Medical valve with positive flow characteristics

276 183 T3

DESCRIPTION

Medical valve with positive flow characteristics.

Scope of the invention

This invention relates generally to a medical valve and, in particular, to a valve which, when connected between a first medical instrument, such as a fluid source, and a second medical instrument, such as a catheter, facilitates the flow of fluid between them and when the first medical element is disconnected therefrom induces a positive flow of fluid through the valve in the direction of the second medical instrument.

Background of the invention

In the state of the art as described in US-A-5730418 a connector for fluid displacement is shown. The connector comprises a valve housing and a rubber valve plug arranged in the valve housing. In addition, an actuator can be inserted into an inlet port of the housing valve to thereby push and bend the plug so that fluid can be introduced through a lumen of the actuator and into an internal chamber. valve.

Furthermore, US-A-5470319 discloses a needleless injection apparatus comprising a housing defining a distal and a proximal end and including a resealing element disposed therein. The resealing element has an opening, which can be elastically opened and closed, formed therein and is normally housed within the housing in a closed position where the opening is in a closed configuration. The resealing element is deformable, such that insertion of the tip of an introducer device causes the resealing element to advance distally within the housing to its open position, in which the opening assumes an open configuration.

US-A-5555908 describes a valve adapter for connecting a fluid handling device to a medical device. The valve adapter includes a body with a longitudinal axis having a female luer adapter at a proximal end, a distal end, and a passageway therethrough. The conduit has a chamber between the proximal and distal ends that contains a valve. The valve has a normally closed position but operative to an open position. The valve includes an elongated resilient member. In addition, the valve includes a pusher disposed at the proximal end of the elongated resilient member. The pusher includes a telescopic portion that has an extended position and a folded position.

In US-A-5578059 a medical apparatus is disclosed comprising a housing including a male luer lock hydraulic connector, an actuator housing and a wedge threaded housing. The actuator housing includes a disc valve comprising an actuator and a resilient disc, the lower base of which is housed in a sleeve of the connector. Typically the disc rests against a valve seat in the actuator housing. In case a syringe is inserted into or through a slot in a reinforcement, which is arranged in the wedge threaded housing, the actuator is pushed against the disc and fluid communication is allowed.

Handling fluids for parenteral administration in hospitals and medical settings involves the routine use of connectors and valves to selectively facilitate the movement of fluids between two points. Typically, such valves are placed along a fluid flow line leading to a patient or other destination. For example, the tube can lead to a catheter that has its tip positioned within a patient.

The valve is arranged so that a fluid source or other line can be connected to it to provide fluid flow from the source to the patient. When the fluid source or line is removed, the valve closes, hermetically closing the line leading to the patient.

The element that connects to the valve can comprise a tube or other medical instrument, such as a conduit, a syringe, an intravenous infusion set (both peripheral and central lines), a cascade line or similar component that is adapted for connection to the medical valve. Unfortunately, prior art valves have a problem arising from disconnection of such medical instruments from the valve.

Said valves define a space within them through which a fluid or other material can flow from the instrument to the line in which the valve is mounted. When the medical instrument is connected to the valve, it normally occupies a part of said internal space of the valve, displacing the fluid (either liquid or air) within the valve.

When the medical instrument is disconnected from the valve, a problem arises. When the instrument is disconnected, it no longer occupies a part of the valve space. The increase in space within the valve results in the fluid in the valve and the line to which the valve is connected to move to fill the space. In fact, removal of the instrument creates a suction force that draws fluid into the valve.

In the medical setting, this fluid movement is highly ill-advised. When the valve is connected to a fluid line leading to a patient, the movement of fluid through the line into the valve space has the effect of drawing blood from the patient in the direction of the valve. It can result in a serious problem, as the blood can clot and clog the catheter near its tip, making it unviable, and can even result in a blood clot in the patient, which could be fatal.

One attempt to overcome this clogging problem has been to coat the inner surface of the catheter near its tip in order to prevent blood from adhering to its inner surfaces. In general, this procedure has not been successful in preventing catheter obstruction.

The risk of blocking the catheter with blood is considerably heightened when the inside diameter of the catheter is small (eg, 27 gauge). However, such small catheters have the advantage that they reduce trauma and discomfort caused by insertion in a patient. Since these catheters have a very small conduit

ES 2 276 183 T3 through them, even a small suction force can draw a sufficient amount of fluid back through a catheter towards the valve to introduce blood into the catheter tip, which blood can clog the catheter conduit .

The solution to the problem mentioned above becomes more difficult when other criteria that the valve must meet are taken into account. For example, the valve should be arranged so that it does not have fluid stagnation points. Allowing fluid to stagnate in one or more areas of the valve can lead to bacterial growth and other problems.

Also, the valve should have an internal flow path that is smooth. Sharp edges and corners can damage blood cells and lead to hemolysis.

A valve is desired that solves the problems mentioned above.

Summary of the invention

In accordance with the present invention there is provided a valve that is advantageously used between two medical instruments as defined in claim 1. The valve of this invention has several characteristics, none of which is exclusively responsible for its desirable attributes.

Most importantly, the valve is arranged to provide positive flow (that is, the movement of fluid in the outward direction of the valve as opposed to the inward direction of the valve) when one of the instruments is disconnected from the valve. doctors. At the same time, the valve is safe, reliable and can be used repeatedly, it is simple to manufacture and use, and it is suitable for high pressure applications.

The valve of the present invention is especially suitable for use in an application where one of the medical instruments comprises a catheter having its tip positioned in a patient. In a preferred embodiment the second medical instrument comprises a fluid source having a connector for connection to the valve.

The valve of the present invention has a fluid space that expands when the second medical instrument is connected and contracts when the medical instrument is disconnected. When the valve is connected to a catheter, disconnection of the second medical instrument creates positive flow from the valve to the tip of the catheter prior to disconnection of the medical instrument to avoid possible problems of blockage with blood. The valve is especially suitable for applications with a catheter where it is advisable to avoid negative flow, but it can also be used for other applications.

Preferably, the valve includes a housing adapted for connection to a first medical instrument and a second medical instrument. The valve defines a fluid space therein and includes means for increasing the fluid space, when the second medical instrument is connected, and for reducing the fluid space, when the second medical instrument is disconnected. Also preferably, means are provided for defining a fluid path through the valve when both medical instruments are connected thereto and for closing the fluid path when the second medical instrument is disconnected.

Additional objections, features and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings that follows, when taken into account with the accompanying figures.

Brief description of the drawings

Figure 1 illustrates a valve in accordance with the present invention as used to selectively provide fluid from a fluid source connected to a fluid line leading to a catheter that is inserted into a patient.

Figure 2 is a plan view of a valve housing in accordance with a first embodiment of the present invention.

Figure 3 is a top view of the housing illustrated in Figure 2,

Figure 4 is a side view of the housing illustrated in Figure 2.

Figure 5 is an end view of the housing illustrated in Figure 2.

Figure 6 is a cross-sectional side view of the housing illustrated in Figure 2 and taken along line 6-6 thereof.

Figure 7 is a perspective view of the valve in accordance with the first embodiment of the present invention.

Figure 8 is a top view of the valve illustrated in Figure 7.

Figure 9 is a first end view of the valve illustrated in Figure 7.

Figure 10 is an opposite end view of the valve illustrated in Figure 9.

Figure 11 is a cross-sectional view of the valve illustrated in Figure 7, taken along line 11-11 thereof, illustrating a valve piston in an uncompressed position.

Figure 12 is a cross-sectional view of the valve as illustrated in Figure 11, with the piston in a second or compressed position using the tip of a medical instrument.

Figure 13 is a perspective view of the valve piston of the first embodiment of the present invention.

Figure 14 is a top view of the piston illustrated in Figure 13.

Figure 15 is a side view of the piston illustrated in Figure 13.

Figure 16 is a cross-sectional side view of the piston illustrated in Figure 14, taken along line 16-16 thereof.

Figure 17 is an end view of the piston illustrated in Figure 14.

Figure 18 is a cross-sectional side view of a valve in accordance with a second embodiment of the present invention, illustrating a valve piston in a first position.

Figure 19 is a cross-sectional side view of the valve as illustrated in Figure 18, with the piston in a second position.

Figure 20 is a cross-sectional side view of a valve, not part of the present invention, illustrating a valve piston in a first position.

Figure 21 is a cross-sectional side view of the valve as illustrated in Figure 20, with the piston in a second position.

Figure 22 is a cross-sectional side view of a valve, which is not part of the present invention,

ES 2 276 183 T3 illustrating a valve piston in a first position.

Figure 23 is a cross-sectional side view of the valve as illustrated in Figure 22, with the piston in a second position.

Figure 24 is a cross-sectional side view of a valve, not part of the present invention, illustrating a pair of valve pistons in a first position.

Figure 25 is a cross-sectional side view of the valve as illustrated in Figure 24, with the piston in a second position.

Figure 26 is a cross-sectional side view of a valve, not part of the present invention, illustrating a valve piston in a first position.

Figure 27 is a cross-sectional side view of the valve as illustrated in Figure 26, with the piston in a second position.

