdo con la reivindicación 8, caracterizado porque antes de remover la primera fuerza de la membrana flexible, los puertos de entrada de fluido y puertos de salida de fluido se cierran.
- 810. El método de acuerdo con la reivindicación 1, caracterizado porque además comprende esperar un período de tiempo dado para pasar entre separar el pistón de la membrana flexible y hacer avanzar el pistón contra la membrana flexible.
- 911. El método de acuerdo con la reivindicación 10, caracterizado porque el periodo de tiempo dado de tiempo está en un rango de 15 segundos a 60 segundos.
- 1012. El método de acuerdo con la reivindicación 1, caracterizado porque el casete de fluido médico incluye puertos de entrada de fluido y puertos de salida de fluido que proporcionan comunicación entre el pasaje de fluido y un puertos de salida de fluido de manera que el fluido quede atrapado dentro del casete de fluido médico.
- 1113. El método de acuerdo con la reivindicación 12, caracterizado porque el método incluye aplicar un vacío a una superficie exterior de la membrana flexible entre remover la primera fuerza de la membrana y aplicar la segunda fuerza a la membrana.
- 1214. El método de acuerdo con la reivindicación 1, caracterizado porque el casete de fluido médico incluye puertos de entrada de fluido y puertos de salida de fluido que proporcionan comunicación entre el pasaje de fluido y un exterior del casete de fluido médico, y antes de aplicar la primera fuerza a la membrana flexible, el método comprende cerrar los puertos de entrada de fluido y los puertos de salida de fluido de manera que se atrape el fluido dentro del casete de fluido médico.
- 1315. El método de acuerdo con la reivindicación 14, caracterizado porque entre cerrar los puertos de entrada de fluido y los puertos de salida de fluido de manera que se atrape el fluido dentro del casete de fluido médico y aplicar la primera fuerza a la membrana flexible, el fluido dentro del casete es redistribuido.
- 1416. El método de acuerdo con la reivindicación 1, caracterizado porque la máquina de bombeo de fluido médico comprende un pistón, y la aplicación de la primera fuerza a la membrana flexible comprende hacer avanzar el pistón hacia el casete a una posición predeterminada en una forma de manera que el espacio entre la membrana flexible y la base tiene un volumen predeterminado. posición correspondiente a la primera propiedad física.
- 1518. El método de acuerdo con la reivindicación 1, caracterizado porque la primera propiedad física comprende una primera presión dentro del casete de fluido médico y la segunda propiedad física comprende una segunda presión dentro del casete de fluido médico.
- 1619. El método de acuerdo con la reivindicación 18, caracterizado porque se determina que el casete de fluido médico tiene una filtración si la segunda presión es mayor que la primera presión, y una diferencia entre la segunda presión y la primera presión es al menos un valor de diferencia dado.
- 1720. El método de acuerdo con la reivindicación 18, caracterizado porque que se determina que el casete fluido médico tiene una filtración si la segunda presión es menor que la primera presión, y una diferencia entre la primera presión y la segunda presión es al menos un valor de diferencia dado. RESUMEN DE LA INVENCIÓN Se proporciona un método para detectar filtraciones en un casete de fluido médico desechable que incluye una base y 5 una membrana flexible fijada a la base de tal forma que la base y la membrana flexible cooperan para formar al menos parcialmente un pasaje de fluido. En método incluye aplicar una primera fuerza a la membrana flexible, medir una primera propiedad física de un sistema que incluye el casete de 10 fluido médico, una máquina de bombeo de fluido médico, remover la primera fuerza de la membrana flexible, aplicar una segunda fuerza a la membrana flexible, medir una segunda propiedad física del sistema, y determinar si el casete de fluido médico se filtra basándose en una comparación de la 15 primera propiedad física y la segunda propiedad física. 1/11 AL DRENAJE 124 F\G· 2 3/11 FIG. 3 4/11 153Β h'- O CD FIG. 4 5/11 6/11 I tT fv. O -I I, co ' lll O 3Q «o σ ιζ z o UJ ►Q pLoo J lll iii FIG. 6 TANQUE DE PRESION POSITIVA I-- x1082 Oü iii O 29^ O T“ z o gj 55 ÍT CN O T“ UJ O 7/11 8/11 FIG. 8 9/11 FIG. 9 10/11 FIG. 10 11/11 COLOCAR EL CASETE DENTRO DEL CICLADOR DE PD, Y CERRAR LA PUERTA DE CIERRE (PASO 400) Ψ INFLAR EL ALMOHADILLA INFLABLE (PASO 402) i AVANZAR LAS CABEZAS DE PISTON DENTRO DEL CASETE (404) T CERRAR LA ABRAZADERA DE SEGURIDAD (PASO 406) .. —~T —MEDIR UNA PRESION INICIAL (Pínioal) OEL CASETE (PASO 408) ...... ¿ RETRAER LAS CABEZAS DE PISTON MAS ALLA DEL CASETE (PASO 410) .............................. ---DESINFLAR LAALMOHADILLA INFLABLE (PASO 412) I APLICAR EL SISTEMA DE VACIO (PASO 414) Mi PERMITIR QUE TRANSCURRA UN PERIODO DADO DE TIEMPO (PASO 416) VENTILAR EL SISTEMA DE VACIO A LAATMOSFERA (PASO 418) INFLAR LAALMOHADILLAIMFLABLE (PASO 420) ............. i -----AVANZAR LAS CABEZAS DE PISTON EN EL CASETE (PASO 422) Perforar No Perforar Δ t 10seg. i MEDIR UNA PRESION FINAL (PfJ DEL CASETE (PASO 424) P»w.-Pinkx»l LIMITE2 COMPARAR LAPOSCONFNAL PARA DETERMINAR SI EXISTE UNA ILTRACION EN EL CASETE PASO 426 FIG. 11 (P-nJ CON LA POSICION INCIAL (P^) Pfwu.P»«»u. 2 LIMITE2
Independent claims17
197 paragraphs in 6 sections, as filed
This description refers to methods and devices for detecting medical fluid cassette filtration.
BACKGROUND
Dialysis is a treatment used to support a patient with insufficient renal function. The two main dialysis methods are hemodialysis and peritoneal dialysis.
During hemodialysis (HD), the patient's blood passes through a dialyzer of a dialysis machine while also passing the dialysate through the dialyzer. A semipermeable membrane in the dialyzer separates the blood from the dialysate within the dialyzer and allows diffusion and osmosis exchanges to be carried out between the dialyzer and the blood stream. These exchanges across the membrane result in the removal of residual products including solutes such as urea and creatinine, from the blood. These exchanges also regulate the levels of other substances, such as sodium and water, in the blood. In this way, the dialysis machine acts as an artificial kidney to clean the blood.
During peritoneal dialysis (PD), a patient's peritoneal cavity is periodically infused with dialysate. The membranous lining of the patient's peritoneum acts as a natural semi-permeable membrane that allows diffusion exchanges and osmosis to take place between the solution and the blood stream. These exchanges through the patient's peritoneum, such as continuous exchange through the HD dialyzer, result in the removal of residual products, including solutes such as urea and creatinine, from the blood, and regulate the levels of other substances, such as sodium. and water, in the blood.
Many PD machines are designed to automatically infuse, remain and drain dialysate to and from the patient's peritoneal cavity. The treatment typically lasts several hours, often beginning with an initial drainage cycle to empty the peritoneal dialysate cavity used or spent. The sequence then proceeds through the succession of filling, permanence, and drainage phases that follow one after the other. Each phase is called a cycle.
BRIEF DESCRIPTION OF THE INVENTION
In some aspects, a method is provided for detecting leaks in a disposable medical fluid cassette. The medical fluid cassette includes a base and a flexible membrane fixed to the base such that the base and the flexible membrane cooperate to at least partially form a fluid passage. The method includes applying a first force to the flexible membrane; measuring a first physical property of a system that includes the medical fluid cassette and a medical fluid pumping machine while the first force is applied to the flexible membrane; remove the first strength of the flexible membrane; apply a second force to the flexible membrane; measuring a second physical property of the system that includes a medical fluid cassette and the medical fluid pumping machine while the second force is applied to the flexible membrane; and determine if the medical fluid cassette is filtered based on a comparison of the first physical property and the second physical property.
In some aspects, a method of detecting leaks in a disposable medical fluid cassette is provided. The medical fluid cassette includes a base and the flexible membrane fixed to the base such that the base and the flexible membrane cooperate to at least partially form a fluid passage having fluid inlet ports and fluid outlet ports that They provide communication between the fluid passage and an outside of the medical fluid cassette. The method includes applying a first force to the base; apply a second force to the membrane; close the fluid inlet ports and fluid outlet ports; measuring the first physical property of a system that includes the medical fluid cassette and a medical fluid pumping machine while the first force is applied to the base and the second force is applied to the membrane; remove the first force from the base; remove the second force the flexible membrane; after measuring a first physical property and removing the first force and the second force, waiting for a predetermined period of time; apply a third force to the base; apply a fourth force to the flexible membrane; measure a second physical property of the system while the third is force applied to the base and the fourth force is applied to the membrane; and determine if the medical fluid cassette is filtered based on a comparison of the first physical property and the second physical property.
The methods may include one or more of the following steps or additional features: the first physical property comprises a first pressure within the medical fluid cassette and the second physical property comprises a second pressure within the medical fluid cassette. It is determined that the medical fluid cassette has a leak if the second pressure is greater than the first pressure, and a difference between the second pressure and the first pressure is at least a given difference value. It is determined that the medical fluid cassette has a leak if the second pressure is less than the first pressure, and a difference between the first pressure and the second pressure is at least a given difference value. The medical fluid pumping machine comprises a piston configured to advance against and retract from the flexible membrane, applying the first force to the flexible membrane comprises advancing the piston against the flexible membrane until a given pressure is achieved within the fluid cassette medical, applying the second force to the flexible membrane comprises advancing the piston against the flexible membrane until the pressure given within the medical fluid cassette is achieved, The first physical property comprises a first piston position corresponding to the piston position when the given pressure is achieved while the first force is applied, and the second physical property comprises a second piston position corresponding to the piston position when the piston position is achieved. pressure given while applying the second force. The comparison of the first physical property and the second physical property comprises calculating a difference between the first position and the second position. The first force is the same as the second force.
