Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-1-
HEMOSTASIS VALVE AS~FOrRI.v
INCLUDING GUIDE WIRE SEAL
Background of the Invention
1. Field of the Invention
The present invention relates generally to medical devices and, more
particularly, to hemostasis valves for use within percutaneous catheter
introducers.
2. Description of the Prior A_rt
The use of catheter introducers in percutaneous medical procedures is
well known in the art. A catheter introduces typically includes a long sheath
having a
first end positioned within a vein or artery of a patient arid a second end
positioned
immediately external to the epidermis of the patient. Since the control of
bleeding is
obviously essential when such catheter introducers are utilized, conventional
catheter
introducers include a hemostasis valve assembly positioned at the second end
of the
sheath to permit a loader, catheter or other medical instrument to be
introduced into
the body of the patient through the sheath while precluding blood from flowing
out
of the introduces.
In many percutaneous medical procedures, a small diameter guide
wire is passed through the sheath of the introduces and inserted into a vein
or artery.
The guide wire serves as a guide for a large diameter loader, catheter or
other
medical instrument employed later in the procedure. It is therefore necessary
for the
valve assembly to provide a sufficient seal around the small diameter guide
wire to
prevent excessive blood loss through the introduces. However, the valve
assembly
must also allow passage of, and sealingly engage, the large diameter loader,
catheter,
or other medical instrument, so as to prevent the flow of blood through the
introduces.
One type of valve commonly used to control the flow of blood is
referred to as a "duckbill" valve. A conventional duckbill valve includes a
pair of
walls, each having a generally planar configuration, which converge and
intersect
along a line or slit. However, such duckbill valves are not well suited for
use alone
in catheter introducers where medical instruments are to be inserted through
the
valve. When an instrument is inserted into a conventional duckbill valve, it
passes
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-2-
between the converging walls of the valve and through the slit. This causes
the walls
to separate and to create an undesirable flow channel between the slit and the
instrument.
U.S. Patent 4,929,235 discloses a catheter introduces valve assembly
designed to overcome the (imitations of the prior art duckbill valves. The
valve
assembly includes a first valve having a Y-shaped slit which seals off any
flow of
blood from the sheath of the introduces during the time a catheter tube is not
present.
A second valve, typically a disc seal with a small through-hole, seals around
the
catheter tube during and after the insertion of the catheter tube into the
introduces so
as to seal off any flow of blood.
The prior art catheter introduces valve assemblies have been
successful in accomplishing the primary purpose of shutting off the flow of
blood in
the sheath when no medical instrument is present therein. Further, the prior
art valve
assemblies have been effective in allowing passage of and sealingly engaging
the
outer diameter of a catheter or other medical instrument.
However, the prior art catheter introduces valve assemblies have been
unable to provide adequate seals around both a small diameter guide wire and
large
diameter medical instrument passing through the introduces. The prior art
valve
assemblies typically include a seal which is adapted to sealingly engage
around the
relatively large diameter medical instrument such that no seal is formed
around a
relatively small diameter guide wire. With further reference to U.S. Patent
4,929,235, the through-hole of the second valve has a diameter adapted to
sealingly
engage a catheter or loader having a diameter typicalhr of approximately .3
inches. A
typical guide wire has a diameter of approximately .035 inches such that once
the
catheter or loader has been removed, leaving the guide wire alone within the
valve
assembly, a substantial gap exists between the second valve and the guide wire
whereby blood may pass through the introduces.
Accordingly, there is a need for a catheter introduces valve assembly
which provides for the effective sealing of blood flow during three separate
and
distinct conditions: when no medical instrument is inserted through the
assembly,
when a relatively large diameter medical instrument is inserted through the
valve
assembly, and when a relatively small diameter guide wire is inserted through
the
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99105121
-3-
valve assembly. In addition, there is a need for a guide wire seal which
provides an
effective seal around the exterior of a guide wire which alone has been
inserted
through the valve assembly, but which also provides far the easy passage of a
relatively large diameter catheter or loader.
Summary of the Invention
The present invention provides a hemostasis valve assembly adapted
for use within a catheter introduces. In a first mode of operation, the valve
assembly
seals blood from flowing through the catheter introduces when no instnunent or
device is passing therethrough. In a second mode of operation, the valve
assembly
seals around a relatively small diameter guide wire, while in a third mode of
operation the valve assembly seals around a relatively large diameter
elongated
member or catheter. The valve assembly consistently and continuously seals off
the
flow of blood during all three modes of operation.
