Note: Descriptions are shown in the official language in which they were submitted.
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E2press Mail Label No.: TB216123798US
Date of Deposit: September29, 1993
PATENT APPLICATION OF FLOYD V. EDWARDS, ~ ~
5TIMOTHY J. ERSKINE, GERALD H. PETERSON AND ;
E. ROBERT PVRDY
CATHETER INTRODUCER WITH BLOOD SEAL
BACKGROUND
This invention relates generally to the field of catheter introducers. It ~-
15 relates specifically to a catheter introducer with a blood seal to reduce leakage of
blood during the introduction of the catheter into a blood vessel.
Catheters are commonly used in the practice of medicine as a means of
gaining access to the vascular system of a patient. Typically a catheter is -
20 introduced into a blood vessel with the assistance of a needle which pierces the
blood vessel, creating an opening through which the catheter can enter the vessel.
During this process the needle may become contaminated with blood. Since the
advent of AIDS, there has been an increased awareness of the possibility of blood
from a patient containing the AIDS virus or other pathogens such as the hepatitis
25 virus. The leakage of blood during the introduction of a catheter into a patient
may increase the risk of the transmission of such blood borne pathogens.
The present invention is intended to reduce the risk of such transmission by
providing a blood seal which minimizes the leakage of blood.
SUl\~ARY OFTHEINVENTION -
The present invention is a catheter introducer assembly. The assembly is - -
made up of a needle having proximal and distal ends. A hub is attached to the
35 needle at the pro~imal end of the needle. A catheter assembly made up of a
cannula and a catheter adapter attached to the cannula is mounted axially on the ~ ;
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needle. The cannula is mountable concentrically around the needle such that the
catheter assembly is slidable on the needle and the needle can be withdrawn fromthe catheter assembly. The introducer assembly is provided with a seal assembly
mountable on the needle adjacent the catheter adapter such that the seal assembly -
is slidable on the needle. The seal assembly carries a seal adapted to limit blood
flow from the catheter adapter.
BRIEF DESCRIPTION OF THE DR~VVINGS
Fig. 1 is a perspective view of the invention;
Fig. 2 is a detailed perspective view showing the needle cover and blood
seal of the invention;
Fig. 3 is a detailed sectional view of a portion of the needle cover;
Fig. 4 is a perspective view of the latch mechanism which secures the
needle cover to the needle;
Figs. 5, 6, 7 and 8 are cross-sectional views of the invention through ~ -
section 5-5 showing the operation of the device;
Fig. 9 is an e~ploded perspective view of a second embodiment of the
needle shield and blood seal;
Fig 10 is a cross-sectional view of the second embodiment. ~ ~
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DETAILED DESCRIPIION
Introducer assembly 10 includes a needle hub 12, a needle 14, having a
distal end 15 and a proximal end 17 secured to needle hub 12, and a needle tip
cover 16 slidably mounted to the shaft of the needle. A catheter assembly 18
comprising a cannula 19 and an adapter 52 is slidably rnounted to the nesdle shaft ;
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of the needle. Cannula 19 has a lumen 13. Catheter assembly 18 is s1idably
mounted to the needle shaft and releasably secured to the needle tip cover 16.
Needle hub 12 includes an integrally molded, transparent body 20 having
S substantially planar top and bottom surfaces 22a, æb and a pair of side walls 24,
26 which are generally concave to facilitate manipulation of the hub between thethumb and finger. Each end of the side walls in~ludes a stepped portion 28. The
rear end of the needle hub is bifurcated. A cylindrical tube 29 e~ctends throughthe bifurcated end portion and communicates with the rear end of the needle. A
lO plug 30 may be secured to the rear end of the tube 29.
Needle tip cover 16 includes an elongate, generally hollow body 38.
Needle cover 16 carries seal 100 described infra. Since needle tip cover 16
functions to carry seal 100 as well as to protect needle 14, the terms "seal
15 assembly" will be used interchangeably with the term "needle tip covern. A
longitudinal slot 40 e~ctends through one side of the body 38 and rectangular
opening 42 e~ctends through the opposite side thereof. A pair of flat surfaces
defines-portions of two other sides of the body.
A cylindrical passage 32 is defined within the needle hub. Pro~cimal end
38b of the needle tip cover 16 may be positioned within this passage. A slot 34
e~ctends within hub 12 adjacent bottom surface 22b and adjoins passage 34. (See
Fig. 3). The pro~imal 38b end of needle tip cover 16 includes a radially
e~ctending projection 70 which e~ctends and is slidable within the slot 34. Needle
tip cover 16 is thereby prevented from rotating with respect to the needle hub 12.
