U.S. patent number 3,707,146 [Application Number 04/621,174] was granted by the patent office on 1972-12-26 for means to inject a plastic into a cavity to produce a replica thereof.
This patent grant is currently assigned to Products Research & Chemical Corporation. Invention is credited to Ralph J. Cook, Clifford C. Moline, Joseph M. Schumann.
United States Patent |
3,707,146 |
Cook , et al. |
December 26, 1972 |
MEANS TO INJECT A PLASTIC INTO A CAVITY TO PRODUCE A REPLICA
THEREOF
Abstract
The particular embodiment of the invention disclosed herein is
specifically designed to produce a soft resilient plastic
impression of the interior configuration of a body cavity, the
invention having special utility for the purpose of medical
diagnosis for exploring the lower portion of the large intestine.
For this purpose, the invention provides a catheter for insertion
into the body cavity in combination with a disposable cartridge
containing isolated ingredients of a fast curing polymer, the
cartridge being adapted for rapid preparatory intermixture of the
ingredients and immediate extrusion of the mixture to and through
the catheter.
Inventors: |
Cook; Ralph J. (Torrance,
CA), Moline; Clifford C. (Malibu, CA), Schumann; Joseph
M. (Inglewood, CA) |
Assignee: |
Products Research & Chemical
Corporation (Burbank, CA)
|
Family
ID: |
24489049 |
Appl.
No.: |
04/621,174 |
Filed: |
March 7, 1967 |
Current U.S.
Class: |
600/593; 604/920;
604/98.02; 604/97.02 |
Current CPC
Class: |
A61B
5/1078 (20130101); A61B 1/00082 (20130101); B29C
39/026 (20130101); A61M 31/00 (20130101); A61M
3/005 (20130101); B29C 39/24 (20130101); A61M
25/02 (20130101); A61M 25/10183 (20131105) |
Current International
Class: |
B29C
39/24 (20060101); B29C 39/02 (20060101); A61B
5/107 (20060101); A61M 25/02 (20060101); A61B
1/12 (20060101); A61M 25/10 (20060101); A61M
31/00 (20060101); A61M 3/00 (20060101); A61b
005/10 () |
Field of
Search: |
;128/2,218M,218NV,220,230,234,235,237,240-246,276,344,349-351
;222/132,136,309,497 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Truluck; Dalton L.
Claims
We claim:
1. In a medical device of the character described for injecting an
uncured fluent plastic material into a cavity of a patient's body
to be cured therein to form a soft resiliently flexible molded
replica of the configuration of the interior of the cavity, the
combination of:
a catheter for insertion into the cavity, said catheter including
an injection nozzle for introduction of the uncured plastic;
a guard flange fixedly united with the catheter to limit the
insertion of the injection nozzle;
an absorbent collar embracing the catheter forward of the guard
flange for confinement between the guard flange and the patient's
body when the catheter is inserted into the cavity,
said collar being made of a soft porous material to serve as a
cushion and to absorb and retain fluids released from the cavity
after the catheter is inserted and during the injection operation;
and
means to release to the atmosphere air that is displaced into the
catheter by the flow of plastic to the catheter thereby to prevent
the displaced air from causing a misleading void in the molded
replica.
2. In a medical device of the character described for injecting an
uncured fluent plastic into a cavity of a patient's body to be
cured therein to form a soft resiliently flexible molded replica of
the configuration of the interior of the cavity, the combination
of:
a catheter for insertion into the cavity, said catheter including
an injection nozzle for introduction of the uncured plastic;
means including a passage means to deliver uncured plastic to the
catheter;
a hollow cuff embracing the catheter rearward of the tip of the
nozzle for inflation to close off the body cavity back of the
nozzle during the injection operation; and
means to release to the atmosphere air that is displaced from said
passage means into the catheter by the advance of the plastic
through the supply passage thereby to avoid entrapment of such
displaced air in the cavity as would prevent the plastic from
filling the cavity.
3. A combination as set forth in claim 2 in which said means to
release air has a flow passage of restricted cross section to
prevent significant diversion of the uncured plastic into the flow
passage.
4. A combination as set forth in claim 2 which includes a passage
means connected to the catheter and a cartridge connected at its
front end to the passage means,
said cartridge having a plurality of separate compartments to store
separate ingredients of the uncured plastic,
said cartridge including a dasher operable from the rear end of the
cartridge to intermix the ingredients to form the uncured
plastic,
said cartridge including means to extrude the uncured plastic into
the passage means.
5. A combination as set forth in claim 2 in which said catheter has
a guard rearward of the nozzle tip fixedly secured thereto to limit
insertion of the catheter into the body cavity; and
in which said releasing means extends through the guard to the
region rearwardly thereof.
