U.S. patent application number 12/785710 was filed with the patent office on 2010-10-28 for two-way slit valve.
This patent application is currently assigned to ALLERGAN, INC.. Invention is credited to Janel Birk, Owen Shawn Sobelman.
Application Number | 20100274194 12/785710 |
Document ID | / |
Family ID | 34078447 |
Filed Date | 2010-10-28 |
United States Patent
Application |
20100274194 |
Kind Code |
A1 |
Sobelman; Owen Shawn ; et
al. |
October 28, 2010 |
TWO-WAY SLIT VALVE
Abstract
A slit valve 10 for use with an inflatable medical device having
a flange surface 12 with an opening therein. The slit valve 10 has
a valve body 14 connected to the flange surface 12 and a chamber
formed in the valve body 14 for accepting an inflation tube 34
inserted through the opening in the flange surface 12. The slit
valve 10 has a concave section at one or both ends, which are
connected by a slit 24 formed in the valve body 14.
Inventors: |
Sobelman; Owen Shawn;
(Shingle Springs, CA) ; Birk; Janel; (Oxnard,
CA) |
Correspondence
Address: |
ALLERGAN, INC.
2525 DUPONT DRIVE, T2-7H
IRVINE
CA
92612-1599
US
|
Assignee: |
ALLERGAN, INC.
Irvine
CA
|
Family ID: |
34078447 |
Appl. No.: |
12/785710 |
Filed: |
May 24, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10561515 |
Dec 20, 2005 |
7749254 |
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PCT/US03/19414 |
Jun 20, 2003 |
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12785710 |
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Current U.S.
Class: |
604/167.04 ;
128/898 |
Current CPC
Class: |
A61M 29/02 20130101;
A61M 39/26 20130101; A61M 2039/0036 20130101; A61F 5/003 20130101;
A61F 5/0036 20130101 |
Class at
Publication: |
604/167.04 ;
128/898 |
International
Class: |
A61M 5/00 20060101
A61M005/00; A61B 19/00 20060101 A61B019/00 |
Claims
1. A combination of a two-way medical valve and an inflation tube,
comprising: an elastomeric slit valve having a valve body defining
proximal and distal ends, and an opening at the proximal end, an
internal chamber including a first chamber immediately adjacent and
wider than the opening and a second chamber in open fluid
communication with the first chamber, wherein the internal chamber
in the valve body narrows between the first and second chambers to
form a neck, and a normally closed slit formed in a solid portion
of the valve body connecting a concave section at a distal end of
the second chamber and the distal end of the valve body; and an
inflation tube having a lumen therethrough, the inflation tube
defining an injection tip having a wedge shaped distal end, the
injection tip further including an insertion stop located proximal
to the distal end and a reduced diameter portion therebetween;
wherein the elastomeric valve body is adapted to receive the
inflation tube such that fluid may be introduced into the internal
chamber and at a threshold pressure differential across the slit
open and pass distally through the slit, and wherein the slit also
permits fluid to pass proximally therethrough upon a predetermined
backflow pressure differential, and wherein the insertion stop is
sized to positively engage the opening and limit the distance to
which the injection tip extends into the internal chamber, at which
distance the wedge shaped distal end forms a seal within the narrow
neck in the valve body.
2. The combination of claim 1, wherein the inflation tube includes
a flexible tube and the injection tip is a rigid piece having a
barbed proximal end to retain the injection tip in fluid-tight
engagement with the flexible tube.
3. The combination of claim 2, wherein the flexible tube is
provided with reference length markers.
4. The combination of claim 1, wherein the distal end of the valve
body defines a second concave section such that the slit connects
the concave section of the second chamber and the second concave
section.
5. The combination of claim 4, wherein the shape of the second
chamber relative to the second concave section is such that a
smaller threshold pressure differential is required to open the
slit and pass fluid distally therethrough than a backflow pressure
differential required to open the slit and pass fluid proximally
therethrough.
6. The combination of claim 5, wherein the backflow pressure
differential required to open the slit and pass fluid proximally
therethrough is no more than 40 psi (2.81 Kg/cm.sup.2).
7. The combination of claim 1, wherein the proximal opening of the
valve body is sized to form a second fluid seal against the reduced
diameter portion of the injection tip.