Figure 28 is a cross-sectional side view of a valve, not part of the present invention, illustrating a valve piston in a first position.

Figure 29 is a cross-sectional side view of the valve as illustrated in Figure 28, with the piston in a second position.

Figure 30 is a cross-sectional side view of a valve, not part of the present invention, illustrating a resilient element of the valve in a first position.

Figure 31 is a cross-sectional side view of the valve as illustrated in Figure 30, with the element in a second position.

Figure 32 is a cross-sectional side view of a valve not forming part of the present invention, illustrating a valve seal in a first position.

Figure 33 is a cross-sectional side view of the valve as illustrated in Figure 32, with the seal in a second position.

Figure 34 is a cross-sectional side view of a valve not part of the present invention, illustrating a valve diaphragm in a first position.

Figure 35 is a cross-sectional side view of the valve as illustrated in Figure 34, with the diaphragm in a second position.

Figure 36 is a perspective view of a valve in accordance with a third embodiment of the present invention.

Figure 37 is a top view of the valve illustrated in Figure 36.

Figure 38 is a cross-sectional view of the valve illustrated in Figure 37 taken along the line

38-38 thereof and illustrating a valve piston in a first position.

Figure 39 is a cross-sectional view of the valve illustrated in Figure 37 taken along the line

39-39 thereof and illustrating the valve piston in a second position.

Figure 40 is a perspective view of a valve housing illustrated in Figure 36.

Figure 41 is a top view of the housing illustrated in Figure 40.

Figure 42 is a cross-sectional view of the housing illustrated in Figure 41 taken along line 42-42 thereof.

Figure 43 is a cross-sectional view of the housing illustrated in Figure 41 taken along line 43-43 thereof.

Figure 44 is a perspective view of the valve piston.

Figure 45 is a top view of the piston illustrated in Figure 44.

Figure 46 is a side view of the piston illustrated in Figure 44.

Figure 47 is a second side view of the piston illustrated in Figure 44.

Figure 48 is a cross-sectional view of the piston illustrated in Figure 46 taken along line 48-48 thereof.

Figure 49 is a cross-sectional view of a valve, which does not form part of the present invention, illustrated with a seal thereof in a first position

Figure 50 is a cross-sectional view of the valve illustrated in Figure 49 with the seal in a second position.

Figure 51 is a cross-sectional view of a valve, which does not form part of the present invention, illustrated with the seal thereof in a first position.

Figure 52 is a cross-sectional view of the valve illustrated in Figure 51 with the seal in a second position.

Detailed description of the preferred embodiments

Figures 1 to 17 illustrate a valve 20 in accordance with a first embodiment of the present invention. Figure 1 illustrates a specific use of valve 20 for which valve 20 is well suited. Of course, valve 20 can be used in many other ways.

As illustrated in Figure 1, valve 20 can be advantageously used to selectively control the flow of fluid to a catheter 22 from a source of fluid 24, such as an intravenous infusion bag. In this arrangement, a first medical instrument 21 is connected to valve 20. The first medical instrument 21 comprises a tube 23 leading to a catheter 22. One end of tube 23 is connected to valve 20 and the tip of catheter 22 is placed on a patient.

A second medical instrument 26 is also connected to the valve 20. The second medical instrument 26 comprises a connecting element 27 positioned at one end of a tube 29 leading to the intravenous infusion bag 24.

When so connected, valve 20 allows fluid to flow from intravenous infusion bag 24 or other source of medical fluid to catheter 22 and to the patient. Valve 20 is also arranged such that when second medical instrument 26 is disconnected, fluid flow through valve 20 is impeded. Furthermore, when the second medical instrument 26 is disconnected, the valve 20 generates a "positive" fluid flow, that is, fluid flow in the direction of the patient, thereby preventing clogging of the catheter 22 with blood.

Next, the first embodiment of the valve 20 of the present invention will be described in more detail. As illustrated in Figures 2 through 6, valve 20 includes a housing 28. Housing 28 is generally T-shaped, having a main portion with a first end 30 defining

ES 2 276 183 T3 a first hole 31 and having a second closed opposite end 32.

A branch 33 extends out of the main part of the housing 28. The branch 33 has a third end 34 that defines a second orifice or branch 35. (See Figure 7)

Referring to Figure 6, an interior surface of a housing wall 28 defines a main conduit 36 ​​and extends from the first end 30 to the second end 32 thereof. Furthermore, a branch conduit 38 extends from the main conduit 36 ​​through the branch port to the third end 34.

As noted above, the second end 32 of the housing 28 is closed. Preferably, an end cap 40 is positioned at the second end 32 of the housing 28.

With the exception of the bifurcation portion 33, the housing 28 is generally cylindrical, as is the main conduit 36. The first end 30 of the housing 28 is adapted to receive the front or cannula tip 37 of a standard ANSI syringe, as illustrated in Figure 12. As such, the first end conduit 36 ​​has a larger diameter than the front of this type of syringe. However, it is possible for the diameter of the conduit 36 ​​to be of any size to accommodate the coupling of other connection devices thereto.

Preferably, means are provided for retaining the medical instrument 26 to the first end 30 of the valve 20. In the preferred embodiment, threads 44 are positioned on the outer surface of the housing 28 at the first end 30 for mating engagement with threads. of the connector 27 of the second medical instrument 26. In place of the threads 44, other retention means known to those skilled in the art may be used.

Since main conduit 36 ​​is generally cylindrical, end cap 40 is generally circular. Cap 40 engages housing wall 28 at second end 32 to close the conduit. Preferably, end cap 40 includes an outwardly extending tab 46, at its peripheral edge, for engaging the interior surface of casing 28 of conduit 36 ​​to retain end cap 40 in place.

For reasons described in more detail below, the diameter of conduit 36 ​​at first end 30 of housing 28 is smaller than that of second end 32. As illustrated, conduit 36 ​​narrows (moving in a direction from the second toward the first end 32, 30) near where the branch conduit 38 extends from the main conduit 36. In addition, the main conduit 36 ​​tapers again past the branch conduit 38 near the first end 30. A circumferential protrusion 48 is formed at that point where the main conduit 36 ​​narrows near the first end 32.

As illustrated in Figures 11 and 12, a piston 42 is slidably positioned within the main conduit 36. Referring to Figures 13 to 17, the piston 42 is generally cylindrical, having a maximum outside diameter that is only slightly smaller than the maximum diameter of conduit 36. The piston 42 has a first end 50 and a second end 52 and an end-to-end length that is less than the distance from the first end 30 to the second end 32 of the housing 28.

The piston 42 has a head 54 at its first end 50. As illustrated, the head 54 has a circular outer shape, however it has a sloping end surface 56. A neck 58 extends from the head 54 to a body 60. Preferably, neck 58 has a reduced diameter compared to head 54. An O-ring 67 or similar gasket is positioned around the reduced diameter neck 58 for engagement with the adjacent wall of the housing 28.

A first position of the body 60 adjacent to the neck 58 has a smaller diameter than a second part of the body 60 positioned closer to the second end 52. The transition surface between these two sections creates a flange 62. The flange 62 is arranged to mesh. projection 48 of casing conduit 36, preventing piston 42 from coming out of first end 30 of casing 28.

A pair of elongated recesses or depressions 64 are formed on opposite sides (ie, 180 degrees from each other) in the second portion of the body 60 of piston 42. The recesses 64 are channel-shaped and extend inwardly to a depth radial that is equal to the height of the flange 62 (so that the bottom of the recess is flush with the exterior of the housing in the first body part).

A groove 66 is formed in the piston 42 near its second end 52. Preferably, a gasket 68 (see Figures 11 and 12) is positioned in said groove 66. The gasket 68 is preferably an O-ring. made of rubber or similar resilient sealing material.

In the preferred embodiment, the piston 42 is hollow having a recessed area therein. As illustrated, the recessed area comprises a bore or conduit 72 that extends inwardly from the second end 52 thereof. Preferably, the bore 72 has three diameters, the largest of which is near the second end 52 and tapers in diameter by two steps to two diameters that are less than the first. The bore 72 is in communication with the conduit 36 ​​within the casing 28. Preferably, the bore 72 has all three diameters so that the casing wall 28 has a generally uniform thickness which facilitates molding. Those skilled in the art will understand that the perforation 72 can have more or less than three different diameters.

In Figures 7 to 12, the assembled valve 20 is illustrated, in which the piston 42 is positioned in the housing 28. As illustrated, the gasket 68 divides the main conduit 36 ​​into a first cavity or chamber 39 and a second cavity or chamber 41. First chamber 39 comprises the space between end cap 40 and second end 52 of piston 42, as well as the space defining bore 72 within piston 42. The second chamber 41 is the space from the seal 68 to the first end 30 of the housing 28 that is not occupied by the piston 42.

As illustrated in Figures 11 and 12, piston 42 can be moved from a first or "uncompressed" position, in which flange 62 engages boss 48

ES 2 276 183 T3 and the first end 50 of the piston 42 extends outward from the first end 30 of the housing 28, to a second or "compressed" position in which the piston 42 moves in the direction of the second end 32 of casing 28.