6. A combination as set forth in claim 5 which includes an
absorbent collar embracing the catheter forward of the guard for
confinement between the guard and a patient's body when the
catheter is inserted into the cavity,
said collar being made of a soft porous material to serve as a
cushion and to absorb and retain fluid released from the body
cavity after the catheter is inserted and during the injection
operation.
7. A combination as set forth in claim 5 in which said catheter,
hollow cuff and guard are covered by a layer of plastic material
forming a smooth surface that is continuous from the region of the
tip of the injection nozzle to the rim of the guard.
8. A combination as set forth in claim 2 which includes a cartridge
connected at its forward end to the catheter to deliver uncured
plastic thereto,
said cartridge having a plurality of separate compartments to store
separate ingredients of the uncured plastic,
said cartridge including a dasher manually operable from the rear
end of the cartridge to intermix the ingredients to form the
uncured plastic,
said cartridge including manually operable means to extrude the
uncured plastic into the catheter.
9. Means for intermixing a plurality of ingredients and then
promptly dispensing the mixture, comprising:
a dispensing container having a forward end and a rearward end with
a normally closed dispensing port in the forward end,
said container having multiple compartments for multiple
ingredients of the mixture;
means operable from the rear end of the dispensing container to
bring said ingredients together;
dasher means operable from the rear end of the dispensing container
to intermix the ingredients;
means operable from the rear end of the dispensing container to
extrude the ingredients through said dispensing port; and
valve means normally closing said dispensing port,
said valve means being in the form of a tubular valve member
slidingly telescoped into the dispensing port to control flow
therethrough,
said tubular valve member protruding from the dispensing port to
form a dispensing nozzle capable of attachment to a flexible tube
by insertion of the valve member into the end of the tube,
said tubular valve member being axially retractable from a forward
closed position to a rearward open position.
10. A combination as set forth in claim 9 which includes manually
releasable means to retain the valve member normally at its forward
closed position.
11. A combination as set forth in claim 10 in which said manually
releasable means is a removable locking member in engagement both
with the dispensing container and with the valve member to hold the
valve member in closed position.
12. A combination as set forth in claim 11 in which said valve
member has a peripheral rearwardly facing shoulder and said
container forms a forwardly facing shoulder;
and in which said locking member is a U-shaped member to releasably
embrace the valve member with opposite sides of the U-shaped member
in abutment with said two shoulders respectively.
13. Means for intermixing a plurality of ingredients and then
promptly dispensing the mixture, comprising:
a dispensing container having a forward end and a rearward end with
a normally closed dispensing port in the forward end;
a dispensing piston in said dispensing container defining therewith
a first ingredient-containing compartment in communication with the
dispensing port;
a dasher in said first compartment;
a manually operable rod extending from the dasher through the
piston to the rear end of the dispensing container to actuate the
dasher independently of the piston,
said rod being hollow to form a second ingredient-containing
compartment;
means operable from the rear end of the operating rod to extrude
the content of said second compartment into the first compartment;
and
manual means to operatively connect the piston to the rod member
for actuation of the piston by the rod member to extrude the mixed
ingredients from the first compartment through the dispensing
port.
14. A combination as set forth in claim 13 which includes:
a normally closed valve at the inner end of the hollow rod, said
valve being responsive to pressure in the hollow rod to open in
response to rise in the pressure; and
a second piston normally closing the outer end of the hollow rod,
whereby said second piston may be manually advanced towards said
pressure-responsive valve to create pressure within the hollow rod
member to open the pressure-responsive valve and then to displace
the content of the second compartment into the first
compartment.
15. Means for intermixing at least two ingredients and then
dispensing the mixture, comprising:
a container having compartments to store the ingredients
separately, said container having a forward dispensing port and
having a rearward piston serving as a rear wall for one of the
compartments;
means to place the compartments in communication with each other to
bring the ingredients into mutual contact;
a dasher to intermix the mutually contacting ingredients;
a manually operable rod slidingly extending through the rearward
piston to reciprocate said dasher; and
manually operable means to connect the piston to the rod for
actuation of the piston by the rod to extrude the mixed ingredients
from the container through the dispensing port,
said means to operatively connect the rod to the piston
comprising:
shoulder means on the periphery of the rod;
and a cooperative retainer element outside of the container
slidingly mounted on the rod and normally spaced from said shoulder
means,
said retainer element being manually movable into engagement both
with said shoulder means and with the piston for the purpose of
operatively connecting the piston to the rod.
16. A combination as set forth in claim 15 in which said retainer
element is slidingly mounted on the rod and which includes a sleeve
slidingly embracing the rod to serve as manual means for pushing
the retainer element from its normal position to a position in
engagement with said shoulder means.
17. A combination as set forth in claim 15 in which said shoulder
means comprises a circumferential groove on the periphery of the
rod and said retainer element is a snap ring slidingly embracing
the rod.
