U.S. patent number 3,827,434 [Application Number 05/264,888] was granted by the patent office on 1974-08-06 for catheter insertion device.
This patent grant is currently assigned to Vicra Sterile, Inc.. Invention is credited to John A. Gula, Thomas C. Thompson.
United States Patent |
3,827,434 |
Thompson , et al. |
August 6, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
CATHETER INSERTION DEVICE
Abstract
A catheter insertion device having a needle assembly comprising
a hollow slotted needle with a needle hub affixed to its proximal
end and a catheter assembly comprising a flexible catheter having a
sealing segment with an enlarged outside diameter to prevent
bleedback and a hollow catheter hub secured to its proximal end,
the two assemblies being releasably locked together to prevent
relative longitudinal movement of the catheter in the needle, the
locking being releasable without relative longitudinal movement of
the catheter and needle. The catheter is provided with a wire
stylet having an enlarged rounded distal tip.
Inventors: |
Thompson; Thomas C. (Dallas,
TX), Gula; John A. (Farmers Branch, TX) |
Assignee: |
Vicra Sterile, Inc. (Dallas,
TX)
|
Family
ID: |
23008046 |
Appl.
No.: |
05/264,888 |
Filed: |
June 21, 1972 |
Current U.S.
Class: |
604/160 |
Current CPC
Class: |
A61M
25/065 (20130101) |
Current International
Class: |
A61M
25/06 (20060101); A61m 005/00 () |
Field of
Search: |
;128/214R,214.4,221,348,35R,DIG.16 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
904,237 |
|
Aug 1962 |
|
GB |
|
628,292 |
|
Oct 1961 |
|
CA |
|
Other References
C R. Bard Catalogue 1940 - p. 23 - (Item No. 403). .
Gaertner - Surg. Gyne. & Obstet. - Vol. 119, No. 3, Sept. 1964,
pp. 599-600..
|
Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Richards, Harris & Medlock
Claims
What is claimed is:
1. A catheter insertion device comprising:
a hollow slotted needle;
a needle hub secured to the needle and having a pair of axially
spaced, oppositely facing locking surfaces;
a catheter lying in the needle; and
a catheter hub secured to the proximal portion of the catheter
having a pair of oppositely facing complimentary locking surfaces
axially spaced substantially equally to the spacing of the needle
hub locking surfaces and engaging said needle hub locking surfaces
to prevent relative longitudinal movement of the catheter and
needle, said catheter hub being movable by relative lateral
movement from said engagement to a second position, in which said
locking surfaces are not engaged.
2. The device of claim 1, in which the needle hub includes a flat
base extending proximally of the needle, and said pair of needle
hub locking surfaces comprise spaced facing shoulders upstanding
from said base.
3. A catheter insertion device comprising:
a hollow slotted needle having a pointed distal end and a proximal
end;
a needle hub secured to the proximal end of the needle and having a
distally facing shoulder formed thereon spaced from the proximal
end of the needle;
a catheter lying in the needle; and
a catheter hub secured to the proximal portion of the catheter
having a complimentary proximally facing shoulder formed thereon
and spaced from the proximal end of the needle an amount
substantially equal to the spacing of the needle hub shoulder from
the proximal end of the needle and engaging said needle hub
shoulder to prevent relative proximal longitudinal movement of the
catheter with respect to the needle, said catheter hub being
movable by relative lateral movement from said engagement to a
second position, in which said shoulders are not engaged.
4. A catheter insertion device comprising:
a hollow slotted needle having a pointed distal end;
a needle hub secured to the proximal end of the needle and having a
base for releasably receiving a catheter hub;
a pair of axially spaced facing shoulders on said base for
receiving a catheter hub therebetween;
a catheter lying in the needle; and
a catheter hub extending from the proximal end of the catheter and
releasably held between said spaced facing shoulders on the needle
hub to prevent longitudinal movement of the catheter with respect
to the needle.
