U.S. patent number 3,826,256 [Application Number 05/217,468] was granted by the patent office on 1974-07-30 for catheter delivery device.
This patent grant is currently assigned to Medidyne Corporation. Invention is credited to Gordon E. Smith.
United States Patent |
3,826,256 |
Smith |
July 30, 1974 |
CATHETER DELIVERY DEVICE
Abstract
In a device for ejecting a catheter into a passageway like a
blood vessel, the device including a housing containing a catheter
extending or extendable into a feeding nose, such as a cannulated
needle, the housing interior to be fluid pressurized to effect
fluid flow around the catheter. The catheter is inwardly
compressible and of a size where the outer diameter is about equal
to and preferably somewhat greater than the inner diameter of the
needle lumen. The build-up of fluid pressure within the housing of
the device was found to compress the catheter making it of a
smaller diameter than the needle lumen and in the process forming,
at least during the initial stages of catheter movement, a catheter
with a piston-like profile so that the catheter is impelled by
fluid friction and piston action.
Inventors: |
Smith; Gordon E. (Sun Prairie,
WI) |
Assignee: |
Medidyne Corporation (Chicago,
IL)
|
Family
ID: |
22811211 |
Appl.
No.: |
05/217,468 |
Filed: |
January 13, 1972 |
Current U.S.
Class: |
604/159; 221/278;
226/97.1; 221/64 |
Current CPC
Class: |
A61M
25/0122 (20130101) |
Current International
Class: |
A61M
25/01 (20060101); A61m 005/18 () |
Field of
Search: |
;128/214.4,221,218R,262,348-351 ;221/64,278 ;226/97 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: McGowan; J. C.
Attorney, Agent or Firm: Wallensteen, Spangenberg, Hattis
& Strampel
Claims
I claim:
1. In a medical device for injecting an elongated member into a
passageway of the body of an animal or human, the device including
a housing having a feeding nose portion with means for emplacing
the feeding nose portion in said passageway and from which feeding
nose portion said elongated member is to be ejected into said
passageway after the feeding nose portion has been inserted
therein, said feeding nose portion having an open-ended lumen
communicating with a fluid-holding space within said housing, said
housing to contain fluid to be pressurized and including means for
effecting the pressurizing of said fluid so as to cause a flow of
fluid through said lumen and around an elongated member therein
with sufficient velocity to impel the elongated member
therethrough, the improvement comprising: an elongated member
contained within said housing space, said elongated member having
limp and elastic consistency and extending into or in close
proximity to said lumen of said feeding nose portion, said
elongated member having an outside diameter at least about the size
of the minimum diameter of the lumen of said feeding nose portion
so as not to be freely passable through the lumen when the
elongated member is in its initial state, said elongated member
being sufficiently compressible that under said fluid
pressurization the elongated member compresses to a size less than
said minimum diameter of said lumen where fluid is forced by said
pressure around the elongated member in said lumen to eject the
same therefrom, and means for preventing the ejection of the rear
end portion of the elongated member from said feeding nose portion
lumen.
2. The medical device of claim 1 wherein the portion of the
elongated member to be ejected from the lumen is at least about the
size of substantially all portions of the lumen of said feeding
nose portion.
3. The medical device of claim 1 wherein the lumen of said feeding
nose portion has a construction therein and the portion of the
elongated member to be ejected from the lumen is at least about the
size of said construction but smaller than the size of the rest of
the lumen.
4. The medical device of claim 1 wherein the portion of the
elongated member to be ejected from the lumen is initially slightly
larger than substantially all portions of the lumen of said feeding
nose portion.
5. The medical device of claim 1 wherein said pressure effecting
means is a manually movable means which is a part of said medical
device, said elongated member being so compressible that a modest
application of force applied to said movable means is sufficient to
create the pressure in said housing which compresses the elongated
member to a size less than said minimum diameter of the feeding
nose portion lumen.
6. The medical injection device of claim 2 wherein said pressure
effecting means is a manually movable means incorporated in said
medical device, said elongated member being so compressible that a
modest application of force applied to said movable means is
sufficient to create said pressure in said housing which compresses
the elongated member to a size less than said minimum diameter of
the feeding nose portion lumen.
7. The medical device of claim 1 wherein said elongated member is a
catheter having a passageway extending therethrough.
8. The medical device of claim 7 wherein said fluid is a sterile
liquid but said housing is initially free of such liquid, there is
provided connector means for filling said housing with said sterile
liquid from a source of such liquid which may have only a few feet
of head pressure, the rear end of said catheter is permanently
completely open, and said catheter having such a length such that
the resistance to liquid flow through said passageway thereof
reduces the pressure therein at the points where the catheter
engages the walls of said feeding nose portion lumen, so that
filling said housing with said liquid at said head pressure
provides sufficient pressure around the catheter at said points
that the catheter will compress so said liquid and air ahead of the
same pass around the catheter.
9. The medical device of claim 7 wherein said fluid is a sterile
liquid but said housing is initially free of such liquid, there is
provided connector means for filling said housing with said sterile
liquid from a source of such liquid which may have only a few feet
of head pressure, said catheter is of insufficient length that
liquid flow through the same under said head pressure will cause a
sufficient pressure drop at the points where the catheter engages
the walls of said feeding nose portion lumen to enable said head
pressure to compress the catheter to permit flow of air and fluid
flow around the catheter, and there is provided catheter closure
means for obstructing the open rear end of said catheter to produce
said pressure drop at said points where the catheter engages the
walls of the feeding nose portion lumen.
10. The medical injection device of claim 9 wherein said feeding
nose portion is a cannulated needle, said means for preventing the
ejection of the rear end of said catheter including an enlargement
on the end thereof which is not compressible by said fluid
pressurization to the degree to pass through said lumen of said
needle under the fluid pressure and which becomes frictionally
locked in the needle lumen when it reaches the same, the fluid
pressure in the catheter then expanding the catheter outwardly to
lock the same in the lumen, and said catheter closure means
temporarily initially obstructs said rear open end of said catheter
so that the ejection of said catheter through said feeding nose
portion lumen separates the rear end of the catheter from said
catheter closure means.
11. The medical device of claim 10 wherein said catheter closure
means includes a portion projecting loosely within the rear end of
the catheter.
12. The medical device of claim 11 wherein said device is provided
with a compressible tubular extension having a passageway for
making connection between an external source of liquid to
constitute said fluid in said device and the interior of said
housing, there being a plug-forming member snugly fitted within
said passageway to close the same off from the exterior of the
device, said tubular extension when pinched between the user's
fingers elongates in a given direction to separate the same from
said plug-forming member at the points of elongation thereof to
form clearance spaces for the passage of said liquid into said
housing, and said portion projecting into said rear end of the
catheter being a forwardly projecting extension on said
plug-forming member.
13. The medical device of claim 4 wherein the front end of the
elongated member is initially positioned immediately contiguous to
the inlet end of the lumen of said feeding nose portion.
14. The medical device of claim 13 wherein the front end of said
elongated member is tapered readily to be guided into said feeding
nose portion lumen.