18. A combination as set forth in claim 17 which includes a sleeve
slidingly embracing the rod, said sleeve being manually operable to
push said snap ring into said circumferential groove.
19. In a medical device of the character described for injecting an
uncured fluent plastic material into a cavity of a patient's body
to be cured therein to form a soft resiliently flexible molded
replica of the configuration of the interior of the cavity, the
combination of:
a catheter for insertion into the cavity, said catheter including
an injection nozzle for introduction of the uncured plastic;
a dispensing container having a forward dispensing port connected
to said catheter;
said container having multiple compartments for multiple
ingredients of the mixture;
means operable from the rear end of the dispensing container to
bring said ingredients together;
a dasher operable from the rear end of the dispensing container to
intermix the ingredients;
manual means operable from the rear end of the dispensing container
to extrude the ingredients manually through said dispensing port;
and
means to prevent extrusion from the dispensing container while the
dispensing container is connected to the catheter when the dasher
is in operation.
20. In a medical device of the character described for injecting an
uncured fluent plastic material into a cavity of a patient's body
to be cured therein to form a soft resiliently flexible molded
replica of the configuration of the interior of the cavity, the
combination of:
a catheter for insertion into the cavity, said catheter including
an injection nozzle for introduction of the uncured plastic;
a dispensing container having a forward end with a dispensing port
for connection with the catheter;
a dispensing piston in said dispensing container defining therewith
a first ingredient-containing compartment in communication with the
dispensing port;
a dasher in said first compartment;
a manually operable rod extending from the dasher through the
piston to the rear end of the dispensing container to actuate the
dasher independently of the piston,
said rod being hollow to form a second ingredient-containing
compartment;
means operable from the rear end of the operating rod to extrude
the content of said second compartment into the first compartment;
and
manual means to operatively connect the piston to the rod member
for actuation of the piston by the rod member to extrude the mixed
ingredients from the first compartment through the dispensing
port.
21. In a device for injecting an uncured plastic into a cavity to
form therein a replica of the cavity that is sufficiently
resiliently deformable to permit withdrawal of the replica without
destroying the configuration of the replica, the combination
of:
a catheter for insertion into the cavity;
a dispensing container having a forward end and a rearward end with
a dispensing port in the forward end;
said container having multiple compartments for multiple
ingredients of the plastic;
means operable from the rear end of the dispensing container to
bring said ingredients together;
means operable from the rear end of the dispensing container to
intermix the ingredients;
means operable from the rear end of the dispensing container to
extrude the ingredients through said dispensing port;
a hollow valve member slidingly mounted in the dispensing port and
protruding axially from the dispensing port to serve as a
dispensing nozzle; and
a flexible tube having one end telescoped over said hollow valve
member and having its other end connected to the catheter to place
the dispensing container in flow communication with the
catheter,
said hollow valve member being axially retractable from a forward
closed position to a rearward open position,
whereby manually telescoping the end of the tube over the hollow
valve member involves applying axial force to the valve member to
retract the valve member to its open position.
22. In a medical device of the character described for injecting an
uncured fluent plastic into a cavity of a pateient's body to be
cured therein to form a soft resiliently flexible molded replica of
the configuration of the interior of the cavity which includes a
catheter for insertion into the cavity and means to extrude the
fluent plastic into the cavity through the catheter,
the improvement comprising:
means to release to the atmosphere air that is displaced from the
interior of the catheter by initial advance of the extruded plastic
thereby to avoid forcing the displaced air into the cavity and
consequent failure of the plastic to substantially completely fill
the cavity.
23. In a method of diagnosing the condition of a cavity of a living
person wherein a catheter with a passage therethrough is inserted
into the cavity and uncured plastic material is extruded through
said passage into the cavity to result in a soft resilient flexible
replica of the configuration of the interior of the cavity, and
wherein escape of the plastic material from the cavity along the
outer surface of the catheter is blocked,
the improvement comprising:
venting air from said passage of the catheter to the atmosphere as
the plastic material progressively occupies the passage thereby to
prevent the air from being forced into the cavity with consequent
failure of the plastic material to substantially completely fill
the cavity.