Means are provided to bias piston 42 to its first position. Preferably, these means comprise a spring 70. The spring 70 is of the helical type and has its first end engaging the cover 40 and its second end engaging the piston 42, preferably, within the bore 72 in a projection created in a change of diameters Of the same.

The first chamber 39 is filled with air. In order to accommodate movement of piston 42 toward second end 32 of housing 28, preferably, a vent hole 75 is provided through end cap 40 (see also Figure 5). Vent hole 75 is a conduit through cap 40 from chamber 39 to the exterior of valve 20 that allows air to enter and exit chamber 39.

Branch 33 extends generally perpendicular from the remainder of housing 28 between its first and second ends 30, 32. Usually a cylindrical wall 76, extending outward from the wall defining the main portion of the casing 28 defines branch 33. Wall 76 defines branch duct 38.

As best illustrated in Figures 7 and 11-12, preferably, a threaded sleeve 78 extends around the casing bifurcation 28. Sleeve 78 has an inside diameter that is larger than the outside diameter of wall 76. In fact, the inside diameter is large enough to define a space between wall 76 and sleeve 78 into which the end of a tube or other element can be inserted.

Preferably, sleeve 78 is connected to wall 76. As illustrated in Figures 7 and 9 through 12, the outer surface of sleeve 78 has a series of recesses 80 therein so that it can be more easily grasped by the user.

The operation of the valve 20 will now be described in detail with reference to the figures. First, a user connects the first medical instrument 21 to the bifurcation hole 35 at the third end 34. When the first medical instrument 21 is of the type described above, one end of the tube 23 having a connector therein is guided on wall 76 between the outside of the wall and the inside of the sleeve 78. Preferably, the connector is threadedly engaged with sleeve 78 to retain it in place.

Subsequently, the user engages the second medical instrument 26 to the first port 31 of the valve 20. Preferably, the medical instrument has a blunt cannula tip 37 positioned within a connector 27 that has a retention structure matching the threads 44 or with other retention means located in the housing 28.

The user advances the cannula tip 37 until it engages the end surface 56 of the piston 42. As the user advances the instrument further, the piston 42 is pressed in the direction of the second end 32 of the housing 28, compressing spring 70. Air within conduit 36 ​​between end cap 40 and piston 42 and within piston bore 72 is exhausted through vent 75 in end cap 40.

Once the connector 27 of the instrument 26 extends around the first end 30 of the housing 28, the user attaches the connector 27 to the housing 28 to provide a secure connection. Thus engaged, instrument 26 is connected to valve 20 in the position illustrated in Figure 12.

When the piston 42 is in this position, a fluid flow path is established from the second medical instrument 26 (and through the tubing 29 of the intravenous infusion bag 24 of the arrangement illustrated in Figure 1) through valve 20 to first medical instrument 21 (and consequently through catheter 22 to the patient). Fluid flows through cannula tip 37 along first end 54 of piston 42 into second chamber 41, that is, the space between piston 42 and the interior surface of housing 28, which includes the space within the recesses 64. The total volume of fluid within the valve 20, when the second medical instrument is engaged and the fluid fills the second chamber 41, is an amount V1.

The gasket 68 prevents fluid from moving past the second end 52 of the piston 42 into the first chamber 39. Consequently, fluid flowing from the second medical instrument 26 to the valve 20 is caused to enter the bifurcation conduit 38 and from this to tube 23 to the patient.

Most importantly, when the second medical instrument 26 is disconnected from the valve 20, the valve 20 causes fluid to flow in the direction of the first medical instrument through the bifurcation conduit 38. When the second medical instrument 26 is disconnected , spring 70 biases piston 42 toward first end 30 of housing 28. As piston 42 moves in this direction, piston 42 slides through the narrowest part of passage 36 near first end 30 of housing 28. This movement causes the total volume or fluid space of the chamber to be reduced. second chamber 41 between piston 42 and housing 28. Once shoulder 62 of piston 42 hits shoulder 48, piston stops moving and the volume of fluid within valve 20 is at a minimum amount V2.

Since the volume of fluid in valve 20 decreases when second medical instrument 26 is disconnected, some of the fluid within housing 28 must be displaced. Said fluid moves along channels 64 and into bifurcation conduit 38 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being V₀(displaced volume) equal to the difference between the maximum volume V1 minus the minimum volume V2.

Once the piston 42 has returned to its place, the valve 20 prevents a further flow of fluid from the first medical instrument 21 back through the valve 20, since the piston closes the passage 36 near the first end 30 of the housing 28. This prevents, for example, the patient's blood pressure from pushing the blood back into the valve 20 and out of the first port 31.

Aside from providing positive flow, the valve 20 of the present invention has other distinct advantages. First, it is often the case that medical valves have a zone of con6

ES 2 276 183 T3 fluid content within them in which the fluid can stagnate. Fluid stagnation is ill-advised as it can lead to bacterial overgrowth and similar problems.

The valve 20 of the present invention has its fluid containment zone between the piston 42 and the housing wall 28 that defines the main conduit 36. Said generally annular space fills each time fluid is injected from the upper end 50 of the piston 42.

Another aspect of the present invention is that the end surface 56 of the first end 50 of the piston 42 is smooth. This allows a user of the valve 20 to clean the cannula's engagement surface prior to connecting the medical instrument to the first port 31 of the valve. Cleaning can be done with alcohol or a similar disinfectant that serves to prevent the entry of bacteria and the like into the fluid system through valve 20.

It can be understood that the valve 20 includes both means to reduce the volume of fluid or space therein, when the second medical instrument 26 is disconnected (i.e., in this case, a reduction in the volume of the chamber or cavity 41), as means for establishing a flow path through valve 20 when the second medical instrument 26 is connected and for closing said fluid path when the instrument is disconnected. In this first embodiment, the single piston 42 provides said means.

A second embodiment valve 120 in accordance with the present invention is illustrated in Figures 18 and 19. As illustrated, said valve 120 includes a housing 128 that is similar to valve housing 20 described above, except that said housing has a shorter length between a first end 128 and a second end 130, and likewise a piston 142 of valve 120 is shorter.

As illustrated, the first end 130 defines a first hole 131 and the second opposite end 132 is closed. A branch 133 extends to a third end 134 which defines a branch hole 135.

A main conduit 136 extends from the first end 130 toward the second end 132 of the housing. An interior surface of a housing wall 128 defines the main conduit 136. The main conduit 136 is generally cylindrical in shape, in this embodiment without protrusions or steps.

A bifurcation conduit 138 extends perpendicular from the main conduit 138 between the first and second ends 130, 132 of the housing 128. Preferably, a wall 176 defines the bifurcation conduit 138. The bifurcation conduit 138 is generally cylindrical in shape .

Piston 142 is movably positioned within conduit 136 of housing 128. Piston 142 has a body 160 that is generally cylindrical in shape and has a first end 150 and a second end 152. The first end 150 defines a head 154 having an inclined surface. In this embodiment, the piston 142 is similar to that of the first embodiment, except that the piston is much shorter and does not have the different diameter sections.

A groove 166 is formed in the body 160 between its first and second ends 150, 152. As illustrated, a gasket 168 is positioned in the groove 166 of the piston 142. Said gasket 168 divides the conduit 136 from the housing 128 in a first chamber 139 and in a second chamber 141.

A recess or bore 172 is formed in the body 160 of the piston 142 extending from the second end 152. A first end of a spring 170 is positioned in the recess 172 and extends therefrom to the second end 132 of the housing 128 to diverting piston 142 toward first end 130 of housing 128.

A vent hole 175 is disposed through the second end 132 of the housing 128. The vent hole 175 allows air to flow between the first chamber 139 and the exterior of the housing 128.

A precut, resilient gasket 182 is disposed near the first end 130 of housing 128. Gasket 182 is generally circular to fit within conduit 136 and preferably includes a preformed slit 184 through which it can pass the tip of a medical instrument. Preferably, the gasket 182 is constructed of a resilient material, such that it naturally returns to the position (i.e., recloses) illustrated in Figure 18, in which the slit 184 is closed. and fluid is prevented from passing through it.

As in the first embodiment, a sleeve 178 is positioned around wall 176 defining a bifurcation 133 of housing 128. Preferably, sleeve 178 has threads 179 on an interior surface thereof.

The operation of valve 120 will now be described in detail with reference to Figures 18 and 19. First, a user connects the first medical instrument (not shown, but which may be similar to that illustrated in Figure 1 ) to the bifurcation hole 135 at the third end 134. When the first medical instrument is of the type described above, the free end of the tube is guided on the wall 176 between the outside of the wall and the inside of the sleeve 178.

Subsequently, the user engages the second medical instrument 126 to the first part 131 of the valve 120. Preferably, the medical instrument has a blunt cannula tip 137.

The user advances the cannula tip 137 until it engages the end surface 156 of the piston 142. As the user advances the instrument further, the piston 142 is pressed in the direction of the second end 132 of the housing 128, compressing pier 170. Air within first chamber 139, between end cap 140 and piston 142, and within piston bore 172 is expelled through vent hole 175 in end cap 140.

