Medical valve with positive flow characteristics
A medical valve device for use in selectively establishing a fluid flow between first and second medical implements is disclosed. The valve has a body defining a passage from a first port to a second port. The valve defines a first fluid volume when both medical implements are connected thereto, and a second, smaller volume when one of the implements is disconnected, thereby causing a positive flow of fluid from the valve to the second medical implement when the first implement is disconnected.
This application is a continuation of U.S. patent application Ser. No. 09/879,364 filed Jun. 12, 2001, which is a continuation of U.S. patent application Ser. No. 09/078,941 filed May 14, 1998, which is a continuation-in-part of U.S. patent application Ser. No. 08/767,587 filed Dec. 16, 1996, all of which are incorporated by reference in their entirety.
FIELD OF THE INVENTIONThis invention relates generally to a medical valve, and in particular to a valve which, when connected between a first medical implement, such as a fluid source, and a second medical implement, such as a catheter, facilitates fluid flow therebetween, and when the first medical implement is disconnected therefrom, induces a positive flow of fluid through the valve in the direction of the second medical implement.
BACKGROUND OF THE INVENTIONThe manipulation of fluids for pareriteral administration in hospitals and medical settings routinely involves the use of connectors and valves for selectively facilitating the movement of fluids between two points. These valves are typically placed along a fluid flow line leading to a patient or other destination. For example, the tube may lead to a catheter having its tip positioned within a patient.
The valve is arranged so that a fluid source or other line may be connected thereto for providing a fluid flow from the source to the patient. When the fluid source or line is removed, the valve closes, sealing the line leading to the patient.
The element which is connected to the valve may comprise a tube or other medical implement such as a conduit, syringe, IV set (both peripheral and central lines), piggyback line, or similar component which is adapted for connection to the medical valve. Unfortunately, prior art valves suffer from a problem arising from the disconnection of these medical implements from the valve.
These valves define a space within them through which a fluid or other material may flow from the implement to the line on which the valve is mounted. When the medical implement is connected to the valve, it typically occupies a portion of this internal valve space, displacing the fluid (whether it be a liquid or air) within the valve.
A problem arises when the medical implement is disconnected from the valve.
When the implement is disconnected, it no longer occupies a portion of the space in the valve. The increase in space within the valve results in the fluid in the valve and line to which the valve is connected moving to fill the space. In effect, the removal of the implement creates a suction force which draws fluid into the valve.
In the medical setting, this movement of fluid is very undesirable. When the valve is connected to a fluid line leading to a patient, the movement of fluid through the line towards the space in the valve has the effect of drawing blood from the patient in the direction of the valve. A serious problem may result in that this blood may clot and clog the catheter near its tip, rendering it inoperable, and may even result in a clot of blood in the patient, which may prove fatal.
One attempt at overcoming this clogging problem has been to coat the inner surface of the catheter near its tip in order to prevent blood from sticking to its interior surfaces. This method has generally been unsuccessful in preventing clogging of the catheter.
The risk of blood clogging of the catheter is significantly heightened where the inner diameter of the catheter is small (e.g., 27 gauge). These small catheters have the advantage, however, that they reduce the trauma and discomfort caused by insertion into a patient. Because these catheters have a very small passage therethrough, even a small suction force may draw sufficient amount of fluid back through a catheter toward the valve to introduce blood into the catheter tip, which blood may clog the catheter's passage.
Overcoming the above-stated problem is made more difficult when considering other criteria which the valve must satisfy. For example, the valve should be arranged to so that it does not have any fluid stagnation points. If the fluid is allowed to stagnate in one or more areas of the valve, bacteria growth and other problems may occur.
In addition, the valve should have an internal flow path which is smooth. Sharp edges and corners may damage blood cells and cause hemolysis.
A valve which overcomes the above-stated problems is desired.
SUMMARY OF THE INVENTIONIn accordance with the present invention there is provided a valve which is advantageously utilized between two medical implements. The valve of this invention has several features, no single one of which is solely responsible for its desirable attributes.
Most importantly, the valve is arranged to provide a positive flow (i.e. the movement of fluid in the direction out of the valve as opposed to into the valve) when one of the medical implements is disconnected therefrom. At the same time, the valve is safe, reliable and capable of being used repeatedly, is simple to manufacture and use, and is suitable for high pressure applications.
The valve of the present invention is particularly suited to use in an application where one of the medical implements comprises a catheter having its tip positioned in a patient. In a preferred embodiment the second medical implement comprises a fluid source having a connector for connection to the valve.
The valve of the present invention has a fluid space which expands upon connection of the second medical implement and contracts upon disconnection of the medical implement. When the valve is connected to a catheter, disconnection of the second medical implement creates a positive flow from the valve to the catheter tip upon disconnection of the medical implement to avoid the potential problems of blood-clogging. The valve is particularly suited for applications with a catheter where it is desirable to avoid negative flow, but may be used for other applications as well.
Preferably, the valve includes a housing adapted for connection to a first medical implement and a second medical implement. The valve defines a fluid space therein, and includes means for increasing the fluid space when the second medical implement is connected, and for decreasing the fluid space when the second medical implement is disconnected. Means are also preferably provided for defining a fluid path through the valve when both medical implements are connected thereto, and for closing the fluid path when the second medical implement is disconnected.
Further objections, features and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures.
BRIEF DESCRIPTION OF THE DRAWINGS
As illustrated in
A second medical implement 26 is also connected to the valve 20. The second medical implement 26 comprises a connecting member 27 positioned at one end of a tube 29 which leads to the I.V. bag 24.
When so connected, the valve 20 permits fluid to flow from the I.V. bag 24 or other medical fluid source to the catheter 22 and into the patient. The valve 20 is also arranged so that when the second medical implement 26 is disconnected, fluid flow through the valve 20 is prevented. In addition, when the second medical implement 26 is disconnected, the valve 20 generates a “positive” fluid flow, i.e. flow of fluid in the direction of the patient, thereby preventing blood clogging of the catheter 22.
The first embodiment of the valve 20 of the present invention will now be described in more detail. As illustrated in
A branch 33 extends outwardly from the main portion of the housing 28. The branch 33 has a third end 34 defining a second or branch port 35. (See
As stated above, the second end 32 of the housing 28 is closed. Preferably, an end cap 40 is positioned in the second end 32 of the housing 28.
Excepting the branch portion 33, the housing 28 is generally cylindrical, as is the main passage 36. The first end 30 of the housing 28 is adapted to receive the cannula tip or nose 37 of an ANSI standard syringe, as illustrated in
Preferably, means are provided for locking the medical implement 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 on the connector 27 of the second medical implement 26. Other locking means known to those skilled in the art may be used instead of the threads 44.