24. In a medical device of the character described for injecting an
uncured fluent plastic into a cavity of a patient's body to be
cured therein to form a soft resiliently flexible molded replica of
the configuration of the interior of the cavity, the combination
of:
a catheter for insertion into the cavity for injection the uncured
plastic into the cavity through the catheter;
a hollow cuff embracing the catheter rearward of the leading end of
the catheter for inflation to close off the body cavity back of the
leading end of the catheter during the injection operation;
a cartridge containing a supply body of the uncured plastic,
said cartridge having a dispensing port;
a tubular valve member in the dispensing port protruding therefrom
to serve as a nozzle for the cartridge;
a flexible tube connecting the tubular valve member to the
catheter, the upstream end of the tube being telescoped over the
tubular valve member,
the tubular valve member being retractable from a forward closed
position to a rearward open position whereby manually telescoping
the upstream end of the tube over the protruding end of the tubular
valve member involves applying axial force to the valve member to
retract the valve member to its open position;
means to extrude the uncured plastic from the container to the
catheter through said dispensing port, said tubular valve member
and through the flexible tube; and
a vent tube placing the interior of the catheter near its leading
end in communication with the atmosphere to release to the
atmosphere air that is displaced from said flexible tube by the
advance of the plastic through the flexible tube thereby to avoid
such entrapment of displacement air in the cavity as would keep the
plastic from substantially filling the cavity.
Description
BACKGROUND OF THE INVENTION
Broadly described the invention is a means for injecting a fast
curing plastic into a cavity to produce a replica of the interior
configuration of the cavity where the shape of the cavity would
make it impossible to withdraw a rigid replica from the cavity. The
required replica is produced by a plastic that cures to form a soft
resiliently deformable plastic body that is capable of yielding in
shape as required for withdrawal and when withdrawn may be relied
upon to return to the exact configuration of the cavity.
Medical diagnosis by this procedure has now become possible by the
development of a plastic material that has the following necessary
characteristics: (1) physiologically inert in the sense of being
harmless to internal surfaces of the human body; (2) sufficiently
fluent in uncured state for extrusion from a dispensing container
into a body cavity; (3) quick setting to cure in a short time
period, preferably well under 5 minutes; (4) capable of being
molded to stable solid state by light contact with soft internal
body surfaces to produce an accurate configuration of the internal
body surfaces; (5) rubber-like when cured and sufficiently soft and
resilient for yielding distortion as required for withdrawal
through restricted portions of the body cavity without physical
harm to the tissues and without undue discomfort to the patient and
capable after such distortion of returning to precisely the
configuration of the cavity. A suitable plastic for this purpose
that is produced by The Dow Chemical Co. and is available from
Travenol Laboratories Inc., Morton Grove, Illinois, is a
polysiloxane foam produced by catalyzing a silicon polymer by
stannous octoate. Mixing together the polymer and catalyst produces
a fluent uncured plastic which begins to cure in less than 1 minute
and completely cures in approximately 3 minutes.
One subcombination of the structure for practicing the invention is
a suitable catheter through which the uncured plastic is extruded
from a dispensing container into a body cavity such as the lower
portion of the large intestine. It has heretofore been proposed to
provide such a catheter with a guard flange to limit the extent to
which the catheter may be inserted into a body cavity and it has
also been proposed to provide the catheter with an enlargement for
the dual purpose of retaining the catheter in the body cavity and
of preventing reverse extrusion of the uncured plastic out of the
body cavity. It has been further proposed to provide such an
enlargement in the form of a thin walled cuff that may be collapsed
to facilitate insertion of the catheter and after insertion may be
inflated to an effective size by an external means, for example, by
a pump in the form of an elastomer bulb.
One problem relating to such a catheter that is solved by the
present invention is that while such an enlargement is effective
for its two purposes, nevertheless it cannot be depended upon to
prevent leakage from the body cavity of small amounts of fluid
including body fluids and residuals of fluids previously introduced
to evacuate the cavity in preparation for the molding
operation.
Another problem solved by the invention arises from the fact that a
passage space of substantial volume exists between the dispensing
port of the container and the nozzle of the catheter. Displacement
of the air from this passage space into the body cavity by
extrusion of the plastic interferes with the injection of the
plastic and results in trapping of air in the cavity with
consequent deformation of the molded plastic.
A second subcombination of the invention is a dispensing container
in the form of a disposable cartridge that stores the polymer and
catalyst in separate compartments and is adapted not only for
intermixing the two ingredients but also for connection to the
catheter for prompt extrusion of the uncured plastic into the body
cavity.
Examples of multiple compartment disposable cartridges capable of
mixing and dispensing uncured plastic are disclosed in the Cook
U.S. Pat. No. 3,144,966 in Class 222, Sub Class 136 and in the Cook
U.S. Pat. No. 3,153,531 in Class 259, Sub Class 113. While these
prior art cartridges are effective for their intended purposes of
mixing and dispensing sealants for industrial use they are not
suitable for the present invention because of the requirement that
the separate ingredients be thoroughly intermixed and dispensed
into the body of the patient within the total time period of 45
seconds. In both disclosures of the two above-mentioned Cook
patents, the ingredients are intermixed by a dasher on an operating
rod that extends through the dispensing port of the cartridge and
normally closes the dispensing port. Consequently, the operating
rod must be withdrawn to open the dispensing port after the mixing
operation and in addition further manipulation of the cartridge
structure is required to ready the cartridge for actual extrusion
of the uncured plastic.
An important problem to which the present invention is directed is
to avoid these disadvantages by providing a disposable dispensing
cartridge that may be manipulated in a simple and convenient manner
to intermix the different ingredients and to dispense the mixture,
all within 30 seconds without requiring specialized skill or even
experience and practice. This problem involves the more specific
problem of providing a simple, reliable, fool-proof and easily
explained step-by-step procedure for producing the desired
diagnostic plastic replica.
Other more specific problems to which the invention is directed
include: elimination of the need for manipulating a dasher by means
extending through the dispensing port of the cartridge so that the
dispensing port may be continuously available for transferring the
uncured plastic to the catheter; the problem of providing an
operating rod that may be freely reciprocated through a dispensing
piston independently of the piston to actuate a dasher beyond the
dispensing piston, which operating rod may be subsequently directly
connected to the dispensing piston for the purpose of extruding the
plastic mixture; the problem of providing a positively locked
dispensing valve to prevent premature extrusion of the mixture
through the dispensing port of the cartridge without the penalty of
losing precious time to unlock the valve; the problem of enabling
the normally closed dispensing valve to open automatically in
response to the step of connecting the cartridge to the catheter;
the problem of providing a dispensing cartridge in which the mixing
operation may be carried out while the cartridge is connected to
the catheter, thus making it possible to connect the cartridge in
advance if it is desired to eliminate the necessity of making the
connection during the allowed 30 seconds; and the problem of
constructing the catheter and dispensing cartridge so economically
that the whole combination may be disregarded after one use to
avoid the need for cleaning and sterilizing the combination for
repeated use.
SUMMARY OF THE INVENTION
The problem presented by minor leakage of fluid from the body
cavity of the patient past the inflated enlargement of the catheter
is met by dimensioning the catheter and its guard flange to provide
space between the guard flange and the body of the patient to
accommodate a suitable sponge and by providing such a sponge in the
form of a collar made of foamed plastic or the like. Such a collar
may be easily mounted on the catheter or removed from the catheter
while the catheter enlargement is deflated. The sponge collar not
only captures and retains the leakage fluid but also serves as a
cushion for the flanged guard to minimize discomfort to the
patient.
The problem created by the presence of air in the passageway
between the dispensing port of the cartridge and the nozzle of the
catheter is solved by providing a vent tube which establishes
communication between the ambient atmosphere and the interior of
the catheter nozzle. It has been found that such a vent tube may
serve its purpose even when it is sufficiently restricted to
prevent any significant diversion of the advancing plastic along
the vent path.
The problem of avoiding use of the dispensing port at the front end
of the cartridge for carrying out the mixing operating is solved by
extending a dasher-actuating rod through the dispensing piston from
the rear end of the cartridge thereby making the dispensing port
continuously available.
The problem of enabling an operating rod initially to actuate the
dasher independently of the dispensing piston and subsequently to
operate the dispensing piston is solved by slidingly mounting the
operating rod in the dispensing piston and by providing means to
subsequently connect the operating rod directly to the dispensing
piston.
In the preferred practice of the invention the subsequently
operable means comprises a circumferential groove in the operating
rod, a snap ring to seat in the groove and a manually operable push
sleeve to shift the snap ring along the operating rod to the
groove. After employing the operating rod to reciprocate the dasher
for thoroughly intermixing the two ingredients, it is a simple
matter to retract the operating rod to bring the dasher into
abutment with the leading face of the dispensing piston and then to
seat the snap ring in the groove at the rear face of the piston for
fixedly connecting the piston to the operating rod.
The problem of providing the cartridge with a positively locked
dispensing valve that may be quickly unlocked at the end of the
mixing operation is solved by providing a valve member that
protrudes through the dispensing port and is opened by axial
retraction into the dispensing port. An easily removable locking
collar normally embraces the protruding portion of the valve member
to keep the valve member in its extended closed position. It is a
simple matter to remove the locking collar to free the valve member
for axial retraction to its open position.
The problem enabling the dispensing valve to open in response to
the step of connecting the cartridge to the catheter is solved by
making the valve member hollow and by connecting the cartridge to
the catheter by telescoping the end of a connecting tube over the
protruding end of the valve member. Thus with the lock removed from
the dispensing valve member, the mere act of manually forcing the
connecting tube over the end of the valve member pushes the valve
member rearward to its open position.
Solving the above mentioned problems relating to the operation of
the dispensing cartridge also solves the problem of making it
possible to connect the cartridge to the catheter in advance
thereby to eliminate the need to make the connection within the
allowed thirty seconds. At the end of the mixing operation it is
necessary merely to pull the valve lock free and then push the
dispensing cartridge slightly forward relative to the connecting
tube to retract the dispensing valve member to its open position.