Description
This invention relates to catheter insertion devices, and more
particularly to such devices for introduction of a catheter through
a slotted needle.
A number of self-contained catheter insertion devices have
previously been used in the art for intravenous or other infusion
of fluid into a patient. One type of such device is sometimes
called "through the needle." A through the needle unit involves the
use of a hollow needle to accomplish puncture while containing a
flexible catheter. If the needle is appropriately slotted, the
needle can be subsequently separated from the catheter and removed
from the area of the body.
This invention provides improved structure for catheter insertion
employing the principle of the hollow slotted needle. The device of
this invention provides a catheter-needle combination which is
positively locked to prevent any relative longitudinal movement
between the two prior to or during puncture or during initial
separation of the two. Locking of the device may be accomplished
upon initial assembly of the device so that the proper relationship
between the parts is maintained during shipment and storage.
One aspect of the invention is the provision for, and positive
maintenance of, the proper relative positioning of the catheter and
needle through the time during utilization when the needle is
separated from the catheter. It is important that the end of the
catheter be maintained at least as far along the needle as
approximately the end of the slot in the needle, to prevent
channeling of blood flow out through the needle slot. At the same
time, the catheter should not extend so far out as to interfere
with the piercing function of the needle.
In a further aspect of the invention, structure is provided so that
the separation of needle and catheter may be made without causing
longitudinal movement of the catheter in the needle, as might cause
blood to spurt through the needle slot. The separation step is a
readily performed manual separation of the two separate
assemblies.
One of the advantages of the invention is the ease of fabrication
of the components of the device, and the ease and sureness with
which the device may be manipulated to accomplish a proper
insertion.
The device will properly perform insertion, while positively
locking the catheter and needle together, no matter what portion of
the supporting structure is grasped by the user. The concomitant
functions of locking and separation are provided by locking
catheter and needle assemblies together in side-by-side relation
without the necessity of complicated subassemblies or moving parts
which make the physical manipulations required more difficult, and
which increase the level of understanding and skill necessary to
proper utilization.
While the present invention is suitable for a variety of catheter
applications, the invention is particularly useful in connection
with intravenous catheters. The invention will be described in
terms of a catheter device for intravenous infusion of fluids,
although it is not intended to limit the invention to such uses
alone.
Intravenous injections are most desirably accomplished by catheters
possessing a number of specific attributes. The device should be
short, to minimize the length of catheter inside the blood vessel.
The device should be simple in operation, to minimize the physical
manipulations required in its use particularly during the delicate
stage of catheter insertion, and also to make its use more readily
understood and properly carried out by medical personnel.
Implantation and maintenance of the catheter should be affected
with as little bleeding as possible. The material of the catheter
itself should be body compatible to the greatest extent possible,
including being inert to organic tissues and fluids, non-clotting
as to the blood, and highly flexible.
One material which has been found to possess the desirable
characteristics demanded of catheter tubing is a silicated rubber,
such as one being sold under the trade name "Silastic." While the
material does provide desirable characteristics of body
compatibility, tubing formed therefrom is somewhat difficult to
handle and insert because of its extreme delicateness, pliability
and elasticity. One objective of this invention is to provide a
device which is well suited to overcoming the problems associated
with the use of Silastic catheters so that the advantages of such
catheters may be fully exploited and enjoyed.
Another object of this invention is to provide a catheter implanted
employing a "through the needle" device which will not be subject
to bleeding around the catheter.
There is provided by this invention a through the needle catheter
with a provision for a positive puncture seal after insertion of
the catheter, utilizing an enlarged segment on the proximal end of
the catheter.
The invention also contemplates means for forwarding a catheter
after insertion, such as a stiffening wire stylet in the catheter
which stylet has an enlarged rounded distal tip to avoid puncture
of the catheter, particularly in the case of the delicate
"Silastic" catheters.