8. The combination of claim 1, wherein at least a portion of the
first chamber substantially conforms to the wedge shaped distal end
of the inflation tube.
9. An inflatable medical implant having a two-way valve for
accepting an inflation tube, comprising: an inflatable balloon
formed of a flexible polymer material suitable for residence in the
body; a slit valve provided in a wall of the balloon, the slit
valve comprising: an elastomeric valve body having a width and
proximal and distal ends and received in an opening in the wall of
the balloon; a proximal flange at the proximal end of the valve
body that conforms to an outer surface of the wall of the balloon
and has an opening therein; an open internal chamber formed within
the valve body in open fluid communication with the flange opening,
the internal chamber having a concave section at its distal end;
and a normally closed slit formed in a solid portion of the valve
body connecting the concave section of the internal chamber and the
distal end of the valve body, wherein the valve body is adapted to
receive an inflation tube through the flange opening such that
fluid may be introduced into the internal chamber and at a
threshold pressure differential across the slit open and pass
distally through the slit and into the balloon, and wherein the
slit also permits fluid to pass proximally therethrough upon a
predetermined backflow pressure differential.
10. The implant of claim 9, wherein the medical implant is a
gastric balloon and the polymer material is suitable for residence
in the stomach.
11. The implant of claim 9, wherein the medical implant is a
mammary implant and the polymer material is suitable for residence
in a breast cavity.
12. The implant of claim 9, wherein the medical implant is a tissue
expander and the polymer material is suitable for residence in a
breast cavity.
13. The implant of claim 9, wherein the flange opening is smaller
than the width of the immediately adjacent internal chamber.
14. The implant of claim 9, wherein the internal chamber includes a
proximal first chamber immediately adjacent the flange opening and
a distal second chamber in open fluid communication with the first
chamber, the concave section being located at a distal end of the
second chamber, and wherein the internal chamber in the valve body
narrows between the first and second chambers to form a neck.
15. The implant of claim 9, wherein the distal end of the valve
body defines a second concave section such that the slit connects
the concave section of the internal chamber and the second concave
section.
16. The implant of claim 15, wherein the shape of the internal
chamber relative to the second concave section is such that a
smaller threshold pressure differential is required to open the
slit and pass fluid distally therethrough than a backflow pressure
differential required to open the slit and pass fluid proximally
therethrough.
17. The implant of claim 16, wherein the backflow pressure
differential required to open the slit and pass fluid proximally
therethrough is no more than 40 psi (2.81 Kg/cm.sup.2).
18. A medical system having an inflatable implant with a two-way
valve for accepting an inflation tube, comprising: an inflatable
implant formed of a flexible polymer material suitable for
residence in the body; slit valve provided in a wall of the
flexible polymer material comprising an elastomeric valve body
defining proximal and distal ends, the proximal end of the valve
body having a proximal opening therein, an open internal chamber
formed within the valve body being in open fluid communication with
the proximal opening, the internal chamber having a concave section
at its distal end, and a normally closed slit formed in a solid
portion of the valve body connecting the concave section of the
internal chamber and the distal end of the valve body; and an
inflation tube having a lumen therethrough, the inflation tube
defining an injection tip having a distal end, the injection tip
further including an insertion stop located proximal to the distal
end, wherein the elastomeric valve body is adapted to receive the
inflation tube through the proximal opening such that fluid may be
introduced into the internal chamber and at a threshold pressure
differential across the slit open and pass distally through the
slit and into the inflatable implant, and wherein the slit also
permits fluid to pass proximally therethrough upon a predetermined
backflow pressure differential, and wherein the insertion stop is
sized to positively engage the opening and limit the distance to
which the injection tip extends into the internal chamber, at which
distance the distal end is sized to form a first fluid seal with a
portion of the internal chamber and remains spaced from the concave
section.
19. The system of claim 18, wherein the distal end of the injection
tip is wedge shaped, and the injection tip further includes a
reduced diameter portion located between the distal end thereof and
the insertion stop, the proximal opening of the valve body being
sized to form a second fluid seal against the reduced diameter
portion of the injection tip.