There is no special need for making such a connection in advance of
the mixing operation, however, because of the above described
time-saving features of the dispensing cartridge and some operators
prefer to have the dispensing cartridge disconnected from the
catheter for greater freedom to perform the mixing operation.
The problem of producing the whole assembly so inexpensively that
it may be discarded after a single use is solved largely by making
both the catheter and the dispensing cartridge out of plastic parts
that may be molded on a mass production basis. In addition the
various parts are designed to make possible a simple assembly
procedure that requires neither special skill nor special
tools.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which are to be regarded as merely
illustrative;
FIG. 1 is a longitudinal sectional view of the device showing the
dispensing container connected to the catheter;
FIG. 2 is a greatly enlarged longitudinal sectional view of the
catheter;
FIG. 3 is a longitudinal sectional view of the dispensing cartridge
serving as a multiple compartment container prior to use of the
device;
FIG. 4 is a face view of the dasher in the dispensing
cartridge;
FIG. 5 is an enlarged fragmentary sectional view showing the valve
at the inner end of the hollow operating rod, the valve being in
closed position;
FIG. 6 is a view similar to FIG. 5 showing the valve in open
position;
FIG. 7 is a fragmentary longitudinal sectional view showing the
operating rod retracted for the purpose of operatively connecting
the operating rod to the piston;
FIG. 8 is an enlarged longitudinal sectional view of the dispensing
end of the cartridge with the dispensing valve closed and locked;
and
FIG. 9 is a perspective view of the clip for locking the dispensing
valve in closed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the operation of injecting an uncured polymer
into the rectum of a patient to mold a replica of the interior
configuration of the sigmoid colon. It is obvious that a rigid
molded replica could not be withdrawn from the colon whereas an
exceedingly soft and flexible replica may be expelled by the
patient.
The preferred embodiment of the invention shown complete in FIG. 1
comprises the combination of a catheter, generally designated 10,
and a dispensing container, generally designated 12, that is
releasably connected to the catheter by means of a flexible tube
14. It will be appreciated that both the catheter and the
dispensing container may be of various constructions within the
scope of the invention. A feature of the preferred practice of the
invention is that both the catheter 10 and the dispensing container
12 are disposable for discard after a single use.
The catheter 10 has a one-piece molded body 15 of relatively rigid
plastic material, the body being of tubular configuration with an
integral rearwardly flared guard flange 16. The forward end of the
tubular body 15 is formed with nozzle apertures 18 and the rear end
of the tubular body is telescoped into the forward end of the
previously mentioned flexible tube 14. A feature of the invention
is that the tubular body 15 is embraced by a resilient absorbent
collar 20 forward of the guard flange 16, which collar is
preferably made of a suitable open-celled foamed plastic with
sponge-like characteristics. The guard flange 16 limits the extent
to which the catheter may be inserted into the body cavity and the
collar 20 not only serves as a cushion but also absorbs minor
leakage of fluid from the body cavity during the injection
procedure.
The tubular body 15 of the catheter 10 is provided with a cuff 22
of relatively thin elastomeric material which is deflated when the
catheter is inserted into the body cavity and then is inflated to
serve the dual purpose of preventing inadvertent withdrawal of the
catheter during the injection operation and of blocking leakage of
the polymer from the body cavity during the operation. For the
purpose of inflating the cuff 22 when desired, a small flexible
tube 24 extends from the interior of the cuff along an exterior
groove 25 (FIG. 2) of the tubular body 15 and through the guard
flange 16. The second end of the small tube is connected to a
bulb-type hand pump 26 of a well known type, the pump being
provided with a manually operable release valve 28. The catheter is
inserted into the body cavity with the cuff 22 deflated and then
the cuff is inflated by manual operation of the bulb-type pump.
After the plastic replica cures, the release valve 28 is
manipulated to deflate the cuff in preparation for withdrawal of
the catheter.
Preferably the catheter 10 is covered with a smooth layer 29 of a
suitable material such as latex which extends from the nozzle end
of the catheter to the rim of the guard flange 16. The purpose of
this layer is to provide a smooth surface for the catheter. In the
construction shown the tubular body 15 of the catheter is slightly
reduced in diameter to form a rearwardly circumferential shoulder
30 against which the forward edge of the layer 29 abuts in a flush
manner.
In the preferred practice of the invention the catheter is provided
with a small flexible vent tube 31. The forward end of the vent
tube is inside the tubular body 15 near the nozzle apertures 18 and
the tube extends outward through an aperture 32 of the tubular body
rearward of the guard flange 16. When the uncured plastic is
advanced through the flexible tube 14 into the tubular body 15 of
the catheter, the air displaced by the advancing polymer escapes to
the atmosphere through the vent tube 31. The vent tube 31 is of
sufficiently restricted internal diameter to prevent any
appreciable amount of the uncured polymer from entering the tube
after the air is expelled.