As the main passage 36 is generally cylindrical, the end cap 40 is generally circular. The cap 40 engages the wall of the housing 28 at the second end 32 to close the passage. The end cap 40 preferably includes an outwardly extending tab 46 on its peripheral edge for engaging the inside surface of the housing 28 in the passage 36 for locking the end cap 40 in place.
For reasons described in more detail below, the diameter of the passage 36 at the first end 30 of the housing 28 is smaller than that at the second end 32. As illustrated, the passage 36 narrows (moving in a direction from the second towards the first end 32,30) near where the branch passage 38 extends from the main passage 36. In addition, the main passage 36 narrows again beyond the branch passage 38 near the first end 30. A circumferential ledge 48 is formed at that point where the main passage 36 narrows near the first end 32.
As illustrated in
The piston 42 has a head 54 at its first end 50. As illustrated, the head 54 is circular in outer shape, but has a slanted end surface 56. A neck 58 extends from the head 54 to a body 60. The neck 58 preferably has a reduced diameter as compared to the head 54. An “O”-ring 67 or similar seal is positioned around the reduced diameter neck 58 for engagement with the adjacent wall of the housing 28.
A first portion of the body 60 adjacent the neck 58 has a smaller diameter than a second portion of the body 60 positioned nearer the second end 52. The transition between these two sections creates a shoulder 62. The shoulder 62 is arranged to engage the ledge 48 in the passage 36 of the housing, preventing removal of the piston 42 from the first end 30 of the housing 28.
A pair of elongate cut-outs or depressions 64 are formed on opposite sides (i.e. 180 degrees from one another) in the second portion of the body 60 of the piston 42. The cut-outs 64 are trough shaped, and extend inwardly to a radial depth which is equal to the height of the shoulder 62 (so that the bottom of the cut-out is at the same level as the exterior of the housing at the first portion of the body).
A groove 66 is formed in the piston 42 near its second end 52. Preferably, a seal 68 (see
In the preferred embodiment, the piston 42 is hollow, having a recessed area therein. As illustrated, the recessed area comprises a bore or passage 72 extending inwardly from the second end 52 thereof. The bore 72 preferably has three diameters, the largest of which is near the second end 52, and tapering in diameter in two steps to two other diameters which are less than the first. The bore 72 is in communication with the passage 36 within the housing 28. The bore 72 preferably has the three diameters so that the wall of the housing 28 has a generally uniform thickness, which facilitates molding. Those of skill in the art will appreciate that the bore 72 may have more or less than three different diameters.
The assembled valve 20, wherein the piston 42 is positioned in the housing 28, is illustrated in
As illustrated in
Means are provided for biasing the piston 42 into its first position. Preferably, this means comprises a spring 70. The spring 70 is of the helical variety, and has its first end engaging the cap 40 and its second end engaging the piston 42, preferably inside the bore 72 at a ledge created at a change in diameters thereof.
The first chamber 39 is air filled. In order to accommodate the movement of the piston 42 towards the second end 32 of the housing 28, an air vent 75 is preferably provided through the end cap 40 (see also
The branch 33 extends generally perpendicularly from the remainder of the housing 28 between its first and second ends 30,32. The branch 33 is generally defined by a cylindrical wall 76 extending outwardly from the wall which defines the main portion of the housing 28. The wall 76 defines the branch passage 38.
As best illustrated in
The sleeve 78 is preferably connected to the wall 76. As illustrated in
The operation of the valve 20 will now be described in detail with reference to the figures. A user first connects the first medical implement 21 to the branch port 35 at the third end 34. When the first medical implement 21 is of the type disclosed above, an end of the tube 23 having a connector thereon is guided over the wall 76 between the outside of the wall and the inside of the sleeve 78. The connector is preferably threaded into engagement with the sleeve 78 to retain it in place.
The user then engages the second medical implement 26 to the first port 31 of the valve 20. Preferably, the medical implement has a blunt cannula tip 37 positioned within a connector 27 having a mating locking structure to the threads 44 or other locking means positioned on the housing 28.
The user advances the cannula tip 37 until it engages the end surface 56 of the piston 42. As the user further advances the implement, the piston 42 is pressed in the direction of the second end 32 of the housing 28, compressing the spring 70. Air within the passage 36 between the end cap 40 and the piston 42 and within the bore 72 of the piston is forced out through the vent 75 in the end cap 40.
Once the connector 27 of the implement 26 extends about the first end 30 of the housing 28, the user locks the connector 27 to the housing 28 to provide a secure connection. So engaged, the implement 26 is connected to the valve 20 in the position illustrated in
When the piston 42 is in this position, a fluid flow path is established from the second medical implement 26 (and through the tube 29 from the I.V. bag 24 in the arrangement illustrated in
Fluid is prevented from travelling beyond the second end 52 of the piston 42 into the first chamber 39 by the seal 68. As a result, the fluid flowing from the second medical implement 26 towards the valve 20 is forced to flow into the branch passage 38 and thereon into the tube 23 to the patient.
Most importantly, when the second medical implement 26 is disconnected from the valve 20, the valve 20 causes fluid to flow in the direction of the first medical implement through the branch passage 38. As the second medical implement 26 is disconnected, the spring 70 forces the piston 42 towards the first end 30 of the housing 28. As the piston 42 moves in this direction, the piston 42 slides through the narrowest portion of the passage 36 near the first end 30 of the housing 28. This movement causes the total volume or fluid space in the second chamber 41 between the piston 42 and the housing 28 to reduce. Once the shoulder 62 of the piston 42 hits the ledge 48, the piston stops moving, and the fluid volume within the valve 20 is at a minimum amount V2.
Because the fluid volume in the valve 20 decreases as the second medical implement 26 is disconnected, some fluid within the housing 28 must be displaced. This fluid moves along the troughs 64 and into the branch passage 38 in the direction of the patient, the total volume of fluid flowing in the “positive” direction VD (volume displaced) being equal to the difference between the maximum volume V1 less the minimum volume V2.
Once the piston 42 has reseated, the valve 20 prevents later flow of fluid from the first medical implement 21 back through the valve 20, since the piston closes off the passage 36 near the first end 30 of the housing 28. This prevents, for example, the blood pressure of the patient from forcing blood back to the valve 20 and out the first port 31.
Besides providing a positive flow, the valve 20 of the present invention has several other distinct advantages. First, it is often the case that medical valves have a fluid containing area within them in which the fluid may stagnate. Fluid stagnation is undesirable, as it may result in bacteria growth and similar problems.
The valve 20 of the present invention has its fluid containing area between the piston 42 and the wall of the housing 28 which defines the main passage 36. This generally annular space is flushed each time fluid is injected from the top 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 swab the cannula engaging surface before connecting the medical implement to the first port 31 of the valve. The swabbing may be with alcohol or a similar disinfectant which serves to prevent the entry of bacteria and the like into the fluid system through the valve 20.