The methods may also include one or more of the following steps or additional features. The medical fluid cassette includes fluid inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and applying the first force is performed with the fluid inlet ports and ports. fluid outlet open, Before removing the first force of the flexible membrane, the fluid inlet ports and fluid outlet ports are closed. The medical fluid cassette includes fluid inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and the application of the first force is performed within the inlet ports of fluid and fluid outlet ports closed. The method also includes waiting for a given period of time to pass between removing the first force from the flexible membrane and applying the second force to the flexible membrane. The given period of time is in a range of 15 seconds to 60 seconds. The given period of time is in a range of 20 seconds to 30 seconds. The medical fluid cassette includes fluid inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and between applying the first force to the flexible membrane and measuring the first physical property of the system, the method comprises closing the fluid inlet ports and the fluid outlet ports so that the fluid is trapped within the medical fluid cassette. The method includes applying a vacuum to an outer surface of the flexible membrane between removing the first force of the membrane and applying the second force to the membrane. The medical fluid cassette includes inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and before applying the first force to the flexible membrane, the method comprises closing the ports. of fluid inlet and fluid outlet ports so that fluid is trapped inside the medical fluid cassette. Between the closure of the fluid ports and the fluid outlet ports so that the fluid is trapped inside the medical fluid cassette and the first force is applied to the flexible membrane, the fluid inside the cassette is redistributed. The application of the first force to the flexible membrane comprises applying the force minus a portion of the flexible membrane makes the base. The piston medical fluid pumping machine, and applying the first force to the membrane comprises advancing the piston towards the cassette to a predetermined one in such a way that the flexible membrane space and the base comprise an application of the second force to the comprising advancing the piston corresponding to the first property includes applying a vacuum to a flexible membrane surface between removing the first membrane and applying the second force to the membrane.
In some aspects, a doctor is set up for a disposable doctor. The base cassette and a flexible membrane make the base and the membrane until in contact with it it comprises a flexible position between the predetermined. The flexible membrane to a physical position. The external method of the force of the fluid pumping machine receiving a medical fluid fluid cassette includes one fixed to the base in such a flexible manner cooperate at least partially to form a fluid passage. The medical fluid pumping machine includes a compartment that receives the medical fluid cassette and a pressure applicator configured to apply a force of the medical fluid cassette when the medical fluid cassette is disposed within the compartment. The medical fluid pumping machine also includes a processor that is configured to: control the pressure applicator so that a first force is applied to the flexible membrane when the medical fluid cassette is disposed within the compartment; measuring a first physical property of a system that includes the medical fluid pumping machine with the medical fluid cassette disposed within the compartment while the first force is applied to the flexible membrane; control the pressure applicator so that the first force of the flexible membrane is removed when the medical fluid cassette is disposed within the compartment; control the pressure applicator so that a second force is applied to the flexible membrane when the medical fluid cassette is disposed within the compartment; measuring a second physical property of the system that includes the medical fluid pumping machine within the medical fluid cassette disposed within the compartment while the second force is applied to the flexible membrane; and determine if the medical fluid cassette is filtered based on a comparison of the first physical property and the second physical property.
In some aspects, a medical fluid pumping machine is configured to receive a disposable medical fluid cassette. The medical fluid cassette includes a base and a flexible membrane fixed to the base such that the base and the flexible membrane cooperate to at least partially form a fluid passage having fluid inlet ports and fluid outlet ports that They provide communication between the fluid passage and an outside of the medical fluid cassette. The medical fluid pumping machine includes a compartment that receives the medical fluid cassette, a piston disposed within a compartment and configured to apply a force to the flexible membrane when the medical fluid cassette is disposed within the compartment, an inflexible pad arranged in the compartment between the base and a surface of the compartment, the inflexible bladder configured to apply a force to the base when the medical fluid cassette is disposed within the compartment, a clamp configured to close the fluid inlet ports and fluid outlet ports when the medical fluid cassette is disposed within the compartment, and a processor. The processor is configured to control the piston so that a first force is applied to the flexible membrane when the medical fluid cassette is disposed within the compartment; control the inflatable pad so that a second force is applied to the base when the medical fluid cassette is disposed within the compartment; control the clamp so that the fluid inlet ports and fluid outlet ports are closed; measuring a first physical property of a system that includes a medical fluid pumping machine with the medical fluid cassette disposed within the compartment while the first force is applied to the flexible membrane and the second force is applied to the base; control the piston so that the first force is removed from the flexible membrane when the medical fluid cassette is disposed within the compartment; control the inflatable pad so that the second force of the base is removed when the medical fluid cassette is disposed within the compartment; controlling the piston so that a third force is applied to a flexible membrane when the medical fluid cassette is disposed within the compartment; control the inflatable pad so that a fourth force is applied to the base when the medical fluid cassette is arranged inside the compartment; measuring a second physical property to the system that includes the medical fluid pumping machine within the medical fluid cassette disposed within the compartment while the third force is applied to the flexible membrane and the fourth force is applied to the base; and determine if the medical fluid cassette is filtered based on a comparison of the first physical property and the second physical property.
Medical fluid pumping machines may include one or more of the following characteristics: The machine includes a vacuum source controllable by the processor and disposed within the compartment such that when activated while the medical fluid cassette is inside the compartment, the vacuum source can apply a force to the flexible membrane, and the processor It is configured to change a gap between the flexible membrane and the base when the vacuum source is activated. The processor is configured to change the separation after controlling the pressure applicator so that the first force of the flexible membrane is removed and before controlling the pressure applicator so that the second force is applied to the flexible membrane. The vacuum source can apply a force to an outer surface of the flexible membrane. The machine includes a door that is configured to selectively close the compartment and retain the medical fluid cassette inside the compartment, and an inflatable bladder arranged on an interior surface of the door and configured such that when it is inflated while the fluid cassette doctor is inside the compartment, The inflatable bladder is configured to compress the medical fluid cassette and when it is deflated while the medical fluid cassette is inside the compartment, the inflatable bladder is configured to act against the surface side of the door and generate a space between the bladder Inflatable and medical fluid cassette. The processor is configured to deflate the door bladder between controlling the pressure applicator so that the first force is removed from the flexible membrane and controlling the pressure applicator so that the second force is applied to the flexible membrane. Controlling the pressure applicator so that the first force is applied to the flexible membrane comprises controlling the pressure applicator such that the flexible membrane is compressed against the base. The pressure applicator comprises a piston configured to move forward and retract from the compartment. The medical fluid cassette includes fluid inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and control the pressure applicator so that the first force is applied to The flexible membrane is made with fluid inlet ports and fluid outlet ports open. The medical fluid cassette includes fluid inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and the processor is configured to close the fluid inlet ports and fluid ports. fluid outlet after controlling the pressure applicator so that the first force is applied to the flexible membrane and before measuring the first pressure inside the medical fluid cassette. The medical fluid cassette includes fluid inlet ports and fluid outlet ports that provide communication between the fluid passage and an outside of the medical fluid cassette, and control the pressure applicator so that first force is applied to the Flexible membrane is made with fluid inlet ports and fluid outlet ports closed.
The implementations may include one or more of the following advantages.
In some implementations, a method of determining if a medical fluid cassette (for example, a PD fluid cassette) is being filtered includes applying a force of the medical fluid cassette, measuring a first pressure of the medical fluid cassette, and then remove the applied force from the medical fluid cassette. After a predetermined period of time, a force is applied to the medical fluid cassette, and a second pressure of the medical fluid cassette is measured. Based on a comparison of the first and second pressure measurements, it is possible to determine whether there is a leak in the flexible membrane of the medical fluid cassette. This method is advantageous over some conventional filtration detection methods since the applied force is removed from the medical fluid cassette between pressure measurements. In particular, for example where force is applied to a medical fluid cassette using pistons of a medical fluid pumping machine (for example, a PD cycler) and a leak is located in the medical fluid cassette membrane in the proximity of the pump chambers, particularly in the center the pump chambers, The same piston can obstruct the filtration and provide false confidence in the membrane integrity during tests performed using a continuous applied force. By removing the applied force (for example, by retracting the pistons) between pressure measurements, the accuracy of filtration detection measures is improved since membrane filtrations in the vicinity of the applied force are not obstructed, allowing detection of leaks in the proximity of the applied force (for example, in the membrane that covers the pump chambers).
In some implementations, a dry method for detecting leaks in a disposable medical fluid cassette is provided. For example, before performing peritoneal dialysis, the method is also performed using air (instead of dialysate or other liquid) as a test fluid to determine if there is a leak in a PD fluid cassette. Since the method includes testing the PD fluid cassette in a PD cycler before treatment, they are detected and from these leaks before starting treatment cycles form can be remedied more conveniently than if they will be detected during a treatment cycle .
In addition, since air is used as the test fluid, the dialysis machine is protected from damage caused by leaks in the cassette.
If a leak is detected in the cassette, there is no need to throw anything from the dialysate to disinfect any portion of the apparatus. In addition, if a leak is detected, the liquid is prevented from entering the mechanical and pneumatic systems of the PD cycler.
In some embodiments, the dialysis machine, upon detecting a leak, can alert the user to take remedial action such as replacing the cassette with a different cassette before permanent damage to the dialysis machine or certain critical machine components occurs. of dialysis
Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a peritoneal dialysis (PD) system that includes a PD cycler placed on a portable frame.
Figure 2 is a perspective view of the PD cycler and a PD cassette of the PD system of Figure 1, with a PD cycler door in the open position to show the interior surfaces of the PD cycler that interfere with the PD cassette during use.
Figure 3 is an exploded perspective view of the PD cassette of the PD system of Figure 1.
Figure 4 is a perspective view of the PD cassette assembled in Figure 3. A rigid cassette base is visible through a transparent flexible membrane that is fixed to the base.
Figure 5 is a perspective view of an open cassette compartment of the PD cycler of Figure 1.
Figure 6 is a schematic illustration of an air distribution system of the PD cycler of Figure 1.
Figure 7 is a schematic illustration of a PD cycler control system of Figure 1.
Figure 8 is a partial perspective view of the PD cassette in the cassette compartment of the PD cycler of the PD system of Figure 1.
Figure 9 is a flow chart illustrating a position based method for detecting leaks in a medical fluid cassette.
Figure 10 is a flow chart illustrating a volume based method for detecting leaks in a medical fluid cassette.
Figure 11 is a flow chart illustrating a minimum volume method for detecting leaks in a medical fluid cassette.
DETAILED DESCRIPTION
In general, this description refers to a method for detecting leaks in medical fluid cassettes, and medical fluid pumping machines equipped to perform the methods. Filtration detection methods include placing a medical fluid cassette (for example, a PD fluid cassette) in a medical fluid pumping machine (for example, a PD cycler), using the pistons of the PD cycler to apply a disturbance (for example, a force) to the cassette, and measure a physical property of the cassette PD cycler system while the force is applied. The force is removed from the cassette, and, after a brief waiting period, the pistons of the PD cycler are used again to apply a force to the cassette. At this time, a second measurement of physical property is made while the force is applied to the cassette. The PD cycler determines whether the cassette is filtered based on a comparison of the first physical property and the second physical property. By removing the force of the cassette (for example, retracting the pistons of the PD cyclist away from the cassette) during method implementation, the leaks in the cassette in the vicinity of the applied force are released, thereby detecting filtration detection measurements reflecting more precisely the condition of the cassette than some methods in which force is applied continuously through the test method. In response to detecting a leak, action may be taken by the user and / or by the same medical fluid pumping machine to reduce the possibility or prevent permanent damage to the medical fluid pumping machine or to certain components within the pumping machine. of medical fluid.