In accordance with the invention, there is provided a catheter
insertion device having a needle assembly with a hollow slotted
needle and a needle hub secured to the proximal end of the needle.
A catheter assembly includes an elongate catheter positioned in the
needle and a catheter hub fixed to the proximal end of the catheter
adjacent the needle hub. Releasable locking means are secured to
the assemblies to prevent relative movement of the catheter and
needle in at least one longitudinal direction, which means is
releasable without relative longitudinal movement of the needle and
catheter. The catheter has an effective sealing segment proximal of
the needle having an outer diameter at least as large or slightly
larger than the needle diameter. A wire stylet in the catheter has
an enlarged rounded distal tip.
For a more complete understanding of the present invention and for
further objects and advantages thereof, reference may now be had to
the following description taken in conjunction with the
accompanying drawings, in which:
FIG. 1 is a plan view of a catheter insertion device made in
accordance with the invention;
FIG. 2 is a perspective view of the device shown in FIG. 1, with
catheter assembly and needle assembly shown separated;
FIG. 3 is a side view of the device as presented in FIG. 2;
FIG. 4 is a plan view of the plug and stylet portion of the
catheter assembly of FIGS. 1-3;
FIG. 5 is a plan view of a modified form of catheter assembly for
use in devices such as shown in FIGS. 1-4;
FIG. 5A is a plan view of a portion of a further modified catheter
assembly for use in devices such as shown in FIGS. 1-4;
FIG. 6 is a plan view of a modified needle assembly for use with
the catheter assembly shown in FIGS. 5 and 5A;
FIG. 7 is a perspective view of another embodiment of a needle
assembly suitable for use in the device of FIGS. 1-3;
FIG. 8 is a partial perspective view of another embodiment of the
invention, with the catheter and needle assemblies shown
separated;
FIG. 9 is a partial perspective view of yet another embodiment of
the present invention; and
FIG. 10 is a partial perspective view of another embodiment of the
invention.
Referring now to FIGS. 1-3, views of a catheter insertion device
generally indicated by the reference numeral 10 are illustrated.
The device 10 comprises a needle assembly 12 and a catheter
assembly 14 cooperating therewith. As shown in FIG. 1, a removable
needle cover 16 is provided as a shield for the needle prior to
use.
The needle assembly 12 has an elongate hollow needle 18 which is
pointed at its distal end 20 and may be formed from any suitable
material, preferably stainless steel such as, for example, AISI
Type 304. Needle 18 is secured at its proximal end to a needle hub
22. Needle hub 22 may be formed from any suitable relatively rigid
material, such as a plastic, for example polyethylene or other
moldable plastic. Needle hub 22 carries a mounting collar 24 in
which the needle 18 is received by any convenient means such as
press fitting or molding of the collar 24 and hub 22 directly on
the needle 18. The wall of needle 18 is provided with a slot
extending the length thereof, which registers with a slot provided
in collar 24.
Mounting collar 24 is joined to the base 26 of needle hub 22 by
neck portion 28, which terminates in rearwardly axially facing
shoulders 30 rising from base 26. A pair of restraining lugs 32 are
provided on base 26 spaced from the shoulders 30.
Catheter assembly 14 is provided with an elongate flexible catheter
tube 34 which passes, at its proximal end, into a hollow catheter
hub 36 at the distal end 37 of the hub 36. The catheter may be any
of the accepted types of tubing used in catheters although a
silicated rubber such as "Silastic" is preferred. Hub 36 may be
formed from any relatively rigid material, including a moldable
plastic such as polyethylene, for example. Hub 36 is provided with
conventional means for receiving an infusion line or the like, such
as a conventional luer fitting 38, in which a luer plug 40 is
removably secured. Hub 36 provides a channel for fluid flow between
the catheter tube 34 and the fitting 38. Tie-down ears 42 extend
outwardly from the catheter hub 36.