It may now be understood that the valve 20 includes both means for reducing the fluid volume or space therein when the second medical implement 26 is disconnected (i.e., in this case, a reduction in the volume of chamber or cavity 41), and means for establishing a flow path through the valve 20 when the second medical implement 26 is connected and for closing this fluid path when the implement is disconnected. In this first embodiment, these means are provided by the single piston 42.
A second embodiment valve 120 in accordance with the present invention is illustrated in
As illustrated, the first end 130 defines a first port 131, and the opposing second end 132 is closed. A branch 133 extends to a third end 134 defining a branch port 135.
A main passage 136 extends from the first end 130 towards the second end 132 of the housing. The main passage 136 is defined by an inner surface of a wall of the housing 128. The main passage 136 is generally cylindrical in shape, in this embodiment having no ledges or steps.
A branch passage 138 extends perpendicularly from the main passage 138 between the first and second ends 130,132 of the housing 128. The branch passage 138 is preferably defined by a wall 176. The branch passage 138 is generally cylindrical in shape.
The piston 142 is movably positioned within the passage 136 of the housing 128. The piston 142 has a body 160 which 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 a slanted surface. In this embodiment, the piston 142 is similar to that of the first embodiment, except the piston is much shorter and does not have the differing diameter sections.
A groove 166 is formed in the body 160 between its first and second ends 150,152. As illustrated, a seal 168 is positioned in the groove 166 of the piston 142. This seal 168 divides the passage 136 in the housing 128 into a first chamber 139 and 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 for biasing the piston 142 towards the first end 130 of the housing 128.
A vent 175 is provided through the second end 132 of the housing 128. The vent 175 permits air to flow between the first chamber 139 and the outside of the housing 128.
A resilient, pre-slit seal 182 is provided near the first end 130 of the housing 128. The seal 182 is generally circular for fitting within the passage 136, and preferably includes a pre-formed slit 184 through which the tip of a medical implement may pass. The seal 182 is preferably constructed of a resilient material such that it naturally returns to the position (i.e. reseals) illustrated in
As with the first embodiment, a sleeve 178 is positioned about the wall 176 defining branch 133 of the housing 128. The sleeve 178 preferably has threads 179 on an inner surface thereof.
The operation of the valve 120 will now be described in detail with reference to
The user then engages the second medical implement 126 to the first port 131 of the valve 120. Preferably, the medical implement 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 further advances the implement, the piston 142 is pressed in the direction of the second end 132 of the housing 128, compressing the spring 170. Air within the first chamber 139 between the end cap 140 and the piston 142 and within the bore 172 of the piston is forced out through the vent 175 in the end cap 140.
When the piston 142 is in this position (as illustrated in
Fluid is prevented from travelling beyond the seal 168 into the first chamber 139. As a result, the fluid flowing from the second medical implement 126 into the second chamber 141 is forced to flow into the branch passage 138 and thereon into the tube to the patient.
Most importantly, when the second medical implement 126 is disconnected from the valve 120, the valve 120 causes fluid to flow in the direction of the first medical implement through the branch passage 138. As the second medical implement 126 is disconnected, the spring 170 forces the piston 142 towards the first end 130 of the housing 128. This movement causes the total volume or fluid space in the second chamber 141 between the piston 142 and the seal 182 at the first end 130 of the housing 128 to reduce. Once the piston 142 encounters the seal 182, the piston stops moving, and the fluid volume within the valve 120 is at a minimum amount V2.
Because the fluid volume in the valve 120 decreases as the second medical implement 126 is disconnected, some fluid within the housing 128 must be displaced. This fluid moves through the branch passage 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 less the minimum volume V2.
Once the implement tip 137 is removed, the valve 120 prevents later flow of fluid from the first medical implement back through the valve 120, since the slit 184 in the seal 182 reseals, closing off the passage 136 near the first end 130 of the housing 128.
Besides providing a positive flow, the valve 120 of the present invention has other advantages. Again, the valve 120 of this embodiment has its fluid containing area between the piston 142 and the housing 128 which defines the main passage 136. This space is flushed each time fluid is injected from the top end 150 of the piston 142.
Advantageously, a needle may be used to penetrate the seal 182 instead of the blunt tip cannula 137. In this arrangement, the seal 182 is preferably resilient so that it reseals, but need not be pre-slit.
As may now be understood, the means for selectively establishing the fluid flow path through the valve 120 and the means for causing a reduction in fluid space in the valve 120 when the second medical implement 126 is removed are separate in this embodiment. 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 biased piston 142.
A third embodiment valve 220 in accordance with the present invention is illustrated in
A main passage 236 extends from the first end 230 towards the second end 232 of the housing. The main passage 236 is defined by an inner surface of the housing 228. The main passage 236 is generally cylindrical in cross-section. An extension passage 238 of smaller diameter extends from the main passage 238 to the second end 232 of the valve 220, the passage 238 being defined partly by a wall 276. A sleeve 278 is positioned about the outside of the wall 276. The sleeve 278 preferably has threads 279 on an inner surface thereof.
The piston 242 is movably positioned within the passage 236 of the housing 228. The 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 the head 250. A number of passages 257 are provided through the head 250 of the piston 242.
A biasing member 270 is positioned between the piston 242 and a ledge 261 formed by the wall of the housing 238 at the intersection of two portions of the passage 236 having differing diameters. The biasing member 270 is preferably an annular, compressible and generally close-cell material, such as foam or the like.
A resilient, pre-slit seal 282 is provided near the first end 230 of the housing 228. The seal 282 is generally circular for fitting within the passage 236, and includes a pre-formed slit 284 through which the tip of a medical implement may pass. The seal 282 is preferably constructed of a resilient material such that when it returns to an unbiased position as illustrated in
The operation of the valve 220 will now be described in detail with reference to
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 further advances the implement, the piston 242 is pressed in the direction of the second end 232 of the housing 228, compressing the biasing member 270.
When the piston 242 is in this position (as illustrated in
Most importantly, when the second medical implement 226 is disconnected from the valve 220, the valve 220 causes fluid to flow in the direction of the first medical implement through the extension passage 238. As the second medical implement 226 is disconnected, the biasing member 270 forces the piston 242 towards the first end 230 of the housing 228. As the piston 242 moves in this direction, the biasing member 270 expands. This causes the total volume or fluid space in the housing 228 to reduce. Once the piston 242 encounters the seal 184, the piston stops moving, and the fluid volume within the valve 220 is at a minimum amount V2.
Because the fluid volume in the valve 220 decreases as the second medical implement 226 is disconnected, some fluid within the housing 228 must be displaced. This fluid moves through the branch passage 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 less the minimum volume V2.
Once the implement tip 237 is removed, the valve 220 prevents later flow of fluid from the first medical implement back through the valve 220, since the slit 284 in the seal 282 reseals, closing off the passage 236 near the first end 230 of the housing 228.