20. The system of claim 18, wherein the internal chamber includes a
proximal first chamber immediately adjacent the proximal opening
and a distal second chamber in open fluid communication with the
first chamber, the concave section being located at a distal end of
the second chamber, and wherein the internal chamber in the valve
body narrows between the first and second chambers to form a neck
that defines the portion of the internal chamber that forms the
first fluid seal with the distal end of the injection tip.
21. The system of claim 18, wherein the distal end of the valve
body defines a second concave section such that the slit connects
the concave section of the internal chamber and the second concave
section.
22. The system of claim 21, wherein the shape of the internal
chamber relative to the second concave section is such that a
smaller threshold pressure differential is required to open the
slit and pass fluid distally therethrough than a backflow pressure
differential required to open the slit and pass fluid proximally
therethrough.
23. The system of claim 18, wherein the inflation tube includes a
flexible tube and the injection tip is a rigid piece, the flexible
tube being provided with reference length markers.
24. The system of claim 18, wherein the inflatable implant is a
gastric balloon and the flexible polymer material is suitable for
residence in the stomach.
25. A method of inflating a medical implant with an inflation tube
through a two-way valve, comprising: providing an inflatable
implant formed of a flexible polymer material suitable for
residence in the body, the implant including a slit valve provided
in a wall of the flexible polymer material comprising an
elastomeric valve body defining proximal and distal ends, the
proximal end of the valve body having a proximal opening therein,
an open internal chamber formed within the valve body being in open
fluid communication with the proximal opening, the internal chamber
having a concave section at its distal end, and a normally closed
slit formed in a solid portion of the valve body connecting the
concave section of the internal chamber and the distal end of the
valve body; providing an inflation tube having a lumen
therethrough, the inflation tube defining an injection tip having a
distal end, the injection tip further including an insertion stop
located proximal to the distal end; inserting the inflation tube
through the proximal opening of the valve body until the insertion
stop positively engages the proximal opening and limits the
distance to which the injection tip extends into the internal
chamber, at which distance the distal end is sized to form a first
fluid seal with a portion of the internal chamber and remains
spaced from the concave section; delivering the inflatable implant
with the inflation tube inserted in the valve body to a body
cavity; and introducing fluid through the inflation tube into the
internal chamber until a threshold pressure differential across the
slit causes the slit to open and permit fluid to pass distally
therethrough into the inflatable implant.
26. The method of claim 25, wherein the slit valve is a two-way
valve such that in the absence of the inflation tube the slit also
permits fluid to pass proximally therethrough upon a predetermined
backflow pressure differential.
27. The method of claim 26, wherein the distal end of the valve
body defines a second concave section such that the slit connects
the concave section of the internal chamber and the second concave
section, and wherein the shape of the internal chamber relative to
the second concave section is such that a smaller threshold
pressure differential is required to open the slit and pass fluid
distally therethrough than a backflow pressure differential
required to open the slit and pass fluid proximally
therethrough.
28. The method of claim 25, wherein the injection tip further
includes a reduced diameter portion located between the distal end
thereof and the insertion stop, the proximal opening of the valve
body being sized to form a second fluid seal against the reduced
diameter portion of the injection tip.
29. The method of claim 28, wherein the injection tip is held in
place within the valve body such that a force of less than 4 lb
(17.8 N) is required to disengage the injection tip from the valve
body.
30. The method of claim 25, wherein the inflatable implant is a
gastric balloon and the flexible polymer material is suitable for
residence in the stomach, and wherein the step of delivering the
inflatable implant includes passing it through the esophagus.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent
application Ser. No. 10/561,515, filed Jun. 20, 2003, which is
incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. FIELD OF THE INVENTION
[0003] The present invention is directed to a slit valve that
enables two-way fluid flow, and in particular a slit valve for use
with implantable, inflatable medical devices such as gastric
balloons for the treatment of obesity.
[0004] 2. DESCRIPTION OF THE RELATED ART
[0005] There are a wide variety of known inflatable devices that
can be implanted in the body. One such inflatable implantable
medical device is a gastric balloon, as described in U.S. Pat. No.
5,084,061, or commercially available as the BioEnterics
Intragastric Balloon System (sold under the trademark BIB.RTM.).
These devices are designed to provide therapy for moderately obese
individuals who need to shed pounds in preparation for surgery, or
as part of a dietary or behavioral modification program.