When the piston 142 is in this position (as illustrated in Figure 19), a fluid flow path is established from the second medical instrument 126 (such as through the tubing of an intravenous infusion bag) through the valve 120 to the first medical instrument (and, consequently, through the catheter to the patient). Fluid flows through cannula tip 137 along first end 154 of piston 142 to second chamber 141.

IS 2 276 183 T3

The total volume of fluid within valve 120, when the second medical instrument is engaged and the fluid fills the second chamber 141, is an amount V1.

Fluid is prevented from moving past the seal 168 to the first chamber 139. Accordingly, fluid flowing from the second medical instrument 126 to the second chamber 141 is caused to enter the bifurcation conduit 138 and from this to the tube to the patient.

Most importantly, when the second medical instrument 126 is disconnected from the valve 120, the valve 120 causes fluid to flow in the direction of the first medical instrument through the branch conduit 138. When the second medical instrument 126 is disconnected , spring 170 biases piston 142 toward first end 130 of housing 128. This movement reduces the total volume or fluid space of the second chamber 141 between the piston 142 and the seal 182 at the first end 130 of the housing 128. Once the piston 142 encounters the seal 182 , the piston stops moving and the volume of fluid within valve 120 is at a minimum amount V2.

Since the volume of fluid in valve 20 decreases when second medical instrument 126 is disconnected, some of the fluid within housing 128 must be displaced. Said fluid moves through the bifurcation conduit 138 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

After the tip of instrument 137 is removed, valve 120 prevents further flow of fluid from the first medical instrument back through valve 120, as slot 184 in seal 182 closes again, closing the valve. conduit 136 near first end 130 of housing 128.

Besides providing positive flow, the valve 120 of the present invention has other advantages. Again, the valve 120 of this embodiment has its fluid containment zone between the piston 142 and the housing 128 that defines the main conduit 136. This space fills each time fluid is injected from the upper end 150 of the piston 142 .

As an advantage, to pass through the seal 182 a needle can be used instead of the blunt tip cannula 137. In this arrangement, preferably, the seal 182 is resilient so that it closes again, but it is not necessary that is pre-cut.

As can be understood, in this embodiment, the means for selectively establishing the fluid flow path through the valve 120 and the means for reducing the space for fluid in the valve 120, when the second medical instrument 126 is withdrawn , They are independent. In this embodiment, the means for selectively establishing the fluid flow path comprises the seal 184, while the means for reducing the fluid space comprises the bypass piston 142.

An example of a valve 220 that is not in accordance with the present invention is illustrated in Figures 20 and 21. As illustrated, said valve 220 includes a housing 228. As illustrated, housing 228 is a generally cylindrical body having a first end 230 defining a first port 231 and having an opposite second end 232.

A main conduit 236 extends from the first end 230 toward the second end 232 of the housing. An interior surface of the housing 228 defines the main conduit 236. The main conduit 236 is generally cylindrical in cross section. A smaller diameter extension conduit 238 extends from main conduit 238 to second end 232 of valve 220, conduit 238 being partially defined by wall 276. Preferably, sleeve 278 is positioned around the outside of wall 276. Preferably, sleeve 278 has threads 279 on an interior surface thereof.

Piston 242 is movably positioned within passage 236 of housing 228. Piston 242 has a body 260 having a generally circular first end 250 or head. A flange or skirt 255 extends outwardly from a circumference of head 250. A series of passages 257 are disposed through head 250 of piston 242.

A bypass member 270 is positioned between the piston 242 and a boss 261 formed by the casing wall 238 at the intersection of two conduit parts 236 having different diameters. Preferably, bypass member 270 is an annular, compressible, and generally closed-cell material, such as foam or the like.

A pre-cut, resilient gasket 282 is disposed near the first end 230 of the housing 228. The gasket 282 is generally circular to fit within the conduit 236 and includes a preformed slot 284 through which the tip of the tube can pass. a medical instrument. Preferably, the gasket 282 is constructed of a resilient material such that when it returns to a non-bypass position, as illustrated in Figure 20, the slit 284 is closed and fluid is prevented from passing through the seal. herself.

The operation of valve 220 will now be described in detail with reference to Figures 20 and 21. First, a user connects the first medical instrument (not shown, but which may be similar to that illustrated in Figure 1 ) to the second end 232. When the first medical instrument is of the type described above, the free end of the tube is guided on the wall 276 between the outside of the wall and the inside of the sleeve 278. Subsequently, the user engages the second medical instrument 226 with the first port 231 of the valve 220. Preferably, the medical instrument has a blunt cannula tip 237.

The user advances the cannula tip 237 through the seal 282 until it engages the end surface 256 of the piston 242. As the user advances the instrument further, the piston 242 is pressed in the direction of the second end 232 of housing 228, compressing bypass member 270.

When piston 242 is in this position (as illustrated in Figure 21), a fluid flow path is established from second medical instrument 226 (such as through an infusion bag tubing

ES 2 276 183 T3 intravenous) through valve 220 to the first medical instrument (and therefore through the catheter to the patient). Fluid flows, through cannula tip 237, through conduits 257 to conduit 236. In addition, the fluid fills space 241 between seal 282 and piston 242. The total volume of fluid within of valve 220, when the second medical instrument is engaged, is a quantity V1.

Most importantly, when the second medical instrument 226 is disconnected from the valve 220, the valve 220 causes fluid to flow in the direction of the first medical instrument through the extension conduit 238. When the second medical instrument 226 is disconnected , the bypass member 270 pushes the piston 242 toward the first end 230 of the housing 228. When the piston 242 moves in this direction, the bypass member 270 expands. This reduces the total volume or fluid space of the housing 228. Once the piston 242 encounters the seal 184, the piston stops moving and the volume of fluid within the valve 220 is at a minimum amount. V2.

Since the volume of fluid in valve 220 decreases when second medical instrument 226 is disconnected, some of the fluid within housing 228 must be displaced. Said fluid moves through the bifurcation conduit 238 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

After instrument tip 237 is removed, valve 220 prevents further flow of fluid from the first medical instrument back through valve 220, as groove 284 in gasket 282 closes again, closing the conduit 236 near first end 230 of housing 228.

Besides providing positive flow, valve 220 has other advantages. Valve 220 has its fluid containment zone between gasket 282 and housing 228 that defines main conduit 236. This space fills each time fluid is injected from upper end 250 of piston 242.

Another advantage is that the straight fluid flow path from the first to the second end 230, 232 serves to eliminate stagnant areas.

A further example of a valve 320 which is not in accordance with the present invention is illustrated in Figures 22 and 23. Said valve 320 includes a housing 328 that is generally cylindrical in shape, like the housing 228 of the third embodiment. Housing 328 has a first end 330 defining a first hole 331 and a second end 332 defining a second hole 335. A conduit 336 extends through housing 328 end-to-end.

A piston 342 is movably positioned within passageway 336. Piston 342 has a generally circular head 354 with a flange or skirt 355 extending downward thereof around the outer edge of head 354. At least A passage 357 is disposed through the head 354 of the piston 342.

A bypass element 370 is positioned within housing 328 between piston 342 and second end 332. As illustrated, element 370 is a resilient element having a circular shape with a generally "C" shaped cross section with a inner side closed and one outer side open.

Element 370 cooperates with an interior surface of housing 328 to define a chamber 339, which is sealed, from conduit 336. One or more vent holes 375 are disposed through the housing wall from an exterior point of the chamber. same to camera 339.

In this example, a sleeve 378, which surrounds a wall 376, is integrally formed with the rest of the housing 328. The sleeve 378 has threads 379 on an interior surface thereof for use in a mating gear with threads of a medical connector.

A gasket 382 is disposed near the first end 330 of the housing 328. Preferably, the gasket 382 selectively hides or closes the conduit 336 through the housing 328. The gasket 382 is precut to form a slit 384 that, when the seal 382 is in its non-bypass position, as illustrated in Figure 22, it is closed.

The use of valve 320 in this example is as follows. First a user connects a first medical instrument (see Figure 1) to hole 335 in second end 334 of housing 328. When the first medical instrument is of the type described above, a free end of the tube is guided on the wall 376 between the outside of the wall and the inside of the sleeve 378.

Subsequently, the user engages the second medical instrument 326 with the first portion 331 of the valve 320. Preferably, the medical instrument has a blunt cannula tip 337. The user advances the cannula tip 337 through the slit 384 of the gasket 381 until it engages end surface 354 of piston 342. As the user advances the instrument further, the piston 342 is pressed in the direction of the second end 332 of the housing 328, compressing the shunt member 370 radially outward. Air within chamber 339 is exhausted through vents 375 in the wall of casing 328.

When piston 342 is in this position, a fluid flow path is established from the second medical instrument through valve 320 to the first medical instrument. Fluid flows through cannula tip 337 through passage 357 from first end 354 of piston 342 to passage 336. The total volume of fluid within valve 320, when the second medical instrument is coupled and the fluid fills conduit 336 with compressed bypass member 370, is an amount V1.

