U.S. patent application number 09/879364 was filed with the patent office on 2001-12-06 for medical valve with positive flow characteristics.
Invention is credited to Bui, Dennis M., Fangrow, Thomas F. JR., Schmidt, Jonathan T., Wait, Daniel J..
Application Number | 20010049508 09/879364 |
Document ID | / |
Family ID | 22147146 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010049508 |
Kind Code |
A1 |
Fangrow, Thomas F. JR. ; et
al. |
December 6, 2001 |
Medical valve with positive flow characteristics
Abstract
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.
Inventors: |
Fangrow, Thomas F. JR.;
(Mission Viejo, CA) ; Schmidt, Jonathan T.;
(Newport Beach, CA) ; Wait, Daniel J.; (Santa Ana,
CA) ; Bui, Dennis M.; (Orange, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
620 NEWPORT CENTER DRIVE
SIXTEENTH FLOOR
NEWPORT BEACH
CA
92660
US
|
Family ID: |
22147146 |
Appl. No.: |
09/879364 |
Filed: |
June 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09879364 |
Jun 12, 2001 |
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09078941 |
May 14, 1998 |
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6245048 |
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09078941 |
May 14, 1998 |
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08767587 |
Dec 16, 1996 |
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Current U.S.
Class: |
604/256 ;
604/167.01; 604/284 |
Current CPC
Class: |
A61M 2039/263 20130101;
A61M 39/045 20130101; A61M 39/26 20130101; A61M 2039/266
20130101 |
Class at
Publication: |
604/256 ;
604/284; 604/167.01 |
International
Class: |
A61M 005/00; A61M
005/14 |
Claims
What is claimed is:
1. A method of effecting a positive flow of fluid through a first
medical implement automatically upon disconnection of a second
medical implement from a valve having a housing with an element
therein for controlling the flow of fluid through said housing,
said valve defining a fluid volume within said housing and said
valve in communication with said first medical implement,
comprising the steps of: disconnecting said second medical
implement from said valve; moving at least a portion of said
element to a position in which fluid flow through said valve to
said second medical implement is prevented; decreasing the fluid
volume within said valve; and forcing fluid from said housing
towards said first medical implement.
2. The method in accordance with claim 1, wherein said element
comprises a resilient seal positioned in said housing, said seal
having a passage therethrough and wherein said moving step
comprises allowing said seal to expand to a position in which said
passage therethrough is occluded.
3. The method in accordance with claim 1, wherein a piston member
is movably positioned within said housing of said valve and said
decreasing step comprises moving said piston member.
4. The method in accordance with claim 3, wherein said step of
disconnecting comprises removing said first medical implement from
a first end of said valve, and wherein said decreasing step
comprises moving said piston towards said first end of said
valve.
5. The method in accordance with claim 1, wherein a member is
positioned within said housing, said member arranged to increase
said fluid volume in said housing when said first medical implement
is connected to said valve, and wherein said step of decreasing the
volume within said housing comprises the step of allowing said
member to expand in volume.
6. The method in accordance with claim 1, wherein a member is
positioned within said housing and cooperates with said housing to
form a chamber, and said step of decreasing the volume within said
housing comprises the step of enlarging the volume of said
chamber.
7. The method in accordance with claim 1, wherein said element
comprises a seal, and further including a piston movably positioned
within said valve, said piston cooperating with said seal and
housing to define said fluid volume, and wherein said step of
decreasing the fluid volume comprises the step of moving said
piston towards said seal.
Description
RELATED APPLICATIONS
[0001] This application 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.
FIELD OF THE INVENTION
[0002] This 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 INVENTION
[0003] The manipulation of fluids for parenteral 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] In addition, the valve should have an internal flow path
which is smooth. Sharp edges and corners may damage blood cells and
cause hemolysis.
[0013] A valve which overcomes the above-stated problems is
desired.