Referring to Figure 1, a peritoneal (PD) dialysis system 100 includes a PD cycler (also referred to as a PD machine) 102, and a disposable PD fluid cassette 112 disposed within the PD cycler 102. The PD 102 cycler is placed on a car 104. Referring also to Figure 2, the PD cycler 102 includes a housing 106, a door 108, and an adjacent cassette surface 110 that engages with the cassette 112 when the cassette 112 is disposed within a cassette compartment 114 formed between the adjoining surface of cassette 110 and door 108. As discussed below, cassette 112 includes a flexible membrane secured to a rigid base 156 to form pump chambers 138A, 138B and fluid passages through which the dialysate passes during use. A heater tray is placed
116 in the upper part of the housing 106. The heater tray 116 is sized and formed to incorporate a dialysate bag (for example, a 5 liter dialysate bag). The PD cycler 102 also includes a touch screen 118 and additional control buttons 120 that can be operated by a user (eg, a patient) to allow, for example, configuration, start, and / or termination of a PD treatment. .
The dialysate bags 122 are suspended from fingers on the sides of the frame 104, and a heating bag 124 is placed on the heating tray 116. The dialysate bags 122 and the heating bag 124 are connected to the cassette 112 through bag lines of dialysate 126 and a heater bag line 128, respectively. The dialysate bag lines 1 26 can be used to pass dialysate from the dialysate bags 122 to the cassette 112 during use, and the heater bag line 128 can be used to pass dialysate back and forth between the cassette 112 and the bag of the heater 124 during use. In addition, a patient line 130 and a drain line 132 are connected to cassette 112. Patient line 130 can be connected to a patient's abdomen through a catheter and can be used to pass dialyzed back and forth between cassette 112 and the patient during use. The drain line 132 can be connected to a drain or drain receptacle and can be used to pass dialysate from cassette 112 to the drain or drain receptacle during use.
First, the cassette 112 will be described. That discussion will be followed by a description of the PD 102 cycler. Figure 3 is an exploded, perspective view of the cassette.
112 As shown in Figure 3, the cassette 112 includes the rigid base 156 similar to a tray and a flexible membrane 140, which is fixed to the periphery of the base 156 when the cassette 112 is completely assembled. The base 156 includes recessed regions 163A, 163B partially defining the pump chambers 138A, 138B of the cassette 112. Elevated grooves 165A, 165B extend from a flat surface of the base 156 around each of the recessed regions 163A, 163B and extend towards and in contact with the inner surface of the flexible membrane 140 when the cassette 112 is compressed between the door 108 and the adjoining surface of cassette 110 of PD 102 cycler. In addition to the raised grooves 165A, 165B surrounding the recessed regions 163A, 163B, a series of raised grooves 167 extend from the flat surface of the base 156 towards and in contact with the inner surface of the flexible membrane
140 when the cassette 112 is compressed between the door 108 and the adjoining surface of the cassette 110 of the PD 102 cycler.
Figure 4 is a perspective view of the assembled cassette 112. The characteristics of the rigid base 156 are visible through the transparent flexible membrane 140. Referring to both Figures 3 and 4, the recessed regions 163A, 163B of the base 156 cooperate with the flexible membrane 140 to form the pump chambers 138A, 138B when the cassette 112 is compressed between the door 1 08 and the adjoining surface of cassette 110 of the PD cycler 102 resulting in flexible membrane 140 that is pressed against raised grooves 165A, 165B of base 156. In particular, the volumes between the membrane 140 and the hollow projections that form the recessed regions 163A, 163B of the base 156 serve as the pump chambers 138A, 138B. The membrane 140, when compressed against the base 156, cooperates similarly with the series of raised grooves 167 extending from the base 156 to form a series of fluid paths 158 and to form multiple oppressive dome regions 146, which are portions widened (for example, substantially circular enlarged portions) of the fluid paths 158. The membrane 140, when compressed against the base 156, also cooperates with certain grooves 167 to form pressure sensor chambers 153A,
153B.
During use, a liquid, such as dialysate, flows to and from the pump chambers 138A, 138B through the fluid paths 158 in the dome regions 146. In each oppressive dome region 14 6, the membrane 140 can deflect to make contact with the flat surface of the base 156 from which the raised grooves 167 extend. Such contact can substantially prevent (for example, prevent) the flow of dialysate along the region of path 158 associated with that dome region 14 6. Thus, as described in further detail below, the flow of dialysate through the cassette 112 can be controlled through the selective repression of the oppressive dome regions 146 by selectively inflating inflexible coupling members on the adjoining surface of the cassette. 110 of the PD 102 cycler.
As noted above, the membrane 140 is fixed (for example, adhesive and / or thermally bonded) to the periphery of the base 156. The portion of the membrane 140 placed on the central portion of the base 156 is not necessarily fixed to the base 156. Rather, this portion of the membrane 140 can sit loosely on the raised grooves 165A, 165B, 167 extending from the flat surface of the base 156. The thickness and material (s) of the membrane 140 are selected such that the membrane 140 has sufficient flexibility to flex towards the base 156 in response to the force applied to the membrane 140 by piston heads and inflexible members of the PD cycler 102 , which will be described in more detail below. In certain implementations, the membrane 140 is about 0.100 microns to about 0.150 microns thick. However, several other thicknesses may be sufficient depending on the type of material used to form the membrane 140.
Any of several different medical grade materials that allow the membrane 140 to deflect in response to movement of the piston heads and inflation of the inflatable members of the PD 102 cycler without tearing can be used to form the membrane 140. In some implementations , membrane 140 includes a three layer laminate. In certain implementations, for example, inner and outer layers of laminate are formed of a compound that is made of 60% Septon® 8004 thermoplastic rubber (i.e., hydrogenated styrenic block copolymer) and 40% ethylene, and a middle layer It is formed of a compound that is formed of 25% Tuftec® H1062 (SEBS: hydrogenated styrene thermoplastic elastomer), 40% Engage® 8003 polyolefin elastomer (ethylene octene copolymer), and 37% Septon® 8004 thermoplastic rubber (i.e. hydrogenated styrenic block copolymer). The membrane 140 may alternatively include more or less layers and / or may be formed of different materials.
As shown in Figure 4, the fluid line connectors 160 are placed along the lower edge of the cassette 112. The fluid paths 158 in the cassette 112 are carried from the pumping chambers 138A, 138B to the various connectors 160. Connectors 160 are configured to receive accessories at the ends of dialysate bag lines 126, heater bag line 128, patient line 130, and drain line 132. One end of the accessory can be inserted inside and attached to its respective line and the other end can be inserted inside and attached to its associated connector 160. By allowing the dialysate bag lines 126, the heater bag line 128, the line of patient 130, and drain line 132 are connected to the cassette, as shown in Figures 1 and 2, connectors 160 allow dialysate to be pumped into and out of cassette 112 during use.
Figure 5 shows a detailed view of the adjacent cassette surface 110 and the door 108 of the PD cycler 102. As shown, the PD cycler 102 includes pistons 132A, 132B with substantially hemispherical piston heads 134A, 134B that can move axially within piston access ports 136A, 136B formed on the adjoining surface of cassette 110. The piston access ports 136A, 136B form annular passages 137A, 137B that surround the piston heads 134A, 134B and are in fluid communication with portions of the cassette membrane 140 covering the pump chambers 138A, 138B when the cassette 112 is disposed in the cassette compartment 114 of the PD 102 cycler. As a result, the vacuum pressure applied to the annular passages 137A, 137B during use of the PD cycler 102 can be used to extract the membrane 140 from the cassette 112 against the piston heads 134A, 134B.
Even with reference to Figure 5, the pistons 132A, 132B are coupled to engines that can be operated to move the piston heads 134A, 134B axially in and out into the piston access ports 136A, 136B. When the cassette 112 is placed inside the cassette compartment 114 with the door 108 closed, the piston heads 134A, 134B, of the PD cycler 102 align with the pump chambers 138A, 138B of the cassette 112. As a result, the piston heads 134A, 134B can move in the direction of the cassette 112 to force the membrane 140 of the cassette 112 towards the rigid base 156, causing the volume defined by the pump chambers 138A, 138B to decrease and force the dialyzed out of pump chambers 138A, 138B. The piston heads 134A, 134B can also retract away from the base 156 of the cassette 112. The portions of the cassette membrane 140 covering the pump chambers 138A, 138B are removed towards the piston heads 134A, 134B with vacuum force as the piston heads 134A, 134B retract. In particular, the annular passages 137A, 137B surrounding the piston heads 134A, 134B (i.e., the portions of the piston access ports 136A, 136B surrounding the piston heads 134A, 134B) can be used to apply a force of vacuum to those portions of the membrane 140 covering the pump chambers 138A, 138B. The piston access ports 136A, 136B are connected to a vacuum source (for example, an air pump or vacuum tank) to allow the vacuum pressure to be applied to the membrane 140 of the cassette 112 through the passages Annular 137A, 137B. As a result, the volume defined by the pump chambers 138A, 138B increases and dialysate is extracted into the pump chambers 138A, 138B as the piston heads 134A, 134B retract together with respective portions of the cassette membrane 140.
As shown in Figure 5, the PD cycler 102 also includes multiple inflexible members 142 placed within the inflexible membrane access ports 144 on the adjoining surface of the cassette 110. The inflatable members 142 align with the oppressive dome regions 146 of cassette 112 when cassette 112 is placed inside cassette compartment 114. The inflatable members 142 are connected to fluid lines that act as conduits to apply positive pressure and / or vacuum pressure to the inflexible members 142 so that the inflatable members 142 can be inflated and deflated during use. Although not all inflatable members 142 are labeled in Figure 5, it should be understood that the PD cycler 102 includes an inflatable member associated with each of the oppressed dome regions 146 of cassette 112 (shown in Figure 4). The inflatable members 142 act as valves to direct dialysate upside down of the cassette 112 in a desired manner during use. In particular, the inflexible members 142 protrude beyond the surface of the adjacent surface of the cassette 110 and in contact with the oppressive dome regions 14 6 of the cassette 112 when inflated, and retract into the access ports of Inflexible member 144 and out of contact with cassette 112 when deflated. By inflating certain inflexible members 142 to oppress their associated dome regions
146 on the cassette 112 certain fluid flow paths within the cassette 112 can be blocked.