The distal section 44 of catheter hub 36 is of reduced external
diameter, so that a forwardly axially facing shoulder 46 is formed
on catheter hub 36. Catheter hub 36 has a locking flange 48 formed
thereon, spaced rearwardly from shoulder 46.
The needle assembly 12 and catheter assembly 14 are releasably
locked together in the catheter insertion device 10 of this
invention. The catheter tube 34 lies within the hollow needle 18,
and extends rearwardly through the mounting collar 24 on needle hub
22. The distal end of the catheter tube is aligned with the distal
end of the slot in the needle 18, which point is indicated in FIG.
3 by the numeral 49. The two assemblies 12 and 14 are releasably
locked together by the mating of the axially facing surfaces
provided on needle hub 22 and catheter hub 36. Longitudinal
movement of the two assemblies is prevented by the engagement of
locking surfaces on the respective assemblies. Relative forward
movement of the catheter assembly 14 with respect to the needle
assembly 12 is prevented by engagement of shoulders 30 on needle
hub 22 with the shoulder 46 on catheter hub 36. Relative rearward
motion of the catheter assembly with respect to the needle assembly
is prevented by the engagement of the lugs 32 of needle hub 22 with
the locking flange 48 of catheter hub 36. The engagement of the
surfaces is sufficient to releasably lock the assemblies 12 and 14
together, but the distances between the surfaces is dimensioned so
that the assemblies may readily be snapped apart by digital
manipulation of the assemblies 12 and 14 to apply lateral
separating pressure.
As shown in FIG. 4, the luer plug 40 for each of the catheter
assemblies herein disclosed can be provided with a thin wire stylet
50 or other stiffening member extending through catheter hub 36 and
through the length of the catheter tube 34, to facilitate
manipulation of the catheter tubing 34 after insertion. The stylet
50 is provided with a rounded distal tip 51 so that the danger of
the stylet tearing or piercing the catheter or vein is reduced. The
spherical distal tip 51 may be formed by heating the end of the
stylet 50 using an arc welder.
The catheter insertion devices illustrated in FIGS. 1-6 may be
provided in sterilized form for shipment and storage prior to use.
When the device is ready for use, the needle cover 16 is removed,
and the distal end 20 of the needle 18 is inserted through the end
at the location on the patient's body desired. After insertion of
the needle 18 and catheter tube 34 has been achieved, the needle
hub 22 may be laterally separated from the catheter hub 36 by the
application of relative manual pressure thereon, which pressure
need not involve pressure in the longitudinal direction so as to
cause the catheter 34 to move in the needle 18. Thereafter the
needle 18 may be separated from the catheter tube 34 and withdrawn.
Typically, however, the needle 18 will be held in position after
separation of the needle hub 22 and catheter hub 36 while the
catheter tubing 34 is manipulated further into the body by manual
force exerted on the catheter hub 36 or plug 40. In the case of the
catheter shown in FIG. 4, the catheter is forwarded until at least
a portion of the segment 35 is inserted into the wound to prevent
bleedback around the catheter. The stylet 50 within the catheter
tube 34 facilitates in the process of forwarding the catheter
tubing 34 if that is desired. The stylet is particularly useful in
connection with exceedingly delicate flexible tubing 34 which would
otherwise be extremely difficult to forward into the vein after
insertion.
Two preferred forms of catheter assembly modified to assist in
preventing "bleedback" around the catheter are illustrated in FIGS.
5 and 5A. In part because of the blood compatibility property of
silicated rubber catheters, the bleedback is a particular problem
in such catheters. These catheter assemblies are similar to the
assembly of FIGS. 1-3, and the same reference numbers as described
above are applied to common portions of FIGS. 5 and 5A. The
modification of the catheter assemblies of FIGS. 5 and 5A is in the
proximal end of the catheter 34. The catheter 34 is provided with a
section 35 having an enlarged outside diameter adjacent the
catheter hub. The needle assembly of FIG. 6 is slightly modified to
accommodate the enlarged section of the catheters of FIGS. 5 and
5A.