The valve assembly of the present invention comprises a valve body
including first and second sealing members. The valve body defines a central
passage having a longitudinal center axis and opposed inlet and outlet ends.
The
inlet end is adapted for introducing a guide wire and elongated member. The
elongated member may comprise a loader or catheter, but is not limited thereto
and
may further comprise any conventional medical instrument used in percutaneous
catheter introducers.
The first sealing member, or duckbill seal, includes a resilient body
having a cylindrical support wall and a plurality of lip members extending
radially
inwardly from the support wall. The lip members are spaced circumferentially
from
each other and define at least one normally closed slit extending transversely
to the
central passage for preventing fluid flow out of the housing through the valve
assembly.
The second sealing member, or guide wire seal, includes a resilient
body having a cylindrical support wall and a plurality of radially extending
lip
members. The lip members are spaced circumferentially from each other and
define
at least one slit extending transversely to the central passage and an
aperture coaxial
with the longitudinal center axis. The aperture is adapted to sealingly engage
the
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-4-
guide wire for preventing fluid flow out of the housing through the valve
assembly
when the guide wire is positioned within the second sealing member and the
elongated member is absent from the second sealing member. At least one pre-
load
rib extends from the support wall towards the aperture for pressing at least
two of the
plurality of lip members together in sealing engagement. A substantially
spherical
inner surface opens toward the inlet end for guiding the guide wire to the
aperture.
The valve assembly preferably further comprises a third sealing
member, or catheter disc seal, including a resilient body having cylindrical
support
wall and a disc extending radially inwardly from the support wall. The disc
defines
I 0 an aperture coaxial with the longitudinal center axis and adapted to
sealingly engage
the elongated member for preventing fluid flow out of the housing through the
valve
assembly when the elongated member, or catheter, is positioned within the
third
sealing member.
Therefore, it is an object of the present invention to provide a
hemostasis valve assembly that effectively seals the flow of blood through the
valve
assembly when no medical instrument is inserted therethrough.
It is another object of the present invention to provide a valve
assembly which seals off the flow of blood when no medical instrument is
inserted
therethrough and which also readily seals around medical instruments having a
wide
variety of diameters.
It is a further object of the invention to provide a guide wire seal
which effectively seals about a relatively small diameter guide wire but also
provides
for the easy passage of a relatively large diameter medical instrument.
It is yet another object of the invention to provide a valve assembly
which sealingly engages a relatively large diameter medical instrument, and
which
also upon removal of the instrument, sealingly engages a relatively small
diameter
guide wire thereby preventing the flow of blood through the valve assembly.
brief Description of the Drawines
Fig. 1 is a cmss-sectional view of a catheter introducer including the
valve assembly of the present invention;
Fig. 2 is a cross-sectional view of the valve assembly of the present
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-5-
invention in a first mode of operation;
Fig. 3 is a cross-sectional view of the valve assembly of the present
invention in a second mode of operation wherein a guide wire is positioned
therein;
Fig. 4 is a cross-sectional view of the va.Ive assembly of the present
invention in a third mode of operation wherein a catheter is positioned
therein;
Fig. S is a top plan view of the duckbill seal of the valve assembly of
the present invention;
Fig. 6 is a perspective view of the guide wire seal of the present
invention;
Fig. 7 is a top plan view of the guide wire seal of the present
invention;
Fig. 8 is a cross-sectional view of the guide wire seal taken along Line
8-8 of Fig. 7;
Fig. 9 is a bottom plan view of a catheter disc seal of the valve
assembly of the present invention; and
Fig. 10 is a top plan view thereof.
Detailed Description of the Preferred Embodiment
Referring initially to Fig. 1, a catheter introduces 10 is illustrated as
including a hemostasis valve assembly 12, a sheath tube 14 and a housing 16.
An
angularly extending portion 18 is located adjacent a distal end 19 of the
housing 16
and provides a means for introducing some material, e.g., a contrast or
imaging
medium, into the catheter introduces I 0. The sheath tube 14 extends outwardly
from
the distal end 19 of the housing and is adapted to be introduced into the body
of a
patient in a manner as is known in the art. A locking cap 20 is received
within a
proximal end 22 of the housing 16 and Locks the valve assembly 12 in both
radial and
axial position within the catheter introduces 10.
An elongated member, preferably a hollow loader or catheter 24, is
adapted for introduction into the locking cap 20 and through the valve
assembly 12
and sheath tube 14 for final positioning within a blood vessel of the patient.