The container 12 is a disposable plastic cartridge which is
provided with a dispensing piston 34 for the purpose of extruding
the uncured plastic into the flexible tube 14 and through the
catheter 10 into the body cavity. The dispensing piston 34 is
adapted to be actuated manually by a rearwardly extending operating
rod that terminates in a handle or palm knob 36.
A feature of the invention is that the dispensing container 12 also
serves as a multiple compartment container to store the separate
ingredients of the plastic material prior to use of the device as a
dispensing means. FIG. 3 shows the dispensing container or
disposable cartridge 12 in the form in which it is handled and
shipped prior to use.
As shown in FIG. 3 the cartridge has a cylindrical shell of
suitable plastic material, the shell being reduced in diameter at
the front to form a nipple 38 that provides the discharge port of
the container. The rear open end of the cylindrical shell is
equipped with a ring 40 having an axial opening 42 to clear the
operating rod 35, the purpose of the ring being to reinforce the
rear end of the shell and to serve as a stop to prevent inadvertent
withdrawal of the dispensing piston 34.
As shown in FIG. 3 the dispensing piston 34 is initially in a
retracted position to cooperate with the shell of the container to
form a first relatively large compartment 44 for the silicone
polymer. The operating rod 35 is of hollow or tubular construction
to form a second smaller compartment 45 for the required catalyst.
For this purpose the outer end of the tubular operating rod 35 is
closed by a small slidable plug 46 which may be termed a second
piston and the inner end of the tubular operating rod is normally
blocked by a valve member 48 which is adapted to open in response
to rise in pressure in the second compartment.
As shown in FIGS. 5 and 6, the inner end of the tubular operating
rod 35 is reduced in diameter to form an outlet port 50 and a
tapered inner circumferential shoulder 52 leading to the outlet
port. The valve member 48 has a rear end enlargement 54 for guiding
cooperation with the inner wall of the operating rod and has a
forward end portion 55 which is formed with a slight
circumferential enlargement 56 to seal off the outlet port 50. The
valve member 48 is formed with a passage 58 through the rear
enlargement 54, the passage communicating with a longitudinal
recess 60 in one side of the valve member.
At the normal closed position of the valve member 48 shown in FIG.
5, the forward end portion 55 seals off the outlet port 50 of the
tubular operating rod. When the second piston 46 is manually
advanced in the tubular operating rod, the consequent rise in fluid
pressure of the catalyst inside the operating rod causes the valve
member 48 to be advanced from its retracted closed position shown
in FIG. 5 to its forward open position shown in FIG. 6. Thus
manually forcing the second piston 46 forward to the region of the
valve member 48 results in extrusion of the catalyst from the
second compartment 45 into the first compartment 44.
The preferred embodiment of the invention includes a ram rod 62
formed with a palm knob 64 at one end, the ram rod being initially
releasably tied to the dispensing container by means such as string
65. It is contemplated that the length of the ram rod 62 will be
such that when the palm knob 64 abuts the palm knob 36 of the
operating rod 35, the second piston 46 will reach the open valve
member 48 for substantially complete extrusion of the catalyst into
the first compartment 44.
The operating rod 35 is permanently connected at its inner end to a
dasher 66 which is of a suitable configuration for efficient mixing
action in response to reciprocation of the dasher by the operating
rod 35. As shown in FIG. 4, the dasher 66 preferably has two
openings 68 in two of its quadrants, the remaining half of the
dasher being blank. The operating rod 35 initially slidingly
extends through the dispensing piston 34 to permit reciprocation of
the dasher 66 independently of the dispensing piston.
Any suitable means may be provided to fixedly connect the
dispensing piston 34 to the operating rod when the time arrives for
using the piston to dispense the mixed uncured polymer. In this
particular embodiment of the invention the tubular operating rod 35
is provided with a circumferential groove 70 to cooperate with a
split snap ring 72 and when it is desired to operate the dispensing
piston 34, the snap ring is advanced from a retracted position to a
position seated in the groove 70. At the seated position of the
snap ring 72, the snap ring abuts the rear side of the dispensing
piston and the forward side of the dispensing piston abuts the
dasher 66. Thus the seated snap ring, in effect clamps the
dispensing piston 34 against the dasher 66.
A feature of this embodiment of the invention is the provision of a
plastic sleeve 74 which loosely embraces the operating rod 35 to
serve as manual means for pushing the snap ring 72 from its
restricted position to its effective seated position. FIG. 3 shows
the snap ring 72 and the plastic sleeve 74 in their normal
retracted positions. FIG. 7 shows the tubular operating rod 35
fully retracted to bring the dasher 66 against the front wall of
the dispensing piston 34. With the operating rod 35 fully retracted
in this manner, it is a simple matter to advance the plastic sleeve
74 manually from its retracted position to the position shown in
solid lines in FIG. 7 for the purpose of advancing the snap ring 72
into engagement with the circumferential groove 70.
The dispensing port at the forward nipple 38 of the dispensing
cartridge may be normally closed in any suitable manner. A feature
of this particular embodiment of the invention is the use of a
special valve member 75 for this purpose which is tubular to permit
dispensing flow therethrough and which is adapted to serve as a
fitting for connecting the dispensing container to the previously
mentioned flexible tube 14.
As best shown in FIG. 8 the dispensing valve member 75 is closed at
its inner end by a transverse wall 76, and is further provided with
a radial flange 78 at its rear end which normally abuts the inner
rim of the dispensing port. The valve member 75 is further provided
with a radial port 80 which is normally closed by the inner
circumferential wall 82 of the dispensing port. A substantial
portion of the valve member 75 protrudes forward from the
dispensing port of the container and the protruding portion of the
valve member is formed with a rearwardly facing circumferential
shoulder 84 and a series of rearwardly inclined sharp ribs 85,
which ribs serve as barbs for engagement with the inner
circumferential wall of the flexible tube 14. It is apparent in
FIG. 8 that at the forward position of the valve member 75 that is
shown in solid lines, the valve member completely cuts off the
dispensing port and when the valve member is retracted to the
position shown in dotted lines with the shoulder 84 in abutment
against the forward rim 86 of the nipple 38, the uncured plastic
material may be extruded through the valve member, the plastic
material flowing into the radial port 80 of the valve member.
When the dispensing container is handled, stored and shipped prior
to use, the dispensing valve member 75 is locked in its forward
closed position by means of a locking clip 88, the locking clip
being interposed between the shoulder 84 of the valve member and
the forward rim 86 of the nipple 38. As best shown in FIG. 9 the
locking clip 88 has a curved body 90 dimensioned to extend more
than half way around the valve member 75. The locking clip is made
of sufficiently resilient plastic material to yieldingly grip the
valve member in a removable manner and the clip is formed with a
ribbed tab 92 to serve as a convenient handle for removing the
clip.
The manner in which the described structure serves its purpose may
be readily understood from the foregoing description.
The catheter 10 with the flexible tube 14 connected thereto but
separated from the dispensing container 12 is inserted into the
body cavity and then the cuff 22 is inflated by means of the pump
device 26. The first step in preparation for the injection
operation is to reciprocate the dasher 15 for approximately fifteen
full length strokes by means of the operating rod 35, stopping with
the dasher approximately half way through the last stroke. When the
polymer formula in the first compartment 44 stands for considerable
period of time, there is a tendency for segregation of the liquid
and solid ingredients and the purpose of this initial mixing action
is to make the polymer homogeneous.
The next step is to use the ram rod 62 to force the second piston
46 forward in the tubular operating rod 35 thereby to move the
valve member 48 to open position for extrusion of the catalyst from
the second compartment 45 into the first compartment 44. The ram
rod is advanced to the maximum to displace substantially all of the
catalyst. The displacement of the catalyst into the first
compartment 44 starts the time period of 30 seconds during which
the two ingredients of the uncured plastic must be thoroughly
intermixed. After this 30 -second time interval the extrusion of
the mixed plastic into the body cavity must be completed within an
additional time interval of 15 seconds before the plastic starts to
cure. Thorough intermixture of the two ingredients is required and
is accomplished by reciprocating the operating rod 35 for its full
length approximately 25 times. The introduction of the catalyst
into the first compartment 44 causes the dispensing piston 34 to
retract slightly on the first stroke of the operating rod.
The mixing operation is terminated with the operating rod 35 fully
retracted and then the plastic sleeve 74 is advanced from the
position shown in FIG. 3 to the position shown in FIG. 7 for the
purpose of shifting and seating the snap ring 72 to anchor the
dispensing piston 34 to the operating rod.
The next step is to grasp the tab 92 of the locking clip 88 to
remove the locking clip and thus free the dispensing valve 75. With
the locking clip removed, the barbed end of the dispensing valve 74
is inserted into the end of the flexible tube 14. This act of
forcing the dispensing valve member 75 into the tube 14 causes
retraction of the dispensing valve to its open position in reaction
to the applied force. Thus the operator is not required to take
time to open the dispensing valve. With the dispensing valve open,
the operator advances the dispensing piston 34 to the maximum by
means of the operating rod 35 to extrude the uncured plastic
through the flexible tube 14 and through the catheter 10 into the
body cavity. After a short time, the release valve 28 of the bulb
pump 26 may be opened for deflation of the cuff 22 to permit
withdrawal of the catheter.
Our description in specific detail of the preferred embodiment of
the invention will suggest various changes, substitutions and other
departures from our disclosure within the spirit and scope of the
appended claims.
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