Besides providing a positive flow, the valve 220 of the present invention has other advantages. The valve 220 of the present invention has its fluid containing area between the seal 282 and the housing 228 which defines the main passage 236. This space is flushed each time fluid is injected from the top end 250 of the piston 242.
Another advantage is that the straight-through fluid flow path from the first to the second end 230,232 serves to eliminate stagnation areas.
A fourth embodiment valve 320 in accordance with the present invention is illustrated in
A piston 342 is movably positioned within the passage 336. The piston 342 has a generally circular head 354 with a flange or skirt 355 extending downwardly therefrom circumferentially around the outer edge of the head 354. At least one passage 357 is provided through the head 354 of the piston 342.
A biasing element 370 is positioned within the housing 328 between the piston 342 and the second end 332. As illustrated, the element 370 is a resilient member which is circular in shape having a generally “C” shaped cross-section with a closed interior side and an open exterior side.
The element 370 cooperates with an inner surface of the housing 328 to define a chamber 339 which is sealed from the passage 336. One or more vents 375 are provided through the housing wall from a point exterior thereof to the chamber 339.
In this embodiment, a sleeve 378 is surrounding a wall 376 is formed integrally with the remainder of the housing 328. The sleeve 378 has threads 379 on an inner surface thereof for use in mating engagement with threads on a medical connector.
A seal 382 is provided near the first end 330 of the housing 328. The seal 382 preferably selectively obscures or seals the passage 336 through the housing 328. The seal 382 is pre-cut to form a slit 384 which, when the seal 382 is in its unbiased position as illustrated in
Use of the valve 320 of this embodiment is as follows. A user first connects a first medical implement (see
The user then engages the second medical implement 326 with the first port 331 of the valve 320. Preferably, the medical implement has a blunt cannula tip 337. The user advances the cannula tip 337 through the slit 384 in the seal 382 until it engages the end surface 354 of the piston 342. As the user further advances the implement, the piston 342 is pressed in the direction of the second end 332 of the housing 328, compressing the biasing element 370 radially outward. Air within the chamber 339 is forced out through the vents 375 in the wall of the housing 328.
When the piston 342 is in this position, a fluid flow path is established from the second medical implement through the valve 320 to the first medical implement. Fluid flows through the tip 337 of the cannula through the passage 357 in the first end 354 of the piston 342 into the passage 336. The total volume of fluid within the valve 320 when the second medical implement is attached and fluid fills the passage 336 with the biasing element 370 compressed is an amount V1.
Most importantly, when the second medical implement 326 is disconnected from the valve 320, the valve 320 causes fluid to flow in the direction of the first medical implement through the second port 335. As the second medical implement 326 is disconnected, the biasing element 370 forces the piston 342 towards the first end 330 of the housing 328.
At the same time, the biasing element 370 expands inwardly, causing a reduction in the total volume or fluid space in the passage 336 between the piston 342 and second end 332 of the housing 328 to reduce. Once the piston 342 moves upwardly to a point at which it encounters the seal 382, the piston stops moving, and the fluid volume within the valve 320 is at a minimum amount V2.
Because the fluid volume in the valve 320 decreases as the second medical implement 326 is disconnected, some fluid within the housing 328 must be displaced. This fluid moves through the passage 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 less the minimum volume V2.
Once the implement tip 337 is removed, the valve 320 prevents later flow of fluid from the first medical implement therethrough, since the seal 382 closes off the passage 336 near the first end 330 of the housing 328.
Besides providing a positive flow, the valve 320 of the present invention has other advantages. Fluid stagnation is generally prevented since the fluid flows through the housing 328 in generally a straight path.
A fifth embodiment valve 420 in accordance with the present invention is illustrated in
Again, a portion of the passage 436 near the second end 432 is defined by a wall 476. A sleeve 478 extends about the wall 476, the sleeve 478 having a number of threads 479 on an internal surface thereof.
A seal 482 which has a pre-cut slit 484 is provided near the first end 430 of the housing 428 as in the last embodiment.
In this embodiment, the biasing element 470 comprises a donut-shaped, resilient element having a hollow interior 471. The interior 471 of the element 470 is in communication with the outside of the housing 428 via one or more passages or vents 475. A connection is provided between the element 470 and the passages 475, however, so that air flowing through the passages 475 to or from the element 470 does not flow into the passage 436.
In this embodiment, a pair of pistons 442, 443 move radially instead of linearly as in the previously described embodiments. Each piston 442,443 preferably includes a head 450 and a base 452 which are half-circle shaped. An upstanding wall 455 connects the head and base 450,452 of each piston 442,443 in a manner that the head and base thereof extends radially outwardly around a portion of the biasing element 470. Each piston 442,443 preferably has a tapered area 453 in the head 450 thereof, the area 453 in the pistons 442,443 cooperating to form a guide, as described in more detail below.
The pistons 442,443 are arranged to abut each other along their walls 455 in their normal position, as illustrated in
Use of the valve 420 of this embodiment is as follows. A user first connects a first medical implement (see
The user then engages the second medical implement 426 to the first port 431 of the valve 420. Preferably, the medical implement has a blunt cannula tip 437. The user advances the cannula tip 437 through the slit 484 in the seal 482 until it engages the head 450 of each piston 442,443. As the user further advances the implement, the pistons 442,443 are pressed radially outwardly from one another, compressing the biasing element 470. Air within the hollow interior 471 of the biasing element 470 is forced out through the vents 375 in the wall of the housing 328.
When in this position, a fluid flow path is established from the second medical implement 426 through the valve 420 to the first medical implement. Fluid flows through the tip 437 of the cannula into the passage 436. The total volume of fluid within the valve 420 when the second medical implement is attached and fluid fills the passage 436 with the biasing element 470 compressed is an amount V1.
Most importantly, when the second medical implement 426 is disconnected from the valve 420, the valve 420 causes fluid to flow in the direction of the first medical implement through the second port 435. As the second medical implement 426 is disconnected, the biasing element 470 forces the pistons 442,443 radially inwardly to that position illustrated in
At the same time, the biasing element 470 expands inwardly, causing a reduction in the total volume or fluid space in the passage 436 between the piston 442 and second end 432 of the housing 428. Once the pistons 442, 443 encounter one another, they stop moving and the volume within the valve 420 is at a minimum amount V2.
Because the fluid volume in the valve 420 decreases as the second medical implement 426 is disconnected, some fluid within the housing 428 must be displaced. This fluid moves through the passage 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 less the minimum volume V2.
Once the tip 437 of the implement 426 is removed, the valve 420 prevents later flow of fluid from the first medical implement therethrough, since the seal 482 closes off the passage 436 near the first end 430 of the housing 428.
Besides providing a positive flow, the valve 420 of the present invention has other advantages. Fluid stagnation is generally prevented since the fluid flows through the housing 428 in generally a straight path.