In this way, dialysate can be pumped through cassette 112 by actuating piston heads 134A, 134B, and can be guided along desired flow paths within cassette 112 by inflating and deflating selectively definable members 142.
Referring still to Figure 5, the adjacent cassette surface 110 also includes vacuum ports 151 that are connected to vacuum lines placed within the PD 102 cycling housing. Vacuum ports 151 allow vacuum pressure to be applied to the cassette membrane 140 when the cassette 112 is placed adjacent to the adjacent cassette surface 110. By applying vacuum pressure of the membrane 140 through the vacuum ports 151, the membrane 140 is removed towards the adjacent cassette surface 110, thereby forming a seal between the adjacent cassette surface 110 and the membrane 140.
The adjacent cassette surface 110 also includes pressure sensors 149A, 149B. These sensors may, for example, be solid-state silicon diaphragm infusion pump force / pressure transducers. An example of a transducer is the Model 1865 made by Sensym Foxboro ICT. Output signals generated by pressure sensors 149A, 149B are transmitted to a control unit (for example, processor) 1090 (shown in Figure 7) of the PD 102 cycler via a wired or wireless connection. When the cassette 112 is inserted into the cassette compartment 114, the pressure detection chambers 153A, 153B (shown in Figure 4) of the cassette 112 are aligned and are in contact with the pressure sensors 149A, 149B. These pressure sensing chambers 153A, 153B are connected directly to the pump chambers 138A, 138B, respectively, of the cassette 112 so that when the dialysate moves in and out of the pump chambers 138A, 138B, the pressure sensors 149A, 149B can measure the pressure of the dialysate that passes through the pressure detection chambers 153A, 153B, and thereby can detect the pressure of the idealized associated pump chambers 138A, 138B. Cassette membrane 140 is extracted against pressure sensors 149A, 149B using vacuum pressure. In particular, annular passages 137A, 137B surrounding the pressure sensors 149A, 149B allow vacuum pressure to be applied to the cassette membrane 140. Removal of the cassette membrane 140 near the pressure sensors 149A, 149B can be improved. the accuracy of the pressure readings detected by those sensors.
Door 108, as shown in Figure 5, defines gaps or depressions 152A, 152B that are. substantially align with the piston heads 134A, 134B when the door 108 is in the closed position. When the cassette 112 is placed inside the cassette compartment 114, hollow projections that form the recessed regions 163A, 163B at the base 156 of the cassette 112 and cooperate with the membrane 140 to form the pump chambers 138A, 138B fit within the gaps 152A, 152B at door 108. An inflexible pad 135 at door 108 may be inflated during use to compress cassette 112 between door 108 and adjacent cassette surface 110. With the pad 135 inflated, the portions of the door 108 forming the gaps 152A, 152B support the hollow projections of the base 156 of the cassette 112 and the flat surface of the door 108 supports the other regions of the base 156 of the cassette 112. The gate 108 can counteract the forces applied by the piston heads 134A, 134B and the inflatable members 142 and thus allows the piston heads 134A, 134B to oppress the portions of the cassette membrane 140 that cover the pump chambers 138A , 138B and similarly allows the inflatable members 142 to operate the oppressive pump regions 146 on the cassette 112.
The PD cycler also includes a safety clamp 150, which serves to close all inputs to and from the cassette, for example, in the case of a system error. As seen in Figure 5, the safety clamp 150 is a bar arranged under the cassette compartment. The safety clamp 150 is spring-deflected to a closed position in which the bar is propelled against the inner surface of the door 108.
When in the closed position, the safety clamp 150 extends through all lines 126,
128, 130, 132 connected to cassette 112, whereby all lines 126, 128, 130, 132 extending from the cassette
112 They are held tightly. During normal operation, the safety clamp 150 retracts away from the door 108 using pneumatic pistons operated by the pneumatic system, as discussed further below.
Figure 6 is a diagram of an air distribution system 1000 of the PD 102 cycler. The air distribution system 1000 includes an air pump 1004 that is configured to generate positive air pressure or negative air pressure (vacuum) and can be used to apply positive pressure or vacuum pressure to annular passages 137A, 137B which they surround the piston heads 134A, 134B, the inflexible members 142, the vacuum ports 151, and / or the annular passages 147A, 147B surrounding the pressure sensors 149A, 149B. Air pump 1004 is connected through air lines or tubes 1040, 1070 through a valve manifold 1012. Air line 1040 is connected to a vacuum outlet port of air pump 1004 to supply pressure vacuum to manifold 1012, and air line 1070 is connected to a positive pressure outlet port of air pump 1004 to supply positive pressure from manifold 1012. The air line 1070 and other air lines of the air distribution system 1000 carrying positive pressure air are shown in dashed lines in Figure 6.
The manifold 1012 includes multiple valves that can be actuated to guide positive and negative pressure received from the air pump 1004 in a desired manner through any of several different air lines 1042, 1046, 1050, 1072, 1074, 1075, and 1078 connected to manifold 1012. Collector valves 1012, for example, can be solenoid valves that are controlled by the control unit (eg, processor) 1090 (shown in Figure 7) of the PD 102 cycler.
An air line 1048 is connected through a connection T to the air line 1042. An opposite end of the air line 1048 is connected to an inflatable member valve manifold 1080. The air line 1074 extending from manifold 1012 is also connected to the valve manifold of inflatable member 1080. In that way, positive air pressure can be transported from the air line 1042 to the valve manifold of the inflatable member 1080 through the air line 1048, and vacuum pressure can be transported from the manifold 1012 to the inflatable member valve manifold 1080 through the 1074 air line.
Positive air pressure or vacuum pressure can be supplied to the inflexible members 142 through one or more lines connecting each of the inflexible members 142 to the valve manifold of the inflatable member 1080. Figure 6 shows a separate pressure line and vacuum line connected to each other to the eight inflexible members 142 placed along the lower region of the adjacent cassette surface 110. It should be understood that similar lines connect each other to the inflexible members 142 to the inflatable member valve manifold 1080, but, for clarity, that line is not illustrated in Figure 6. Also, while each inflatable member 142 has been described as being connected to a separating line and vacuum line, it should be understood that positive pressure and vacuum pressure could be distributed to each inflatable member 142 using only an individual line connecting the manifold. from inflatable member valve 1080 to that of inflatable member 142. The valve manifold of the inflatable member 1080, such as the manifold 1012, includes multiple valves that can selectively control by the control unit 1090 to apply vacuum pressure or positive air pressure to the various inflatable members 142. By controlling the pressure supplied to Inflatable valve members 142, each of the inflexible valve members 142 may be retained in an inflated or deflated state. As noted above, inflating and deflating the various inflation members 142 can be used to control the flow of fluid through the cassette 112.
An air line 1054 is also connected through a connector T to the air line 1042. The air lines 1058, 1060, 1062, and 1064 extend between the air line 1054 and the vacuum ports 151. Of that Thus, the air lines 1054, 1058, 1060, 1062, and 1064 can be used to supply vacuum pressure from the air line 1042 to the vacuum ports 151 formed in the adjacent cassette surface 110 of the PD 102 cycler. The vacuum pressure applied to the vacuum ports 151 can be used to pull the membrane 140 to the cassette 112 against the adjacent cassette surface 110 of the PD 102 cycler.
One end of the air line 1042 opposite the manifold 1012 is connected to the air lines 1066, 1068 by a T connector. The air lines 1066, 1068 are in fluid communication with the annular passages 147A, 147B surrounding the sensors chamber pressure 149A, 149B. The supply of vacuum pressure to the annular passages 147A, 147B can help ensure that the membrane 140 of the cassette 112 is pulled firmly against the pressure sensors 149A, 149B and thus can increase the accuracy of pressure measurements detected by those sensors
One end of the air line 1046 opposite the manifold 1012 is connected to air lines 1047, 1049, which are in fluid communication with the annular passages 137Ά, 137B surrounding the piston heads 134A, 134B. As a result, vacuum pressure can be supplied to annular passages 137A, 137B through air lines 1046, 1047, and 1049. This vacuum pressure can help secure the membrane 140 of the cassette 112 to the piston heads 134A, 134B as the piston heads 134A, 134B move reciprocally during use.
The inflatable pad 135 located at the gate 108 of the PD cycler 102 receives air pressure through an air line 1056, which is connected through a connector T to the air line 1042, and receives positive air pressure at through an air line 1072, which is connected to the manifold 1012. Positive pressure (ie, by controlling the manifold valves 1012) can be selectively applied to the inflatable pad 135 in order to inflate the inflatable pad 135. In order to deflate the inflatable pad 135, the pressure is escaped into the atmosphere (that is, by controlling the manifold valves 1012). The inflatable pad 135, as described above, can be used to compress the cassette 112 against the adjacent cassette surface 110 of the cycler.
PD 102, which can help ensure that the membrane 140 of the cassette 112 remains firmly in contact with the various components exposed on the surface of the adjacent cassette surface 110 of the PD 102 cycler during use.
The safety clamp 150 located on the PD cycler 102 along a lower edge of the cassette component receives a vacuum pressure through an air line 1076, which is connected through a T-connection to the line of air 1042, and receives positive air pressure through an air line 1078, which is connected to the manifold 1012. Positive pressure (i.e., when controlling manifold valves 1012) can be selectively applied to safety clamp 150 in order to retract safety clamp away from gate 108 against the deflection force of the deflection spring (not shown) . In order to operate the safety clamp 150, the pressure escapes into the atmosphere (that is, by controlling the manifold valves 1012), allowing the deflection spring to advance the safety clamp towards the gate 108. The clamp Safety 150, as described above, serves to close all inputs to and outputs of cassette 112 in the event of a system error.
Even with reference to Figure 6, a vacuum tank 1016 is also connected to the valve manifold through manifold 1012 and air line 1052. The vacuum tank 1016 contains an air supply maintained at a negative pressure (e.g., at a pressure of about -150 mbaria to about -200 mbaria). During use, the valves of the connector 1012 can operate in a manner to pull a vacuum in the annular passages 137A, 137B through the air lines 1046, 1047, 1049. The vacuum tank 1016 can be used as an alternative to or in addition to the air pump 1004 in order to supply vacuum pressure to the annular passages 137A, 137B. Typically, the air pump 1004 is used s intermittently to ensure that the vacuum tank 1016 is maintained at a desired negative pressure, and the vacuum tank is used to apply negative pressure to the annular passages 137A, 137B. A vacuum pressure of about -150 mbaria to about -200 mbaria is typically applied to annular passages 137A, 137B and thus the portions of the membrane of cassette 140 positioned adjacent to those annular passages 137A, 137B. By using the vacuum tank 1016 as a supplement to a replacement for the air pump 1004 during use, the period of time during which the air pump 1004 needs to operate during use can be reduced. This can advantageously reduce the noise associated with operating the air pump.