A radially e~ctending flange 48 e~ctends from the body and adjoins one end
of the longitudinal slot 40. Flange 48 has a generally annular configuration with
the e~ception of a flat surface 48a on one side thereof and tab 48b projecting
from the opposite side. This tab 48b is provided to enable the user to push the
needle tip cover and catheter assembly away from the needle hub during insertionof the catheter and removal of the needle. A plurality of arcuate projections 50e~ctends from the flange 48, and together the arcuate projections define a
receptacle 53 for retaining catheter adapter 52. The ends of the projections
include inwardly projecting lips 54 for releasably connecting flange 56 of the
catheter adapter to seal assembly 16. Arcuate projections 50 and lips 54 are
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designed to engage flange 56 so that it is easier to push the needle tip cover away
from the needle hub by means of tab 48b than it is to remove catheter adapter 52from receptacle 53. The user is therefore discouraged from removing catheter
adapter 52 and thus e~cposing distal end of the needle 15 and is encouraged to use
5 the passive shielding feature of the intention as further described herein. One
end of the tubular body 38 defines a projection or nose portion 38a e~tending into
the catheter adapter.
Seal 100 is placed in nose portion 38a of needle tip cover 16. Seal 100 is a
10 generally cylindrical member made of an elastomeric material, preferably
silicone rubber. It is generally cylindrical and is provided with a circumferential
lip 106 to facilitate the location of seal 100 in nose portion 38a. Circumferential
lip 106 front portion 104 contacts the inside of catheter adapter
52, thereby providing a seal between nose portion 38a and catheter adapter 52.
15 An elongate back portion 102 e~ctends within nose portion 38a. Front portion 104
is p~ovided with an opening 108 dimensioned such that seal 100 fits tightly
around needle 14, thereby providing a blood seal. Seal 100 is placed in nose
portion 38a in radial compression to facilitate the closure of opening 108 on
passage of needle 14 therethrough. Opening 108 is also dimensioned and
20 designed such that when distal end 15 of needle 14 is withdrawn as shown in Fig
8, opening 108 substantially closes, preventing blood from entering nose portion38a.
Prior to use, opening 108 of seal 100 abuts needle 14 as shown in Fig. 5
25 Once the venipuncture has been made by needle 14, needle 14 is withdrawn and
distal end 15 is drawn by the user towards needle cover 16 as shown in Figs. 6-8.
As needle 14 moves within lumen 13 of cannula 19, third shaft portion 14c of
needle 14 provides a blood seal since it fits tightly within lumen 19. ~he
structure of needle 14 is described in detail i~fra). However, as distal end 15
30 enters catheter adapter 52 and third shaft portion 14c no longer touches lumen 19
(see Fig. 7), blood may enter receptacle 53 of adapter 52 In the absence of seal100, this blood may leak out of catheter adapter 52 and into needle tip coyer 16.
On passage of distal end 15 through opening 108 of seal 100, opening 108
35 reseals, thus preventing blood from leaking into needle tip cover 16. As needle
14 moves from the position shown in Fig. 5, to the position shown in Fig. 8, on
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the walls 110 of opening 108 wipe needle 14 thus causing needle 14 to be
substantially free of blood when it exits catheter assembly 18.
A second embodiment of the invention is shown in Figs. 9 and 10. The
5 second embodiment differs from the first, preferred embodiment in that nose
portion 38a is eliminated. E~cept to the e~ctent they are identified otherwise, the
numbered elements in Figs. 9 and 10 are substantially identical to those of Figs.
1-8, e~ccept that theyare preceded by the numeral "2" in Figs. 9 and 10.
Seal 200 is seated in recess 238 in needle tip cover 216. Recess 238 is
circular and coa~ial with the a~cis of needle 214. Seal 200 is an elastomeric disc,
preferably silicone rubber. Seal 200 is provided with an opening in the form of ~ ~ -
slit 208 dimensioned such that seal 200 fits tightly around needle 214, thereby
providing a blood seal. On passage of the distal end of needle 214 through
opening 208 of seal 200, opening 208 reseals, thus minimizing leakage of blood
into needle tip cover 216. Seal 200 wipes needle 214 in the manner described
above with regard to the first embodiment. The luer connector of catheter ;
adapter 252 has a surface 219. Prior to introduction of the catheter into a vessel,
surface 219 abuts front surface 202 of seal 200, thus forming a seal behveen
catheter adapter 252 and the assembly comprising needle tip cover 216 and seal --
200. This minimizes blood flow between needle tip cover 216 and catheter hub
duri~g activation of the device.
In the preferred embodiment, catheter introducer assembly 10 is provided
with a needle tip shielding device. A full description of such a device is
contained in U.S. Patent No. 5,215,52~ which is incorporated herein by
reference.
Referring to Fig. 5, needle 14 includes a first shaft portion 14a adjoining
the needle hub 12 and a second shaft portion 14b adjoining the sharp tip 15. Thefirst and second shaft portions have substantially the same outside diameters. Athird shaft portion 14c is located between the first and second shaft portions.