As will be appreciated by those skilled in the art, there may be provided more than two pistons cooperating together to perform the above-described function, such as three or four “pie”-shaped pistons.
A sixth embodiment valve 520 in accordance with the present invention is illustrated in
The valve 520 of this embodiment has a housing 528 which is generally cylindrical in shape. The housing 528 has a first end 530 defining a first port 531 and a second end 532 defining a second port 535. A passage 536 extends through the housing 528 from end to end.
A piston 542 is movably positioned within the passage 336. The piston 542 has a generally circular head 554 with a tubular section 555 extending centrally downwardly therefrom. A passage 557 is provided through the head 554 and tubular section 555 of the piston 542.
A spring 570 or other means for biasing is positioned within the housing 528 between the head 554 of the piston 542 and a ledge 561 formed in the housing 528 along the passage 536 between the first and second ends 530,532.
A seal 568 is provided in a groove in the circumferential surface of the head 554 of the piston 542. A similar seal 568 is provided around the tubular section 555 near its end opposite the head 554. The seals 568,569 seal off a portion of the passage 536, thereby defining a sealed, air-filled chamber 539.
One or more vents 575 are provided through the housing wall from a point exterior thereof to the chamber 539.
The sleeve 578 and wall portion 576 are integrally formed with the remainder of the housing, the wall 576 defining the passage 536 at the second end 532. The sleeve 578 has threads 579 thereon for use in mating engagement with threads on a medical connector.
A seal 582 is provided near the first end 530 of the housing 528. The seal 582 preferably obscures or seals the passage 536 through the housing 528. The seal 582 is pre-cut to form a slit 584 which, when the seal 582 is in its unbiased position as illustrated in
Use of the valve 520 of this embodiment is as follows. A user first connects a first medical implement (see
The user then engages the second medical implement 526 to the first port 531 of the valve 520. Preferably, the medical implement has a blunt cannula tip 537. The user advances the cannula tip 537 through the slit 584 in the seal 582 until it engages the head 554 of the piston 542. As the user further advances the implement, the piston 542 is pressed in the direction of the second end 532 of the housing 528, compressing the spring 570. Air within the chamber 539 is forced out through the vents 575 in the wall of the housing 528.
When the piston 542 is in this position (as illustrated in
Most importantly, when the second medical implement 526 is disconnected from the valve 520, the valve 520 causes fluid to flow in the direction of the first medical implement through the second port 535. As the second medical implement 526 is disconnected, the spring 570 forces the piston 542 towards the first end 530 of the housing 528. This piston 542 movement causes a reduction in the total volume or fluid space in the passage 536 between the piston 542 and second end 532 of the housing 528. Once the piston 542 moves upwardly to a point at which it encounters the seal 582, the piston stops moving, and the fluid volume within the valve 520 is at a minimum amount V2.
Because the fluid volume in the valve 520 decreases as the second medical implement 526 is disconnected, some fluid within the housing 528 must be displaced. This fluid moves through the passage 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 less the minimum volume V2.
Once the implement tip 537 is removed the valve 520 prevents later flow of fluid from the first medical implement therethrough, since the seal 582 closes off the passage 536 near the first end 530 of the housing 528.
Besides providing a positive flow, the valve 520 of the present invention has other advantages. Fluid stagnation is generally prevented since the fluid flows through the housing 528 in a continuous path.
A seventh embodiment valve 620 in accordance with the present invention is illustrated in
The housing 628 has a first end 630 defining a first port 631 and a second end 632 defining a second port 635. A passage 636 extends through the housing 628 from the first to the second ends 630,632.
Again, a portion of the passage 636 near the second end 632 is defined by a wall 676. A sleeve 678 extends about the wall 676, the sleeve 678 having a number of threads 679 on an internal surface thereof.
A seal 682 which has a pre-cut slit 684 is provided near the first end 630 of the housing 628 as in the last embodiment.
A piston 642 is positioned adjacent the seal 684. The piston 642 is preferably generally disc-shaped, having a circular outer shape. The piston 642 has a top or first end 650 which is slanted, and a second or bottom end 652 which is flat.
In this embodiment, a resilient element 670 comprises a generally cylindrical, resilient and non-porous material. In its resting state, the element 670 preferably has an outer diameter which is smaller than the diameter of the passage 636 in which it is positioned. The element 670 is positioned on a ledge 661 formed within the passage 636, and the bottom end 652 of the piston 642.
Grooves 685,686 are formed in the side wall of the housing 628 within the passage 636, including the portion defining the ledge 661. The grooves 685,686 are arranged to support the outside surfaces of the element 670 in a manner which permits fluid to flow between the element 670 and the housing 628, as described below.
Use of the valve 620 of this embodiment is as follows. A user first connects a first medical implement (see
The user then engages the second medical implement 626 to the first port 631 of the valve 620. Preferably, the medical implement has a blunt cannula tip 637. The user advances the cannula tip 637 through the slit 684 in the seal 682 until it engages the top 650 of the piston 642. As the user further advances the implement, the piston 642 is pressed downwardly compressing the element 670.
When in this position, a fluid flow path is established from the second medical implement 626 through the valve 620 to the first medical implement. Fluid flows through the tip 637 of the cannula through the passage 636. Fluid is allowed to flow past the element 670 through the grooves 685, 686. The total volume of fluid within the valve 620 when the second medical implement is attached and fluid fills the passage 636 and that space between the top 650 of the piston 642 and the bottom of the seal 682 when the piston 642 is depressed is an amount V1.
Most importantly, when the second medical implement 626 is disconnected from the valve 620, the valve 620 causes fluid to flow in the direction of the first medical implement through the second port 635. As the second medical implement 626 is disconnected, the element 670 expands, forcing the piston 642 upwardly to that position illustrated in
At the same time, a reduction in the total volume or fluid space in the passage 636 between the piston 642 and seal 682 occurs. Once the piston 642 moves upwardly to a point at which it encounters the seal 682, the piston stops moving, and the fluid volume within the valve 620 is at a minimum amount V2.
Because the fluid volume in the valve 620 decreases as the second medical implement 626 is disconnected, some fluid within the housing 628 must be displaced. This fluid moves through the passage 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 less the minimum volume V2.
Once the tip 637 of the implement 626 is removed, the valve 620 prevents later flow of fluid from the first medical implement therethrough, since the seal 682 closes off the passage 636 near the first end 630 of the housing 628.
Besides providing a positive flow, the valve 620 of the present invention has other advantages. Fluid stagnation is generally prevented since the fluid flows through the housing 628 in generally a straight path.
An eighth embodiment valve 720 in accordance with the present invention is illustrated in
The housing 728 has a first end 730 defining a first port 731 and a second end 732 defining a second port 735. A passage 736 extends through the housing 728 from the first to the second ends 730,732.