SUMMARY OF THE INVENTION
[0014] In 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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
[0020] FIG. 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 which is inserted
into a patient;
[0021] FIG. 2 is a plan view of a housing of the valve in
accordance with a first embodiment of the present invention;
[0022] FIG. 3 is a top view of the housing illustrated in FIG.
2;
[0023] FIG. 4 is a side view of the housing illustrated in FIG.
2;
[0024] FIG. 5 is an end view of the housing illustrated in FIG.
2;
[0025] FIG. 6 is a cross-sectional side view of the housing
illustrated in FIG. 2 and taken along line 6-6 therein;
[0026] FIG. 7 is a perspective view of the valve in accordance with
the first embodiment of the present invention;
[0027] FIG. 8 is a top view of the valve illustrated in FIG. 7;
[0028] FIG. 9 is a first end view of the valve illustrated in FIG.
7;
[0029] FIG. 10 is an opposite end view of the valve illustrated in
FIG. 9;
[0030] FIG. 11 is a cross-sectional view of the valve illustrated
in FIG. 7, taken along line 11-11 therein, illustrating a piston of
the valve in an uncompressed position;
[0031] FIG. 12 is a cross-sectional view of the valve as
illustrated in FIG. 11, with the piston in a second or compressed
position utilizing the tip of a medical implement;
[0032] FIG. 13 is a perspective view of the piston of the valve of
the first embodiment of the present invention;
[0033] FIG. 14 is a top view of the piston illustrated in FIG.
13;
[0034] FIG. 15 is a side view of the piston illustrated in FIG.
13;
[0035] FIG. 16 is a cross-sectional side view of the piston
illustrated in FIG. 14, taken along line 16-16 therein;
[0036] FIG. 17 is an end view of the piston illustrated in FIG.
14;
[0037] FIG. 18 is a cross-sectional side view of a valve in
accordance with a second embodiment of the present invention,
illustrating a piston of the valve in a first position;
[0038] FIG. 19 is a cross-sectional side view of the valve as
illustrated in FIG. 18, with the piston in a second position;
[0039] FIG. 20 is a cross-sectional side view of a valve in
accordance with a third embodiment of the present invention,
illustrating a piston of the valve in a first position;
[0040] FIG. 21 is a cross-sectional side view of the valve as
illustrated in FIG. 20, with the piston in a second position;
[0041] FIG. 22 is a cross-sectional side view of a valve in
accordance with a fourth embodiment of the present invention,
illustrating a piston of the valve in a first position;
[0042] FIG. 23 is a cross-sectional side view of the valve as
illustrated in FIG. 22, with the piston in a second position;
[0043] FIG. 24 is a cross-sectional side view of a valve in
accordance with a fifth embodiment of the present invention,
illustrating a pair of pistons of the valve in a first
position;
[0044] FIG. 25 is a cross-sectional side view of the valve as
illustrated in FIG. 24, with the pistons in a second position;
[0045] FIG. 26 is a cross-sectional side view of a valve in
accordance with a sixth embodiment of the present invention,
illustrating a piston of the valve in a first position;
[0046] FIG. 27 is a cross-sectional side view of the valve as
illustrated in FIG. 26, with the piston in a second position;
[0047] FIG. 28 is a cross-sectional side view of a valve in
accordance with a seventh embodiment of the present invention,
illustrating a piston of the valve in a first position;
[0048] FIG. 29 is a cross-sectional side view of the valve as
illustrated in FIG. 28, with the piston in a second position;
[0049] FIG. 30 is a cross-sectional side view of a valve in
accordance with a eighth embodiment of the present invention,
illustrating a resilient element of the valve in a first
position;
[0050] FIG. 31 is a cross-sectional side view of the valve as
illustrated in FIG. 30, with the element in a second position;
[0051] FIG. 32 is a cross-sectional side view of a valve in
accordance with a ninth embodiment of the present invention,
illustrating a seal of the valve in a first position;
[0052] FIG. 33 is a cross-sectional side view of the valve as
illustrated in FIG. 32, with the seal in a second position;
[0053] FIG. 34 is a cross-sectional side view of a valve in
accordance with a tenth embodiment of the present invention,
illustrating a diaphragm of the valve in a first position;
[0054] FIG. 35 is a cross-sectional side view of the valve as
illustrated in FIG. 34, with the diaphragm in a second
position;
[0055] FIG. 36 is a perspective view of a valve in accordance with
an eleventh embodiment of the present invention;
[0056] FIG. 37 is a top view of the valve illustrated in FIG.