Most importantly, when the second medical instrument 326 is disconnected from the valve 320, the valve 320 causes fluid to flow in the direction of the first medical instrument through the second port 335. When the second medical instrument 326 is disconnected, bypass member 370 urges piston 342 toward first end 330 of housing 328.

At the same time, bypass element 370 expands inward, reducing the total volume or space for fluid in conduit 336 between piston 342.

ES 2 276 183 T3 and the second end 332 of the housing 328. Once the piston 342 moves up to a point where it meets the seal 382, ​​the piston stops moving, and the fluid volume inside valve 320 is at a minimum amount V2.

Since the volume of fluid in valve 320 decreases when second medical instrument 326 is disconnected, some of the fluid within housing 328 must be displaced. Said fluid moves through conduit 336 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

After instrument tip 337 is removed, valve 320 prevents further flow of fluid from the first medical instrument through it, since gasket 382 closes conduit 336 near first end 330 of housing 328.

Besides providing positive flow, valve 320 has other advantages. Generally, fluid stagnation is prevented since fluid flows through housing 328 in a generally straight path.

A further example of a valve 420 which is not in accordance with the present invention is illustrated in Figures 24 and 25. Said valve 420 includes a housing 428 that is generally identical to the housing 328 of valve 320 described above and illustrated in Figures 22 and 23, having a first end 430 defining a first orifice 431 and a second end 432 defining a second hole 435. A conduit 436 extends through housing 428 from first to second ends 430, 432.

Again, a wall 476 defines a portion of the conduit 436 near the second end 432. A sleeve 478 extends around the wall 476, the sleeve 478 having a series of threads 479 on an internal surface thereof.

A gasket 482 having a precut groove 484 is disposed near the first end 430 of the housing 428 as in the last embodiment.

In this example, bypass element 470 comprises a resilient, circular-shaped element having a hollow interior 471. The interior 471 of element 470 is in communication with the exterior of housing 428 through one or more conduits or holes. Vent 475. However, a connection is provided between element 470 and conduits 475, such that air flowing through conduits 475 to or from element 470 does not enter conduit 436.

In this example, a pair of pistons 442, 443 move radially rather than linearly, as in the embodiments described above. Preferably, each piston 442, 443 includes a head 450 and a base 452 that is in the shape of a half circle. A vertical wall 455 connects the head and base 450, 452 of each piston 442, 443 so that the head and base thereof extend radially outward around a portion of the bypass member 470. Preferably, each piston 442, 443 has a wedge area 453 on the head 450 thereof, with area 453 of pistons 442, 443 cooperating to form a guide, as described in more detail below.

As illustrated in Figure 24, the pistons 442, 443 are arranged to abut each other along their walls 455 in their normal position. As illustrated in Figure 25, the pistons 442, 443 are arranged to move radially outward when a medical instrument is pressed between them.

The use of valve 420 in this example is as follows. First a user connects a first medical instrument (see Figure 1) to the hole 435 in the second end 434 of the housing 428. When the first medical instrument is of the type described above, a free end of the tube is guided on the wall 476 between the outside of the wall and the inside of the sleeve 478.

Subsequently, the user engages the second medical instrument 426 to the first port 431 of the valve 420. Preferably, the medical instrument has a blunt cannula tip 437. The user advances the cannula tip 437 through the slot 484 of the gasket. seal 482 until it engages the head 450 of each piston 442, 443. As the user advances the instrument further, the pistons 442, 443 are pressed radially outward from one another, compressing the bypass member 470. Air within the hollow interior 471 of the bypass member 470 is expelled through the holes. vent 375 from the casing wall 328.

When in this position, a fluid flow path is established from the second medical instrument 426, through the valve 420, to the first medical instrument. Fluid flows through cannula tip 437 into conduit 436. The total volume of fluid within valve 420, when the second instrument is engaged and fluid fills conduit 436 with shunt 470 compressed, is a quantity V1.

Most importantly, when the second medical instrument 426 is disconnected from the valve 420, the valve 420 causes fluid to flow in the direction of the first medical instrument through the second port 435. When the second medical instrument 426 is disconnected, bypass member 470 urges pistons 442, 443 radially inward to the position illustrated in Figure 24.

At the same time, bypass member 470 expands inward, reducing the total volume or space for fluid in conduit 436 between piston 442 and second end 432 of housing 428. Once pistons 442, 443 meet , they stop moving and the volume within valve 420 is at a minimum amount V2.

Since the volume of fluid in valve 420 decreases when second medical instrument 426 is disconnected, some of the fluid within housing 428 must be displaced. Said fluid moves through conduit 436 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

Once tip 437 is removed from instrument 426, valve 420 prevents further flow of fluid from the first medical instrument through it, since gasket 482 closes conduit 436 near first end 430 of housing 428 .

Aside from providing positive flow, the valve

ES 2 276 183 T3 the 420 has other advantages. Generally, fluid stagnation is prevented since fluid flows through housing 428 in a generally straight path.

As those skilled in the art will understand, more than two pistons may be provided that cooperate together to perform the function described above, such as three or four "cookie" shaped pistons.

A further example of a valve 520 which is not in accordance with the present invention is illustrated in Figures 26 and 27. The valve of this embodiment 520 is similar to the valve of the first embodiment 20, except that the valve 520 is arranged to have a forward flow arrangement similar to that illustrated in the last example.

Valve 520 in this example has a housing 528 that is generally cylindrical in shape. Housing 528 has a first end 530 defining a first hole 531 and a second end 532 defining a second hole 535. A conduit 536 extends through housing 528 end-to-end.

A piston 542 is movably positioned within passage 336. Piston 542 has a generally circular head 554 with a tubular section 555 extending centrally downward thereof. A conduit 557 is disposed through the head 554 and a tubular section 555 of the piston 542.

A spring 570 or other bias means is positioned within housing 528 between head 554 of piston 542 and a boss 561 formed in housing 528 along conduit 536 between first and second ends 530, 532.

A gasket 568 is disposed in a groove in the circumferential surface of the head 554 of the piston 542. A similar gasket 568 is disposed around the tubular section 555 near its end opposite the head 554. The gaskets 568, 569 seal a portion of conduit 536, thereby defining an air-filled, hermetically sealed chamber 539.

One or more ventilation holes 575 are disposed through the housing wall from a point external thereto to the chamber 539.

Sleeve 578 and wall portion 576 are integrally formed with the rest of the housing, with wall 576 defining conduit 536 at second end 532. Sleeve 578 has threads 579 therein for use in mating engagement with threads of a medical connector.

A seal 582 is disposed near the first end 530 of the housing 528. Preferably, the seal 582 conceals or seals the conduit 536 through the housing 528. The seal 582 is precut to form a slit 584 that, when the seal 582 is in its non-bypass position, as illustrated in Figure 26, it is closed.

The use of valve 520 in this embodiment is as follows. First, a user connects a first medical instrument (see Figure 11) to the hole 535 of the second end 534 of the housing 528. When the first medical instrument is of the type described above, a free end of the tube is guided on wall 576 between the outside of the wall and the inside of the sleeve 578.

Subsequently, the user engages the second medical instrument 526 to the first port 531 of the valve 520. Preferably, the medical instrument has a blunt cannula tip 537. The user advances the cannula tip 537 through the slot 584 of the seal seal 582 until it engages head 554 of piston 542. As the user advances the instrument further, the piston 542 is pressed in the direction of the second end 532 of the housing 528 compressing the spring 570. The air within the chamber 539 is expelled through the ventilation holes 575 of the casing wall 528.

When piston 542 is in this position (as illustrated in Figure 27), a fluid flow path is established from the second medical instrument through valve 520 to the first medical instrument. Fluid flows, through cannula tip 537, through passage 557 of piston 542 to passage 536. Also, the fluid fills the space between seal 582 and head 554 of piston 542. The total volume of fluid within valve 520, when the second medical instrument is engaged and the fluid fills these areas when spring 570 is compressed, is an amount V1.

Most importantly, when the second medical instrument 526 is disconnected from the valve 520, the valve 520 causes fluid to flow in the direction of the first medical instrument through the second port 535. When the second medical instrument 526 is disconnected, spring 570 urges piston 542 toward first end 530 of housing 528. Such movement of piston 542 reduces the total volume or space for fluid in conduit 536 between piston 542 and second end 532 of housing 528. Once piston 542 moves up to a point where it meets the seal seal 582, the piston stops moving and the fluid volume inside the valve 520 is at a minimum amount V2.

Since the volume of fluid in valve 520 decreases when second medical instrument 526 is disconnected, some of the fluid within housing 528 must be displaced. Said fluid moves through conduit 536 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

After the instrument tip 537 is removed, the valve 520 prevents further flow of fluid from the first medical instrument through it, since the seal 582 closes the conduit 536 near the first end 530 of the housing 528.

Besides providing positive flow, valve 520 has other advantages. Generally, fluid stagnation is prevented since fluid flows through housing 528 in a continuous path.

Another example of a valve 620 that is not in accordance with the present invention is illustrated in Figures 28 and 29. Such valve 620 includes a housing 628 that is similar to those previously described for valves 320, 420, and 520.