1004.
A vacuum tank 1017 is similarly connected to the valve manifold 1012 through an air line 1044. The vacuum tank 1017 can be operated in a manner similar to the vacuum tank 1016 to supply vacuum pressure to the inflexible members 142, the vacuum ports 151, and the annular passages 147A, 147B surrounding the pressure sensors 149A, 149B through the air lines 1042 and the various air lines connected to that air line 1042. A vacuum pressure of approximately -550 mbar can be applied to the inflexible members 142, the vacuum ports
<td> 151,</td><td>Y</td><td>the annular passages</td><td>147A,</td><td>147B that</td><td>surround the</td>
<td colspan="2">sensors</td><td>pressure 149A, 149B.</td><td></td><td></td><td></td>
<td></td><td>The</td><td>1052 air lines and</td><td> 1044</td><td>that are</td><td>connected to</td>
<td>the</td><td colspan="2">1016 and 1017 vacuum tanks</td><td>is it so</td><td>equipped</td><td>with sensors</td>
of vacuum 1081 that can detect vacuum pressure within those lines. Any of several different types of vacuum sensors capable of detecting the vacuum pressure within the air lines 1052, 1044 can be used. An example of a suitable vacuum sensor is the Honeywell ASDX-15 force / pressure transducer available ( Morristown,
NJ). Other suitable vacuum sensors, including
Technics RXUP015 sensors and all 15 PSI-Dx-4VMINI sensors, can be used additionally or alternatively.
In addition, a positive pressure tank 1082 is connected to manifold 1012 through an air line 1075. Tank 1082 contains air that is positively pressurized. The air inside the tank can, for example, be pressurized at a pressure of approximately 1.40 kg / cm<sup>2</sup> at approximately 4.21 kg / cm<sup>2</sup> (for example, approximately 2.81 kg / cm<sup>2</sup>). Air line 1075 is equipped with a pressure sensor 1084 configured to measure air pressure within line 1075. An example of a suitable pressure sensor is the ASDX-10 force / pressure transducer available from Honeywell (Morristown, NJ). Other suitable pressure sensors, including the Technics RXUP0100 Sensor and all 100 PSI-Dx-4V-MINI sensors can be used alternatively or additionally.
During use, manifold 1012 may operate in a manner that pressurized air is supplied from positive pressure tank 1082 to inflatable member valve manifold 1080 and / or inflatable pad 135. For example, when opening manifold valves 1012 associated with the air line
1075 and the air line 1074, positive pressure can be supplied from the positive pressure tank 1082 through the air line 1074 to the inflatable member valve manifold 1080. Similarly, when opening the manifold valves 1012 associated with the air line 1075 and the air line 1072, positive pressure from the positive pressure tank 1082 can be supplied through the air line 1072 to the inflatable pad 135 at the gate 108 of the PD cycler 1 02. The positive pressure tank 1082 can be used instead of or in addition to the air pump 1004 to supply positive pressure to the inflatable pad 135 and the inflatable member valve manifold 1080. As discussed above, by limiting the operation of the pump of air 1004, the noise level associated with operating the PD 102 cycler can be advantageously reduced.
A fan or silencer 1014 is connected to a line 1050 extending from the manifold 1012. The ventilation 1014 can be used to ventilate air lines (for example, positively pressurized air lines and / or negatively pressurized air lines) to the atmosphere during use This can help regulate air pressures within the various air lines of the air distribution system 1000.
Referring to Figure 7, the PD 102 cycler control system includes the 1090 control unit that receives input signals from various PD cycler systems and devices including touch screen 118, control buttons 120, stepper motors 1094A, 1094B, cassette chamber pressure sensors 149A, 149B, position sensors 1092A, 1092B (for example, encoders) used to detect the position of pistons 132A, 132B, 1081 vacuum tank pressure sensors, and 1082 positive pressure tank pressure sensors. Based on this and other inputs (ie, previously stored instructions, etc.), the 1090 controller sends control signals to various systems and devices. Cycler PD including vacuum tanks 1016, 1017, positive pressure tank 1082, ventilation 1014, air pump
1004, collectors 1012, 1080, safety clamp
150, and the inflexible pad 132. Signals can be sent to and from the control unit 1090 via cable or wireless connection.
In addition to these features described above, the PD 102 cycler includes several other features not described herein in detail. Additional details regarding the PD 102 cycler and its various components may
<td>meet</td><td colspan="2">in the Publication of</td><td>Request</td><td>from</td><td>Patent</td><td>from</td>
<td>USA No.</td><td> 2007/0112297,</td><td>what</td><td colspan="2">is incorporated</td><td>here</td><td>by</td>
<td>reference.</td><td></td><td></td><td></td><td></td><td></td><td></td>
<td colspan="2">It will now describe a</td><td>method</td><td>to operate</td><td>the</td><td>cyclist</td><td>from</td>
PD 102. As shown in Figure 8, before treatment, the door 108 of the PD 102 cycler opens to expose the adjoining cassette surface 110, and the cassette 112 is placed with its membrane 140 adjacent to the adjoining surface of cassette 110. The cassette 112 is positioned so that the pump chambers 138A, 138B of the cassette 112 are aligned with the piston heads 134A, 134B, the oppressive dome region 146 of the cassette 112 are aligned with the inflexible members 142, and the cavities of Pressure detection 153A, 153B of cassette 112 are aligned with pressure sensors 149A, 149B.
Referring also to Figure 6, which schematically illustrates the air distribution system 1000 of the PD 102 cycler, after loading the cassette 112 into the cassette compartment 114 of the PD 102 cycler, positive pressure is supplied through the air line 1072 to the inflatable pad 135 at the door 108 of the PD 102 cycler. In particular, positive pressure is supplied from the air pump 1004 and / or positive pressure tank
1082 through the air line 1072 to the inflatable pad 135. Positive pressure inflates the inflatable pad 135 to secure the cassette 112 inside the cassette compartment 114 such that the membrane 140 of the cassette 112 is pressed firmly against the adjoining surface of cassette 110 of the PD 102 cycler.
In addition, vacuum pressure is supplied to the vacuum ports 151 to form a seal between the membrane 140 and the adjoining cassette surface 110. Vacuum pressure is also supplied to the annular passages 147A, 147B formed around the pressure sensors 149A , 149B to extract the membrane 140 against those pressure sensors 149A, 149B.
The vacuum pressure is supplied from the air pump 1004 a and / or the vacuum tank 1017 to the vacuum ports 151 and the annular passages 147A, 147B. The vacuum pressure is directed through the air lines 1042, 1054, 1058,
1060, and 1062 to the vacuum ports 151. Similarly, the vacuum pressure is directed through the air lines 1042, 1066, and, 1068 to the annular passages 147A, 147B surrounding the pressure sensors 149A, 149B.
The vacuum pressure is also applied to the annular passages 137A, 137B surrounding the piston heads 134A,
134B. The vacuum pressure is supplied from the air pump 1004 and / or the vacuum tank 1016 to the annular passages 137A, 137B through the air lines 1046, 1047, 1048. With the cassette 112 loaded inside the cassette compartment. 114, the membrane 140 of the cassette 112 covers the annular passages 137A, 137B. As a result, when the piston heads 134A, 134B retract away from the cassette 112 during use, the vacuum pressure applied to the membrane 140 through the annular passages 137A, 137B causes the portions of the membrane 140 covering the piston heads 134A, 134B are removed towards the adjacent cassette surface 110 in harmony with the piston heads 134A, 134B that retract. As a result, the volume defined by the pump chambers 138A, 138B increases, and, depending on the state of the inflatable members 142, dialysate can be extracted within the pump chambers 138A, 138B as the piston heads 134Ά, 134B they retract together with respective portions of the membrane 140. Similarly, depending on the state of the various inflexible members 142, as the piston heads 134A, 134B advance, the volume of the pump chambers 138A, 138B decreases, forcing the dialysate of the pump chambers 138A, 138B.
As the pistons 132A, 132B of the PD cycler 102 move reciprocally, each of the inflexible members 142 is inflated or deflated to control the flow of dialysate through the cassette 12. To inflate the inflexible members 142, it is apply positive pressure from the air pump 1004 and / or the positive pressure tank 1082 to the inflexible member valve manifold 1080 through the air line 1074. The valves of the valve manifold of the inflexible member 1080 operate in a manner to deliver the positive pressure only to those inflexible members 142 that will be or will remain inflated. To deflate the inflatable members 142, vacuum pressure is supplied from the air pump 1004 and / or the vacuum tank 1017 to the inflexible member valve manifold 1080 through the air line 1048. The valves of the inflatable member valve manifold 1080 operate in a manner to supply the vacuum pressure only to those inflatable members 142 that are going to or will remain inflated. Pressure-related signals are transmitted within the air line 1046 from the vacuum sensor 1081 to the control unit 1090 of the PD cycler 102 through treatment.
In rare cases, the flexible membrane 140 of the PD 112 fluid cassette may have leaks due to small holes or tears caused, for example, by damage during handling. Such holes or tears can allow the dialysate to seep through the flexible membrane 140 and enter the mechanical and pneumatic systems of the PD cycler 102. Dialysate filtrations can render the PD cycler inoperable. In order to avoid using a leaking PD 112 fluid cassette, the PD 102 cycler perform a cassette leak detection test on the PD 112 fluid cassette before use (for example, before treatment of peritoneal dialysis) . In some cases, methods used by the PD 102 cycler to detect leaks in the cassette 112 include using air as the test fluid so that, if a leak is detected, the liquid is prevented from entering the mechanical and pneumatic systems of the PD 102 cycler.
Referring to Figure 9, a position based method for detecting leaks in the PD 112 fluid cassette will now be described.
The PD 112 fluid cassette is placed inside the PD 01 02 cycler in the manner described above, for example, in a manner consistent with normal use. Door 108 then closes and secures (step 200).
With the safety clamp 150 open, the piston heads 134Ά, 134B retract completely into the piston access ports 136A, 136B, for example, away from the flexible membrane 140 of the PD 112 fluid cassette (step
202). In some embodiments, this step is performed before placing the cassette 112 into the PD 102 cycler to reduce the risk of damage to the flexible cassette membrane.
140 during placement.
At this time, a procedure is performed that is done to generate leaks in a defective cassette 112, including those that have sharp edges formed in the rigid base 156 or weaknesses in the flexible membrane 140. In particular, with the safety clamp open, The inflatable pad 135 inside the door 108 is inflated (step 204), and a system vacuum is applied to the flexible cassette membrane 140 (Step 206). Here, the term system vacuum refers to the application of a vacuum using each of the vacuum ports 151, the annular passages 137A, 137B surrounding the piston access ports 136A, 136B, and the annular passages 147A, 147B surrounding pressure sensors 149A, 149B. Since the system vacuum is applied to the membrane with the piston heads 134A, 134B in a retracted position, this procedure (steps 204-206) allows the maximization of a volume of air at atmospheric pressure inside the cassette 112. In some modalities, to maximize the possibility of exposing any defect in the cassette
112, this procedure (steps 204-206) can be repeated one or more times after deflating the inflatable pad 135 and venting the system vacuum.