36;
[0057] FIG. 38 is a cross-sectional view of the valve illustrated
in FIG. 37 taken along line 38-38 therein and illustrating a piston
of the valve in a first position;
[0058] FIG. 39 is a cross-sectional view of the valve illustrated
in FIG. 37 taken along line 39-39 therein and illustrating the
piston of the valve in a second position;
[0059] FIG. 40 is a perspective view of a housing of the valve
illustrated in FIG. 36;
[0060] FIG. 41 is a top view of the housing illustrated in FIG.
40;
[0061] FIG. 42 is a cross-sectional view of the housing illustrated
in FIG. 41 taken along line 42-42 therein;
[0062] FIG. 43 is a cross-sectional view of the housing illustrated
in FIG. 41 taken along line 43-43 therein;
[0063] FIG. 44 is a perspective view of the piston of the
valve;
[0064] FIG. 45 is a top view of the piston illustrated in FIG.
44;
[0065] FIG. 46 is a side view of the piston illustrated in FIG.
44;
[0066] FIG. 47 is a second side view of the piston illustrated in
FIG. 44;
[0067] FIG. 48 is a cross-sectional view of the piston illustrated
in FIG. 46 taken along line 48-48 therein;
[0068] FIG. 49 is a cross-sectional view of a valve in accordance
with a twelfth embodiment of the present invention, illustrated
with a seal thereof in a first position;
[0069] FIG. 50 is a cross-sectional view of the valve illustrated
in FIG. 49 with the seal in a second position;
[0070] FIG. 51 is a cross-sectional view of a valve in accordance
with a thirteenth embodiment of the present invention, illustrated
with a seal thereof in a first position; and
[0071] FIG. 52 is a cross-sectional view of the valve illustrated
in FIG. 51 with the seal in a second position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0072] FIGS. 1-17 illustrate a valve 20 in accordance with a first
embodiment of the present invention. FIG. 1 illustrates a
particular use of the valve 20 to which the valve 20 is well
suited. Of course, the valve 20 may be used in a variety of other
manners.
[0073] As illustrated in FIG. 1, the valve 20 may advantageously be
used to selectively control the flow of fluid to a catheter 22 from
a fluid source 24 such as an I.V. bag. In this arrangement, a first
medical implement 21 is connected to the valve 20. The first
medical implement 21 comprises a tube 23 leading to a catheter 22.
One end of the tube 23 is connected to the valve 20, and the
catheter 22 has its tip positioned in a patient.
[0074] 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.
[0075] 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.
[0076] The first embodiment of the valve 20 of the present
invention will now be described in more detail. As illustrated in
FIGS. 2-6, the valve 20 includes a housing 28. The housing 28 is
generally "T"-shaped, having a main portion with a first end 30
defining a first port 31 and having an opposing closed second end
32.
[0077] 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 FIG. 7.) Referring to FIG. 6, a main passage
36 is defined by an inner surface of a wall of the housing 28, and
extends from the first end 30 to the second end 32 thereof. In
addition, a branch passage 38 extends from the main passage 36
through the branch port to the third end 34.
[0078] 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.
[0079] 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 FIG. 12. As such, the
passage 36 at the first end has a diameter larger than the nose of
this type of syringe. It is, however, contemplated that the
diameter of the passage 36 can be of any size to accommodate the
attachment of other connector devices thereto.