The
catheter 24 typically has a relatively large outer diameter, or member
diameter, in the
order of 0.3 inches. The valve assembly 12 provides for the passage of and
sealing
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-6-
engagement with the outer circumference of the catheter 24 thereby minimizing
or
preventing the loss of blood from the patient through the catheter introduces
I0. A
guide wire 26, having a relatively small outer diameter, or wire diameter, of
approximately .035 inches, is adapted to be received within and pass through
the
catheter 24 into the blood vessel of the patient.
In conventional medical procedures, the catheter 24 is removed while
the guide wire 26 remains in position within the patient's blood vessel. The
valve
assembly 12 also provides for sealing engagement with the outer surface of the
guide
wire 26 at this point in the procedure. The catheter 24, supporting a
specialized
medical instrument (not shown), such as a balloon catheter, is then reinserted
through
the valve assembly 12 of the catheter introduces 10. T he catheter 24 passes
through
the sheath tube 14 while being guided over the guide wire 26 to a desired
location
within the patient's blood vessel. It should be noted that instead of the
catheter 24
being reinserted through the valve assembly 12, an elongated member or medical
instrument having an outer diameter intermediate the outer diameters of the
catheter
24 and guide wire 26, is often substituted therefor.
The hemostasis valve assembly 12 comprises a valve body 28
including first, second and third sealing members 30, 32 and 34, respectively.
The
valve body 28 defines a central passage 36 having a longitudinal center axis
38 and
opposed inlet and outlet ends 40 and 42. The inlet end 40 faces the proximal
end 22
of the housing 16 and is adapted to receive the catheter 24 and guide wire 26.
The
outlet end 42 is positioned adjacent the distal end 19 of the housing 16.
As shown in Fig. 2, the first sealing member 30 is adapted to seal off
any flow of blood through the catheter introduces 10 during the time that no
medical
instrument, including the catheter 24 and guide wire 26, are positioned within
the
valve assembly 12. The second sealing member 32 is adapted to seal off any
blood
flow through the catheter introduces 10 during the time in which the guide
wire 26
alone is positioned within the valve assembly 12 as illustrated in Fig. 3.
Turning
now to Fig. 4, the third sealing member 34 is adapted to sealingly engage the
outer
circumference of the catheter 24 thereby preventing blood flow through the
catheter
introduces 10 when the catheter 24 is positioned within the valve assembly 12.
It
should be further noted that the third sealing member 34 is also adapted to
sealingly
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
_'J_
engage the outer circumference of a medical instrument having a diameter
intermediate that of the guide wire 26 and catheter 24. The second sealing
member
32 is positioned between the first and third sealing members 30 and 34 such
that the
third sealing member 32 defines the inlet end 40 and the first sealing member
30
defines the outlet end 42 of the valve body 28.
Turning now to Figs. 2 and 5, the first sealing member 30, or duckbill
seal, includes a body 44 axially aligned with the center axis 38. The body 44
is
preferably made of a flexible, resilient material such a:> polyisoprene or
silicone. A
mounting flange 46 is integrally formed as part of the body 44 for locating
and
sealingly engaging the inner surface 48 of the housing 16.
A cylindrical support wall 50 extends towards the outlet end 42 of the
valve assembly i2 concentric with the mounting flange 46. A pair of lip
members,
preferably circumferentially spaced web members 52, extend radially inwardly
from
the cylindrical support wall 50 and axially outwardly towards the outlet end
42 to
converge and force a normally closed slit 54. It should be apparent that the
slit 54
forms what is known in the art as a duckbill seal 30.
Slit 54 is shown in its closed position in Fig. 2 and in its forced open
position in Figs. 3 and 4 wherein the guide wire 26 (Fig. 3) or catheter 24
(Fig. 4) is
positioned between the web members 52 which have been pressed apart. In the
closed position, increasing fluid pressure against the outlet end 42 of the
web
members 52 causes the slit 54 to remain firmly closed. When the guide wire 26
or
catheter 24 is inserted from the inlet end 40, it will contact the edges of
the web
members 52 to cause the slit 54 to open and allow passage of the guide wire 26
or
catheter 24. It should be noted that the web members 52 are capable of
providing a
large diameter opening whereby a catheter 24 or other medical instrument
having an
outer diameter proximate the inner diameter of the cylindrical support wall
50, may
be inserted without tearing, stretching or otherwise damaging the duckbill
seal 30.