[0006] The BIB System, for example, consists of a silicone
elastomer gastric balloon that is inserted into the stomach and
filled with fluid. Commercially available gastric balloons are
filled with saline solution or air. The gastric balloon functions
by filling the stomach and enhancing appetite control. Placement of
the gastric balloon is non-surgical, usually requiring no more than
20-30 minutes. The procedure is performed endoscopically in an
outpatient setting, using local anesthesia and sedation. Placement
is temporary, and gastric balloons are typically removed after six
to twelve months.
[0007] There are known in the prior art a variety of valves for use
with such gastric balloons. For example, the valve described in
U.S. Pat. No. 5,084,061, shown in FIG. 1, consists essentially of a
leaf valve (also known as a duckbill valve) comprising two
relatively flat pieces of silicone elastomer bonded along their
longitudinal edges and affixed by adhesive to the end of the valve
stem. In operation, a filler tube, which is usually a plastic or
silicone tube containing a stainless steel stiffening rod, is
inserted through an X-shaped slot, through a hole, through a
tubular valve stem, through a second X-shaped slot in the membrane,
and through the leaf valve until the filler tube itself is in the
interior of the shell. In such a position, both addition and
withdrawal of fluid can be accomplished. For addition of fluid
only, the filler tube does not need to penetrate through the leaf
valve.
[0008] However, valves of this sort have several disadvantages.
Initially, these valves are prone to leaking. One way in which a
duckbill valve may develop leaks is through the initial filling of
the balloon when one of the flat pieces of elastomer becomes kinked
or develops a curvature through which the fluid can pass. Another
way is through the fluid removal process, which requires the
insertion of the filler tube completely through the valve and into
the interior of the shell. Following removal of a portion of the
fluid and the filler tube, the leaf valve can remain partially
open. This causes even greater amounts of the fluid to be released
from the implant. Accordingly, there is a need for a valve that
does not leak following either filling or removal of fluid from the
shell. Second, the prior art leaf valves face opposing problems in
that it is necessary to reduce the pressure necessary to insert the
filler tube into the valve to ease in installation and filling, but
if there is not a sufficiently tight fit between the filler tube
and the valve, then the pressure of the fluid in the balloon or
valve may force the filler tip out of the valve before filing is
complete. Further, it is necessary to consider the amount of force
necessary to remove the fill tube from the valve. Current designs,
such as that discussed above, often require too much pressure to
insert the filler tube into the valve and too much pressure to
remove the filler tube from the valve. Alternatively, in instances
where the pressure necessary to insert and remove the filler tube
are not great, the filler tube may pop out of the valve while
filling the balloon. Accordingly, there is a need for a valve that
promotes easy insertion and removal of the filler tube, but does
not force the filler tube out of the valve while filling the
balloon. Prior art leaf valves are also unsuitable at fluid
inflation pressures above 30 psi, which may damage the valve.
[0009] Finally, the prior art duckbill valves have the shortcoming
that they are only one-way valves. They cannot be used to direct
fluid flow in both directions without inserting a tube completely
through the valve. Situations arise where it is preferable to have
a two-way valve. For example, when a device absorbs additional
fluid through osmosis after being implanted in the body and filled
to a proper volume, it may be desirable to reduce the fluid volume
of that implant. In the duckbill valve described above, no amount
of pressure on the interior of the balloon will permit egress of
the fluid contained therein. Accordingly, there is a need to a
valve that is capable, of permitting back flow of fluid (i.e., from
the interior to the exterior), while generally preventing egress of
fluid when under normal pressure.
[0010] Another type of valve often used in implant technology is a
diaphragm valve, such as a that discussed in U.S. Pat. No.
6,419,699 assigned to McGhan Medical Corporation. The diaphragm
valve requires insertion of a rigid male component on the inflation
tube to open the valve and allow fluid transfer. Upon removal of
the inflation tube, fluid pressure within the implant forces the
valve closed and creates a leak proof seal. As with the leaf valve,
such a valve does teach any means for backflow through the
valve.
[0011] Other valves that are used in medical applications include a
connector for an instrument insertion passage described in U.S.