[0080] 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.
[0081] 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.
[0082] 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.
[0083] As illustrated in FIGS. 11 and 12, a piston 42 is slidably
positioned within the main passage 36. Referring to FIGS. 13-17,
the piston 42 is generally cylindrical, having a maximum outer
diameter which is just slightly smaller than the maximum diameter
of the passage 36. The piston 42 has a first end 50 and a second
end 52 and a length from end to end which is less than the distance
from the first end 30 to the second end 32 of the housing 28.
[0084] 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.
[0085] 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.
[0086] 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).
[0087] A groove 66 is formed in the piston 42 near its second end
52. Preferably, a seal 68 (see FIGS. 11 and 12) is positioned in
this groove 66. The seal 68 is preferably an "O"-ring comprised of
rubber or a similar resilient, sealing material.
[0088] 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.
[0089] The assembled valve 20, wherein the piston 42 is positioned
in the housing 28, is illustrated in FIGS. 7-12. As illustrated,
the seal 68 divides the main passage 36 into a first cavity or
chamber 39 and a second cavity or chamber 41. The first chamber 39
comprises the space between the end cap 40 and the second end 52 of
the piston 42, as well as the space defined within the piston 42 by
the bore 72. The second chamber 41 is that space from the seal 68
to the first end 30 of the housing 28 not occupied by the piston
42.
[0090] As illustrated in FIGS. 11 and 12, the piston 42 is moveable
from a first or "uncompressed" position in which the shoulder 62
engages the ledge 48 and the first end 50 of the piston 42 extends
outwardly of the first end 30 of the housing 28, to a second or
"compressed" position in which the piston 42 is moved in the
direction of the second end 32 of the housing 28.
[0091] 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.
[0092] 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 FIG. 5). The air vent 75 is a passage through the
cap 40 from the chamber 39 to the exterior of the valve 20 which
allows air to flow into and out of the chamber 39.
[0093] 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.
[0094] As best illustrated in FIGS. 7 and 11-12, a threaded sleeve
78 preferably extends about the branch of the housing 28. The
sleeve 78 has an inner diameter which is larger than the outer
diameter of the wall 76. In fact, the inner diameter is large
enough to define a space between the wall 76 and sleeve 78 in which
the end of a tube or other member may be inserted.
[0095] The sleeve 78 is preferably connected to the wall 76. As
illustrated in FIG. 7 and 9-12, the outer surface of the sleeve 78
has a number of recesses 80 therein for aiding in gripping by a
user.
[0096] 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.
[0097] 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.
[0098] 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.
[0099] 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 FIG. 12.
[0100] 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 FIG.
1) through the valve 20 to the first medical implement 21 (and thus
through the catheter 22 to the patient). Fluid flows through the
tip 37 of the cannula along the first end 54 of the piston 42 into
the second chamber 41, i.e. that space between the piston 42 and
the inner surface of the housing 28, including the space within the
cut-outs 64. The total volume of fluid within the valve 20 when the
second medical implement is attached and fluid fills the second
chamber 41 is an amount V1.
[0101] 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.
[0102] 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.
[0103] 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.
[0104] 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.
[0105] 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.
[0106] 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.
[0107] 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.
[0108] 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.
[0109] A second embodiment valve 120 in accordance with the present
invention is illustrated in FIGS. 18 and 19. As illustrated, this
valve 120 includes a housing 128 which is similar to the housing of
the valve 20 described above, except that this housing is shorter
in length between a first end 128 and a second end 130, as a piston
142 of the valve 120 is also shorter.
[0110] 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.
[0111] 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.
[0112] 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.
[0113] 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.
[0114] 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.
[0115] 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.
[0116] 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.
[0117] 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 FIG. 18, where the slit 184 is closed and
fluid is prevented from passing therethrough.
[0118] 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.
[0119] The operation of the valve 120 will now be described in
detail with reference to FIGS. 18 and 19. A user first connects the
first medical implement (not shown, but which may be similar to
that illustrated in FIG. 1) to the branch port 135 at the third end
134. When the first medical implement is of the type disclosed
above, the free end of the tube is guided over the wall 176 between
the outside of the wall and the inside of the sleeve 178.
[0120] 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.
[0121] 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.
[0122] When the piston 142 is in this position (as illustrated in
FIG. 19), a fluid flow path is established from the second medical
implement 126 (such as through a tube from an I.V. bag) through the
valve 120 to the first medical implement (and thus through the
catheter to the patient). Fluid flows through the tip 137 of the
cannula along the first end 154 of the piston 142 into the second
chamber 141. The total volume of fluid within the valve 120 when
the second medical implement is engaged and fluid fills the second
chamber 141 is an amount V1.
[0123] 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.
[0124] 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.
[0125] 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.
[0126] 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.
[0127] 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.
[0128] 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.
[0129] 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.
[0130] A third embodiment valve 220 in accordance with the present
invention is illustrated in FIGS. 20 and 21. As illustrated, this
valve 220 includes a housing 228. As illustrated, the housing 228
is a generally cylindrical body having a first end 230 defining a
first port 231 and having an opposing second end 232.
[0131] 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.
[0132] 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.
[0133] 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.
[0134] 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 preformed 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 FIG. 20, the slit
284 is closed and fluid is prevented from passing therethrough.
[0135] The operation of the valve 220 will now be described in
detail with reference to FIGS. 20 and 21. A user first connects the
first medical implement (not shown, but which may be similar to
that illustrated in FIG. 1) to the second end 232. When the first
medical implement is of the type disclosed above, the free end of
the tube is guided over the wall 276 between the outside of the
wall and the inside of the sleeve 278. The user then engages the
second medical implement 226 with the first port 231 of the valve
220. Preferably, the medical implement has a blunt cannula tip
237.
[0136] 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.
[0137] When the piston 242 is in this position (as illustrated in
FIG. 21), a fluid flow path is established from the second medical
implement 226 (such as through a tube from an I.V. bag) through the
valve 220 to the first medical implement (and thus through the
catheter to the patient). Fluid flows through the tip 237 of the
cannula through the passages 257 into the passage 236. In addition,
fluid fills the space 241 between the seal 282 and the piston 242.
The total volume of fluid within the valve 220 when the second
medical implement is engaged is an amount V1.
[0138] 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.
[0139] 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.
[0140] 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.
[0141] 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.
[0142] Another advantage is that the straight-through fluid flow
path from the first to the second end 230, 232 serves to eliminate
stagnation areas.
[0143] A fourth embodiment valve 320 in accordance with the present
invention is illustrated in FIGS. 22 and 23. This valve 320
includes a housing 328 which is generally cylindrical in shape,
like the housing 228 of the third embodiment. The housing 328 has a
first end 330 defining a first port 331 and a second end 332
defining a second port 335. A passage 336 extends through the
housing 328 from end to end.
[0144] 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.
[0145] 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.
[0146] 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.
[0147] 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.
[0148] 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 FIG. 22, is closed.
[0149] Use of the valve 320 of this embodiment is as follows. A
user first connects a first medical implement (see FIG. 1) to the
port 335 at the second end 334 of the housing 328. When the first
medical implement is of the type disclosed above, a free end of the
tube is guided over the wall 376 between the outside of the wall
and the inside of the sleeve 378.
[0150] 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.
[0151] 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.
[0152] 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.
[0153] 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.
[0154] 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.
[0155] 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.
[0156] 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.
[0157] A fifth embodiment valve 420 in accordance with the present
invention is illustrated in FIGS. 24 and 25. This valve 420
includes a housing 428 which is generally identical to the housing
328 of the valve 320 described above and illustrated in FIGS. 22
and 23, having a first end 430 defining a first port 431 and a
second end 432 defining a second port 435. A passage 436 extends
through the housing 428 from the first to the second ends 430,
432.
[0158] 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.
[0159] 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.
[0160] 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.
[0161] 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.
[0162] The pistons 442, 443 are arranged to abut each other along
their walls 455 in their normal position, as illustrated in FIG.
24. The pistons 442, 443 are arranged to move radially outward when
a medical implement is pressed between them, as illustrated in FIG.
25.
[0163] Use of the valve 420 of this embodiment is as follows. A
user first connects a first medical implement (see FIG. 1) to the
port 435 at the second end 434 of the housing 428. When the first
medical implement is of the type disclosed above, a free end of the
tube is guided over the wall 476 between the outside of the wall
and the inside of the sleeve 478.
[0164] 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.
[0165] 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.
[0166] 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 FIG. 24.
[0167] 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.
[0168] 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.
[0169] 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.
[0170] 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.
[0171] 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.
[0172] A sixth embodiment valve 520 in accordance with the present
invention is illustrated in FIGS. 26 and 27. This embodiment valve
520 is similar to the first embodiment valve 20, except that the
valve 520 is arranged to have a direct flow-through arrangement
similar to that illustrated in the last embodiment.
[0173] 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.
[0174] 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.
[0175] 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.
[0176] 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.
[0177] One or more vents 575 are provided through the housing wall
from a point exterior thereof to the chamber 539.
[0178] 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.
[0179] 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 FIG. 26, is closed.
[0180] Use of the valve 520 of this embodiment is as follows. A
user first connects a first medical implement (see FIG. 1) to the
port 535 at the second end 534 of the housing 528. When the first
medical implement is of the type disclosed above, a free end of the
tube is guided over the wall 576 between the outside of the wall
and the inside of the sleeve 578.
[0181] 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.
[0182] When the piston 542 is in this position (as illustrated in
FIG. 27), a fluid flow path is established from the second medical
implement through the valve 520 to the first medical implement.
Fluid flows through the tip 537 of the cannula through the passage
557 in the piston 542 into the passage 536. Fluid also fills the
space between the seal 582 and the head 554 of the piston 542. The
total volume of fluid within the valve 520 when the second medical
implement is attached and fluid fills these areas when the spring
570 is compressed is an amount V1.
[0183] 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.
[0184] 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.
[0185] 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.
[0186] 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.
[0187] A seventh embodiment valve 620 in accordance with the
present invention is illustrated in FIGS. 28 and 29. This valve 620
includes a housing 628 which is similar to those described above
with respect to valves 320, 420 and 520.
[0188] 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.
[0189] 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.
[0190] 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.
[0191] 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.
[0192] 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.
[0193] 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.
[0194] Use of the valve 620 of this embodiment is as follows. A
user first connects a first medical implement (see FIG. 1) to the
port 635 at the second end 634 of the housing 628. When the first
medical implement is of the type disclosed above, a free end of the
tube is guided over the wall 676 between the outside of the wall
and the inside of the sleeve 678.
[0195] 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.
[0196] 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.
[0197] 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 FIG. 28.
[0198] 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.
[0199] 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.
[0200] 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.
[0201] 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.
[0202] An eighth embodiment valve 720 in accordance with the
present invention is illustrated in FIGS. 30 and 31. This valve 720
includes a housing 728 which is similar to those described above
with respect to valves 220, 320 etc.
[0203] 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.
[0204] 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.
[0205] 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.
[0206] 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.
[0207] 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.
[0208] Use of the valve 720 of this embodiment is as follows. A
user first connects a first medical implement (see FIG. 1) to the
port 735 at the second end 734 of the housing 728. When the first
medical implement is of the type disclosed above, a free end of the
tube is guided over the wall 776 between the outside of the wall
and the inside of the sleeve 778.
[0209] 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.
[0210] 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.
[0211] 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 FIG.