A pair of diametrically opposed pre-load ribs 56 extend between the
cylindrical support wall 50 and the slit 54 in a manner transverse, or
perpendicular, to
the slit 54. The pre-load ribs 56 in combination with the support wall 50
stiffen or
rigidify the web members 52 to resist opening of the slit 54 by outward
movement of
the web members 52. In particular, radially outwardly acting forces are
resisted by
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
_g_
an inwardly acting reaction force produced by the pre-load ribs 56 being
forced
against the cylindrical support wall 50. This inwardly acting force results in
the web
members 52 being pressed together in a sealing relatianship so that the
leakage of
blood is prevented or minimized. Further, the pre-load ribs 56 help to
reliably close
the web members 52 immediately after the withdrawal of the guide wire 26 or
catheter 24 from the valve assembly 12.
Turning now to Figs. 2 and 6-8, the second sealing member 32, or
guide wire seal, includes a body 58 axially aligned with the center axis 38.
The
guide wire seal 32 includes an inlet end which defines the inlet end 40 of the
valve
assembly 12, and an outlet end 62. The body 58 preferably comprises a
flexible,
resilient material such as polyisoprene or silicone. First and second mounting
flanges 64 and 66 are integrally formed as part of the body 58 wherein the
first
mounting flange 64 sealingly engages the inner surface 48 of the housing 16.
The
second mounting flange 66 sealing engages a cylindrical spacer 68 made of a
material similar to that of the guide wire seal 32 (Fig. 2). The guide wire
seal 32 is
tightly positioned within the housing 16 between the third sealing member 34,
spacer
68 and locking cap 20 such that axial and radial displacement of the guide
wire seal
32 is prevented.
A cylindrical support wall 70 extends towards the outlet end 62 of the
guide wire seal 32 concentrically to the mounting flanges 64 and 66. A disc 72
extends radially inwardly from the support wall 70 and includes lip members
74, four
of which are presented for illustrative purposes in Figs. 6 and 7. The lip
members 74
extend in a direction radially outwardly from the center axis 38 and are
circumferentially spaced an equal distance from each other. Each adjacent pair
of lip
members 74 converge to form a normally closed slit T6 at the outlet end 62 of
the
guide wire seal 32. As shown in Figs. 6 and 7, four slits 76a, 76b, 76c and
76d are
formed in the preferred embodiment. The lip members 74 combine to form a
circular
shaped planar surface 78 at the outlet end 62 and to define first and second
pairs of
diametrically opposed slits 76. More particularly, slits 76a and 76c define
the first
pair of diametrically opposed slits 76 while slits 76b and 76d form the second
pair of
diametrically opposed slits 76. In the preferred embodiment, the planar
surface 78
has a diameter of approximately 0.2 inches such that each pair of
diametrically
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99105121
-9-
opposed slits has a total width of approximately 0.2 inches. Each pair of
slits 76a,
76c and 76b, 76d are radially aligned through the center axis 38. The slits 76
extend
axially through the planar surface 78 and each pair of slits 76a, 76c and 76b,
76d are
perpendicularly disposed to the other pair of slits 76b, 76d and 76a, 76c
thereby
forming a cross slit centered on axis 38.
The slits 76 are illustrated in their closed position in Figs. 2 and 6-7
and in their forced open position in Fig. 4. In the closed position, the lip
members 74
sealingly engage each other thereby closing the slits 76 and preventing blood
from
flowing therebetween. When the catheter 24 is inserted from the inlet end 60,
it will
contact the edges of the lip members 74 to cause the slits 76 to open and
allow
passage of the catheter 24. The Iip members 74 are capable of providing a
large
diameter opening whereby the resilient body 58 permits a catheter 24 or other
medical instrument having an outer diameter greater than the outer diameter of
the
circular planar surface 78 to be inserted without tearing, stretching or
otherwise
damaging the guide wire seal 32. Furthermore, because the diameter of the
catheter
24 (0.3 inches) exceeds the maximum width of the pairs of slits 76 (0.2
inches), the
guide wire seal 32 forms a fluid tight seal against the catheter 24 as it is
extended
therethrough.