Again, a portion of the passage 736 near the second end 732 is defined by a wall 776. A sleeve 778 extends about the wall 776, the sleeve 778 having a number of threads 779 on an internal surface thereof.
A seal 782 which has a pre-cut slit 784 is provided near the first end 730 of the housing 728 as in the last embodiment.
In this embodiment, a resilient element 770 comprises a generally cylindrical, resilient and hollow member. In its resting state, the element 770 preferably has an outer diameter which is smaller than the diameter of the passage 736 in which it is positioned. The element 770 defines a interior space 771 which is sealed from the passage 736. The element 770 is positioned on a ledge 761 formed within the housing 728. A sloped cannula-engaging surface 781 is defined at the top of the element 770.
A vent 775 extends through the housing 628 from the interior space 771 within the element 770 to a point exterior of the housing 628. In the embodiment illustrated, the vent 775 terminates in the space between the wall 776 and the sleeve 778.
Use of the valve 720 of this embodiment is as follows. A user first connects a first medical implement (see
The user then engages the second medical implement 726 to the first port 731 of the valve 720. Preferably, the medical implement has a blunt cannula tip 737. The user advances the cannula tip 737 through the slit 784 in the seal 782 until it engages the sloped surface 781 at the top of the element 770. As the user further advances the implement, the element 770 is compressed downwardly and outwardly, reducing the volume of the space 771, but increasing the fluid space within the valve 720.
When in this position, a fluid flow path is established from the second medical implement 726 through the valve 720 to the first medical implement. Fluid flows through the tip 737 of the cannula along the sloped surface 781 (whereby the tip of the cannula is not obstructed) and through the passage 736. The total volume of fluid within the valve 720 when the second medical implement is attached and fluid fills the passage 736 and that space between the top of the element 770 and the bottom of the seal 782 is an amount V1.
Most importantly, when the second medical implement 726 is disconnected from the valve 720, the valve 720 causes fluid to flow in the direction of the first medical implement through the second port 735. As the second medical implement 726 is disconnected, the element 770 moves upwardly to that position illustrated in
At the same time, a reduction in the total volume or fluid space in the passage 736 between element 770 and the seal 782 occurs, until the fluid volume within the valve 720 is at a minimum amount V2.
Because the fluid volume in the valve 720 decreases as the second medical implement 726 is disconnected, some fluid within the housing 728 must be displaced. This fluid moves through the passage 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 less the minimum volume V2.
Once the tip 737 of the implement 726 is removed, the valve 720 prevents later flow of fluid from the first medical implement therethrough, since the seal 782 closes off the passage 736 near the first end 730 of the housing 728.
Besides providing a positive flow, the valve 720 of the present invention has other advantages. Fluid stagnation is generally prevented since the fluid flows through the housing 728 in generally a straight path.
A ninth embodiment valve 820 in accordance with the present invention is illustrated in
As illustrated, the housing 828 has a body having a first end 830 defining a first port 831 and an opposing second end 832. A main passage 836 extends from the first end 830 towards the second end 832 of the housing. The main passage 836 is defined by an inner surface of a wall of the housing 828. The main passage 836 is cylindrical in shape.
An extension passage 838 extends from the main passage 836 to the second end 832. The extension passage 838 is preferably defined by a wall 876 and is generally cylindrical in shape, although smaller in diameter than the main passage 836.
A resilient, seal 882 is provided near the first end 830 of the housing 828. The seal 882 has a generally circular or peripheral outer shape for fitting within the passage 836, and preferably includes a pre-formed slit 884 through which the tip of a medical implement may pass. The seal 882 is preferably constructed of a resilient material such that it naturally returns to the position as illustrated in
More importantly, however, the seal 882 is arranged so that when an implement is pressed through the slit 884, at least a portion of the seal 882 moves in the direction of the first end 830 of the housing 828 whereby the fluid space or volume inside the housing 828 increases. At the same time, the seal 882 is arranged so that when the implement is retracted, the seal 882 moves in the direction of the second end 832 of the housing 828, reducing the fluid space or volume therein.
A sleeve 878 is positioned about the wall 876 at the second end 832 of the housing 828. The sleeve 878 preferably has threads 879 on an inner surface thereof.
The operation of the valve 820 will now be described in detail with reference to
The user then engages the second medical implement 826 to the first port 831 of the valve 820. Preferably, the medical implement has a blunt cannula tip 837. The user advances the cannula tip 837 through the slit 884 in the seal 882. At this time, the seal 882 moves into the position as illustrated in
When in this position, a fluid flow path is established from the second medical implement 826 (such as through a tube from an I.V. bag) through the valve 820 to the first medical implement (and thus through the catheter to the patient). Fluid flows through the tip 837 of the cannula through the main passage 836 and extension passage 838. The total volume of fluid within the valve 820 when the second medical implement is attached is an amount V1.
Most importantly, when the second medical implement 826 is disconnected from the valve 820, the valve 820 causes fluid to flow in the direction of the first medical implement through the extension passage 838. As the second medical implement 826 is disconnected, the seal 882 moves back to its position as illustrated in
Because the fluid volume in the valve 820 decreases as the second medical implement 826 is disconnected, some fluid within the housing 828 must be displaced. This fluid moves through the branch passage 838 in the direction of the patient, the total volume of fluid flowing in the “positive” direction being equal to the difference between the maximinum volume V1 less the minimum volume V2.
Once the implement tip 837 is removed, the valve 820 prevents later flow of fluid from the first medical implement therethrough, since the slit 884 in the seal 882 reseals, closing off the passage 836 near the first end 830 of the housing 828.
Besides providing a positive flow, the valve 820 of the present invention has other advantages. The valve 820 of the present invention has its fluid containing area between the seal 882 and the housing 828 which defines the main passage 836. This space is flushed each time fluid is injected through the implement 826.
A tenth embodiment valve 920 in accordance with the present invention is illustrated in
An opening in the housing 928 at its first end leads to a chamber 936 or passage on one side of a diaphragm member 970 to a branch passage 938. The branch passage 938 extends from the chamber 936 in the direction opposite the second end 930 of the housing 928. The branch passage 938 is preferably defined by a wall 976. The branch passage 938 is generally cylindrical in shape.
A resilient, pre-slit seal 982 is provided near the first end 930 of the housing 928. The seal 982 is generally circular for fitting within the opening in the first end 930 of the housing 928. The seal 982 preferably includes a pre-formed slit 984 through which the tip of a medical implement may pass. The seal 982 is preferably constructed of a resilient material such that it naturally returns to the position illustrated in
The diaphragm 970 is positioned within a hollow space within the housing 928 between the first and second ends 920,932. The diaphragm 970 generally divides this space into the first chamber or cavity 936 and a second chamber 939. The diaphragm 970 is biased in an upward direction, i.e., in the direction of the first end 930 of the housing 929.
