U.S. patent number 3,814,137 [Application Number 05/326,737] was granted by the patent office on 1974-06-04 for injection site for flow conduits containing biological fluids.
This patent grant is currently assigned to Baxter Laboratories, Inc.. Invention is credited to Felix Jesus Martinez.
United States Patent |
3,814,137 |
Martinez |
June 4, 1974 |
INJECTION SITE FOR FLOW CONDUITS CONTAINING BIOLOGICAL FLUIDS
Abstract
An injection site for a flow conduit for biological fluids and
the like, such as blood or parenteral solutions, is provided having
improved resistance to leakage through needle punctures, even when
the pressure within the flow conduit is substantially different
from the pressure outside of the conduit. The conduit comprises
tubing made of a biologically compatible material, in which a
portion of the tubing is surrounded by an elastomeric sleeve
injection site. A second elastic sleeve surrounds the first
elastomeric sleeve, the second sleeve having an unstretched inner
diameter which is less than the outer diameter of the elastomeric
sleeve. As a result, the elastomeric sleeve is compressed by the
second sleeve, whereby the sealing of the elastomeric sleeve after
puncture by a needle is improved.
Inventors: |
Martinez; Felix Jesus
(Palatine, IL) |
Assignee: |
Baxter Laboratories, Inc.
(Morton Grove, IL)
|
Family
ID: |
23273482 |
Appl.
No.: |
05/326,737 |
Filed: |
January 26, 1973 |
Current U.S.
Class: |
138/103; 138/137;
604/86 |
Current CPC
Class: |
A61M
39/04 (20130101) |
Current International
Class: |
A61M
39/02 (20060101); A61M 39/04 (20060101); F16l
011/12 () |
Field of
Search: |
;138/137,140,147,103
;128/214R,214.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myracle; Jerry W.
Attorney, Agent or Firm: Ellis; W. Garrettson
Claims
That which is claimed is:
1. In a conduit for blood and the like which comprises needle
puncturable, biologically compatible tubing, a portion of said
tubing being surrounded by an elastomeric sleeve injection site,
the improvement comprising a second, elastic sleeve surrounding
said elastomeric sleeve, said second sleeve having an unstretched
inner diameter which is less than the outer diameter of said
puncturable tubing, to compress said elastomeric sleeve, whereby
the sealing of said elastomeric sleeve after puncture by a needle
is improved, and in which said second, elastic sleeve is longer
than said elastomeric sleeve and overlies the ends of said
elastomeric sleeve, to seal the ends of said elastomeric sleeve
against fluid leakage between the elastomeric sleeve and the
tubing.
2. The blood conduit of claim 1 in which the wall thickness of said
second sleeve is less than one half the wall thickness of said
elastomeric sleeve.
3. The blood conduit of claim 2 in which said elastomeric sleeve is
made of natural latex.
4. The blood conduit of claim 3 in which said second sleeve is made
of natural latex.
5. The blood conduit of claim 4 in which said tubing is made of a
material selected from the group consisting of vinyl plastisol,
polyurethane, and silicone.
6. The blood conduit of claim 2 in which said tubing has an inner
diameter of about 0.18 to 0.2 inch and a wall thickness of about
0.06 to 0.07 inch; said elastomeric sleeve has an unstretched inner
diameter of about 0.2 to 0.3 inch and a wall thickness of about
0.09 to 0.1 inch, and said second, elastic sleeve has an
unstretched inner diameter of about 0.25 inch and a wall thickness
of about 0.03 inch.
7. The blood conduit of claim 1 in which the unstretched outer
diameter of said elastomeric sleeve is at least two times the inner
diameter of said second elastic sleeve.
8. The blood conduit of claim 1 in which the inner diameter of said
second sleeve is less than the inner diameter of said elastomeric
sleeve.
Description
BACKGROUND OF THE INVENTION
Parenteral solution administration equipment and blood flow
conduits for solution infusion, blood transfusion, or the
conveyance of blood between a patient and an artificial kidney or
blood oxygenator generally require sites where an injection needle
can be inserted into the conduit to withdraw samples, or to
administer medication or the like. When the injection needle is
withdrawn, it is important that there be no leakage of solution or
blood through the needle puncture.
Problems can arise with the leakage of blood and solution,
particularly when the interior of the conduit is under either a
substantially elevated or substantially reduced pressure with
respect to the exterior, as in the case of certain oxygenation and
artificial kidney blood conduits, and in the case of the
pressurized administration of parenteral solution or blood to a
patient.
In the conventional arterial and veinous sets for coil dialyzers,
which sets are used to transfer blood between a patient and the
coil dialyzer, it is well known to provide an injection site which
comprises a latex sleeve surrounding a portion of the blood tubing
which is made of vinyl plastisol or the like. In this prior art
structure, the latex sleeve is stretched over the blood tubing to
attempt to provide a fluidtight seal between the latex sleeve and
the blood tubing. Thus, when a needle penetrates the latex sleeve
and the blood tubing, and is thereafter withdrawn after injecting a
medicament or taking a sample, the latex sleeve is intended to
provide a seal against fluid leaks which occur through the needle
puncture in the blood tubing.
Unfortunately, it has been found that because the latex sleeve has
to be stretched onto the blood tubing to provide a fluid-tight seal
between the two members, the well-known excellent resealing
characteristics of the latex are diminished because of the
stretching of the latex. The needle puncture in the latex has been
observed to sometimes fail to adequately reseal, particularly in
the case where there is a pressure differential between the
interior and exterior of the flow conduit. It is of course highly
undesirable for fluid to leak through the puncture hole, forced out
by an elevated fluid pressure in the flow conduit. Furthermore, it
can be extremely dangerous for air bubbles to be sucked into the
flow line through the needle puncture when the blood tubing
interior is at a pressure of less than atmospheric, especially in
the case where the blood tubing conveys blood between a dialyzer or
an oxygenator and a living patient.
Furthermore, the prior art resealable injection site has also been
observed to leak by the passage of fluid between the vinyl blood
tubing and the latex sleeve, until fluid appears at the end of the
latex sleeve as a continuous slow leak. However, if one uses a
smaller diameter latex sleeve to increase the sealing pressure at
the interface between the blood tubing and the latex sleeve, the
stretching in the latex sleeve is increased, which results in less
capability to seal needle punctures.
DESCRIPTION OF THE INVENTION
In accordance with this invention, the sealing capability of a
fluid conduit of biologically compatable tubing surrounded by an
elastomeric sleeve injection site is improved by a second elastic
sleeve surrounding the first elastomeric sleeve, in which the
second elastic sleeve has an unstretched inner diameter which is
less than the outer diameter of the first elastomeric sleeve. The
result of this is to compress the first elastomeric sleeve, whereby
the sealing of the elastomeric sleeve after puncture by a needle is
improved.
It is preferred for the second elastic sleeve to be longer than the
first elastomeric sleeve, and to overlie the ends of the
elastomeric sleeve. In this case, the unstretched inner diameter of
the second elastic sleeve should be less than the outer diameter of
the biologically compatible tubing, to seal the ends of the first
elastomeric sleeve against fluid leakage between the elastomeric
sleeve and the tubing. It is also desirable for the wall thickness
of the second sleeve to be less than one-half of the wall thickness
of the elastomeric sleeve, and for the inner diameter of the second
sleeve to be less than the inner diameter of the elastomeric
sleeve, so that the degree of stretching of the second sleeve is
greater than that of the first elastomeric sleeve, and it tightly
seals about the ends of the first sleeve. Typically, the outer
diameter of the first elastomeric sleeve as mounted on the tubing
is at least about twice the inner diameter of the second elastic
sleeve for high compression of the first elastomeric sleeve,
although lesser degrees of compression can be used by providing a
second sleeve of larger inner diameter.
The first elastomeric sleeve is preferably made of natural latex or
any other elastomeric material having excellent needle puncture
resealing characteristics. The second elastic sleeve is also
conveniently made of natural latex, although any elastic material
having generally equivalent tensile strength can be used. However,
it is generally desirable for the second sleeve to also have
excellent needle puncture resealing characteristics equivalent to
natural latex. Alternatively, the second elastic sleeve can be made
of a material which shrinks upon drying of solvent in the material
or upon heating, such as certain forms of polytetrafluoro-ethylene
or polyvinylchloride plastisol. The use of such material simplifies
the assembly procedure.
Referring to the drawings:
FIG. 1 is an elevational view of a portion of conduit tubing for
blood, dialysis solution, parenteral solution, or the like,
surrounded by the improved injection site of this invention.
FIG. 2 is a longitudinal sectional view taken along line 2--2 of
FIG. 1, and enlarged in size.
FIG. 3 is a transverse sectional view taken along line 3--3 of FIG.
1 and enlarged in size.
Referring to the drawings, tubing 10 is shown as a conduit for
blood in a medical device such as a conventional arterial or
veinous set for an artificial kidney. Such sets are commercially
available at the present time from Travenol Laboratories, Inc. of
Morton Grove, Ill. Tubing 10 might also be part of a blood line in
a blood oxygenation system. Tubing 10 can be made of any
needle-puncturable, biologically compatible material, for example,
plastic materials including vinyl plastisol or polyurethane, and
silicone rubber.
The improved injection site 12 of this invention comprises an
elastomeric sleeve 14 surrounding a portion of tubing 10. The
unstretched inner diameter of elastomeric sleeve 14 is smaller than
the outer diameter of tubing 10 to provide a compressive seal at
the interface 22 between sleeve 14 and tubing 10.
Second elastic sleeve 16 overlies the first elastomeric sleeve 14,
and is longer than elastomeric sleeve 14, so that overlying
portions 18, 20 cover the ends of sleeve 14 and provide sealing
against any fluid leakage that takes place along the interface 22
between tubing 10 and elastomeric sleeve 14 after puncture by a
needle 24, shown in phantom in FIG. 2. Sleeve 16 has less than half
the wall thickness of sleeve 14, to permit it to closely conform
about the ends of sleeve 14 for improved sealing.
Second sleeve 16 is proportioned to compress elastomeric sleeve 14,
which compression provides improved sealing of needle puncture
holes through sleeve 14 after the puncturing needle 24 has been
withdrawn. The inner diameter of second sleeve 16 is less than the
unstretched outer diameter of sleeve 14, so that sleeve 14 is
substantially compressed.
In one suitable form, tubing 10 has an inner diameter of about 0.18
to 0.2 inch and a wall thickness of about 0.06 to 0.07 inch, to
give a total outer diameter of about 0.3 to 0.34 inch.
Correspondingly, elastomeric sleeve 14 can have an unstretched
inner diameter of about 0.2 to 0.3 inch and a wall thickness of
about 0.09 to 0.1 inch. In one specific embodiment, the inner
diameter is 0.312 inch and the wall thickness 0.094 inch, to give a
total outer diameter of 0.5 inch. In the same specific embodiment,
the outer diameter of tubing 10 is 0.34 inch. Thus, sleeve 14
exerts a substantial compression upon the outer wall of tubing 10
and is correspondingly stretched in the process.
In the above situation, second elastic sleeve 16 may have an inner
diameter of about 0.25 inch and a wall thickness of about 0.03
inch. It can thus be seen in the above specific embodiment that the
outer diameter of elastomeric sleeve 14 is about twice the inner
diameter of second sleeve 16 in the above specific embodiment.
Accordingly, sleeve 14 is placed under quite substantial
compression by second sleeve 16, which results in an improvement in
the sealing characteristics of sleeve 14. Similarly, since the
unstretched inner diameter of second sleeve 16 is less than the
outer diameter of tubing 10, an additional pressure seal is applied
to tubing 10 by end portions 18, 20, resulting in additional
sealing about the ends of elastomeric sleeve 14.
In another suitable configuration, tubing 10 has an inner diameter
of 0.187 inch and a wall thickness of 0.063 inch, while elastomeric
sleeve 14 has an inner diameter of 0.25 inch and a wall thickness
of 0.094 inch. The remaining dimensions are similar to the previous
embodiment.
Elastomeric sleeve 14 is generally about 2 to 6 inches long, while
second sleeve 16 is about 1 to 3 inches longer than sleeve 14, to
provide suitable sealing about the ends of sleeve 14.
Sleeves 14 and 16 can be placed upon tubing 10 simply by expanding
them with a suitable expansion fork made of a plurality of rods,
and lever means for spreading the rods apart, to stretch the
sleeves while threading them onto tubing 10 to the desired
position. Then the expansion fork is allowed to collapse, and is
withdrawn from the inside of each sleeve. Likewise, sleeves 14, 16
can be threaded upon a suitably sized rigid collet, and threaded on
the tubing 10, the collet being then withdrawn.
The above has been offered for illustrative purposes only, and is
not intended to limit the invention which is defined in the
following claims.
* * * * *