Each lip member 74 includes an arcuate notch 82 which combine with
the arcuate notches 82 of each adjacent lip member 74 to form a central
aperture 84
coaxial with the longitudinal center axis 38. The aperture 84 has a circular
cross-
section and has a diameter which is approximately Iess than the outer diameter
of the
guide wire 26 or any other medical instrument or device which is arranged to
be
passed through the valve assembly 12. The aperture 84 therefore seals around
the
smallest diameter instrument or device, typically the guide wire 26, to be
passed
through the catheter introducer 10 and thereby minimize or prevent the outward
flow
of blood when such an instrument is present in the valve assembly 12. In the
preferred embodiment, the aperture 84 has a diameter of approximately .033
inches
to seal around a guide wire 26 of approximately .035 inches.
First and second pairs of diametrically opposed pre-load ribs 86 and
88 extend radially inwardly from the cylindrical support wall 70. The pre-load
ribs
86 and 88 preferably extend radially inwardly into engagement with respective
Iip
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/0512I
-10-
members 74, thereby optimizing resistance of the lip members 74 to movement
such
that adjacent lip members 74 tend to remain in sealing engagement and the
slits 76
remain closed. The first pair of pre-load ribs 86 are disposed perpendicular
to the
second pair of pre-Ioad ribs 88. Each pair of pre-load ribs 86 and 88 are
preferably
positioned at a predetermined angle, preferably 45°, to each adjacent
slit 76 in order
to facilitate sealing engagement of the lip members 74 as described below.
The pre-load ribs 86 and 88 preferably have a sloping or inclined
upper surface 90 extending downwardly from the cylindrical support wall 70
toward
the aperture 84. The angle of inclination of the upper surface 90 extending
from
proximate said aperture 84 toward the support wall 70 is preferably 5°.
The inclined
upper surface 90 provides for a clearance gap 89 (Fig. 2) between the second
and
third sealing members 32 and 34, thereby preventing the pre-load ribs 86 and
88 from
substantially displacing the third sealing member 34 when the guide wire 26
alone is
inserted therethmugh as shown in Fig. 3. The outer end of the inclined upper
surface
90 is level with the upper surface 92 of the support wall 70 while the inner
end of the
inclined upper surface 90 is level with the planar surface 78 of the disc 72.
The pre-load ribs 86 and 88 and support wall 70 stiffen or rigidify the
disc 72 for resisting any force tending to open the slits 76 by outward
movement of
the lip members 74. In particular, the ribs 86 and 88 and support wall 70 hold
the
slits 76 together in sealing engagement to oppose bload pressure exerted
against the
outlet end 62. Additionally, the pre-load ribs 86 and 88 help to reliably
close the lip
members 74 immediately after withdrawal of the catheter 24 from the guide wiry
seal
32. Further, the pre-load ribs 86 and 88 help keep the slits 76 closed in
sealing
engagement as the guide wire 26 is passed through the aperture 84. An offset
angle
of 45° between the first and second pairs of pre-load ribs 86 and 88
and the first and
second pairs of slits 76a, 76c and 76b, 76d, respectively, optimizes the
resistance
against any force tending to open the lip members 74.
The guide wire seal 32 includes a substantially spherical recess 94
which opens toward the inlet end 40 for guiding the tip of the guide wire 26
or
catheter 24 to the aperture 84 during their introduction into the catheter
assembly 12.
The valve disc 72 has opposed inner and outer surfaces 96 and 98 oriented
towards
the inlet and outlet ends 60 and 62, respectively. The inner surface 96 is
substantially
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-11-
spherical from proximate the inlet end 40 to the aperture 84, thereby defining
the
recess 94. By the spherical inner surface 96 extending radially inwardly up to
the
aperture 84, the guide wire 26 is guided through the aperture 84 in sealing
engagement therewith without the tip of the guide wire 26 tending to contact
and
force open the slits 76 between adjacent lip members '74. The outer surface 98
is
substantially spherical from the support wall 70 to the planar surface 78
thereby
forming a plurality of arced recesses I00 between adjacent pre-load ribs 86
and 88
(Fig. 6).
Turning now to Figs. 2 and 9-10, the third sealing member 34, or
catheter disc seal, is positioned in sealing engagement between the duckbill
seal 30
and the guide wire seal 32. Again, the catheter disc seal 34 includes a body
102
preferably made of a flexible, resilient material such as polyisoprene or
silicone. A
mounting flange 104 is integrally formed as part of the body 102 wherein the
flange
104 sealingly engages the inner surface 48 of the housing 16. As illustrated
in Fig. 2,
the catheter disc seal 34 is tightly positioned within the housing 16 between
the guide
wire seal 32, spacer 68 and duckbill seal 30 such that axial and radial
displacement
of the catheter disc seal 34 is prevemed.