This shaft portion has a larger outside diameter than the first and second shaftportions. The diameter of the passage (not shown) e~tending through the shaft issubstantially constant. ~
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A fourth shaft portion 14d having a substantially conical configuration is
provided between the first and third shaft portions. The larger end of fourth
shaft portion 14d adjoins the third shaft portion 14c. As shown in Fig. 5, fourth
shaft portion 14d provides a smooth and uniform transition from the ~rst shaft
S portion to the third shaft portion of the needle.
A fifth shaft portion 14e may be positioned between second and third
needle shaft portions 14b, 14c. Like the fourth shaft portion 14d, it has a
substantially conical configuration.
Third shaft portion 14c is located near the bevelled tip. Preferably it is
about 0.004 inches larger in outside diameter than the nominal needle diameter,
i.e., the diameter of the first and second shaft portions. Preferably it is may also
be about 0.030 to about 0.12 inches in length.
Fourth shaft portion 14d is preferably about O.OlS to 0.045 inches in
length, and is located about 0.3 inches from the end of the bevelled. tip. As the
overall needle length is between about 2.4 and 3.0 inches, third and fourth shaft
portions are substantia11y closer to distal end lS than they are to nesdle hub 12
20 Fifth shaft portion 14e may be substantially identical to fourth shaft portion.
The shape and dimensions of needle 14, including portions 14a-e are such
that needle 14 can be easily inserted into and withdrawn from a vessel and
catheter 18 can be readily slid off the needle.
The enlarged, third shaft portion 14c provides a seal between the inside of
lumen 13 of cannula 19 and the remainder of the needle shaft. The seal hinders
blood leakage until the needle has been completely removed from the cannula.
As shown in Figs. 3 and 4, the tapered forward end of the catheter e~tends
30 beyond the third shaft portion. This is designed to prevent blood from leaking
past the third shaft portion as the needle penetrates a blood vessel.
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Another function of the enlarged, third shaft portion 14c is to prevent the
needle tip cover 16 from being removed from the needle shaft. As needle tip
35 cover 16 is releasably secured to the catheter adapter 52, it remains secured to
the catheter adapter until the enlarged, fourth portion 14d of the needle shaft
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engages the end wall 60 of the leaf spring 58. This engagement prevents cover
16 from being removed from the needle 14 and traps distal end 15 in cover 16
thus minimizing the risk of needle sticks. Further withdrawal of the hub from
this point causes the needle tip cover to be detached from the catheter adapter.The introducer assembly is completely separated from the catheter 18 and
discarded. i
The enlarged area of the needle can be formed by electroetching material
above and below this area to reduce the diameter of the remainder of the needle.Centerless grinding and cold upsetting are other alternatives for shaping the
needle to the desired configuration. Either technique provides a shaped needle of 1
integral construction, which is preferred. Other possible techniques includes
plating the area selected for enlargement or insert molding a band of polymeric -
material around the needle. ~ ~-
As the catheter 18 e~ctends over the enlargedt third shaft portion 14c of the
needle during both the introduction of the needle into the blood vessel and during
most of the time while the catheter is pushed off the needle, leakage between the
catheter and needle is substantially prevented. The frictional engagement
between third shaft portion 14c and the inner wall of the cannula portion of the ~ '
catheter is noticeable as the catheter is moved off the needle.
Distal end 15 of needle 14 is protected during the introduction of cannula ;~
13 into the blood vessel. It is positioned within the catheter 18 when initiallywithdrawn and then finally positioned within the needle tip cover. Once the tip
of the needle is withdrawn past the transverse wall portion 63 of spring 58, thespring moves to the position shown in Fig. 8. The needle tip cover is thereby
prevented ~rom being moved down the needle shaft towards the needle hub. The
distance between the enlarged third shaft portion 14c and the tip 15 of the needle
14 is less than the distance between the transverse wall portion 63 of the spring
and the end wall 60 of leaf spring 58. Third shaft portion 14c accordingly
reaches the end wall 60 just after the spring moves over the tip of the needle. As
this shaft portion 14c is unable to move through the smaller diameter opening 59in the end wall 60, the needle tip cover 16 is prevented from being moved off the
end of the needle.
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Flange 48 also plays a role in preventing needle tip 15 from re-emerging
from needle tip cover 16. If force is applied to pull needle tip cover back along
needle 14 towards hub æ, distal end 15 will tend to push against e~ctending wallportion 63 which will tend to bend in a clockwise direction (see Figs. S and 6). -
S If this happens, e~ctending wall portion 63 will be prevented from further bending
when it strikes the inside of flange 48. The e~cit path of distal end 15 will thus be
securely blocked. ~:
Although illustrative embodiments of the present invention have been
10 described herein with reference to the accompanying drawings, it is to be
understood that the invention is not limited to those precise embodiments, and ~ :
that various other changes and modifications may be effected therein by one
skilled in the art without departing from the scope or spirit of the invention. ;~
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