At least one vent 975 extends through the wall of the housing 928 at its second end 932 to the second chamber 939, permitting air to flow in and out of the chamber.
As with the first embodiment, a sleeve 978 is positioned about the branch 933 of the housing 928. The sleeve 978 preferably has threads 979 on an inner surface thereof.
The operation of the valve 920 will now be described in detail with reference to
The user then engages the second medical implement 926 to the first port 931 of the valve 920. Preferably, the medical implement has a blunt cannula tip 937. The user advances the cannula tip 937 through the slit 984 in the seal 982 and presses upon the diaphragm 970. At this time, the diaphragm 970 moves into the position as illustrated in
When in this position (as illustrated in
Most importantly, when the second medical implement 926 is disconnected from the valve 920, the valve 920 causes fluid to flow in the direction of the first medical implement through the branch passage 938. As the second medical implement 926 is disconnected, the diaphragm 970 moves upwardly back to its position as illustrated in
Because the fluid volume in the valve 920 decreases as the second medical implement 926 is disconnected, some fluid within the housing 928 must be displaced. This fluid moves through the branch passage 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 less the minimum volume V2.
Further, once the implement tip 937 is removed, the valve 920 prevents later flow of fluid from the first medical implement therethrough, since the slit 984 in the seal 982 reseals, closing off the passage 936 near the first end 930 of the housing 928.
Besides providing a positive flow, the valve 920 of the present invention has other advantages. The valve 920 of the present invention has its fluid containing area between the seal 982 and the housing 928 which defines the chamber 936. This space is flushed each time fluid is injected through the implement 926.
An eleventh embodiment valve 1020 in accordance with the present invention is illustrated in
Referring to
As illustrated in
The main passage 1036 has two diameters. A first small diameter portion of the passage 1036 extends from the first end 1030 to near the branch passage 1038. The diameter of the main passage 1036 then increases to a larger diameter section extending to the second end 1032. A ledge 1048 is formed at the intersection of these two portions of the main passage 1036.
A piston 1042 is slidably positioned within the main passage 1036. Referring to
The piston 1042 has a first body portion 1054 extending from the first end 1050 to a second body portion 1056. The outer diameter of the second body portion 1056 is larger than that of the first body portion 1054, with a shoulder 1062 defining the intersection of these two portions. This shoulder 1062 is arranged to engage the ledge 1048 in the housing 1028 in a manner described below.
A groove 1066 is formed in the piston 1042 near its second end 1052. Preferably, a seal 1068 (see
A “V”-shaped notch or cutout 1064 is defined in the first body portion 1056 of the piston 1042. This notch 1064 extends from the first end 1050 towards the second end 1052.
In the preferred embodiment, the piston 1042 is hollow, having a recessed area therein. As illustrated, this area comprises a bore 1072 extending into the piston 1042 from the second end 1052. As illustrated, the bore 1072 has two portions of differing diameters, thereby forming a ledge. When the piston 1042 is positioned in the housing 1028 (see
A seal 1082 is provided at the first end 1030 of the housing 1028 and closes the main passage 1036 at that end. The seal 1082 is preferably mounted to the housing 1028 by an end cap 1083.
The seal 1082 is preferably a resilient, pre-slit re-sealable element. The end cap 1083 has an end with a passage 1085 therethrough which is aligned with the main passage 1036. A cylindrical side wall 1087 extends from the end of the cap 1083 and is arranged to engage the outside of the housing 1028 at the first end 1030. As illustrated, the cap 1083 has a groove on the inside of the wall 1087 which accepts a rib 1089 on the exterior of the housing 1028 in a snap-fit arrangement.
As with the previous embodiments, the branch passage 1038 is defined by a wall structure 1076 which extends outwardly from the main portion of the housing 1028. A sleeve 1078 is spaced outwardly from this wall structure 1076. Threads 1079 are positioned on the inside of the sleeve 1078.
The assembled valve 1020, wherein the piston 1042 is positioned in the main passage 1036 through the housing 1028, is best illustrated in
As illustrated, the piston 1042 is moveable from a first or “uncompressed” position in which the shoulder 1062 engages the ledge 1048, to a second or “compressed” position in which the piston 1042 is moved towards the second end 1032 of the housing 1028.
Means are provided for biasing the piston 1042 into its first position. Preferably, this means comprises a spring 1070. As illustrated, the spring 1070 is a helical spring extending between the second end 1032 of the housing 1028 and the ledge formed in the piston 1042 by the changing diameter bore 1072.
The first chamber 1039 is air-filled. In order to accommodate the movement of the piston 1042 towards the second end 1032 of the housing 1028, an air vent 1075 is provided through the second end 1032.
The operation of the valve 1020 will now be described. A user first connects a first medical implement to the branch port 1035 in a manner as described above. The user then presses a blunt tip cannula or other medical implement 1037 (see
When the piston 1042 is in this position, a flow path is established from the implement 1037 through the second chamber 1041 between the outside of the piston 1042 and the wall of the housing 1028 to the branch passage 1038. Fluid freely flows through the tip of the cannula 1037 because the open “V”-shaped spaced is provided below the tip at the first end 1050 of the piston 1052. In this position, the valve 1020 has a maximum fluid capacity V1.
When the user removes the cannula 1037, the pre-slit seal in the seal 1082 reseals, preventing fluid from flowing from the main passage 1026 out the first end 1030 of the valve 1020. At the same time, when the cannula 1037 or other implement is withdrawn, the piston 1042 moves upwardly to the position illustrated in
Because the fluid volume in the valve 1020 decreases as the piston 1042 moves upwardly, some fluid in the main passage 1026 is displaced. This fluid volume V1-V2 moves along the piston 1042 to the branch passage 1038.
This valve 1020 also has the advantage that flushing occurs at each use and the seal 1082 may be swabbed at its top surface to sterilize it.
A twelfth embodiment valve 1120 in accordance with the present invention is illustrated in
The housing 1128 has a second end 1132 opposite the first end 1130, the second end 1132 being open to the chamber 1141.
A seal 1182 is positioned within the chamber 1141. As illustrated, the seal 1182 is a resilient inverted “U”-shaped member. In a first position, the seal 1182 is arranged to close the branch passage 1138 from the chamber 1141 (see
A piston 1142 is positioned within the main passage 1136 and rests upon a top portion of the seal 1182. As illustrated, the piston 1142 has a flat first end 1150 and a slanted second end 1152. The piston 1142 is generally cylindrical in cross-sectional shape.
The wall defining the main passage 1136 is cylindrical at the first end 1130 of the housing 1128. In a direction towards the second end 1132, the wall slants outward to define a sloped surface 1148.
A seal 1168 is preferably provided at the first end 1130 of the housing 1128. This seal 1168 is designed to seal against the outside of the piston 1142 to prevent fluid flow between the piston 1142 and housing 1128 at the first end 1130 of the valve 1120.