Pat. No. 5,599,327 ("the '327 patent"), a non-binding surgical
valve as described in U.S. Pat. No. 5,916,198 ("the '198 patent"),
and a needle less injection site as described in U.S. Pat. No.
6,261,268 ("the '268 patent"). Each of these valves or connectors
has shortcomings that are addressed by the present invention.
Initially, both the '327 and the '268 patents contemplate an
opening in the valve that forms a seal with the application of
mechanical pressure by a medical instrument. Accordingly, both the
'327 and '268 patents require the use of bulky components and
mechanical force to create a seal. Such components and use of
mechanical force are not conducive for use with implant technology.
Further, the '198 patent describes a one-way valve that is closed
by insufflation gases acting on an interior surface of the valve
via a passage in one of the valve segments. Accordingly, the valve
contemplated by the '198 patent does not overcome the shortcomings
of the prior art discussed above. Therefore, the present invention
is directed at overcoming these problems associated with the prior
art valves. The present invention is related to a two-way valve
that is usable in an implantable medical device such as a gastric
balloon. These and other characteristics of the present invention
will become apparent from the further disclosure to be made in the
detailed description given below.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to a two-way valve having
first and second ends. The two-way valve includes a substantially
cylindrical valve body having a slit connecting the first and
second ends of the valve and concave sections formed in the first
and second ends.
[0013] The present invention is further directed to a slit valve
having a flange surface with an opening therein. The slit valve has
a valve body connected to the flange surface and a chamber formed
in the valve body for accepting an inflation tube inserted through
the opening in the flange surface. The slit valve has a concave
section at one or both ends, which are connected by a slit formed
in the valve body.
[0014] The present invention is also directed to an implantable,
inflatable apparatus having a slit valve. The slit valve includes a
flange surface having an opening. The slit valve also includes a
valve body connected to the flange surface, a first chamber formed
in the valve body for accepting an inflation tube inserted through
the opening in the flange surface, a concave section located at one
or both ends of the valve, and a slit formed in the valve body
connecting the two ends.
[0015] The present invention is also directed to a medical
apparatus for the treatment of obesity. The medical apparatus
includes a balloon formed of a suitable polymer or elastomer
material for insertion into the stomach, and a slit valve for
communication of a fluid from an inflation tube to the balloon. The
slit valve includes a flange surface having an opening therein, a
valve body connected to the flange surface, a first chamber formed
in the valve body for accepting the inflation tube inserted through
the opening in the flange surface, a concave section located at one
or both ends of the valve, and a slit formed in the valve body
connecting the two ends.
[0016] Further characteristics, features, and advantages of the
present invention will be apparent upon consideration of the
following detailed description of the invention take in conjunction
with the following drawings, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a cross sectional view of a prior art gastric
balloon with a one-way valve;
[0018] FIG. 2 is a cross-sectional view of a prior art one-way
valve;
[0019] FIG. 3 is a side view of a two-way slit valve according to
one of the embodiments of the present invention;
[0020] FIG. 4 is a cross-sectional view of the two-way valve shown
in FIG. 3;
[0021] FIG. 5 is a close-up view of a portion of the two-way valve
shown in FIG. 4;
[0022] FIG. 6 is a top view of the two-way valve according to
another aspect of the present invention;
[0023] FIG. 7 is side view of a filler-tube according to another
aspect of the present invention;
[0024] FIG. 8 is a side view of an inflation tip according to
another aspect of the present invention;
[0025] FIG. 9 is a cross-sectional view of the inflation tip of
FIG. 8; and
[0026] FIG. 10 is a cross-sectional view of a two-way valve
according to another aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] A slit valve 10 in accordance with a first embodiment of
this invention is shown in FIG. 3. The valve comprises a valve body
14 and a flange 12. With respect to the description of this
invention, the end of the valve 10 on which the flange 12 is
located will be called the top of the valve and the opposite end
the bottom. The valve 10 is preferably formed of an elastomeric
material such as silicone; however, other materials may be used
without departing from the scope of this invention. The valve body
14 is preferably molded in a substantially cylindrical shape. The
cylindrical shape is preferred as it provides added rigidity and
stiffness for the valve.
[0028] FIGS. 4 and 5 show cross-sectional views of the valve 10.