The body 102 includes a cylindrical support wall 106 and a disc 108
extending radially inwardly from the support wall 106. The disc 108 is formed
with
an aperture 110 coaxial with the longitudinal center axis 38. The aperture 110
has a
diameter which is substantially greater than the outer diameter of the guide
wire 26
but which is Iess than the outer diameter of the catheter 24 for sealing
engagement
between the disc 108 and the catheter 24. In the preferred embodiment, the
diameter
of the aperture 110 equals approximately .075 inches. The disc 108 has
substantially
planar inner and outer surfaces 112 and 114, respectively. It has been
discovered that
the addition of the catheter seal 34 assists in sealing around medical
instruments
passed through the valve assembly 12 which have outer diameters intermediate
the
diameters of the aperture 110 and catheter 24.
Figs. 2-4, illustrate three different modes of operation of the valve
assembly 12 of the present invention. Fig. 2 shows a first mode of operation
wherein
no guide wire 26, catheter 24, nor any other medical instrument is inserted
within the
valve assembly 12. In this first mode, it is readily apparent that the
apertures 84 and
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-12-
110 are coaxially aligned and provide fluid communication between the catheter
disc
seal 34 and the guide wire seal 32. However, the web members 52 of the
duckbill
seal 30 close the slit 54 thereby preventing or mininuzing the flow of blood
from the
outlet end 42 through the catheter introducer 10.
Fig. 3 illustrates the second mode of operation where the guide wire
26 alone is positioned within the valve assembly 12. In this mode, the guide
wire
seal 32 provides the primary seal around the outer surface of the guide wire
26 to
prevent or minimize the flow of blood from the outlet end 42 through the
catheter
introducer 10. As noted above, the guide wire 26 has a relatively small
diameter,
typically about 0.035 inches, such that the relatively large diameter aperture
110 of
the catheter disc seal 34 does not sealingly engage the outer surface of the
guide wire
26. Further, the duckbill seal 30, as described above, only provides a partial
seal
around the guide wire 26. However, since the diameter of aperture 84 of the
guide
wire seal 32 is smaller than the outer diameter of the guide wire 26, sealing
engagement occurs between the guide wire seal 32 and guide wire 26. The slits
76
are simultaneously pressed together in sealing engagement by the pre-Ioad ribs
86
and 88.
The third mode of operation is defined by insertion of the catheter 24
into the valve assembly I2, as illustrated in Fig. 4. As described above, the
catheter
24 typically has a relatively large outer diameter on ttxe order of 0.3
inches. As the
catheter 24 is guided over the guide wire 26 from the inlet end 40 towards the
outlet
end 42, the catheter 24 easily passes through the guide wire seal 32 in
sealing
engagement therewith due to the resilient body 58 and lip members 74. Since
the
diameter of the catheter 24 exceeds the maximum width of the opening defined
by
the pairs of slits 76 of the guide wire seal 32 and the diameter of the
aperture 110 of
the catheter disc seal 34, both the guide wire and catheter disc seals 32 and
34 form
fluid-tight seals against the catheter 24 when passed through the valve
assembly 12.
As may be appreciated, the opening of the slits 76 may provide
limited fluid communication between the guide wire seal 32 and catheter disc
seal 34
if a medical instrument having an outer diameter intermediate the diameter of
the
guide wire 26 and the width of the pairs of slits 76 is :inserted through the
valve
assembly 12. In such a case, where the medical instrument has an outer
diameter
CA 02327657 2000-10-OS
WO 99/45983 PCT/US99/05121
-13-
greater than the diameter of the aperture 110, the catheter disc seal 34
provides the
primary seal around the outer surface of the medical instrument.
From the above description, it should be apparent that the present
invention provides for a hemostasis valve assembly adapted to be received
within a
catheter introducer. The valve assembly continuously seals blood from passing
through the introducer. More particularly, the valve assembly seals the flow
of blood
when no instrument is inserted through the assembly, when a relatively small
diameter guide wire is passed through the assembly, and when a relatively
large
diameter catheter is received within the assembly. Further, the valve assembly
includes a guide wire seal adapted for sealing engaging the guide wire while
providing for the easy passage of the catheter.
While the forms of apparatus herein described constitute preferred
embodiments of the invention, it is to be understood that the invention is not
limited
to these precise forms of apparatus and that changes may be made therein
without
departing from the scope of the invention which is defined in the appended
claims.
What is claimed is:
