U.S. patent number 3,921,631 [Application Number 05/493,987] was granted by the patent office on 1975-11-25 for catheter insertion device and method of catheter introduction.
This patent grant is currently assigned to Vicra Sterile, Inc.. Invention is credited to Thomas C. Thompson.
United States Patent |
3,921,631 |
Thompson |
November 25, 1975 |
Catheter insertion device and method of catheter introduction
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) |
Assignee: |
Vicra Sterile, Inc. (Dallas,
TX)
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Family
ID: |
26950813 |
Appl.
No.: |
05/493,987 |
Filed: |
August 1, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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264888 |
Jun 21, 1972 |
3827434 |
Aug 6, 1974 |
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Current U.S.
Class: |
604/508;
604/160 |
Current CPC
Class: |
A61M
25/065 (20130101) |
Current International
Class: |
A61M
25/06 (20060101); A61M 005/00 () |
Field of
Search: |
;128/214.4,221,DIG.16,348 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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628,292 |
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Oct 1961 |
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CA |
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904,237 |
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Aug 1962 |
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UK |
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Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Richards, Harris & Medlock
Parent Case Text
This invention relates to catheter insertion devices, and more
particularly to such devices for introduction of a catheter through
a slotted needle.
This application is a division of copending application, Ser. No.
264,888, filed June 21, 1972, now issued as U.S. Pat. No. 3,827,434
dated Aug. 6, 1974, and is directed to the invention relating to a
catheter insertion device having an effective sealing segment as
described in that application.
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.
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 cahteter 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 silicone 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.
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.
Claims
What is claimed is:
1. A through the needle catheter insertion device comprising:
a hollow slotted needle for puncturing;
a catheter of generally constant diameter lying in the needle and
extending proximally thereof;
a rigid catheter hub secured to the proximal end of the
catheter;
a pliable enlarged portion formed from a material having the
pliability of silicone rubber secured around the catheter adjacent
the distal end of the rigid catheter hub, the distal end of the
pliable enlarged portion having a diameter substantially equal to
the outer diameter of the catheter, said enlarged portion including
an effective sealing segment having a diameter at least
substantially equal to the outside needle diameter and having no
diameter greater than about 50% larger than the outside needle
diameter, said segment being at least about 0.21 inches long,
whereby the catheter may be inserted into a blood vessel through a
puncture formed by the needle through the skin and vessel and such
sealing segment on the catheter may be engaged with the vessel and
skin punctures to seal such punctures, preventing the escape of
blood from the periphery of such punctures.
2. The device of claim 1 wherein the said sealing segment comprises
a resilient frustoconical segment having an outside diameter
continually increasing with a slope defined by an angle of no
greater than about 10.degree..
3. The device of claim 1 wherein the maximum diameter of the
sealing segment is no greater than 50 percent larger than the
needle diameter.
4. The device of claim 1 wherein the sealing segment is formed by a
separate sleeve secured around the catheter in a catheter hub on
the catheter.
5. A method of introducing a catheter into the vein of a patient
through a hollow slotted needle and preventing the flow of blood
out from around the periphery of the emplaced catheter comprising
the steps of:
positioning the catheter in the needle with the catheter extending
proximally of the needle and with a pliable enlarged sealing
segment secured around the portion of the catheter proximal of the
needle, said sealing segment having a diameter at least about equal
to the diameter of the needle;
piercing the skin and vein of the patient with the needle; and
forwarding the catheter into the vein of the patient through the
puncture formed by the needle until a portion of the enlarged
sealing segment engages the skin puncture.
6. A through the needle catheter insertion device comprising:
a hollow slotted needle for puncturing;
a catheter of generally constant diameter lying in the needle and
extending proximally thereof;
a catheter hub secured to the proximal end of the catheter;
an enlarged portion secured around the catheter, the distal end of
the enlarged portion having a diameter substantially equal to the
outer diameter of the catheter, said enlarged portion including an
effective sealing segment having a diameter at least substantially
equal to the outside needle diameter and having no diameter greater
than about 50% larger than the outside needle diameter, said
effective sealing segment being at least about 0.21 inches long and
including a substantially cylindrical segment, whereby the catheter
may be inserted into a blood vessel through a puncture formed by
the needle through the skin and vessel and such sealing segment on
the catheter may be engaged with the vessel and skin punctures to
seal such punctures, preventing the escape of blood from the
periphery of such punctures.
7. The device of claim 6, in which the substantially cylindrical
segment is at least about 0.25 inches long.
8. The device of claim 6 further comprising a frustoconical
transistion segment distal of the substantially cylindrical
segment.
9. The device of claim 6, in which the substantially cylindrical
segment lies between two segments having frustoconical surfaces
each increasing in diameter in the proximal direction.
Description
anted 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.
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 description of parent application Ser. No.
264,888, now issued as U.S. Pat. No. 3,827,434, dated Aug. 6,
1974;
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; and is an
embodiment of the invention which is being claimed in this
application;
FIG. 6 is a plan view of a modified needle assembly for use with
the catheter assembly shown in FIGS. 5 and 5A; and
FIG. 7 is a perspective view of another embodiment of a needle
assembly suitable for use in the device of FIGS. 1-3.
Referring now to FIGS. 1-3, views of a catheter insertion device
generally indicated by the reference numeral 10 are illustrated, as
described in parent application Ser. No. 264,888, now issued as
U.S. Pat. No. 3,827,434. 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
silicone 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 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 FIGS. 5 and 5A, 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 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
silicone 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. In addition,
the embodiment illustrated in FIG. 5A possesses the advantage of
having less tendency to draw back or be pushed back out of the
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. Preferably the sleeve and the catheter would both be formed of
a silicone 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 a 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.
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.
* * * * *