Then, the safety clamp 150 is actuated, closing all the entrances to and exits of the cassette 112 (step 208). In doing so, an initial volume of atmospheric pressure air is trapped inside the cassette 112. The safety clamp 150 remains closed through the rest of the position based method.
After the closure of the safety clamp, a procedure is followed to ensure that a known initial volume of air is present inside the cassette 112. In particular, the system vacuum is vented to the atmosphere (Step 210) through ventilation. 1014, the inflatable pad 135 deflates (step 212), the inflatable pad is inflated again (step 214), and the system vacuum is reapplied (Step 216). This procedure (Steps 210216) releases captured air into any of the dead spaces within the cassette 112 between the flexible membrane 140 and the rigid base 156 (for example, outside the fluid paths 158, pump chambers 138A, 138B, etc. ) that are not used for the cassette function and that initially retain air. As a result, this procedure (Steps 210-216) ensures that all the air inside the cassette 112 is included in a measurement of initial air volume.
As a next step, the piston heads 134A, 134B are advanced within the flexible membrane 140 until a predetermined pressure is reached, as measured by the pressure sensors 149A, 149B (Step 218). In the illustrated mode, the default pressure is 400 mbar.
When the pressure inside the cassette 112 is at a predetermined pressure (for example, 400 mbar), an initial position (Xiníciai) of the piston heads 134A, 134B relative to the PD 102 cycler is measured (Step 220), using the 1092A, 1092B position sensors connected to the stepper motors 1094A, 1094B. For example, the measured position can be provided in units of steps corresponding to detection by position sensors (eg encoders) 1092A, 1092B.
After the initial position measurement (Xiniciai), the piston heads 134A, 134B are retracted from the cassette 112 until there is a gap between the piston heads 134A, 134B and the membrane 140 (step 222). In some embodiments, the piston heads 134A, 134B fully retract into the piston access ports 136A, 136B to ensure maximum separation. In addition, the system vacuum is vented to the atmosphere (Step 224), and the inflatable pad 135 (Step 226) is deflated. By retracting the piston heads 134A, 134B, venting the system vacuum and deflating inflatable pad 135, the contact between the cassette 112 and the PD 102 cycler is reduced or eliminated.
After the contact between the cassette 112 and the PD 102 cycler is reduced or minimized, a given period of time (waiting period) is allowed to pass before any of the subsequent steps (Step 228). During the waiting period, the cassette is allowed to filter air in an unobstructed manner for any filtration to exist. In some embodiments, the given period of time is in a range of 10 seconds to 60 seconds (for example, 20 seconds to 40 seconds, 30 seconds). Any of several other time periods could alternatively be used as long as sufficient time is provided to allow detectable amounts of air to be filtered.
After the given period of time has elapsed, the initial test conditions are restored. In particular, the inflatable pad 135 inside the door
108 it inflates (Step 230), and the vacuum of the system is applied to the flexible membrane of cassette 140 (Step 232).
After inflating the inflatable pad 135 and applying the system vacuum, the piston heads 134A, 134B are advanced within the flexible membrane 140 until the given pressure is reached (for example, 400 mbars), as measured by the sensors Pressure 149A, 149B (Step 234). When the pressure inside the cassette 112 is at the given pressure, an end position Xfinai) of the piston heads 134A, 134B relative to the PD 102 cycler is measured (Step 236).
The PD 1090 cycler control unit compares the final position (Xfinai) with the initial position (Xiniciai) to determine if there is a leak in the cassette (Step 238). In particular, the initial position (Xiniciai) is subtracted from the final position (Xfinai), and if the difference is equal to or greater than a predetermined amount (LIMIT 1), the control unit 1090 determines that there is a leak in the cassette
112 If the difference is less than the predetermined amount (LIMIT 1), no filtration is detected. For example, the default amount may be in a range of 1000 steps to 3500 steps.
Although the position based filtration detection method described above relies on the positions of the piston heads at a given pressure to determine if there is a leak in the cassette 112, other methods can be used. For example, with reference to Figure 10, an alternative method (for example, a pressure based method) will now be described that relies on the pressure inside the cassette for a given volume.
In the pressure-based method, the PD 112 fluid cassette is placed inside the PD 102 cycler in the manner described above, for example, in a manner consistent with normal use. Door 108 then closes and secures (Step 300).
With the safety clamp 150 open, the piston heads 134A, 134B retract completely into the piston access ports 136A, 136B, for example, away from the flexible membrane 140 of the PD 112 fluid cassette (Step 302) . In some embodiments, this process is performed before placing the cassette 112 into the PD 102 cycler to reduce the risk of damage to the flexible cassette membrane 140 during placement.
At this time, a procedure is carried out that aims to generate leaks in the defective cassette 112, including those that have sharp edges formed in the rigid base 156 or weakness in the flexible membrane 140. In particular, with the safety clamp open, the pad inflate 135 inside the gate 108 is inflated 5 (Step 304), and the system vacuum is applied to the flexible cassette membrane 140 (Step 306). Since the system vacuum is applied to the membrane inside the piston heads 134Ά, 134B in a retracted position, this procedure (Steps 304-306) allows the maximization of an air volume f
of atmospheric pressure inside cassette 112. In some embodiments, to minimize the possibility of any of the defects in cassette 112 being exposed, this procedure (Steps 304-306) may be repeated one or more times after deflating the inflexible pad 135 and The identity of the system vacuum.
Then, the safety clamp 150 is actuated, closing all the entrances to and exits from the cassette 112 (Step 308). By doing so, an initial volume of air at atmospheric pressure is trapped inside the cassette 112. The safety clamp 150 remains closed through the rest of the pressure-based method.
Following the closure of the safety clamp, a procedure is followed to ensure that a known initial volume of air is present within the cassette 112. In particular, the system vacuum is vented to the atmosphere (Step 310) through ventilation. 104, the inflatable pad 135 is deflated (Step 312), the inflatable pad is inflated again (Step 314), and the system vacuum is reapplied (Step 316). As discussed above, this procedure (Steps 310-316) releases captured air into any of the dead spaces inside the cassette 112 between the flexible membrane 140 and the rigid base 156 (for example, outside the fluid paths 158, chambers of pump 138A, 138B, etc.) that are not used for the cassette function and that initially retains air. As a result, this procedure (Steps 310-316) ensures that all air inside cassette 112 is included in the initial air volume measurement.
<td>How</td><td>a</td><td colspan="2">next step,</td><td>the</td><td>heads</td><td>piston</td><td>134A,</td><td>134B</td>
<td>they are made</td><td colspan="2">advance inside</td><td>from</td><td>the</td><td>membrane</td><td>flexible</td><td>140 to</td><td>a</td>
<td>position</td><td>from</td><td>given test</td><td>with</td><td colspan="2">relation to</td><td>cyclist</td><td>from PD</td><td> 102</td>
(Step 318), defining an air test volume inside the cassette 112. In the illustrated mode, a given position of the piston heads is obtained when tracking steps of stepper motors 1094A, 1094B used to position the pistons 132A, 132B inside the piston access ports
136Α, 136Β. For example, the given test position can be 34,000 steps as detected by corresponding sensors 1092A, 1092B. In other examples, a different number of steps could be used as in the test position as long as the number of steps results in a sufficient test volume of air inside the cassette 112.
Although the piston heads 134A, 134B are in the given test position, an initial pressure (Piníciai) inside the cassette 112 is measured using the pressure sensors 149A, 149B (Step 320).
After the initial pressure measurement (Pinícíai), the piston heads 134A, 134B are retracted from the cassette 112 until there is a gap between the piston heads 134A, 134B and the membrane 140 (Step 322). In some embodiments, the piston heads 134A, 134B fully retract into the piston access ports 136A, 136B to ensure maximum separation. In addition, the system vacuum is vented to the atmosphere (Step 324), and the inflatable pad 135 deflates (Step 326). By retracting the piston heads 134A, 134B, ventilating the system vacuum and deflating the inflatable pad 135, the contact between the cassette 112 and the PD cycler is reduced, minimized or eliminated.
102.
After contact between cassette 112 and PD 102 cycler is reduced or minimized, a given period of time (waiting period) is allowed to pass before any of the subsequent steps (Step 328). During the waiting period, the cassette is allowed to filter air in an unobstructed manner so that leaks must exist. In some embodiments, the given period of time is in a range of 10 seconds to 60 seconds (for example, 20 seconds to 40 seconds, 30 seconds). Any of the various other periods of time could alternatively be used as long as sufficient time is provided to allow filtration of detectable amounts of air.
After the given period of time has elapsed, the initial test conditions are restored. In particular, the inflatable pad 135 inside the door 108 is inflated (Step 330), and the system vacuum is applied to the flexible membrane of the cassette 140 (Step 332).
After inflation of the inflatable pad 135 and application of system vacuum, the piston heads 134A, 134B are advanced within the flexible membrane 140 to the test position given relative to the PD 102 cycler (Step 334), to restore the original air test volume inside cassette 112. When the piston heads
134Α, 134Β are in the given test position (for example,
34,500 steps), a final pressure (Pfinai) is sent inside cassette 112 using pressure sensors 149A, 149B (Step 336).
The PD 1090 cycler control unit compares the final pressure (Pfinai) with the initial pressure (Pinicíai) to determine if there is a leak in the cassette (Step 338). In particular, the final pressure (Pfinai) is subtracted from the initial pressure (Piniciai), and if the difference is equal to or greater than a predetermined amount (LIMIT 2), the control unit 1090 determines that there is a leak in the cassette 112 . If the difference is less than the predetermined amount (LIMIT 2), no filtration is detected. For example, for the given test position (for example, 34,500 steps) of the piston heads 134A, 134B, the predetermined amount (LIMIT 2) may be in a range of 6-10 mbar. However, it is understood that differences should be amplified if the piston heads 134A, 134B will be driven further. Although this probably increases the value of LIMIT 2, it would also increase the difference in mbarias between difference readings if there is no filtration and filtration stops, respectively.
Although the filtration detection method described above is a pressure-based method that relies on the pressure inside the cassette for a given volume to determine if there is a leak in the cassette 112, other pressure-based methods can be used. For example, referring to Figure 11, an alternative pressure based method (for example, a minimum volume method) that relies on the pressure inside the cassette for a given volume to determine if there is a leak in the cassette will now be described. 112, where the given volume is a minimized volume.