The purpose of enlarged section 35 of FIGS. 5 and 5A is to provide
an effective sealing segment to prevent bleeding around the outside
of the catheter after insertion. In through the needle devices such
as the present one, the needle is larger than the outside diameter
of the catheter lying inside the needle, and thus creates a larger
puncture than the diameter of the catheter lying in the needle. The
enlarged section 35 of FIGS. 5 and 5A, which is aligned with its
associated structure so as to lie immediately proximal of the
needle 18 in the assembled device, so that it has an effective
sealing segment, that is, one with a diameter, variable or
constant, at least equal to the outside diameter of the needle 18,
and preferably a slightly larger diameter. The section 35 thus
provides a segment having an effective sealing diameter, that is, a
diameter equal to or slightly larger than the needle diameter. The
diameter of the segment provided for sealing should exceed the
needle diameter only slightly, by no more than about 50 percent. In
operation, the section 35 is inserted far enough into the puncture
to create positive sealing of the hole created by the needle.
FIG. 5 illustrates an enlarged section 35 which continually
gradually increases at the proximal end of catheter 34. While the
precise slope of section 35 in FIG. 5 is not critical, it is
important that the slope be relatively gradual, for example, no
greater than that defined by an angle of about 10.degree.. An
example of suitable dimensioning would be for a catheter having
0.045 inch O.D. to increase in diameter to 0.100 inch in a segment
35 length of 0.335 inch. Such a catheter could be used with a
needle of about 0.063 inch diameter, so that segment 35 would have
a diameter equal to the needle diameter about 0.125 inch proximal
of its distal end, which would gradually increase to somewhat over
0.03 inch greater in the remaining 0.210 inch proximal segment of
section 35. The effective sealing segment is formed by the distal
portion of this proximal segment. The proximal end of the catheter
adjacent the catheter hub may have a larger diameter than is
actually usable for sealing, and such end does not form a part of
the effective sealing segment since it would not be inserted into
the puncture.
While the catheter configuration illustrated in FIG. 5 is
ordinarily effective to prevent bleedback by sealing the skin and
vessel punctures, the structure of FIG. 5A is designed with a
longer section having an effective sealing diameter to produce the
desired sealing effect even in situations where the operator makes
entry into the vein at some distance from the skin puncture. In
such circumstances, it is desirable to have a longer segment having
an effective sealing diameter. In this way, sealing of the puncture
of the vessel and the skin can be readily accomplished even with
the entry into the vein spaced from the skin puncture.
Catheter section 35 of FIG. 5A has a distal transition segment 35a,
an elongated central constant-diameter segment 35b and a gently
sloping proximal segment 35c. The segments 35b and 35c provide an
elongated effective sealing catheter segment. The catheter would be
inserted sufficient to seal the needle puncture, ordinarily up to
and perhaps including the distal portion of segment 35c.
The constant diameter segment 35b allows for increase of the length
of the effective sealing segment of the catheter, without
increasing the catheter diameter unduly. An example of suitable
dimensioning for section 35 of FIG. 5A for a 0.045 inch catheter
and 0.063 inch needle is for segment 35a to be about 0.050 inch
long, increasing in diameter from 0.045 to 0.072 inch. Segment 35b
may be about 0.250 inch long, and segment 35c about 0.115 inch
long, with diameter increasing from 0.072 inch to 0.094 inch.
One suitable structure and method for providing the enlarged
segment 35 of both FIGS. 5 and 5A on catheter 34 is by means of a
separate sleeve forming the enlarged section 35 which is placed
over catheter 34 and locked with catheter 34 in the catheter hub
36. Perferably the sleeve and the catheter would both be formed of
a slicated rubber. The sleeve would have an inside diameter
slightly smaller than that of the outer diameter of catheter 34 so
as to be slightly interferingly fit with the catheter. The sleeve
may be positioned on the catheter by swelling the rubber sleeve in
an organic solvent such as xylene, so that it will slip easily over
the catheter tubing. Once in position on the tubing, the solvent
may be evaporated, and the catheter and sleeve secured in the
catheter hub 36 through the distal end 37 of the hub 36 by any
suitable means.