15. In a medical device for feeding a catheter into a blood vessel
or other passageway, the device comprising a housing defining a
catheter holding space and including a feeding nose portion through
which the catheter is to be guided into said passageway, a catheter
in said space, the catheter being made of a resilient readily
manually stretchable material and having an enlarged portion at the
rear end portion thereof which blocks the complete passage thereof
from said space so the rear end portion of the catheter cannot be
ejected from the device, said enlarged portion at the rear end of
the catheter being such that by manually pulling on the portion of
the catheter projecting from the feeding nose portion the enlarged
portion will distend to a point where the catheter slips from said
space through said feeding nose portion, and a liquid-passing
adapter means adapted to fit a complimentary liquid-passing
connector communicating with a liquid-holding container, said
adapter means having an open-ended passageway the defining walls of
which are initially in spaced surrounding relation to said catheter
but slidably frictionally fits around said feeding nose portion,
said adapter means and catheter, on the one hand, and at least said
feeding nose portion of said housing on the other hand, being
manually separable after the catheter has been injected into said
passageway by pulling the same relatively apart, said adapter means
passageway having at least one portion within which the enlarged
rear end portion of the catheter sealingly fits, the improvement
comprising: pull tab means attached to said adapter means and
extendable to a point beyond the end of said feeding nose portion
where the pull tab means and an ejected portion of the catheter can
be held together with one hand while a part of said housing is
grasped with the other hand, so that by pulling one hand away from
the other the adapter means and catheter can be separated from the
feeding nose portion.
16. The medical device of claim 15 wherein said pull tab means is a
flexible elongated member extendable to a point substantially
beyond the end of said feeding nose portion, the initial inlet end
of said adapter means is positioned forwardly of said enlargement
on said catheter when the enlargement is in said locked portion in
said housing, said flexible elongated pull tab member being adapted
initially to be positioned against a portion of the ejected
catheter at the end of the feeding nose portion where there is
slack in the pull tab member and when pulled outwardly with the
catheter from this point until the pull tab is taut the catheter is
distended and pulled without movement of said adapter means, the
slack in said pull tab member when initially positioned at the end
of said feeding nose portion is such that when the catheter and
adapter means are finally separated from the feeding nose portion
by continuation of the pulling of said pull tab member and
catheter, the catheter is at least in the vicinity of said adapter
means where it quickly contracts into a position adjacent to or
inside of said adapter means passageway to avoiding striking
contaminated surface.
17. The medical device of claim 16 when said slack in said pull tab
member is equal to the distance the catheter must be distended to
finally release the rear end of the catheter for movement in said
housing.
18. The medical device of claim 15 wherein the initial normal
position of said adapter means and the enlarged portion of said
catheter in said blocked position is such that upon pulling said
pull tab member and catheter to the point where both are separated
from said feeding nose portion, the rear end of the catheter is
located inside of said adapter means passageway.
19. The medical device of claim 15 wherein said enlarged portion on
the end of said catheter is of a size to become frictionally locked
within said feeding nose portion upon catheter ejection, and said
adapter means is slidably and frictionally mounted around said
feeding nose portion.
20. The medical device of claim 15 wherein said adapter means is
initially mounted around said feeding nose portion and includes a
main body portion made of a relatively rigid material which body
portion includes a passageway which loosely surrounds the feeding
nose portion, a resilient expandable sleeve anchored in the latter
passageway and expanded into frictional engagement around said
feeding nose portion, and the enlarged portion of said catheter
being pullable into sealing relation with said sleeve when said
catheter and adapter means are pulled from said feeding nose
portion, the sleeve being expanded by said enlarged portion of the
catheter against the defining walls of said adapter means
passageway.
21. The medical device of claim 15 wherein said pull tab means has
an opening at the inner end thereof which receives and surrounds
said feeding nose portion at a point rearwardly of said adapter
means, said housing having a portion projecting outwardly thereof
behind said inner end of said pull tab means, said pull tab means
being confined between the rear end of said adapter means and said
enlarged portion of said housing, a forward pull on said pull tab
means bringing the inner end of the pull tab means against the rear
end of said adapter means to move the same forwardly along said
feeding nose portion.
22. The medical device of claim 20 wherein said expandable sleeve
in said adapter means passageway is anchored to said passageway by
a holding member removably anchored within the rear end of said
adapter means passageway which holding member includes an open
ended passageway the defining walls of which initially loosely fit
around said feeding nose portion and upon removal of the adapter
means from the feeding nose portion receives and surrounds a
portion of the catheter ejected from the device, said holding
member being removable from said main body portion of the adapter
means to free the rear end portion of said adapter means passageway
to receive said complimentary liquid-passing connector.
23. The medical device of claim 15 wherein said adapter means has a
main body portion with a relatively flat side adapted to lay
against the skin where the main body portion can be immobilized
thereagainst by a strip of adhesive tape applied thereover.
24. The medical device of claim 23 wherein said main body portion
has outwardly extending portions providing substantial surface
areas both longitudinally and transversely of the main body portion
to stabilize the same when resting against a skin surface.
25. The medical device of claim 23 wherein said main body portion
has outer surfaces meeting the longitudinal side margins of said
flat surface at an acute angle thereby forming relatively thin
longitudinal edges so adhesive tape enveloping the same makes
contact with the skin adjacent the point where it makes contact
with the main body portion of the adapter means.
26. In a device for feeding a catheter through a feeding nose into
a blood vessel or other passageway, the device including a body
from which the feeding nose extends, the body and feeding nose
defining a space, a catheter in said space to be fed through the
feeding nose into the passageway involved, the catheter being made
of a resilient readily manually stretchable material and having an
enlarged portion at the rear end portion thereof which prevents the
passage thereof from said space so the rear end portion of the
catheter cannot be ejected from the device, said enlarged portion
at the rear end of the catheter being such a size that, by manually
pulling on the portion of the catheter projecting from the feeding
nose, the enlarged portion will distend to a point where the
catheter slips from said space through said feeding nose, the
improvement comprising a liquid-passing adapter means adapted to
fit a complimentary liquid-passing connector communicating with a
liquid-holding container, said liquid-passing adapter means
including a main body portion made of a relatively rigid material
and including a passageway the defining walls of which loosely
surround said feeding nose, a resilient expandable seat-forming
sleeve anchored in said passageway and frictionally engaging around
said feeding nose, said adapter means and catheter, on the one
hand, and at least said feeding nose, on the other hand, being
manually separable after the catheter has been injected into said
passageway, and said enlarged portion of said catheter being
pullable into sealing relation with the interior of said sleeve
when said catheter and adapter means are pulled from said feeding
nose, the sleeve being sized to be expanded by the presence therein
of the enlarged portion of said catheter against the defining walls
of said adapter means passageway.
27. The device of claim 26 wherein said seat-forming sleeve is
anchored within said passageway of said main body portion of the
adapter means by a holding member removably anchored within the
rear end portion of said passageway, said holding member being made
of a relatively rigid material and having an open ended passageway
which is initially loosely received around the feeding nose and
which when the adapter means is removed from the feeding nose, is
removable from the rear end of said passageway of said main body
portion of the adapter means to provide clearance for the insertion
of said complimentary liquid-passing connector.
Description
This invention relates to a catheter delivery device which
incorporates the invention of and is an improvement over the
catheter delivery devices disclosed in my application Ser. No.
54,732 entitled METHOD AND APPARATUS FOR CATHETER INJECTION filed
July 14, 1970. The catheter injection devices disclosed in this
application and the catheter device which is the subject of the
present invention utilize the build-up of fluid pressure in a
catheter housing having a feeding nose for guiding the catheter, to
cause the flow of fluid between the catheter and the inside wall of
the feeding nose (which may be a cannulated needle) to inject the
catheter within a body passageway such as a blood vessel. Where the
catheter is to be injected into a blood vessel, the catheter
material is most advantageously very limp to minimize irritation of
the blood vessel walls and to enable the catheter readily to follow
irregular paths within the blood vessel.
It is desirable to make the outside diameter of the catheter as
close as possible to the outer diameter of the needle through which
it passes, so that upon removal of the needle after catheter
injection, the skin, blood vessel wall and other tissue punctured
by the needle will contract as tightly as possible around the
catheter to minimize leakage of fluid around the catheter. Ideally,
therefore, although limitations on the operation of catheter
delivery devices heretofore was thought to mitigate against the
same, it would be desirable for the catheter diameter to be equal
to and even greater than the diameter of the defining walls of the
needle lumen through which it is guided into a blood vessel or
other passageway. However, despite the obvious desirability for
catheters of a diameter as close to the needle diameter as
possible, prior to the present invention, catheters placed in body
passageways, like blood vessels, using the lumen of a cannulated
needle or other feeding nose as an exterior guiding means, were
always of a size smaller than the lumen of the guiding means, so
that the catheter can freely slide or pass through the lumen. For
example, if a stiff catheter of the same size as the lumen of the
guiding means is utilized, the friction between the catheter and
the lumen would be such that the catheter could not be advanced
through the lumen of the guiding means. Even in the case of limp
flexible catheters like that used in the catheter delivery devices
disclosed in said co-pending application, where the catheter is
ejected from the lumen of the guiding means by the flow of fluid
around the catheter, it was thought necessary to utilize a catheter
diameter smaller than the diameter of the lumen of the guiding
means by a number of thousandths of inches to provide clearance for
the ready flow of fluid around the catheter so the fluid would not
flow through the catheter and expand the same against the lumen of
the guiding means, and to keep the manual compression forces
necessary to build up a fluid force of a sufficiently high velocity
to forcibly eject the catheter within limits which can be readily
provided by the nurses and doctors expected to use the catheter
delivery devices. Thus, in one exemplary form of the invention, the
catheter utilized had a 0.047 inch outside diameter when used with
a cannulated needle having a cannula diameter of 0.052 inch. In
such case, the pressure developed by the manual compression of a
squeeze bulb in a liquid filled housing was sufficient to eject a
long catheter an appreciable length from the catheter delivery
device involved. In such case, the impelling force on the catheter
is the friction between the fast moving stream of liquid moving
around the catheter and the outside walls of the catheter. It was
found that in mass producing the catheter delivery devices of
certain catheter sizes, a certain percentage of the catheters would
not eject from the devices.
In the present invention, for a given needle size, a larger
catheter can be ejected from the needle than was thought heretofore
possible and greater catheter ejection velocities are obtained for
a modest increase in fluid pressure making catheter injection more
effective, especially in circumstances when the catheter must be
ejected substantial distances through irregular paths within blood
vessels and the like. Moreover, the present invention has
substantially reduced the reject ratios to a point where
practically all manufactured catheter delivery devices are operable
in ejecting their catheters with appreciable velocities.
The present invention is based on my discovery that where an
elastic catheter which is compressible is utilized, most preferably
one made of a soft, very pliable rubber-like material having the
limp resilient and inert quality of a silicone elastomer and the
outer diameter of the catheter is made at least about equal to at
least the minimum diameter of the needle lumen (i.e. some needle
lumens have a variation in diameter) and preferably at least equal
to or, even better, slightly larger than the diameter of the entire
length of a needle lumen, where it would be assumed that the fit
between the catheter and defining walls of the needle lumen would
prevent any catheter ejection, the catheter is actually ejected at
a higher velocity and more readily for a modest increase in manual
force applied to a squeeze bulb or the like than in the case where
a small but finite clearance was provided as described above.
In examining into the possible reasons, it was concluded that the
fluid pressure within the catheter delivery device housing was
instrumental in compressing the catheter so that the catheter
within the needle lumen is very closely spaced from the walls of
the needle lumen during the application of the fluid pressure.
Also, for a given pressure, a greater velocity of fluid flow
results in the very small clearance between the catheter and needle
lumen walls which increases the fluid shear forces acting on the
catheter. The pressure acting on the catheter is believed to
provide, during at least the initial catheter ejection operation, a
forwardly and outwardly flaring profile which provides a rearwardly
facing shoulder against which the force of fluid ejected from the
needle lumen is applied to substantially increase the ejection
force on the catheter. Thus, there is both a piston-like action and
an increased frictional force acting on the catheter aiding the
cather ejection process. It should be noted that where the catheter
is the same size or larger than substantially the entire length of
the needle lumen while the increase of fluid pressure within the
housing of the catheter delivery device provides an external inward
compressive force on the radially outwardly facing surfaces of the
catheter located rearwardly of the needle lumen, one would think
that the radially outwardly facing surfaces of the portion of the
catheter inside the needle lumen with which the catheter makes
engagement are not so exposed and thus remain uncompressed where it
cannot be moved from the needle. However, the junction between the
initially compressed and uncompressed portions of the catheter is
not an abrupted right angled juncture, but is a gradually forwardly
and outwardly flaring portion which has both radially outwardly and
rearwardly facing components, so that there is a surface against
which the pressure can act to compress the same radially inwardly.
The aforementioned forwardly and outwardly flaring profile of the
catheter, which initially is located at the point where the
catheter first enters the needle lumen of the same or smaller size,
under the application of fluid pressure is caused to progressively
move down the length of the catheter toward the front of the
needle. Finally, the entire catheter leaves contact with the needle
lumen at the end of the needle lumen where the fluid pressure on
the catheter is greatly reduced permitting the catheter to expand
at this point to its initial size. The catheter then has a
piston-like profile at the end of the needle lumen and also, it is
believed, an outwardly flaring profile within the needle lumen and
so presents rearwardly facing surfaces against which the moving
fluid applies a force to aid in catheter ejection. Thus, at the
instant when the catheter looses contact with the needle lumen
walls, the catheter is free to be impelled by both the increased
frictional forces of the flow of fluid which then begins around the
catheter and also by the force of the fluid flow against the
rearwardly facing component of the catheter profile.
In the case where a needle hub is swaged upon the end of a
cannulated needle body, there is generally produced an inwardly
extending shoulder at the point where the swaging operation is
carried out which is of lesser size than the rest of the needle
lumen. A piston-like action described above can be achieved by a
catheter having a diameter which is equal to or somewhat larger
than the diameter of the swaged portion of the needle lumen but of
a smaller diameter than the rest of the lumen. In this case, upon
application of fluid pressure, a piston-like profile is formed just
beyond the shoulder and since the catheter initially engages the
lumen over only a very small length of the needle lumen, the
catheter instantaneously leaves contact with the needle lumen and a
piston-like action immediately takes place to aid in moving the
catheter both by the friction of the moving fluid around the
catheter and by the force of fluid pressure against the rearwardly
facing portion of the catheter profile.
It should be noted that even if it were appreciated that the
application of fluid pressure within the housing of the catheter
delivery device provides an external inward compressive force on
the radially outwardly facing surfaces of the catheter initially
engaging the needle lumen walls, one would think also that there
would be an equal radially outwardly directed pressure on the
inside of the catheter which would cancel out such compressive
force. However, as soon as fluid starts to flow within the
catheter, there is a pressure drop along the catheter interior
which, because the rear end of the catheter is usually a
substantial distance from the point where the catheter makes
contact with the needle lumen walls, results in a substantial
pressure drop thereat. The substantial fluid pressures which are
readily built up within a catheter delivery device by the squeezing
of a bulb or the like was found easily to overcome any opposition
to compression of the catheter even when the catheter is larger in
size than the entire length of the needle lumen because of the
pressure drop within the catheter.
There is, however, a problem with regard to flushing air out of a
catheter delivery device of the invention where liquid is used to
impel the catheter into a blood vessel. In the most preferred form
of the present invention, the catheter delivery device is
manufactured in a state where it has to be subsequently filled with
a sterile liquid like saline solution or other liquid. When air is
expelled by the charging of the catheter delivery device having a
catheter of a smaller size than the needle lumen, by pointing the
needle end thereof upwardly and feeding liquid into the bottom
portion of the device, as the liquid rises within the device it
readily fills both the space around the catheter and the catheter
interior and drives the air ahead of the same. However, when the
catheter is made of a size where it engages the walls of the needle
lumen, the small head pressures which are normally present (for
example where an infusion liquid from a hanging infusion bottle is
caused to enter the catheter delivery device the head pressure is
usually only about 2-3 feet of liquid) are insufficient to overcome
the opposition to compression of the catheter for normal catheter
lengths (e.g. 9 inches) and some air remains trapped within the
device which is expelled when the catheter is impelled by the
liquid moving around the catheter.
Another aspect of the present invention, therefore, is in
overcoming this in one of two ways. In one form of the invention,
the catheter utilized is made of an unusually long length which
length depends upon the inside diameter of the catheter so that the
pressure drop occurring when the liquid rises in the catheter is so
substantial at the point where the catheter contacts the needle
lumen walls that even a few feet of head pressure is sufficient to
compress the catheter to permit liquid and air to pass air around
the catheter. In another form of the invention, where the catheter
is of a more common length, such as 9 inches, a similar result is
achieved by forming a partial obstruction at the rear of the
catheter which effects a substantial pressure drop or hinderance to
liquid flow at this point, so that in effect a similar pressure
drop is present at the points where the catheter makes contact with
the needle lumen walls.
In accordance with another feature of the present invention, the
catheter injection device is provided with its own valve so that at
any desirable time the device can be charged with a sterile liquid
and disconnected from the source of liquid and be ready immediately
to be used where the catheter injection operation is desired.
Another feature of the invention relates to an improved infusion
liquid-receiving adapter assembly carried on the feeding nose of a
catheter delivery device and which can easily be pulled from the
feeding nose together with the rear end portion of an ejected
catheter temporarily held in the feeding nose lumen, and then
sealingly related to the released end of the catheter.
The above and other features and advantages of the invention will
become apparent uponn making reference to the specification to
follow, the claims and the drawings wherein:
FIG. 1 illustrates an initially liquid-free catheter delivery
device in its packaged condition;
FIG. 2 is a longitudinal, sectional view through the catheter
delivery device shown in FIG. 1, after it is removed from the
package;
FIG. 3 is an enlarged, longitudinal, sectional view through the
rear end portion of the catheter delivery device of FIG. 2, taken
along section line 3--3 therein;
FIG. 4 is an enlarged, transverse, sectional view through the rear
end portion of the catheter delivery device of FIG. 2, taken along
section line 4--4 therein;
FIG. 5 is an enlarged, transverse, sectional view through the front
end portion of the catheter delivery device shown in FIG. 2, taken
along section line 5--5 thereof;
FIG. 6 is a view showing the catheter delivery device of FIGS. 1-5
connected to an infusion bottle assembly for filling the delivery
device with liquid and oriented to expunge air therefrom;
FIG. 7 is a transverse sectional view of that portion of the rear
end of the catheter delivery device shown in FIG. 4 when the
portion shown in squeezed to open the check valve formed
thereby;
FIG. 8 is an enlarged, fragmentary, longitudinal, sectional view
through the front end portion of the catheter delivery device of
FIGS. 1-4 during the time air is being expunged therefrom;
FIG. 9A is a greatly enlarged, fragmentary, longitudinal sectional
view of the front and rear end portions of the catheter containing
portions of the catheter delivery device of FIGS. 1-8 after having
been filled with liquid and prior to the application of fluid
pressure within the same and when the catheter has a diameter equal
to the diameter of the main portion of the needle lumen;
FIG. 9B is a longitudinal, sectional view corresponding to FIG. 9A
during the instant when fluid pressure has been applied to the
fluid within the catheter delivery device of FIG. 9A but prior to
the bodily movement of the catheter from the catheter delivery
device;
FIG. 9C is a longitudinal, sectional view corresponding to FIGS. 9A
and 9B at the moment the catheter within the device has a
configuration where the flow of fluid is impelling the same from
the needle thereof;
FIG. 9D is a longitudinal sectional view of the base portion of the
needle and the enlarged rear end portion of the catheter
frictionally locked within the base of the needle after completion
of a catheter ejection operation;
FIG. 10A is a greatly enlarged, fragmentary, longitudinal,
sectional view of the front and rear end portions of the catheter
containing portions of the catheter delivery device of FIGS. 1-8
after having been filled with liquid and prior to the application
of fluid pressure within the same, and when the catheter has a
diameter just equal to the diameter of the narrow swaged point of
the needle lumen;
FIG. 10B is a longitudinal, sectional view corresponding to FIG.
10A during the instant when fluid pressure has been applied to the
fluid within the catheter delivery device of FIG. 9A but prior to
the bodily movement of the catheter from the needle thereof;
FIG. 10C is a longitudinal, sectional view corresponding to FIGS.
10A and 10B at the moment the catheter within the device has a
configuration where the flow of fluid is impelling the same from
the catheter delivery device;
FIG. 11 is a greatly enlarged view of the front end portion of the
catheter containing portions of the catheter delivery device of
FIGS. 1-8 after having been filled with liquid and prior to the
application of fluid pressure within the same, and when the
catheter has a diameter greater than that of the main portion of
the needle lumen;
FIG. 12 is an enlarged, longitudinal, sectional view of the
depressible bulb-like portion of the catheter delivery devices of
FIGS. 1-11 after the bulb-like portion has been fully compressed to
eject the catheter from the catheter delivery device;
FIG. 13 is a view showing the separation of the assembly of the end
of the catheter, infusion liquid-receiving adapter and associated
sleeve from the needle and the attached tubing;
FIG. 14 is a longitudinal, sectional view of the catheter and the
infusion-receiving adapter after the catheter has been fully pulled
into interlocking relationship with the adapter and the adapter
attached to the complimentary connector of an infusion bottle
assembly shown in FIG. 6;
FIG. 15 is a partially sectional view though a modified form of
catheter delivery device which includes a unique infusion
liquid-receiving adapter construction;
FIG. 16 is a fragmentary longitudinal sectional view through the
adapter holding portion of the catheter delivery device of FIG. 15
taken along section lines 16-16 therein;
FIG. 17 is a fragmentary, longitudinal, sectional view showing the
front portion of the catheter delivery device in FIG. 15 with the
catheter injected into a blood vessel and the needle withdrawn from
the blood vessel and in the process of being pulled over the
catheter and through the infusion liquid-receiving adapter;
FIG. 18 is a partly broken away view of the remaining portion of
the infusion liquid-receiving adapter and catheter of FIG. 17 after
separation from the needle, portions of the adapter have been
discarded, the catheter has been pulled securely into interlocking
relationship with the remaining portion of the adapter, and the
adapter taped to the patient's body; and
FIG. 19 is a transverse sectional view through the taped remaining
portion of the adapter of FIG. 18, taken along section line 19--19
thereof.
As shown in FIG. 1, an embodiment of the catheter delivery device
of the invention identified by reference number 1 is shown
initially packaged in a sterilized state in a suitable transparent
package or container 2 in which the device may be sterilized in a
conventional way. The catheter delivery device 1 as illustrated is
designed for injecting a catheter 3 through a cannulated needle 4
or the like into a blood vessel. However, the device can be
modified for other uses and with or without the use of a cannulated
needle as a tissue piercing catheter guiding means. The catheter
delivery device 1 includes a catheter containing body assembly 6
comprising a main tubular body portion 6a which may be made of a
suitable transparent synthetic plastic tubing. The rear end of the
tubing terminates in a laterally extending bulb-like portion 6b,
also made of a synthetic plastic material, which is the fluid
pressure applying means of the catheter injection device 1.
(However, other fluid pressure applying means could be used in the
present invention other than bulb-like portion.) The cannulated
needle 4 is connected to the front end of the tubing 6a by a hollow
needle hub 8 which is somewhat larger than the tubing 6a and over
which hub the tubing is securely anchored. The needle 4 is anchored
within the hub 8. The lumen 4a of the needle 4 forms a continuation
of an open-ended passageway 14 within the tubing 6a. The catheter 3
has an intermediate portion 3a extending through the passageway 14
and a front end portion 3b extending part way into the needle 4.
Where the length of catheter desired is longer than the distance
between the bulb-like portion 6b of the catheter containing body
assembly 6 and a point near the forward end of the needle, the
intermediate portion 3a of the catheter 3 terminates at the rear
thereof in a coiled portion 3c confined in a neatly coiled relation
by the walls of the bulb-like portion 6b.
The bulb-like portion 6b is most advantageously a member having a
dome-shaped depressible wall 15 (FIG. 12). The tubing 6a has a rear
end portion which extends within a tubular extension 20 of the
cylindrical wall 17 where the tubing communicates with a chamber 22
within the bulb-like portion 6b. A short compressible tubular
section 24 extends rearwardly from the bulb-like portion 6b and has
a passageway 18 communicating with the chamber 22 and forming at
the end thereof a portion 18a for snugly receiving a connector 23
at the end of an infusion bottle assembly 26 (FIG. 6) or other
source of a sterile liquid like saline solution. (For blood vessel
applications, gases like carbon dioxide could be used instead of a
liquid, but liquids are greatly preferred as the catheter injection
fluid for this application). The tubular section 24 has friction
fitted in the front end portion of the passageway 18 a plug or
pinch valve-forming member 21 which closes the passageway 18. The
member 21 has a forwardly extending pin-like projection 21a (FIG.
3) over which the rear end portion 3d of the catheter most
desirably loosely extends to form a plug or hinderance to fluid
flow through the catheter. The pinching of the tubular section 24
elongates the cross-section thereof as shown in FIG. 7 to form
openings on opposite sides of the check valve-forming member for
passage of fluid into the catheter delivery device.
When the dome-shaped wall 15 is depressed, it preferably snaps into
an inverted shape as shown in FIG. 12, so that once the bulb is
fully compressed, the depressed wall 15 remains collapsed. However,
if the wall 15 is only slightly depressed and released, it returns
to its initial position. Such slight depression of the wall 15 is
sometimes carried out after the needle has been apparently placed
in a blood vessel as an aid in drawing some blood into the catheter
delivery device which, if visible through the transparent portions
of the device, indicates that the needle tip is located in a blood
vessel.
The end of the needle 4 carries a preferably transparent synthetic
plastic needle cover 25 best shown in FIG. 8 having an opening 25a
at the front end thereof. The needle cover has fixed therein a long
catheter holding member 27 which extends into the front end portion
of the needle lumen 4a to prevent movement of the catheter from the
needle when air is flushed from the device. The catheter holding
member 27, as illustrated, has a flat shank portion 27a
frictionally held in the needle cover and terminates in a head
portion 27b outside of the needle cover. The needle cover 25 has a
front cylindrical portion 25b defining a corresponding
cylindrically shaped passageway 25c therein, the defining walls of
which snugly engage the needle 4. The needle cover 25 has a
rearwardly outwardly flaring portion 25d which engages around the
front end portion of an infusion liquid-receiving adapter member 29
which is used to make connection to the connector 23 of an infusion
bottle assembly 26 shown in FIG. 6 after ejection of the catheter
from the catheter delivery device 1. The flat profile of the shank
portion 27a of the catheter holding member forms clearance spaces
through which air and liquid can pass through the needle lumen 4a
in front of the catheter and the opening 25a at the front end of
the needle cover after flowing between the catheter and the needle
lumen in a manner to be described. The needle cover 25 and the
catheter holding member 27 carried thereby are removed together as
a unit from the needle after air has been expunged from the
catheter delivery device. (Manifestly, the needle cover 25 and the
catheter holding member can have other configurations.)
The base portion of the needle 4 is initially tightly enveloped by
the defining walls of a passageway 46 in the nose portion 30 of the
infusion liquid-receiving adapter member 29 made of an expandable
resilient plastic material which has a hollow cylindrical rear
portion 31 which fits within the front end of a sleeve 34
preferably made of a transparent synthetic plastic material. The
rear end of the sleeve 34 has a flanged end portion 35 with an
opening 36 into a cylindrical space 39 within the sleeve 34. The
tubing 6a fits with a slide or loose fit into the rear sleeve
opening 36. The needle hub 8 secured to the front of the tubing 6a
makes a slide frictional fit within the sleeve 34 and can be
removed with the needle 4 from the sleeve by pulling the same
rearwardly to separate it from the sleeve, as shown in FIG. 13.
The catheter 3 is made of a material which is completely inert to
body fluids and tissue so it can remain indefinitely in the body
passage involved and does not irritate such tissue. The catheter
should also be very limp and elastic and most desirably when it is
to be coiled it should have a resiliency as well as the limpness of
gum rubber or a well cooked wet noodle. An example of what is meant
by a limp and elastic catheter is one which has an elongation of
450 to 800 percent as determined by a STM test procedure P 412.
Unlike gum rubber which is not inert to body fluids, a catheter
material which has all these qualities is silicone elastomer. Limp
materials like silicone elastomer remain in a fairly tightly coiled
condition idefinitely without any significant curvature setting
therein, so that the catheter will at all times uncoil in a
substantially straight condition (i.e. without any significant
curvature). If the catheter has any substantial curvature set
therein, it would catch on the walls of the needle or housing,
making it impossible to feed the catheter from the needle. The
resiliency of the catheter material enables the catheter to feed
easily from a coiled to a straight configuration and keeps the
coils neatly pressed against the walls of the bulb-like portion
6b.
The catheter 3 preferably has a two-step enlargement at the very
rear end thereof, the first enlargement being identified by
reference numeral 3d' and the second enlargement being identified
by reference numeral 3d" (FIG. 9A). The pin-like projection 21a of
the check valve-forming member 21 fits into the interior of the
first enlargement 3d preferably loosely but sufficiently close to
the catheter walls to reduce the opening therein to a size where
liquid cannot readily enter the same, causing a substantial
pressure drop when fluid tries to flow therethrough. For example, a
clearance of about 0.002 inch was found to be satisfactory in one
case. As shown in FIG. 9A, the outer diameter of the first
enlargement 3d' is somewhat greater than the inner diameter of the
needle lumen 4a and joins the portion of the catheter in front of
the same by a forwardly tapered portion 41 so that when catheter
ejection is initiated and the first enlargement reaches the needle
lumen 4a, the tapered part will become wedged in the needle lumen
4a and reduce the catheter clearance to zero. The wedging of the
tapered portion 41 of the first enlargement 3d' of the needl lumen
4a prevents any backward movement of the catheter which could bring
the catheter against the sharp end of the needle to sever the
catheter. Also, the enlargements 3d' and 3d" of the catheter are of
such a length and thickness that by pulling on the catheter 3 the
enlargements will distend in length and contract in diameter so the
catheter can be readily pulled through the needle 4.
Although the needle hub can have a variety of constructions, as
shown, for example, in FIG. 9A, it has a flanged portion 8a from
which extends a reduced forwardly projecting nose portion 8b
defining a passageway 8b' into which the cylindrical cannulated
needle 4 extends and is anchored as by swaging the nose portion
therearound. This forms a short inwardly projecting portion or
constriction at 4a' within the needle lumen which defines an
opening or constriction in the needle lumen of less diameter than
the rest of the needle lumen. The needle hub further has a
rearwardly projecting skirt portion 8c defining an inner
cylindrical bore 8c' of greater size than said nose portion
passageway 8a' and merging therewith through a tapered opening 8d.
The catheter enlargements 3d' and 3d" readily fit within the hub
bore 8c'. The hub bore 8c' communicates with the rear of the hub 8
through a flared entryway 8c". The outer surface of the skirt is
serrated at 45 to form a friction surface over which the tubing 6a
snugly fits.
As best shown in FIG. 14, when the adapter member 29 is separated
from the needle 4 after catheter ejection the connector 23 of the
infusion bottle assembly 26 shown in FIG. 6 fits into an initially
cylindrical opening 40 formed by the rear cylindrical portion 31
thereof. The adapter member 29 is also provided with a recess 42
behind the nose portion 30 for receiving the second enlargement 3d"
of the catheter 3 after completion of catheter ejection and the
removal of the adapter member and the catheter from the rest of the
catheter delivery device in a manner to be explained. The nose
portion passageway 46 of the adapter member after removal from the
needle contracts to a size smaller in size than the first
enlargement 3d' at the end of the catheter and into which such
enlargement 3d' is pulled and seals after catheter ejection.
As previously indicated, the catheter delivery device 1 impels the
catheter 3 by causing a relatively high velocity flow of fluid
between the catheter and the defining walls of the needle lumen.
This requires that at least during the time that the catheter is
being ejected from the catheter delivery device the catheter 1 must
be of a size and shape to pass freely through the needle lumen 4a.
As previously indicated, in accordance with the invention, catheter
ejection is most effectively achieved by making the compressible
catheter of an initial diameter such that it would not freely pass
through the needle lumen unless the size thereof would reduced from
its initial size, which is achieved by the compression of the
catheter when fluid pressure is applied thereto. The catheter is
thus made of a diameter so that it makes initial engagement with
the walls of the needle lumen 4a as, for example, shown in FIG.
9A.
The first step in using the catheter deliverly device 1 is to
connect the catheter delivery device to a source of a sterile
liquid like the infusion bottle assembly 26 shown in FIG. 6, by
removing the device from the package 2 and connecting the
rearwardly projecting tubular section 24 of the device to the
connector 23 at the end of the infusion bottle assembly 26. The
catheter delivery device is then picked up and held so that the tip
of the needle points upwardly, and a pinch clamp 46 of the infusion
bottle assembly is released to permit infusion liquid to pass to
the connector 23. The compressible tubular section 24 of the
catheter delivery device is then squeezed to permit the infusion
fluid to flow into the device until liquid flows through the
opening 25a at the end of the needle cover 25 indicating that the
air above the same has been expunged from the device. The tubular
section 24 is then released and disconnected from the infusion
connector 23. During the filling operation, the liquid readily
rises within the catheter delivery device and first fills the
bulb-like portion 6b and pushes any air upwardly ahead of the same.
The fluid also enters the rear or bottom end of the catheter
because it is only loosely obstructed by the pin-like projection
21a, to flush air from the catheter. When the air and the liquid
reaches the bottom portion of the needle lumen 4a, although the
catheter engages the walls of the needle lumen, the compressible
nature of the catheter and the lower pressure within the catheter
resulting from the drop in fluid pressure as the liquid flows
through the obstructed rear end of the catheter and the length of
the catheter behind the point where the catheter enters the needle
lumen enables the pressure caused by the pressure head of the
infusion bottle system slightly to compress the catheter so the air
and liquid can pass around the catheter and gain access to the
clearance spaces between the shank portion 27a of the catheter
holding member 27 and the upper or front end of the needle lumen
and between the shank portion 27a of the catheter holding member 27
and the needle cover 25, ultimately passing through the opening 25a
in the end of the needle cover.
When the catheter delivery device is ready to be used for catheter
injection, the needle cover 25 and the catheter holding member 27
carried thereby are removed by pulling the same from the end of the
needle 4. The needle 4 is then inserted into the blood vessel
involved and after a tourniquet has been applied in the usual
manner for needle insertion, the depresssible wall 15 of the
bulb-like portion 6b is fully depressed to inject the catheter 3
into the blood vessel involved.
In FIGS. 9A through 9B, the catheter 3 is shown as having a
diameter equal to the diameter of the needle lumen 4a (and
therefore somewhat greater than the diameter of the constricted
portion of the needle lumen at 4a'). For example, the constriction
at 4a' may be 0.003 inch less than the diameter of the rest of the
needle lumen. FIG. 9A illustrates the condition of the catheter
delivery device 1 before application of pressure thereto. When the
catheter 3 is lubricated with alcohol or the like, it has been
found that when its diameter is equal to the diameter of the needle
lumen the catheter can be manually slid by the lumen constriction
at 4a' into the position shown in FIG. 9A. When the bulb-like
portion 6b of the catheter delivery device is depressed, this
sudden application of appreciable pressure initially causes a
compression of the portion of the catheter positioned rearwardly of
the needle lumen 4b as shown in FIG. 9B. While this pressure is not
instantaneously applied to the radially outwardly facing surfaces
of the portion of the catheter within the needle lumen, which
surfaces contact the needle lumen walls, the juncture between the
compressed portion of the catheter within the tubing 6a and the
portion of the catheter within the needle lumen not yet compressed
is a gradually outwardly flaring portion 50. This outwardly flaring
portion exposes a small exterior portion of the catheter at the
base of the needle lumen to which the fluid pressure is applied and
this portion of the catheter is fully compressed to form another
outwardly flaring portion immediately in front of the same. It can
thus be seen that, upon initial application of fluid pressure, the
portion of the catheter within the needle lumen becomes
progressively compressed until the entire length thereof leaves
contact with the needle lumen walls. Then the flow of fluid is
instrumental in effecting movement of the catheter from the needle
lumen, and when the catheter reaches the outer end of the needle
lumen, as shown in FIG. 9C, the catheter sharply expands to the
diameter of the needle lumen. The pressure conditions against the
catheter vary somewhat along the length of the needle lumen from a
point where it leaves the needle lumen where the pressure is a
minimum and equal to the patient's blood pressure to a point deeply
within the lumen where a maximum pressure is realized. There will,
therefore, be a slightly progressive outward flaring of the
catheter for its full length within the needle lumen even after it
completely leaves contact with the needle lumen, and this outwardly
flaring portion of the catheter as well as the more sharply
outwardly expanding portion of the catheter as it leaves the needle
lumen provides rearwardly facing surfaces against which liquid
pressure is applied to form a piston-like action which cooperates
with the force applied to the catheter by the friction of fluid
flow therearound, to impart a greater impelling force to the
catheter.
Some liquid also flows into and along the inside of the catheter as
a result of the depression of the bulb-like portion 6a, but the
friction to such flow in the long and initially obstructed catheter
causes a substantial pressure drop in the catheter aiding in the
catheter compression described. The resulting high velocity flow of
liquid around the catheter causes such a sudden movement of the
catheter that the catheter movement occurs faster than the flow of
liquid in the catheter and little or no liquid actually flows out
of the catheter during catheter ejection. When the enlarged rear
end of the catheter reaches the base of the needle lumen 4a, the
tapered part 41 of the first enlargement 3d' of the catheter wedges
in the needle lumen walls. The rather large momentum of the
catheter does not pull the rear end of the catheter through the
needle lumen because when the enlargement reaches and enters the
needle lumen, there is suddenly only liquid flow in the catheter
(which has left the pin-like extension 21a) which causes a
resultant outward expansion of the catheter within the needle
lumen, firmly to lock the catheter in place within the needle
lumen.
The present invention also includes the use of a catheter whose
outer diameter is approximately equal to or slightly greater than
the diameter of the constricted portion of the needle lumen at 4a'
and somewhat smaller than the remaining diameter of the needle
lumen. This application of the invention is illustrated in FIGS.
10A, 10B and 10C which respectively show the condition of the
catheter before application of fluid pressure, at the instant of
initial application of fluid pressure and when the fluid pressure
and resultant fluid flow has caused the catheter to leave the
needle lumen. As shown in FIG. 10B, the initial compression of the
catheter instantaneously causes the catheter to lose contact with
the constriction of the needle lumen and thereby provides a
piston-like profile which is instantaneously instrumental in
effecting movement of the catheter from the lumen as it provides a
shoulder against which the fluid pressure propels the catheter
forwardly along with the friction of the moving fluid against the
sides of the catheter.
The present invention is also effective when the catheter is of a
greater size than the diameter of the needle lumen for its full
length, such as an oversize of 0.005 inch. In this embodiment of
the invention shown in FIG. 11, it is not readily possible to mount
the catheter within the needle lumen prior to the application of
pressure to the catheter. Accordingly, the front end of a
preferably modified catheter 3' having preferably a beveled tip 53
in the needle hub bore 8c' where there is preferably only the
tapered surface 8d in front of the oversized catheter against which
the catheter can strike. Upon application of fluid pressure by
depression of the bulb-like portion 6b, the catheter is guided into
the needle lumen adjacent to which it is located and is compressed
by the pressure conditions involved for the same reasons and in the
same manner as shown in FIGS. 9A-9C.
After catheter injection, the needle is withdrawn from the patient,
the user grasps the flanged portion 35 of the sleeve 34 with one
hand (usually the left hand) and pulls on the tubing 6a with the
other hand to bring the needle hub 8 against a small shoulder 55
(FIG. 12) at the rear of the sleeve 34 where the tip of the needle
is retracted within the infusion liquid-receiving adapter member
29. The assembly of the adapter member 29, the sleeve and the
catheter are held together as a unit by pinching the portion of the
sleeve 34 around the adapter 29 with one hand which compresses the
desirably compressible adapter around the catheter to hold the same
in place while the tubing 6a is pulled sharply with the other hand.
This stretches and elongates the catheter enlargement 3d' and 3d"
and the rest of the catheter to reduce the size thereof where it
slips from the needle lumen. The sleeve 34 now acts like a catheter
holding skirt by preventing the catheter from dropping upon
contaminating surfaces. The catheter is then pulled fully into the
adapter member 29 where it is drawn into its extreme position
therein, as shown in FIG. 14. The sleeve 34 is pulled from the
adapter member 29 and thrown away. The rear cylindrical portion 31
of the adapter member 29 may then be connected to the connector 23
of the infusion bottle assembly 26.
Refer now to FIGS. 15-19 which illustrates a modification of the
present invention involving, among other things, the elimination of
the sleeve 34 which is primarily for the purpose of protecting the
catheter when the catheter is pulled into position within the
adapter member 29, and the inclusion of a modified infusion
liquid-receiving adapter assembly 29'. Also, the catheter 3"
utilized is much longer than the catheters 3 previously described
in that it is not necessary to use an obstruction like the
plug-forming extension 21a in the open rear end of the catheter to
reduce the pressure at the point where the catheter engages the
needle lumen walls to an extent permitting the escape of air and
fluid around the catheter under relatively small pressure head
conditions. (The catheter 3" is, of course, fully impelled into the
blood vessel involved and after catheter ejection would be
withdrawn from the blood vessel an amount to leave the desired
length of catheter in the blood vessel.)
One of the reasons for the modified adapter assembly 29' in
addition to simplifying the construction of the device by
eliminating the sleeve 34, is that it permits a tighter fit between
it and the enlarged rear end of the catheter 3". It should be noted
that the adapter assembly 29' as well as the adapter member 29
previously described are preferably initially slidably mounted
around the exterior of the needle 4. In order to permit the
expandable adapter member 29 in the previously described
embodiments of the invention to be pulled along the needle without
too much difficulty, the smallest interior passage thereof cannot
be very much smaller than the needle diameter so the adapter member
is not stretched too tightly over the needle lumen. Accordingly,
when the catheter 3 is pulled into sealing position within the base
of the adapter member 29, it is sometimes possible to so distend
the enlarged end of the catheter (whose maximum size is limited) to
a point where it can be pulled completely through the not very much
smaller passageway of the adapter member in which it is to be
locked and sealed. This is not possible with the adapter assembly
29' now to be described.
As best shown in FIG. 15, the modified catheter delivery device,
although having a much longer catheter 3", is of the same overall
length as the previously described catheter delivery device 1, the
additional space for the longer catheter being obtained by
providing many more additional coils in the portion of the catheter
within the bulb-like portion 6b. Also, the enlarged rear end of the
catheter 3" is located completely within the bulb-like portion
6b.
As best shown in FIG. 16, the adapter assembly 29' includes a main
body member 58 which ultimately forms a liquid-passing connector
attachable to the said infusion bottle system connector 23 or other
connectors. The main body member which is preferably made of a
relatively rigid molded synthetic plastic material has a main
central tubular portion 58a having a straight passageway extending
from the inlet to the outlet end thereof. This passageway has a
relatively small front passageway portion 60a at the front end of
the main body member 58 which loosely receives the needle. The
front passageway portion 60a joins a relatively large passageway
portion 62, the front end of which is defined by an abutment
shoulder 64 formed by a transversely extending wall 66. An annular
groove 68 is formed in the larger passageway portion 62.
There is located at the forward end of the larger passageway
portion 62 of the main body member 58 a resilient rubber-like
seat-forming sleeve 70 which is expanded to fit over the needle 4.
The seat-forming sleeve 70 has a passageway 70' extending
therethrough, the defining walls of which in the contracted
condition of the sleeve form a slide friction fit with the catheter
3" and a very tight fit with the first enlargement 3d' at the end
of the catheter 3". The seat-forming sleeve 70 may be held in place
against the aforementioned shoulder 64 by a cylindrical holding
member 72 which fits within the rear end of the large passageway
portion 62 of the main body member 58. The holding member 72 is
releasably interlocked within the main body member 58 and projects
from the rear end thereof where it can be grasped after removal of
the adapter assembly 29' from the needle to separate it from the
main body member 58. To this end, the holding member 72 may include
an annular rib 72a on the outside thereof which releasably snaps
into the aforementioned annular groove 68 in the large passageway
portion 62 of the main body member 58. The holding member 72, which
is also preferably made of a relatively rigid synthetic plastic
material, has an open ended passageway 72b which loosely fits on
the needle 4.
The adapter assembly 29' is frictionally held on the base of the
needle by the seat-forming sleeve 70 which frictionally engages the
needle 4. However, the friction between the confronting surfaces of
the sleeve 70 and the needle 4 is such that a modest longitudinal
force applied to the entire adapter assembly 29' can pull the
assembly off of the needle 4. A needle cover 25' with a catheter
holding member (not shown) is removably secured around the front
end of the main body member 58.
The most advantageous means for effecting movement of the adapter
assembly 29' off of the needle 4 is a flexible elongated pull tab
75, which may be made of any suitable material which can withstand
the tensile strength required to pull the adapter assembly 29' from
the needle 4 and also to overcome the small force which opposes the
pulling of the catheter 3" from the needle lumen. The pull tab 75
has an opening 77 at the inner end thereof which loosely fits
around the holding member 72. This inner end portion of the pull
tab is held in place against the rear end of the holding member 72
by radial projections 80--80 of the main body part 58. The pull tab
75 has a relatively large front end portion 75a having an opening
79 therein.
The pull tab 75 has a length so it can extend substantially beyond
the front end of the needle 4. The degree to which the pull tab 75
extends beyond the needle is important for reasons to be
explained.
The main body member 58 of the adapter assembly 29' is provided
with diametrically opposed radial projections 80--80 which are
adapted to interlock with one form of liquid-passing connector (not
shown) different from the infusion bottle system connector 23 to
which connector the main body member 58 may be secured subsequent
to its separation from the rest of the catheter delivery device. As
will appear, only the main body member 58 is ultimately used to
make connection to an external source of liquid like an infusion
bottle assembly. The holding member 72 is ultimately disconnected
from the main body member 58 to permit the insertion within the
rear end of the larger passageway portion 62 of liquid-passing
connector like connector 23 of the infusion bottle system 26.
After catheter ejection is effected, the removal of the adapter
assembly 29' and the catheter 3" from the needle 4 is effected by
first placing the enlarged front end portion 75a of the pull tab 75
against the portion of the ejected catheter immediately beyond the
front end of the needle 4, as indicated by the dashed line position
thereof shown in FIG. 17. The catheter 3" is gripped tightly
through the opening 79 of the enlarged front end portion of the
pull tab which then has substantial slack therein so the pull tab
and the catheter can be pulled a distance together from the end of
the needle without effecting any movement of the adapter assembly.
In the example of the invention illustrated in the drawings (see
especially FIG. 17), when the pull tab while gripping the catheter
therethrough has been pulled to its fullest extent so any further
movement of the pull tab will effect sliding movement of the
adapter assembly on the needle, the catheter has been distended to
a point where the second enlargement 3d" thereof begins sliding
along the needle lumen. In the illustrated embodiment of the
invention where the rear end of the catheter 3" is initially spaced
behind the adapter assembly 29' (although contiguous thereto), the
distention of the catheter without movement of the adapter assembly
in effect brings the final position of the rear end of the catheter
closer to the inlet end of the adapter assembly 29'. Thus, when the
catheter leaves the needle lumen and the tension in the catheter is
relieved, the rear end of the catheter will snap into a position
within the interior of the adapter assembly where it cannot touch
any contaminating surfaces. (However, the broadest aspect of the
invention envisions a catheter snapping into a position outside of
but yet adjacent to the end of the adapter assembly.) The degree of
slack provided in the pull tab when it is placed against the
catheter just beyond the front end of the needle is, therefore,
selected to provide just this result.
When the portion of the main body member 58 of the adapter assembly
containing the seat-forming sleeve 70 leaves the needle, the sleeve
70 contracts snugly around the catheter 3" thereby to fix the
relative position between the adapter assembly 29' and the rear end
of the catheter 3". After both the catheter 3" and the adapter
assembly 29' have been pulled from the end of the needle, the
catheter is grasped and pulled as far as it can be pulled within
the adapter assembly which brings the first enlargement 3d' of the
catheter within the passageway 70' of the seat-forming sleeve 70.
The distance which the rear end of the catheter has to move upon
leaving the needle lumen to snap into the end of the adapter is
minimized in the illustrated embodiment of the invention by the
fact that the adapter assembly is positioned adjacent the needle
hub 8 at a point preferably spaced only a small distance forwardly
of the point where the enlarged rear end portion of the catheter
becomes wedged in the needle lumen after catheter ejection. The
pulling of the enlargement 3d' within the sleeve 70 expands the
sleeve tightly against the defining walls of the large passageway
section 62 of the main body member 58 to form such a firm and tight
seal and connection between the catheter and the sleeve at this
point that it is impossible to pull the catheter through this
sleeve. The holding member 72 is then pulled from the body member
58 and discarded with the pull tab.
The tubular portion 58a of the main body member 58 of the adapter
assembly has a completely flat surface 82 on one side thereof in a
plane extending longitudinally thereof. The main body member has a
pair of outwardly projecting wings 84--84 which on one side thereof
are coplanar with and form an extension of the flat surface 82. The
wings 84--84 give the main body member 58 lateral stability when
placed against the skin 85 of the user's body adjacent the point
where the catheter 3 enters the same as shown in FIG. 19. The main
body member 58 when viewed in transverse cross ection as shown in
FIG. 19, has a generally triangular or tapered configuration
providing thin, marginal, longitudinal sides so a string of
adhesive tape 86 can securely retain the main body member 58 by
engaging the skin immediately beyond the thin longitudinal sides
82a--82a of the flat surface 82.
It is apparent that the embodiments of the present invention
described above provides an exceedingly effective, easy to use, and
relatively inexpensive means for injecting catheters into blood
vessels and separating the catheters from the same and securing the
catheters to a liquid-passing connector. The same principles of the
invention utilized in the injection of catheters by liquid into
blood vessels can be applied in readily injecting compressible
catheters or other slim elongated members into other passageways of
the body with liquid or air. While elongated members made of
silicone elastomer (which is incompressible in solid form) must be
hollow or have other spaces formed therein like catheters to be
compressible, the invention could be used to inject other elongated
members in solid form which are readily compressible in such
form.
It should be understood that numerous modifications may be made in
the most preferred forms of the invention described without
deviating from the broader aspects of the invention.
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