In the minimum volume method, the PD 112 fluid cassette is placed inside the PD 102 cycler in the manner described above, for example, in a manner consistent with normal use. Door 108 is then closed and secure (Step 400).
With the safety clamp 150 open, the inflatable pad 135 inside the door 108 is inflated, deflated, and inflated again (Step 402). This step (Step 402) distributes atmospheric air inside cassette 112, expels atmospheric air from cassette 112, and can also generate leaks in defective cassette 112, including those that have sharp edges formed in rigid base 156 or weaknesses in flexible membrane 140.
As a next step, the piston heads 134A, 134B are advanced towards the flexible membrane 140 until the pistons 132A, 132B are completely outward (Step 404). In this position, the piston heads 134A, 134B have driven the flexible membrane 140 towards the rigid base 156 until the flexible membrane 140 is in contact with a surface of each of the pump chambers 138Ά, 138B. As a result, the volume of air inside the cassette 112 is minimized.
Although the piston heads 134A, 134B are in the fully outward position, the safety clamp 150 is actuated, closing all the entrances to and exits of the cassette 112 (Step 406). By doing so, a minimum initial volume of atmospheric pressure air is trapped inside the cassette 112. The safety clamp 150 remains closed through the rest of the minimum volume method.
Although the piston heads 134A, 134B are in the fully outward position resulting in a minimum volume of air inside the cassette 112, an initial pressure (Piníciai) inside the cassette 112 is measured using the pressure sensors 149A, 149B (Step 408 ). The Piniciai should be approximately equal to atmospheric pressure. For example,
Pinicíai is typically within 10 mbars of atmospheric pressure.
After measuring the initial pressure (initial P) t the piston heads 134A, 134B are retracted from the cassette 112 until there is a gap between the piston heads 134A, 134B and the membrane 140 (Step 410). In some embodiments, the piston heads 134A, 134B fully retract into the piston access ports 136A, 136B to ensure maximum separation. By retracting the piston heads 134A, 134B, and deflating the inflatable pad 135, the contact between the cassette 112 and the PD 102 cycler is reduced, minimized, or eliminated. For example, the retraction of the piston heads 134A, 134B separates the piston heads 134A, 134B from the flexible membrane 140 thereby exposing any of the leaks in the vicinity of the pump chambers 138A, 138B, and deflation of the Inflatable pad 135 allows filtration of leaks that may exist in regions outside the normal flow paths of cassette 112.
After or concurrent retraction of the piston heads 134A, 134B, the inflatable pad 135 is deflated (Step 412). The deflation of the inflatable pad 135 redistributes air through the cassette 112, and allows leaks outside the normal flow path to exchange air with the pump chamber.
When the piston heads 134A, 134B have been retracted and the inflatable pad 135 deflated, the system vacuum is applied to the cassette 112 (Step 414). The system vacuum serves to separate the flexible membrane 140 from the rigid base 156. In addition, due to the elasticity of the flexible membrane 140 and removal of the piston heads 134A, 134B, the flexible membrane 140 will tend to return to its original flat configuration, and retract away from the surface of the pump chambers 138A, 138B. Because the safety clamp 150 is closed, the separation of the flexible membrane 140 from the rigid base 150 results in the generation of a negative pressure inside the cassette 112. At this time, if filtrations are present within the cassette 112, air is drawn into the space between the flexible membrane 140 and the rigid base 156 due to the negative pressure inside the cassette 112.
After application of the system vacuum, a predetermined period of time (retraction period) is allowed to pass before any of the subsequent steps (Step 416). During the retraction period, the cassette is allowed to filter air in an unobstructed manner so that any of the leaks must exist. In some embodiments, the predetermined period of time is in a range of 2 seconds to 20 seconds. In other embodiments, the predetermined period of time is in a range of 5 seconds to 15 seconds. Even in other modalities the predetermined period of time is 10 seconds.
Once the predetermined period of time has elapsed, the system vacuum is vented to the atmosphere (Step 418) and the inflatable pad 135 is inflated (step 420). This procedure (Steps 418-420) prepares the cassette for the following steps.
Then, the piston heads 134A, 134B are advanced towards the flexible membrane 140 to the pistons 132A, 132B which are completely outward (step 422). As previously discussed, in this position, the piston heads 134A, 134B have driven the flexible membrane 140 towards the rigid base 156 until the flexible membrane 140 is in contact with the surface of each of the pump chambers 138A, 138B .
Although the piston heads 134A, 134B are in the fully outward position resulting in a minimum volume of air inside the cassette 112, a final pressure (Pfinai) is measured inside the cassette 112 using the pressure sensors 149A, 149B (Step 424 ).
The PD 1090 cycler control unit compares the final pressure (Pfinai) with the initial pressure (Piníciai) to determine if there is a leak in the cassette (426). In particular, the initial pressure (Piniciai) is subtracted from the final pressure (Pfinai)<sub>t</sub> and if the difference is equal to or greater than a predetermined amount (LIMIT 3), the control unit 1090 determines that there is a leak in the cassette
112 If the difference is less than the predetermined amount (LIMIT 3), no filtration is detected. For example, the default amount (LIMIT 3) can be in the range of 126 to 150 mbar. Table 1 shows test data obtained using the minimum volume method. Test data is provided for the following flexible cassette membrane conditions: an intact flexible membrane (for example free from filtration) as seen in the first row of Table 1, a flexible membrane of the cassette having a small perforation / stretching (for example, a 0.4 mm filtration) as observed in the second row of Table 1, and a flexible cassette membrane having a large clean hole (for example, a 0.7 mm hole) as seen in the third row of Table 1. The results show that small pressure differences are obtained, not zero for cassettes that have no filtration. Non-zero differences may be related to inefficiencies in pressure redistribution within the cassette during step 412. In addition, although small differences between the initial pressure (Piniciai) and the final pressure (Pfinai) are normal, excessive differences between the initial pressure (Piniciai) and the final pressure (Pfinai) indicate that there is a leak in cassette 112, with larger leaks that result in greater pressure differences. Although the test was performed to verify that the minimum volume method is effective in identifying leaks in cassette 112, it was not optimized to identify a minimum LIMIT 3 required to avoid a false positive result. That is, although the test was sufficient to establish sensitivity and specificity for a rather small orifice in the membrane (perforation / stretching 400 microns), it was not necessarily an optimized procedure, especially for specificity. The value of 126 mbaria for LIMIT 3 can be reduced, for example, by repeating the test several times, thereby expelling some of the air originally trapped in the regions of flowless trajectory. This will have the effect of reducing the value of the pressure difference without 126 mbar filtration.
TABLE 1
<td rowspan="2">Cassette Condition</td><td rowspan="2">Sensor 1 of Difference of pressure (149A)</td><td colspan="2">Sensor 2 of Difference of</td>
<td>Pressure</td><td>(148B)</td>
<td>No filtration</td><td> 116 ± 10</td><td> 106 ± 10</td><td></td>
<td>Perforation / Stretching 0.4 mm</td><td> 251 ± 30</td><td> 243 ± 30</td><td></td>
<td>0.7 Clean Hole mm</td><td> 860 ± 50</td><td> 851 ± 50</td><td></td>
In some implementations, the minimum volume method for detecting leaks in the PD 112 fluid cassette can be simplified while still providing accurate and reliable filtration detection. For example, step 412 (which deflates the inflatable pad 135 in order to redistribute air through the cassette) performed before system vacuum activation, and steps 418-420 (vent the system vacuum and inflate the inflatable pad 135 In order to prepare the application of force and second pressure measurement) performed after activation of system vacuum, it can be omitted. By doing so, the overall time required to perform the method can be reduced. In addition, the value of 126 mbaria for LIMITE 3 can be significantly reduced, by first performing this simplified minimum volume test, where path regions without flow are not accessed, specifically in order to detect leaks in the head region of piston, and then perform another test such as the minimum volume test, specifically in order to detect leaks in the regions of trajectories without flow. In some implementations, by performing more than one type of test, it may be possible to identify the general location (for example, within a flow path region or within a non-flow path region) of a filtration based on which test results in filtration detection.
In each of the methods described above to detect leaks in a disposable medical fluid cassette, a first force is applied to the flexible membrane
140, a first physical property of a system including the medical fluid cassette 112 and the PD cycler 102 is measured, and then the first force of the flexible membrane 140 is removed. After a short waiting period, a Second force to the flexible membrane 140, a second physical property of the system is measured, and then it is determined whether the medical fluid cassette is filtered based on a comparison of a first physical property and the second physical property. In the position-based method, the first measured physical property is the initial position (Xinicíai) of the piston heads 134A, 134B relative to the PD 102 cycler and the second physical property is the final position (Pfinai) of the heads of piston 134A, 134B relative to the PD 102 cycler. In the pressure-based method and minimum volume method, the first measured physics itself is the initial pressure (Pinícíai) inside the cassette 112, and the second physical property is the final pressure (Pfinai) inside the cassette 112.
In each of the modalities illustrated above, the first force is the same as the second force, but the method is not limited to doing that. For example, in the minimum volume method, the forces applied by the piston may be different as long as the volume of air in the cassette is minimized.
In each method described above, the forces applied to the cassette 112 (for example, through the piston, inflatable door pad 135 and system vacuum) are removed between initial and final measurements to ensure that there is a gap between the flexible membrane 140 and the PD cycler, avoiding obstructing any of the leaks in the flexible membrane 140 between measurements of the physical properties of the system. This method is advantageous over some of the conventional filtration detection methods where the force is continuously applied to a medical fluid cassette using pistons of a medical fluid pumping machine (for example, a PD cycler) and a location is located. Filtration of the medical fluid cassette membrane near the pump chambers. In such conventional aspects, the same piston can obstruct the filtration and provide false confidence in membrane integrity. By removing the applied force (for example, by retracting the pistons) between initial and final measurements, the accuracy of filtration detection measurements improves since membrane leaks in the vicinity of the applied force were not obstructed, allowing detection of leaks in the vicinity of the applied force.
Although in each of the methods for detecting leaks in a disposable medical fluid cassette described herein, the first portion and second force are applied to the flexible membrane 140 using the pistons 132A, 132B of the PD 102 cycler, the method is not limited. to use pistons to apply the first force and the second force. For example, in some embodiments, the first force and second force are applied to the flexible membrane 140 pneumatically or using other mechanisms.
Although the position-based method mentions a repetition of steps 222-234 (for example, the steps between the measurement of the initial position (Xinícíai) and the measurement of the final position (Xfinai) <sub>F</sub> The method is not limited to repetition. For example, steps 222-234 can be repeated more than once, resulting in greater sensitivity and certainty. Similarly, although the volume-based method mentions a repetition of steps 322-334 (for example, the steps between the initial pressure measurement (Piniciai) and the final pressure measurement (Pfinai)<sub>t</sub> The method is not limited to repetition. For example, steps 322-334 may be repeated more than once, resulting in greater sensitivity and certainty.