FIG. 7 illustrates a modified form of needle assembly 60 which may
be utilized with the device described above in connection with
FIGS. 1-4 in place of needle assembly 12. For convenience, the
portions of needle assembly 60 which are identical with those of
needle assembly 12 have been provided with the same reference
numerals. The modified needle assembly is provided with a pair of
arms 62 extending laterally outward from the base 26 of needle hub
22. The arms 62 terminate in enlarged upstanding ears 64.
Modification represented in the needle assembly 60 is provided to
assist in the catheter insertion device, specifically to give
better control of the steps wherein the needle assembly is moved
relative to the catheter assembly 14. The ears 64 may be grasped
while the catheter is being forwarded and also while the needle is
being removed.
A large number of other forms of specific embodiments in accordance
with this invention are possible. For example, while the above
described devices have illustrated locking to a catheter hub per
se, such means could be provided on the luer plug or other part of
the catheter assembly. Other forms of catheter hubs are possible,
including ones in which a longer catheter is used so that the luer
fitting is displaced proximally from the catheter hub. It will be
appreciated that a variety of specific forms of catheter hubs may
be applied to the catheter to perform the functions of the catheter
hub illustrated, and the term "catheter hub" is intended to apply
to all such forms.
FIGS. 8-10 illustrate a few of the other possible locking modes
which may be employed in accordance with this invention. Referring
now to FIG. 8, there is depicted portions of a catheter insertion
device which represents a modified embodiment of the present
invention. The modification represented by the device of FIG. 8
resides in the catheter hub and needle hub, and the remainder of
the device and its operation remains the same as that described
above.
In the device of FIG. 8, catheter hub 100 is provided with
downwardly extending tab 102. The needle hub 104 is releasably
engaged with the catheter 100 by the engagement of tab 102 in a
slot 106 provided on needle hub 104.
Yet another embodiment of the concept of this invention is
illustrated by the FIG. 9, which depicts a modified form of
catheter hub 120 and needle hub 122, with the parts thereof shown
separated. Catheter hub 120 is provided with a mounting slot 124
formed by a pair of spaced flanges 126 extending outwardly
therefrom. The needle hub 122 is provided with a pair of
complementary mounting slots 130 which register with the slots 124
of the catheter hub 120. The releasable engagement of the catheter
hub 120 with the needle hub 122 which is provided by snap ring 132
secured through slots 124 and 130. In utilization of this device,
the snap ring 132 is maintained in position until lateral
separation of the catheter hub 120 and needle hub 128 is desired,
at which time the snap ring 132 is removed.
A modification of the form shown in FIG. 9, but not shown in the
drawings, would replace the snap ring by a so-called "living hinge"
formed directly on the needle assembly. In such form, no slots on
the needle assembly would be required. In molding the needle hub, a
hook-shaped plastic tab would be provided on the needle hub to
create a living hinge engaging the slot provided on the catheter
hub.
The device of FIG. 10, in which the parts are shown separated, is
illustrative of the utilization of frictional locking means. In
this device a tape or strap 140 is applied directly to the needle
hub 142 and catheter hub 144 to engage the two hubs firmly in a
locked relationship through frictional engagement. In use, the tape
140 maintains the hubs interlocked until after puncture when the
user removes the tape 140 to free the hubs 142 and 144.
Alternatively, a living hinge such as described above could be
provided on the needle assembly to frictionally engage the surface
of the catheter hub.
Having described the invention in connection with certain specific
embodiments thereof, it is to be understood that further
modifications may now suggest themselves to those skilled in the
art and it is intended to cover such modifications as fall within
the scope of the appended claims.
* * * * *