FIG. 6 shows a top view of valve 10. Starting at the flange surface
12 of the top of the valve 10, there is an opening 16 through the
flange 12 that is in communication with interior surfaces of the
valve 10. Immediately below the opening 16 is a first chamber 18.
Beneath the first chamber 18 is a neck 19. The neck 19 separates
the first chamber 18 from a second chamber 26. At the bottom of the
second chamber is a concave surface 20. The concave surface 20 is
preferred because it provides guidance to a probe in the event that
the sealing properties of valve 10 need to be overcome
mechanically. The concave surface 20 assists in the guidance of a
probe (not shown) that can be used to force the valve to open and
allow for reverse flow of fluid contained by the valve 10.
[0029] Following the concave surface 20 is a slit 24 in a
substantially solid portion of the body 14. The slit 24 connects
and is in fluid communication with a second surface 22, which may
be concave as shown, or flat. In an application such as a gastric
balloon, fluid enters the balloon shell as it exits the bottom side
of the slit 24. The slit 24 may be lubricated with silicone oil.
The use of silicone oil eases the insertion of a removal tip (not
shown) in instances where it is desired to overcome the sealing
properties of the valve 10, and serves to reduce the chance of
cross-linking where the valve body 14 is made of silicone.
[0030] FIG. 7 depicts a filler tube 30. The filler tube is
comprised of a long flexible tube 34 having a lumen therethrough,
an injection tip 32, and a connector 35 for connecting the filler
tube to a fluid supply (not shown). The flexible tube 34 may be
provided with reference length markers 36 to provide medical
personnel with a visual indication of the position of fill tube 30
inside the patient. As shown in FIGS. 8 and 9, the injection tip 32
has an orifice 37 extending therethrough that allows for fluid
communication through the flexible tube 34, and the injection tip
32. One of the ends of the injection tip may be tapered into a
wedge shape 38 having its smallest cross-section at the distal end
of the injection tip 32. The wedge shape 38 assists in the
insertion of the injection tip 32 into slit valve 10. Further, the
injection tip may include a reduced diameter portion 40, and an
insertion stop 42 for positively engaging the opening 16 of valve
10. The other end of the injection tip 32 is provided with barbs 44
to retain flexible tube 34 in fluid-tight engagement with the
injection tip.
[0031] In use, the filler tube 30 is connected to the valve 10 by
inserting the injection tip 32 into opening 16 of the valve 10. The
injection tip 32, upon full insertion into the valve, extends to a
point approximately even with a top surface of the second chamber
26. The substantial wedge shape 38 of the injection tip matches the
orientation of the first chamber 18, and the narrow cross-sectional
portion of the injection tip 32 is held firmly by the neck 19 of
valve 10 to form a seal preventing the egress of fluid from the
second chamber 26 into the first chamber 18 and out through the
opening 16. The insertion stop 42 on the injection tip 32 prevents
the injection tip from being inserted into the valve 10 beyond a
pre-determined point. Upon full insertion, the insertion stop 42
rests against the flange 12 of valve 10. The opening 16 is of a
size that, upon insertion of the injection tip 32, a second seal is
formed by the interference of the flange 12 and the reduced
diameter portion 40 of the injection tip. This second seal further
insures that fluid does not exit the valve 10 and prevents other
contaminants from entering the valve 10.
[0032] The valve 10 may be attached to an inflatable medical device
such as a gastric balloon, a mammary implant, such as a
Becker-style breast implant, a tissue expander, or the like. Other
non-inflatable applications of the valve include devices such as a
shunt drug delivery or therapeutic delivery system, a feeding tube,
or the like. Accordingly, these variations are contemplated within
the scope of the present invention. Where the device is a gastric
balloon, the valve 10 is attached to the shell substantially as
shown in Prior Art FIGS. 1 and 2. The flange surface 12 is placed
flush with the exterior surface of the balloon and may be covered
by an elastomeric sheath material that bonds the components
together forming an integral gastric balloon and valve combination.
The gastric balloon is inserted into a patient in a deflated state
and inflated after insertion. Following insertion of the gastric
balloon, a fluid, typically sterile saline, is injected into the
gastric balloon via the filler tube 30. Other fluids, including
air, silicone, pseudogel, oil, etc., may be used to fill an
implant.