Although the position-based method mentions performing steps 222-234 (for example, the steps between measuring the initial position (Xiniciai) and measuring the final position (Xfinai) once including waiting for an individual, predetermined period of time , it may be possible to minimize the general filtration detection test time by repeating steps 222-234 multiple times using a shorter waiting period (for example, minimized). Similarly, although the volume-based method mentions performing steps 322-334 (for example, the steps between the initial pressure measurement (Piníciai) and the final pressure measurement (Ptinai) once including waiting for an individual period of time By default, it may be possible to minimize the filtration detection test time
<td>generated at</td><td>repeat</td><td>the</td><td>Steps</td><td>322-334 multiple times</td>
<td>using a</td><td>period</td><td>from</td><td>wait</td><td>shorter (for example,</td>
<td>minimized).</td><td></td><td></td><td></td><td></td>
<td>Although the</td><td>method</td><td>from</td><td>volume</td><td>minimum includes applying a</td>
System vacuum when the piston heads 134A, 134B have been retracted and the inflatable pad 135 deflated (Step 414), the minimum volume method is not limited to this. For example, in some implementations, the step of applying a system vacuum may be omitted, whereby the flexible membrane 140 is separated from the rigid base 156 due to the elasticity of the flexible membrane 140, resulting in the generation of a negative pressure. inside cassette 112. If leaks are present inside cassette 112, air is drawn into the space between flexible membrane 140 and rigid base 156 due to the negative pressure inside cassette 112.
Although the 1000 air distribution system has been
<td colspan="2">described as</td><td>including the</td><td>bomb</td><td> 1004</td><td colspan="2">to generate and</td>
<td>supply</td><td colspan="2">positive pressure</td><td>and negat</td><td>VAT,</td><td colspan="2">can be used</td>
<td>alternative</td><td>or</td><td>Additionally</td><td>others</td><td>types</td><td>from</td><td>devices</td>
<td>generators</td><td>from</td><td>Pressure. A</td><td>example</td><td>from</td><td>other</td><td>device</td>
<td>adequate is</td><td>the</td><td colspan="2">Pump and Compressor</td><td colspan="2">diaphragm</td><td>miniature of</td>
<td>double head</td><td>, from</td><td colspan="3">! Hardraves individual body</td><td>BTC-</td><td>IIS</td>
Although a system vacuum is described as application of a vacuum using each of the vacuum ports 151, the annular passages 137A, 137B and the annular passages 147A, 147B, in some embodiments, the system vacuum can only be applied through a subset of these ports.
Although the air distribution system 1000 uses pressurized and vacuum air to drive the inflatable members 142 and the inflatable pad 135 and to extract the membrane 140 against the piston heads 134Ά, 134B and other surfaces of the adjacent cassette surface 110, gases other than air can be supplied alternatively or additionally through the air distribution system.
Also, the inflating members 142 and the inflatable pad 135 can be replaced with mechanically operated devices. Similarly, the pistons can be replaced with hydraulic or pneumatic devices such as diaphragm pumps.
Although in each of the embodiments described above the first force and the second force are applied to an external surface of the cartridge 112, and particularly to the external surface of the flexible membrane 140, the method is not limited to the application of external force.
In certain implementations, for example, those in which the force is applied hydraulically or pneumatically, internal surface forces of the cassette 112 may be applied.
In certain implementations, the vacuum pressure is not used to remove the cassette membrane
140 towards the piston heads 134A, 134B. Instead, other types of vacuum-free mechanisms, such as adhesive, magnetic or mechanical coupling, can be used to ensure that the cassette membrane 140 retracts along with the piston heads 134A, 134B.
In certain implementations, the characteristics of the cassette components are transferred to drive fluid flow through a filtration. For example, in the minimum volume test, the elasticity of the flexible membrane 40 is used to provide a positive or negative pressure in the working fluid that can drive fluid flow through a filtration at a detectable level.
Although the vacuum and pressure sensors of the air distribution system 1000 have been described as being connected to air lines leading to vacuum and positive pressure tanks, other arrangements are possible. In certain implementations, for example, the vacuum and pressure sensors are all part of an input / output card of the PD 102 cycler.
Although the piston heads 134A, 134B of the PD cyclists have previously been described as being hemispherical, the piston heads could be of any other shape. In some embodiments, for example, the piston heads may have flat end surfaces. In such implementations, the cup-shaped members disposed in the cassette pump chambers may have flat surfaces that splice the flat-end surfaces of the piston heads during use. Similarly, although piston heads 134A, 134B have been described as being formed using certain materials and manufacturing techniques, any of several other suitable materials and manufacturing techniques could be used alternatively.
Although the methods to detect leaks described herein employ both pistons 132A, 132B of the PD cycler
102 used at the same time and in the same way, the methods can be performed using both pistons 132A, 132B used at different times and / or in different shapes, or using only one individual piston (for example, piston 132A).
Although the cassettes discussed above have been described as having two pump chambers, the cassettes may alternatively have more or less than two pump chambers.
Although certain PD cyclists have been described as including a touch screen and associated buttons, the PD cycler may include other types of screens and user data entry systems. In certain embodiments, for example, the cycler includes a presentation screen with buttons (for example, pen touch buttons) arranged on the console adjacent to the presentation screen. Certain buttons may be arranged to align with operational options presented on the screen during use so that the user can select a desired operational option by pressing the button aligned with that option. Additional buttons may also be provided in the form of arrow buttons to allow the user to navigate through the various presentation screens and / or the various items presented on a particular screen. Other buttons may be in the form of a numeric keypad to allow the user to enter numerical values in order, for example, to enter operational parameters. A select or enter button can also be provided to allow the user to select an operational option for which the user navigated when using the arrow keys and / or to allow the user to enter values that the user entered using the numeric keypad.
Although the doors of the PD cyclists described above are shown as being placed on a front face of the PD cyclists, the doors can alternatively be placed in several other locations of the PD cyclists. For example, the doors could be placed on an upper face of the PD cycler so that the cassette slides into the cassette compartment in a substantially horizontal orientation instead of a substantially vertical orientation.
Although some of the PD cyclists discussed above have been described as including inflatable pads on their doors to compress the cassette between the door and the adjoining cassette surface, PD cyclists may alternatively or additionally include inflexible pads placed behind the adjoining surface. of cassette
Although the cassettes described above have been described as being part of a PD system, these types of cassettes can be used in any of several other types of cassette-based medical fluid pumping systems. Other examples of medical fluid pumping systems with which cassettes described herein may be used include hemodialysis systems, blood perfusion systems, and intravenous infusion systems.
Although the cassettes have been described as being used to pump dialysate, other types of dialysis fluids can be pumped through the cassettes. As an example, in the case of cassettes used with hemodialysis machines, blood can be pumped through the cassettes. In addition, priming solutions, such as saline, can be similarly pumped through cassettes using the various different systems and techniques described above. Similarly, as an alternative dialysis fluid, any of the various other types of medical fluids can be pumped through the cassettes described above depending on the type of medical fluid pumping machines with which the cassettes are used.
A selected illustrative embodiment of the invention was described above in some detail. It should be understood that only structures deemed necessary to clarify the present invention have been described herein. Another 10 conventional structures, and those of secondary and auxiliary components of the system, are assumed to be known and understood by those skilled in the art. Furthermore, although an operative example of the present invention has been described above, the present invention is not limited to the operative example described above, but several design alterations can be made without departing from the present invention as defined in the claims. .
NEW OF THE INVENTION
Having described the present invention as above, it is considered as a novelty and, therefore, the content in the following is claimed as property:
Contents6
11 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11
23 members in 9 offices
Priority claims9
| Document | Office | Kind | Date |
|---|---|---|---|
| 13804198 | United States of America | – | |
| 201313804198 | United States of America | A | |
| 201313804198 | United States of America | A | |
| 2014019523 | United States of America | W | |
| 2014019523 | United States of America | W | |
| 13804198 | – | – | – |
| PCTUS2014019523 | – | – | – |
| US201313804198 | – | – | – |
| WO2014US19523 | – | – | – |
Members23
| Document | Office | Kind | |
|---|---|---|---|
| US2014276421A1 | United States of America | A1 | |
| CA2894565A1 | Canada | A1 | |
| WO2014158719A1 | World Intellectual Property Organization (WIPO) | A1 | |
| AU2014241932A1 | Australia | A1 | |
| CN105007960A | China | A | |
| MX2015012574A | Mexico | A | |
| EP2968721A1 | European Patent Office (EPO) | A1 | |
| JP2016510670A | Japan | A | |
| HK1216728A | Hong Kong, China | A | |
| HK1216728A1 | Hong Kong, China | A1 | |
| EP2968721B1 | European Patent Office (EPO) | B1 | |
| US9561323B2 | United States of America | B2 | |
| US2017115178A1 | United States of America | A1 | |
| CN105007960B | China | B | |
| AU2014241932B2 | Australia | B2 | |
| JP6419769B2 | Japan | B2 | |
| MX364129BThis record | Mexico | B | |
| US10539481B2 | United States of America | B2 | |
| US2020191682A1 | United States of America | A1 | |
| CA2894565C | Canada | C | |
| US11262270B2 | United States of America | B2 | |
| US2022268661A1 | United States of America | A1 | |
| US12061135B2 | United States of America | B2 |
1 legal event, as the office reported them to INPADOC
Events
| Event | Code | |
|---|---|---|
| Grant or registrationFG | FG |
Numbers
- Publication
- 364129
- Publication, DOCDB
- 364129
- Publication, EPODOC
- MX364129
- Application
- 2015012574
- Application, DOCDB
- 2015012574
- Application, EPODOC
- MX20150012574
Titles2
- Spanish
- METODOS Y DISPOSITIVOS DE DETECCION DE FILTRACION DE CASETE DE FLUIDO MEDICO.
- English
- METHODS AND DEVICES OF DETECTION OF FILTRATION OF MEDICAL FLUID CASSETTE.
Classification
- CPC, 21
- A61M1/16
- G01M3/3218
- A61M1/28
- G01M3/3272
- G01M3/36
- A61M2205/15
- A61M2205/12
- A61M1/1522
- A61M1/155
- A61M1/1524
- A61M1/1561
- A61M1/159
- A61M1/154
- A61M1/282
- A61M2205/50
- A61M2205/3331
- A61M5/142
- A61M1/288
- A61M2205/07
- A61M2205/121
- A61M2205/123
- IPC, 5
- A61M1 16
- A61M1 28
- A61M5 142
- G01M3 32
- G01M3 36