Housing 628 has a first end 630 that defines a first hole 631 and a second end 632 that defines a second hole 635. A conduit11

ES 2 276 183 T3 to 636 extends through the housing 628 from the first to the second end 630, 632.

Again, a wall 676 defines a portion of conduit 636 near second end 632. A sleeve 678 extends around wall 676, with sleeve 678 having a series of threads 679 on an internal surface thereof.

A gasket 682, having a precut groove 684, is disposed near the first end 630 of the housing 628 as in the last embodiment.

A piston 642 is positioned adjacent the seal 684. Preferably, the piston 642 is generally disc-shaped, with a circular outer shape. Piston 642 has a top or first end 650 that is sloped and a second end or bottom 652 that is flat.

In this example, a resilient element 670 comprises a generally cylindrical, non-porous, resilient material. In its rest condition, element 670 preferably has an outer diameter that is smaller than the diameter of conduit 636 in which it is positioned. Element 670 is positioned on a boss 661 formed within conduit 636 and lower end 652 of piston 642.

Grooves 685, 686 are formed in the side wall of housing 628 within conduit 636 that includes the portion defining boss 661. Grooves 685, 686 are arranged to grip the outer surfaces of element 670 in a manner that allows the fluid flows between element 670 and housing 628, as described below.

The use of valve 620 in this example is as follows. First, a user connects a first medical instrument (see Figure 1) to port 635 in second end 634 of housing 628. When the first medical instrument is of the type described above, a free end of the tube is guide on wall 676 between the outside of the wall and the inside of the sleeve 678.

Subsequently, the user engages the second medical instrument 626 to the first port 631 of the valve 620. Preferably, the medical instrument has a blunt cannula tip 637. The user advances the cannula tip 637 through the slot 684 of the gasket. seal 682 until it engages upper portion 650 of piston 642. As the user advances the instrument further, piston 642 is pressed downward compressing element 670.

When in this position, a fluid flow path is established from the second medical instrument 626, through the valve 620, to the first medical instrument. Fluid flows, through cannula tip 637, through conduit 636. Through slots 685, 686 fluid is allowed to flow past element 670. The total volume of fluid within the valve 620, when the second medical instrument is attached and the fluid fills the conduit 636 and the space between the top 650 of the piston 642 and the bottom of the gasket 682, when the piston 642 is tight, it is a V1 quantity.

Most importantly, when the second medical instrument 626 is disconnected from the valve 620, the valve 620 causes fluid to flow in the direction of the first medical instrument through the second port 635. When the second medical instrument 626 is disconnected, Element 670 is expanded by pushing piston 642 up to the position illustrated in Figure 28.

At the same time, the total volume or space for fluid in conduit 636 between piston 642 and gasket 682 is reduced. Once piston 642 moves up to a point where it meets gasket 682 , the piston stops moving and the volume of fluid inside the valve 620 is at a minimum amount V2.

Since the volume of fluid in valve 620 decreases when second medical instrument 626 is disconnected, some of the fluid within housing 628 must be displaced. Fluid moves through conduit 636 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

Once tip 637 is removed from instrument 626, valve 620 prevents further flow of fluid from the first medical instrument through it, since gasket 682 closes conduit 636 near first end 630 of housing 628 .

Besides providing positive flow, valve 620 has other advantages. Generally, fluid stagnation is prevented since fluid flows through housing 628 generally in a flat path.

A further example of a valve 720 which is not in accordance with the present invention is illustrated in Figures 30 and 31. Said valve 720 includes a housing 728 that is similar to those previously described for valves 220, 320, etc.

Housing 728 has a first end 730 defining a first hole 731 and a second end 732 defining a second hole 735. A conduit 736 extends through housing 728 from the first to the second end 730, 732.

Again, a wall 776 defines a portion of conduit 736 near second end 732. A sleeve 778 extends around wall 776, with sleeve 778 having a series of threads 779 on an internal surface thereof.

A gasket 782, having a precut groove 784, is disposed near the first end 730 of the housing 728 as in the last embodiment.

In this example, a resilient member 770 comprises a hollow, resilient, generally cylindrical member. In its rest condition, element 770 preferably has an outer diameter that is smaller than the diameter of conduit 736 in which it is positioned. Element 770 defines an interior space 771, which is sealed from conduit 736. Element 770 is positioned in a boss 761 formed within housing 728.

An inclined surface for cannula engagement 781 is defined at the top of element 770.

A vent hole 775 extends through housing 728 from interior space 771 within element 770 to an exterior point of housing 628. In the illustrated example, vent hole 775 terminates in the space between the wall. 776 and sleeve 778.

The use of valve 720 in this example is like

ES 2 276 183 T3 continues. First, a user connects a first medical instrument (see Figure 1) to the hole 735 in the second end 732 of the housing 728. When the first medical instrument is of the type described above, a free end of the tube is guide on wall 776 between the outside of the wall and the inside of the sleeve 778.

Subsequently, the user engages the second medical instrument 726 to the first port 731 of the valve 720. Preferably, the medical instrument has a blunt cannula tip 737. The user advances the cannula tip 737 through the slot 784 of the seal seal 782 until it engages inclined surface 781 on top of element 770. As the user advances the instrument further, element 770 is compressed downward and outward, reducing the volume of space 771, but increasing the space for fluid within valve 720.

When in this position, a fluid flow path is established from the second medical instrument 726, through the valve 720, to the first medical instrument. Fluid flows through cannula tip 737 along inclined surface 781 (thereby unobstructed by the cannula tip) and through passage 736. The total volume of fluid within valve 720, when the second medical instrument is attached and fluid fills conduit 736, and the space between the top of element 770 and the bottom of gasket 782, is an amount V1.

Most importantly, when the second medical instrument 726 is disconnected from the valve 720, the valve 720 causes fluid to flow in the direction of the first medical instrument through the second port 735. When the second medical instrument 726 is disconnected, element 770 moves up to the position illustrated in Figure 30.

At the same time, the total volume or space for fluid in conduit 736 between element 770 and seal 782 is reduced until the volume of fluid within valve 720 is at a minimum amount V2.

Since the volume of fluid in valve 720 decreases when second medical instrument 726 is disconnected, some of the fluid within housing 728 must be displaced. Said fluid moves through conduit 736 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

After the tip 737 is removed from the instrument 726, the valve 720 prevents further flow of fluid from the first medical instrument through it, since the seal 782 closes the conduit 736 near the first end 730 of the housing 728 .

Besides providing positive flow, valve 720 has other advantages. Generally, fluid stagnation is prevented since fluid flows through housing 728 generally in a flat path.

A further example of a valve 820 that is not in accordance with the present invention is illustrated in Figures 32 and 33. As illustrated, such valve 820 includes a housing 828 that is somewhat similar to the valve housings 220, 320, etc., described above.

As illustrated, housing 828 has a body having a first end 830 defining a first hole 831 and an opposite second end 832. A main conduit 836 extends from first end 830 toward second end 832 of the housing. An interior surface of a wall of the housing 828 defines the main conduit 836. The main conduit 836 is cylindrical in shape.

An extension conduit 838 extends from the main conduit 836 to the second end 832. Preferably, a wall 876 defines the extension conduit 838 and is generally cylindrical in shape, albeit smaller in diameter than the main conduit 836.

A resilient gasket 882 is disposed near the first end 830 of the housing 828. The gasket 882 has a generally circular or peripheral outer surface to fit within the conduit 836 and preferably includes a preformed slit 884 through the that can pass the tip of a medical instrument. Preferably, the gasket 882 is constructed of a resilient material, such that it naturally returns to the position illustrated in Figure 32, in which the slit 884 is closed and fluid is prevented from passing through. Of the same.

Most importantly, however, the seal 882 is arranged so that when an instrument is pressed through the slit 884, at least a part of the seal 882 moves in the direction of the first end 830. of the housing 828, thereby increasing the volume or space for fluid within the housing 828. At the same time, the seal 882 is arranged so that when the instrument is retracted, the seal 882 moves in the direction of the second end 832 of the housing 828, reducing the volume or space for fluid therein.

A sleeve 878 is positioned around wall 876 at second end 832 of housing 828. Preferably, sleeve 878 has threads 879 on an interior surface thereof.

The operation of valve 820 will now be described in detail with reference to Figures 32 and 33. First, a user connects the first medical instrument (not shown, but which may be similar to that illustrated in Figure 1) to the branch hole 835 at the third end 834. When the first medical instrument is of the type described above, the free end of the tube is guided on the wall 876 between the outside of the wall and the inside of the sleeve 878.

Subsequently, the user engages the second medical instrument 826 to the first port 831 of the valve 820. Preferably, the medical instrument has a blunt cannula tip 837. The user advances the cannula tip 837 through the slot 884 in the gasket. seal 882. At this time, seal 882 moves to the position shown in Figure 33.

When in this position, a fluid flow path is established from the second medical instrument 826 (such as through the tubing of an intravenous infusion bag), through the valve 820, to the first medical instrument (and therefore through the catheter to the patient). Fluid flows, through tip 837 of the cannula, through the con13

ES 2 276 183 T3 main line 836 and extension line 838. The total volume of fluid within valve 820, when the second medical instrument is coupled, is a quantity V1.

Most importantly, when the second medical instrument 826 is disconnected from the valve 820, the valve 820 causes the flow to flow in the direction of the first medical instrument through the extension conduit 838. When the second medical instrument 826 is disconnected , the gasket 882 returns to its position, as illustrated in Figure 32. This causes the total volume or space for fluid in the housing 828 to be reduced to a minimum amount V2.

Since the volume of fluid in valve 820 decreases when second medical instrument 826 is disconnected, some of the fluid within housing 828 must be displaced. Said fluid moves through the bifurcation conduit 838 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

After the instrument tip 837 is removed, the valve 820 prevents further flow of fluid from the first medical instrument through it, as the slit 884 in the seal 882 closes again, closing the conduit 836 nearby. of the first end 830 of the housing 828.

Besides providing positive flow, valve 820 has other advantages. Valve 820 has its fluid containment zone between gasket 882 and housing 828 that defines main conduit 836. This space fills each time fluid is injected through instrument 826.

A further example of a valve 920 that is not in accordance with the present invention is illustrated in Figures 34 and 35. As illustrated, housing 928 has a body having a first end 930 defining a first hole 931 and a second closed opposite end 932. A branch 933 extends to a third end 934 defining a branch hole 935.

An opening in the housing 928 at its first end leads a chamber 936 or conduit from one side of a diaphragm element 970 to a bifurcation conduit 938. The bifurcation conduit 938 extends from chamber 936 in the opposite direction to the second end 930 of housing 928. Preferably, a wall 976 defines branch conduit 938. Branch conduit 938 is generally cylindrical in shape.

A pre-cut, resilient gasket 982 is disposed near the first end 930 of the housing 928. The gasket 982 is generally circular to fit within the opening of the first end 930 of the housing 928. Preferably, the gasket 982 includes a preformed slot 984 through which the tip of a medical instrument can pass. Preferably, the gasket 982 is constructed of a resilient material, such that it naturally returns to the position illustrated in Figure 34, in which the slit 984 is closed and fluid is prevented from passing through. Of the same.

The diaphragm 970 is positioned within a hollow space within the housing 928 between the first and second ends 920, 932. Generally, the diaphragm 970 divides this space into the first chamber or cavity 936 and a second chamber 939. The diaphragm 970 is biased in an upward direction, that is, in the direction of the first end 930 of the housing 929.

At least one vent hole 975 extends through the wall of the housing 928 at its second end 932 to the second chamber 939, allowing air to enter and exit the chamber.

As in the first embodiment, a sleeve 978 is positioned around a bifurcation 933 of the housing 928. Preferably, the sleeve 978 has threads 979 on an interior surface thereof.

The operation of valve 920 will now be described in detail with reference to Figures 34 and 35. First, a user connects the first medical instrument (not shown, but which may be similar to that illustrated in Figure 1) to the branch hole 935 at the third end 934. When the first medical instrument is of the type described above, the free end of the tube is guided on the wall 976 between the outside of the wall and the inside of the sleeve 978.

Subsequently, the user engages the second medical instrument 926 to the first port 931 of the valve 920. Preferably, the medical instrument has a blunt cannula tip 937. The user advances the cannula tip 937 through the slot 984 of the gasket. seal 982 and presses on diaphragm 970. At this time, diaphragm 970 moves to the position illustrated in Figure 35.

When in this position (as illustrated in Figure 35), a fluid flow path is established from the second medical instrument 926 (such as through an IV bag tubing), through the valve. 920, to the first medical instrument (and therefore through the catheter to the patient). Fluid flows through cannula tip 937 into chamber 936, subsequently through bifurcation conduit 938. The total volume of fluid within valve 920, when the second medical instrument is attached, is an amount V1.

Most importantly, when the second medical instrument 926 is disconnected from the valve 920, the valve 920 causes fluid to flow in the direction of the first medical instrument through the branch conduit 938. When the second medical instrument 926 is disconnected , the diaphragm 970 is moved upward back into position, as illustrated in Figure 34. This causes the total volume or space for fluid in the housing 928 to be reduced to a minimum amount V2.

Since the volume of fluid in valve 920 decreases when second medical instrument 926 is disconnected, some of the fluid within housing 928 must be displaced. Said fluid moves through the bifurcation conduit 938 in the direction of the patient, the total volume of fluid flowing in the "positive" direction being equal to the difference between the maximum volume V1 minus the minimum volume V2.

In addition, once instrument tip 937 is removed, valve 920 prevents further flow of fluid from the first medical instrument through it, as the slit closes again.

IS 2 276 183 T3

984 of the gasket 982, closing the conduit 936 near the first end 930 of the housing 928.

Besides providing positive flow, valve 920 has other advantages. Valve 920 has its fluid containment zone between gasket 982 and housing 928 that defines chamber 936. This space fills each time fluid is injected through instrument 926.

A valve 1020 of a third embodiment in accordance with the present invention is illustrated in Figures 36 through 49. Such valve 1020 is similar in many respects to the valve of the first embodiment.

Referring to Figure 36, valve 1020 includes a housing 1028 that is "T" shaped, having a main portion with a first end 1030 and a closed opposite second end 1032. A branch 1033 extends outwardly from the portion. main, generally perpendicular thereto, to a third end 1034 defining a bifurcation hole 1035.

As illustrated in Figures 38 and 39, a main conduit 1036 extends from the first end 1030 to the second closed end 1032 within the housing 1028. In addition, a branch conduit 1038 extends from the main conduit 1036, through from the bifurcation hole, to the third end 1034.

Main conduit 1036 has two diameters. A first small diameter portion of conduit 1036 extends from first end 1030 to near branch conduit 1038. Subsequently, the diameter of main conduit 1036 increases to a larger diameter section extending to second end 1032. A boss 1048 is formed at the intersection of these two parts of main conduit 1036.

A piston 1042 is slidably positioned within main conduit 1036. Referring to Figures 44 through 48, piston 1042 is generally cylindrical, having a maximum outer diameter that is slightly less than the maximum diameter of conduit 1036. . The piston 1042 has a first end 1050 and a second end 1052 and an end-to-end length that is less than the distance from the first end 1030 to the second end 1032 of the housing 1028.

The piston 1042 has a first body part 1054 that extends from the first end 1050 to a second body part 1056. The outer diameter of the second body part 1056 is larger than that of the first body part 1054, defining the intersection of these two parts is a flange 1062. Said flange 1062 is arranged to engage the flange 1048 of the housing 1028 in a manner that will be described later.

A groove 1066 is formed in the piston 1042 near its second end 1052. Preferably, a seal 1068 (see Figures 38 and 39) is positioned in said groove 1066. Preferably, the seal 1068 comprises an O-ring.

A notch or notch 1064 in the shape of a "V" is defined in the first body part 1056 of the piston 1042. Said notch 1064 extends from the first end 1050 towards the second end 1052.

In the preferred embodiment, the piston

1042 it is hollow, having a recessed area in it. As illustrated, said zone comprises a bore 1072 extending to piston 1042 from second end 1052. As illustrated, bore 1072 has two parts of different diameters, thereby forming a protrusion. When piston 1042 is positioned in housing 1028 (see Figures 38 and 39), bore 1072 is in communication with conduit 1036.

A gasket 1082 is disposed at the first end 1030 of the housing 1028 and closes the main conduit 1036 at that end. Preferably, the gasket 1082 is mounted to the housing 1028 by means of an end cap 1083.

Preferably, the seal 1082 is a reclosable, pre-cut, and resilient element. End cap 1083 has one end with a conduit 1085 through it that is aligned with main conduit 1036. A cylindrical side wall 1087 extends from the end of cap 1083 and is arranged to engage the exterior of housing 1028. at the first extreme 1030. As illustrated, cover 1083 has a groove on the inside of wall 1087 that receives a rib 1089 from the outside of housing 1028 in a press fit arrangement.

As with previous embodiments, a wall structure 1076, extending outward from the main part of the housing 1028, defines the branch duct 1038. A sleeve 1078 is spaced outwardly from said wall structure 1076 Threads 1079 are located inside the sleeve 1078.

The assembled valve 1020, in which the piston 1042 is positioned in the main conduit 1036, through the housing 1028, is best illustrated in Figures 38 and 39. As illustrated, the gasket 1068 divides the main conduit 1036 in a first chamber 1039 and in a second chamber 1041. The first chamber 1039 comprises a space between the second closed end 1032 of the housing 1028, the second end 1052 of the piston 1042 and the space within the bore 1072 of the piston 1042. The second chamber 1041 is the space between the gasket 1068 of the piston 1042 and the gasket 1082 at the first end 1030 of the housing 1028.

As illustrated, piston 1042 can be moved from a first or "uncompressed" position, in which flange 1062 engages boss 1048, to a second or "compressed" position, in which piston 1042 moves toward the second end 1032 of housing 1028. Means are provided to bias piston 1042 to its first position. Preferably, said means comprise a spring 1070. As illustrated, spring 1070 is a coil spring that extends between second end 1032 of housing 1028 and the boss formed on piston 1042 by means of variable diameter bore 1072.