The operation of this valve 1120 is as follows. A user moves the tip of a cannula or other medical implement into engagement with the first end 1150 of the piston 1142. The user presses the piston 1142 towards the second end 1132 of the housing 1128 until the luer-lock connector or the like may be engaged with mating threads on the housing 1128, as illustrated in
As the piston 1142 moves inwardly, because its tapered second end 1152 engages the seal 1182 and the seal collapses, the piston 1142 tips over against the sloped surface 1148 in the enlarged section of the main passage 1136. At this time, the top end 1150 of the piston 1142 is no longer a flat surface with respect to the end of the cannula. Thus, fluid is allowed to freely flow from the tip of the cannula.
As the piston 1142 moves inwardly, the seal 1182 compresses to a position in which the branch passage 1138 is in communication with the chamber 1141.
A fluid path is established from the cannula along the top end 1150 of the piston 1142, along the main passage 1136 into the chamber 1141, and then into the branch passage 1138. At this time, the fluid volume within the valve 1120 is an amount V1.
When the user withdraws the cannula, the seal 1182 presses the piston 1142 upwardly. The upward movement of the piston 1142 is facilitated by its engagement with the sloping surface 1148. Eventually, the seal 1182 moves the piston 1142 to the position illustrated in
In addition, the seal 1168 seals around the piston 1142, preventing fluid from flowing from the inside of the valve 1120 through the main passage 1136 to the first end 1130, thus effecting a positive flow of fluid.
As the seal 1182 expands, the volume within the chamber 1141 is reduced, forcing fluid into the branch passage 1138.
A thirteenth embodiment valve 1220 in accordance with the present invention is illustrated in
The valve 1220 has a housing 1228 having a first end 1230 and second end 1232. A main passage 1236 extends from the first end 1230 to a smaller extension passage 1238 which extends to the second end 1232. The extension passage 1238 is primarily defined by a wall 1276 which is positioned within a sleeve 1278.
A seal 1282 is positioned in a conical portion 1248 of the main passage 1236 at the first end 1230. The seal 1282 preferably comprises first and second seal portions which, when put together, form an inverted frusto-conical shaped member. Each seal portion is generally semi-circular in cross-sectional shape (in a horizontal plane) and defines a flat inner surface 1283 for engagement with the other seal portion. The outside surface 1185 of each seal portion is curved, and tapers inwardly from top to bottom.
Each seal portion is biased in a direction towards the second end 1232 of the valve 1220. A resilient biasing member 1270 has a first end connected to a bottom surface of each seal portion and a second end secured to the housing 1228 some distance along the main passage 1236. As illustrated, each biasing member 1270 comprises a accordion-like elastic member.
Operation of the valve 1220 is as follows. When not in use, the biasing member 1270 corresponding to each portion of the seal 1282 biases the seal portions towards the second end 1232 of the valve 1220. In this position, the seal 1282 seals the main passage 1236 at the first end 1230 of the valve 1220.
A user inserts a cannula or other medical apparatus, as illustrated in
Once the cannula is inserted, a fluid path is established therefrom through the main passage 1236 and extension passage 1238 through the valve 1230. At this time the fluid volume within the valve 1220 is an amount V1.
When the user withdraws the cannula, the fluid volume in the valve 1220 reduces to an amount V2, causing fluid to be displaced through the extension passage 1238. In particular, once the cannula is removed, the biasing members 1270 draw the seal portions back towards the second end 1232 of the valve 1230 to the position illustrated in
The valves described above having a seal (182, 282, 382, 482, 582, 682, 782, 882, 982, 1082, 1168, 1282) may be adapted for use with a needle or other implement instead of the blunt cannula 37 illustrated. In this arrangement, the seal may be solid (i.e., not pre-slit). In that case, the piston 142 (or similar member in the later described embodiments) is preferably constructed of a durable material which is not ready penetrated by the needle.
As described above, each valve is preferably provided with a means for opening and closing a fluid path through the valve. In at least one embodiment, this means is a moveable piston (ex. piston 42,
In addition, each valve includes a means for decreasing the fluid volume therein when one of the medical implements is disconnected, for producing a positive fluid flow. In some embodiments this means is a piston (ex. piston 42,
In some instances, the means for opening and closing the fluid path is the same as the means for decreasing the fluid volume (ex. piston 42,
In the embodiments described above, the fluid space inside the valve increases upon insertion of a medical implement in the compressed state and decreases upon withdrawal of the medical implement in the decompressed state. In some embodiments, the structure defining the fluid space is substantially relaxed and does not store substantial amount of potential energy. Insertion of the medical implement causes a change in the structure that allows it to store potential energy. The potential energy is released upon withdrawal of the medical implement and the structure returns to a substantially relaxed condition.
The above presents a description of the best mode contemplated of carrying out the present invention, and of the manner and process of using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use this invention. This invention is, however, susceptible to modifications and alternate constructions from that discussed above which are fully equivalent. The embodiments described are meant to be illustrative and not exhaustive. Consequently, it is not the intention to limit this invention to the particular embodiments disclosed. On the contrary, the intention is to cover all modifications and alternate constructions coming within the spirit and scope of the invention as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the invention.
Claims
1. A medical valve for controlling the flow of fluid between a first medical implement and a second medical implement, said valve comprising a housing having a passage configured for communication with a second medical implement and an opening adapted to receive the first medical implement, a rigid piston positioned within the housing and movable between a first position in which fluid flow is impeded through the housing and a second position in which fluid flow through the housing is facilitated, the passage including a fluid space which automatically and reversibly increases in size when the first medical implement is connected to the valve and which contracts in size when the first medical implement is disconnected to generate a positive flow of fluid in the direction of the second medical implement, the piston further including two o-rings.
2. The medical valve of claim 1, wherein the piston additionally comprises a neck and a head, the neck having a reduced cross-sectional width as compared to the head.
3. The medical valve of claim 1, wherein the passage comprises a first end and a second end, the first end having a smaller diameter than the second end.
4. The medical valve of claim 1, wherein a ledge is positioned within the passage.
5. The medical valve of claim 4, wherein the piston comprises a shoulder which engages the ledge when the sealing element is in the first position.
6. The medical valve of claim 1, wherein the housing comprises at least one screw thread for detachably securing the first medical implement to the valve.
7. The medical valve of claim 6, wherein the at least one screw thread is located on an outside surface of the housing.
Type: Application
Filed: May 3, 2006
Publication Date: Sep 21, 2006
Inventors: Thomas Fangrow (Mission Viejo, CA), Jonathan Schmidt (Newport Beach, CA), Daniel Wait (Santa Ana, CA), Dannis Bui (Orange, CA)
Application Number: 11/417,853
International Classification: A61M 25/00 (20060101);