[0033] To inflate the gastric balloon, the valve 10 must have a
slit 24. The slit 24 is preferably a single separation of two sides
of the valve body 14. The slit 24 is formed during manufacturing by
inserting a sharp thin tool (not shown) into the valve body 14. The
length of the slit 24 is variable depending on the application of
the valve and the desired opening pressure of the valve. In certain
applications it may be necessary to insure that slit valve permits
backflow more readily. In such instances, a shorter slit length
would be used, whereas in instances where greater pressure must be
contained by the valve, a longer slit length is desirable.
[0034] To effectuate inflation via the filler tube 30, the
injection tip 32 is inserted into the opening 16 of the flange 12.
The distal end of injection tip 32 extends to form a seal with neck
19. When pressurized fluid is injected through the filler tube 30
and orifice 37 of the injection tip 32, a higher pressure is
created in the second chamber 26 having two effects. The first is
to increase the sealing pressure of the neck 19 on the injection
tip 32. The second effect is to force the slit 24 to open. The
decreased wall thickness of the valve body 14 in the area of the
second chamber 26 is more readily deformed by the pressurized fluid
injected into the second chamber 26 than the area--of the slit 24.
The increased pressure causes the second chamber 26 to expand in a
direction substantially perpendicular to the direction of the slit
24. This expansion in turn causes the slit 24 to be opened and
permits the flow of fluid from the second chamber 26 through the
slit 24 and into the implant. The opening of the slit is assisted
by the concave surface 20. Similarly, if the second surface--22 is
also concave, sufficient pressure may be applied to the shell to
overcome the backflow resistance of the valve to permit the flow of
fluid through the slit 24 to the exterior of the implant. Due to
the relative sizes of the second chamber 26 and the concave surface
22, a far greater pressure is required to permit the backflow of
fluid from the implant out of the valve than is required for
inflation. For this reason the balloon or other implant may also be
deflated or reduced in volume by inserting a small diameter probe
or tube completely through the valve and into the interior of the
implant shell. Concave surface 20 assists in guiding the
small-diameter probe or tube into and through the valve body
14.
[0035] The valve 10 and the filler tip 32 when used in combination
create a system that overcomes many of the shortcomings of the
prior art. Through the use of the opening 16 and its interaction
with the reduced diameter portion 40 of the injection tip 32, and
also because of the interaction of the neck 19 with the injection
tip 32, the injection tip is held firmly in place and is prevented
from being forced out of the valve 10 during the injection of fluid
through the valve 10. Further, because of these same features,
withdrawal of the injection tip 32, when desired by the user, is
greatly eased requiring less than 4 lb (17.8 N) of force to remove
the tip from a balloon filled to 700 cm.sup.3. Still further, the
valve 10 provides for a device that does not leak under normal
operating conditions yet still allows for two-way flow. The valve
of the present invention allows continuous fluid flow at 30 psi
(2.11 Kg/cm.sup.2) and can safely withstand fluid fill pressures of
up to 40 psi (2.81 Kg/cm.sup.2) without damage to the valve.
[0036] FIG. 10 depicts another aspect of the present invention.
FIG. 10 shows a valve 11 having many of the features of the valve
10 shown in FIGS. 3-6. Valve 11 has a first concave surface 20, a
second concave surface 22, and a slit 24, all housed in a body 14.
The valve 11 operates in a similar fashion to valve 10. Upon
application of a predetermined fluid pressure to one of either the
first or second concave surfaces, 20 or 22, the slit 14 will open
and allow fluid to pass. However, at pressures below the
predetermined value, the slit valve insures that there is no fluid
flow. The relative geometries of the concave surfaces 20, 22, the
length of the slit 24, and the valve body 14 determine the opening
pressure of the valve 11 and whether a greater pressure is required
for flow in one direction compared to flow in the other direction.
Such a valve would be useful in applications where the use of a
flange 12, as shown in FIG. 3, is undesirable or unfeasible, for
example in a feeding tube or a drug delivery shunt.
[0037] Although the invention has been particularly shown and
described with reference to certain preferred embodiments, it will
be readily appreciated by those of ordinary skill in the art that
various changes and modifications may be made therein without
departing from the spirit and scope of the invention.
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