30.
[0212] 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.
[0213] 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.
[0214] 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.
[0215] 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.
[0216] A ninth embodiment valve 820 in accordance with the present
invention is illustrated in FIGS. 32 and 33. As illustrated, this
valve 820 includes a housing 828 which is somewhat similar to the
housings of the valves 220, 320 etc. described above.
[0217] 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.
[0218] 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.
[0219] 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 FIG. 32, where the slit 884 is
closed and fluid is prevented from passing therethrough.
[0220] 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.
[0221] 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.
[0222] The operation of the valve 820 will now be described in
detail with reference to FIGS. 32 and 33. A user first connects the
first medical implement (not shown, but which may be similar to
that illustrated in FIG. 1) to the branch port 835 at the third end
834. When the first medical implement is of the type disclosed
above, the free end of the tube is guided over the wall 876 between
the outside of the wall and the inside of the sleeve 878.
[0223] 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 FIG. 33.
[0224] 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.
[0225] 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 FIG. 32. This causes the total volume or fluid space
in the housing 828 to reduce to a minimum amount V2.
[0226] 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 maximum volume V1 less the minimum volume
V2.
[0227] 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.
[0228] 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.
[0229] A tenth embodiment valve 920 in accordance with the present
invention is illustrated in FIGS. 34 and 35. As illustrated, the
housing 928 has a body having a first end 930 defining a first port
931 and an opposing closed second end 932. A branch 933 extends to
a third end 934 defining a branch port 935.
[0230] 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.
[0231] 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 FIG. 34, where the
slit 984 is closed and fluid is prevented from passing
therethrough.
[0232] 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.
[0233] 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.
[0234] 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.
[0235] The operation of the valve 920 will now be described in
detail with reference to FIGS. 34 and 35. A user first connects the
first medical implement (not shown, but which may be similar to
that illustrated in FIG. 1) to the branch port 935 at the third end
934. When the first medical implement is of the type disclosed
above, the free end of the tube is guided over the wall 976 between
the outside of the wall and the inside of the sleeve 978.
[0236] 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 FIG. 35.
[0237] When in this position (as illustrated in FIG. 35), a fluid
flow path is established from the second medical implement 926
(such as through a tube from an I.V. bag) through the valve 920 to
the first medical implement (and thus through the catheter to the
patient). Fluid flows through the tip 937 of the cannula into the
chamber 936, then through the branch passage 938. The total volume
of fluid within the valve 920 when the second medical implement is
attached is an amount V1.
[0238] 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 FIG. 34. This causes the total volume or fluid space
in the housing 928 to reduce to a minimum amount V2.
[0239] 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.
[0240] 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.
[0241] 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.
[0242] An eleventh embodiment valve 1020 in accordance with the
present invention is illustrated in FIGS. 36-49. This valve 1020 is
similar in many respects to the valve of the first embodiment.
[0243] Referring to FIG. 36, the valve 1020 includes a housing 1028
which is "T"-shaped, having a main portion with a first end 1030
and an opposing, closed second end 1032. A branch 1033 extends
outwardly from the main portion generally perpendicular thereto to
a third end 1034 defining a branch port 1035.
[0244] As illustrated in FIGS. 38 and 39, a main passage 1036
extends from the first end 1030 to the closed second end 1032
inside of the housing 1028. In addition, a branch passage 1038
extends from the main passage 1036 through the branch port to the
third end 1034.
[0245] 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.
[0246] A piston 1042 is slidably positioned within the main passage
1036. Referring to FIGS. 44-48, the piston 1042 is generally
cylindrical, having a maximum outer diameter which is slightly less
than the maximum diameter of the passage 1036. The piston 1042 has
a first end 1050 and a second end 1052 and a length from end to end
which is less than the distance from the first end 1030 to the
second end 1032 of the housing 1028.
[0247] 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.