The first chamber 1039 is filled with air. In order to accommodate the movement of the piston 1042 toward the second end 1032 of the housing 1028, a vent hole 1075 is provided through the second end 1032.

The operation of valve 1020 will now be described. First, a user connects a first medical instrument to the branch port15.

ES 2 276 183 T3 1035 in a manner as described above. The user then presses a blunt tip cannula or other medical instrument 1037 (see Figure 39) through the opening 1085 in the cap 1083 and subsequently through the slit in the gasket 1082. The user makes advance instrument 1037 until it presses piston 1042 toward second end 1032 of housing 1028, as illustrated in Figure 39.

When piston 1042 is in this position, a flow path is established from instrument 1037 through second chamber 1041 between the exterior of piston 1042 and the housing wall 1028 to branch passage 1038. Fluid flows freely. through the tip of the cannula 1037 since the "V" shaped open space is disposed below the tip at the first end 1050 of the piston 1052. In this position, valve 1020 has a maximum fluid capacity V1.

When the user removes the cannula 1037, the pre-cut gasket of the gasket 1082 closes again, preventing fluid from flowing from the main conduit 1026 out of the first end 1030 of the valve 1020. At the same time, when When removing cannula 1037 or other medical instrument, piston 1042 moves upward to the position illustrated in Figure 38 as a result of spring force. When piston 1042 is in the position illustrated in Figure 38, the volume within valve 1020 is at a minimum V2.

Since the volume of fluid in valve 1020 decreases as piston 1042 moves upward, some of the fluid in main conduit 1026 is displaced. Said volume of fluid V1-V2 moves along piston 1042 to branch passage 1038.

Also, said valve 1020 has the advantage that it is filled with each use and that the upper surface of the gasket 1082 can be cleaned to sterilize it.

Another example of a valve 1120 that is not in accordance with the present invention is illustrated in Figures 49 and 50. The valve 1120 of this example has a housing 1128 that defines a main conduit 1136 that extends from a first end 1130 to a chamber 1141. A branch conduit 1138 leads from the chamber 1141, generally perpendicular, to the main conduit 1136.

Housing 1128 has a second end 1132 opposite first end 1130, second end 1132 being open toward chamber 1141.

A gasket 1182 is positioned within chamber 1141. As illustrated, gasket 1182 is a resilient element in an inverted "U" shape. In a first position, gasket 1182 is arranged to close branch conduit 1138 from chamber 1141 (see Figure 49).

A piston 1142 is positioned within the main conduit 1136 and rests on an upper portion of the gasket 1182. As illustrated, the piston 1142 has a first flat end 1150 and a second sloped end 1152. The piston 1142 has a shape generally cylindrical in cross section.

The wall defining the main conduit 1136 is cylindrical at the first end 1130 of the housing 1128. In a direction toward the second end

1132, the wall slopes outward to define a sloped surface 1148.

Preferably, a gasket 1168 is disposed at the first end 1130 of housing 1128. Said gasket 1168 is designed to seal against the exterior of piston 1142 to prevent fluid flow between piston 1142 and housing 1128 in the first end 1130 of valve 1120.

The operation of said valve 1120 is as follows. A user engages the tip of a cannula or other medical instrument with the first end 1150 of the piston 1142. The user presses the piston 1142 toward the second end 1132 of the housing 1128 until the luer lock connector or the like can be threadedly engaged. casing 1128, as illustrated in Figure 50.

When the piston 1142 moves inward, because its second wedge end 1152 engages the gasket 1182 and the gasket folds, the piston 1142 falls against the inclined surface 1148 of the enlarged section of the main conduit 1136. At this time, the upper end 1150 of the piston 1142 is no longer a flat surface relative to the end of the cannula. Therefore, the fluid is allowed to flow freely from the tip of the cannula.

As piston 1142 moves inward, gasket 1182 compresses to a position where branch conduit 1138 is in communication with chamber 1141.

A fluid path is established from the cannula along the upper end 1150 of the piston 1142, along the main conduit 1136, to the chamber 1141, and subsequently to the bifurcation conduit 1138. At this time, the volume of fluid within valve 1120 is a quantity V1.

When the user removes the cannula, the seal 1182 presses the piston 1142 upward. Upward movement of piston 1142 is facilitated by its engagement with inclined surface 1148. Finally, gasket 1182 moves piston 1142 to the position shown in Figure 49. At that time, gasket 1182 It reseals branch conduit 1138 from chamber 1141.

In addition, gasket 1168 seals around piston 1142, preventing fluid from flowing from inside valve 1120 through main conduit 1136 to first end 1130, thereby achieving positive fluid flow.

As gasket 1182 expands, the volume within chamber 1141 is reduced, pushing fluid into branch conduit 1138.

A further example of a valve 1220 that is not in accordance with the present invention is illustrated in Figures 51 and 52. Such valve 1220 has a forward flow arrangement similar to the valves illustrated in Figures 20-29.

Valve 1220 has a housing 1228 that has a first end 1230 and a second end 1232. A main conduit 1236 extends from first end 1230 to a smaller extension conduit 1238 that extends to second end 1232. A wall 1276 , which is positioned within a sleeve 1278, primarily defines the extension conduit 1238.

IS 2 276 183 T3

A gasket 1282 is positioned in a conical portion 1248 of the main conduit 1236 at the first end 1230. Preferably, the gasket 1282 comprises first and second gasket portions which, when put together, form an inverted element. frustoconically. Each gasket part has a generally semi-circular cross-sectional shape (in a horizontal plane) and defines a flat inner surface 1283 for engagement with the other gasket part. The outer surface 1185 of each gasket portion is curved and tapers inward from top to bottom.

Each gasket portion is biased in a direction toward the second end 1232 of the valve 1220. A resilient bypass member 1270 has a first end connected to a lower surface of each gasket portion and a second end attached to the casing 1228 some distance along main conduit 1236. As illustrated, each bypass element 1270 comprises an elastic accordion-type element.

The operation of valve 1220 is as follows. When not in use, the bypass member 1270 corresponding to each part of the gasket 1282 bypasses the gasket portions toward the second end 1232 of the valve 1220. In this position, the gasket 1282 seals the conduit. 1236 into the first end 1230 of valve 1220.

A user inserts a cannula or other medical device, as illustrated in Figure 52, between the two parts of the gasket 1282. When the user does this and advances the cannula, the gasket parts must separate to house the cannula. This causes the gasket portions to move upward toward the first end 1230 of the valve 1220 along the conical surface 1248 against the force of the bypass member 1270.

After the cannula is inserted, a fluid path is established from the cannula through main conduit 1236 and extension conduit 1238 through valve 1230. At this time, the volume of fluid within valve 1220 is an amount V1.

When the user removes the cannula, the volume of fluid in valve 1220 is reduced to an amount V2, causing the fluid to travel through extension conduit 1238. In particular, after the cannula is removed, the bypass elements 1270 push the gasket portions back toward the second end 1232 of the valve 1230 to the position illustrated in Figure 51. The gasket 1282 in this position reseals the main conduit 1236 at the first end 1230 of the valve 1220.

The valves described above having a gasket (182, 282, 382, ​​482, 582, 682, 782, 882, 982, 1082, 1168, 1282) may be adapted for use with a needle or other medical instrument in location of blunt cannula 37 shown. In this arrangement, the gasket can be solid (ie not pre-cut). In that case, preferably, the piston 142 (or similar element of the later embodiments described) is constructed of a strong material that cannot be easily pierced with the needle.

As described above, preferably, each valve is provided with a means for opening and closing a fluid path through the valve. In at least one embodiment, said means is a movable piston (for example, piston 42, Figure 12), while in other embodiments it is a pre-cut seal (for example, seal 182, Figure 19). Those skilled in the art will understand that various means can be provided in addition to those described. For example, a reclosable septum or the like can be used.

In addition, each valve includes a means for decreasing the volume of fluid therein when one of the medical instruments is disconnected, to produce positive fluid flow. According to the invention, said means is a piston (for example, piston 42, Figure 12, or piston 1042, Figure 38).

In some cases, the means for opening and closing the fluid path is the same as the means for decreasing the volume of fluid (eg, piston 42, Figure 12).

In the embodiments described above, the fluid space within the valve increases when a medical instrument is inserted in the compressed state and decreases when the medical instrument is removed in the uncompressed state. In some embodiments, the structure defining the fluid space is substantially relaxed and does not store a considerable amount of potential energy. The insertion of the medical instrument produces a change in the structure that allows it to store potential energy. Potential energy is released upon removal of the medical instrument and the frame returns to its substantially relaxed state.

The foregoing presents a description of what is considered the best way to carry out the present invention and the way and procedure of its use, in terms so complete, obvious, concise and precise, as to allow any expert in the field, to which is concerned, make and use this invention. However, this invention is susceptible to modifications and constructions, alternatives to those previously discussed, that are fully equivalent. The embodiments that have been described are intended to be illustrative and not exhaustive. Accordingly, it is not intended to limit this invention to the specific embodiments that have been described. Rather, it is intended to cover all modifications and alternative constructions that are within the scope of the invention as defined by the appended claims.