[0248] A groove 1066 is formed in the piston 1042 near its second
end 1052. Preferably, a seal 1068 (see FIGS. 38 and 39) is
positioned in this groove 1066. The seal 1068 preferably comprises
an "O"-ring.
[0249] 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.
[0250] 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 FIGS. 38 and 39) the bore 1072
is in communication with the passage 1036.
[0251] 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.
[0252] 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.
[0253] 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.
[0254] The assembled valve 1020, wherein the piston 1042 is
positioned in the main passage 1036 through the housing 1028, is
best illustrated in FIGS. 38 and 39. As illustrated, the seal 1068
divides the main passage 1036 into a first chamber 1039 and a
second chamber 1041. The first chamber 1039 comprises a space
between the closed second end 1032 of the housing 1028, the second
end 1052 of the piston 1042, and that space within the bore 1072 in
the piston 1042. The second chamber 1041 is that space between the
seal 1068 on the piston 1042 and the seal 1082 at the first end
1030 of the housing 1028.
[0255] 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.
[0256] 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.
[0257] 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.
[0258] 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 FIG. 39) through
the opening 1085 in the cap 1083, and then through the slit in the
seal 1082. The user advances the implement 1037 until it presses
the piston 1042 towards the second end 1032 of the housing 1028, as
illustrated in FIG. 39.
[0259] 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.
[0260] 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 FIG. 38
as a result of the spring force. When the piston 1042 is in the
position illustrated in FIG. 38, the volume within the valve 1020
is at a minimum V2.
[0261] 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.
[0262] 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.
[0263] A twelfth embodiment valve 1120 in accordance with the
present invention is illustrated in FIGS. 49 and 50. The valve 1120
of this embodiment has a housing 1128 defining a main passage 1136
extending from a first end 1130 to a chamber 1141. A branch passage
1138 leads from the chamber 1141 generally perpendicular to the
main passage 1136.
[0264] The housing 1128 has a second end 1132 opposite the first
end 1130, the second end 1132 being open to the chamber 1141.
[0265] 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 FIG. 49).
[0266] 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.
[0267] 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.
[0268] 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.
[0269] 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 FIG. 50.
[0270] 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.
[0271] 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.
[0272] 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.
[0273] 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 FIG. 49. At that time, the seal 1182 again seals the
branch passage 1138 from the chamber 1141.
[0274] 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.
[0275] As the seal 1182 expands, the volume within the chamber 1141
is reduced, forcing fluid into the branch passage 1138.
[0276] A thirteenth embodiment valve 1220 in accordance with the
present invention is illustrated in FIGS. 51 and 52. This valve
1220 has a straight-flow arrangement similar to that of the valves
illustrated in FIGS. 20-29.
[0277] 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.
[0278] 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.
[0279] 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.
[0280] 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.
[0281] A user inserts a cannula or other medical apparatus, as
illustrated in FIG. 52, between the two portions of the seal 1282.
As the user does this and advances the cannula, the seal portions
must spread apart to accommodate the cannula. This causes the seal
portions to move upwardly towards the first end 1230 of the valve
1220 along the conical surface 1248 against the force of the
biasing member 1270.
[0282] 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.
[0283] 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 FIG. 51. The seal 1282 in this position reseals the
main passage 1236 at the first end 1230 of the valve 1220.
[0284] 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 preslit). 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.
[0285] 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, FIG. 12) while in other embodiments it is a pre-slit seal (ex.
seal 182, FIG. 19). Those of skill in the art will appreciate that
a variety of means may be provided in addition to those described.
For example, a resealable septum or the like may be used.
[0286] 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, FIG. 12 or
piston 1042, FIG. 38) while in other embodiments it is a resilient
member such as a diaphragm or foam-like element (ex. element 670,
FIG. 28 or element 770, FIG. 30). Those of skill in the art will
appreciate that other means may be provided.
[0287] 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, FIG. 12).
[0288] 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.
[0289] 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.
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