Blood Specimen Collection Assembly

Abstract

A blood specimen collection assembly having a fluid inlet and a fluid outlet with valve means disposed within the assembly for movement to and from an open and closed position whereby to prevent the backflow of testing fluid from a specimen receptacle, which is coupled with the assembly, into the patient's bloodstream during use of the assembly. The specimen receptacle is in the form of an evacuated container and is coupled with the collection assembly when the same is in use, the receptacle being in communication with the assembly to provide negative pressure through the assembly for opening the valve and withdrawing the specimen, the valve resuming its closed position upon filling of the receptacle.

Description

This invention relates to improvements in devices used for taking blood samples from patients, and more specifically, to a blood collection assembly having check valve means therein to prevent backflow of the blood specimen and testing solution into the bloodstream of the patient.

Although blood specimen collection devices have been used in the past for obtaining a quantity of blood from the patient suitable for subsequent mixing with a test solution, such devices have generally been so constructed that after withdrawing the blood specimen in one container, it was then necessary to transfer the blood into another container carrying the test fluid. This process subjected the blood specimen to possible contamination from various sources and subsequently increased the changes of obtaining invalid results from the test.

In more recent times devices have been developed which combine the specimen container and the test fluid container into one unit such that the blood specimen, upon being withdrawn through a hollow needle inserted in the patient's vein, flows directly into the container having the testing solution therein. The test is thus carried out without requiring that the blood be transferred from one container to another. Since the needle remains in the patient's arm during mixing of the blood specimen with the test fluid, however, there is a very grave danger that some of the mixture may flow back into the vein before the needle can be removed. Oftentimes the test fluid is of such a nature that only a very small amount need be released into the bloodstream before causing serious damage or even death to the patient being examined.

A primary object of the present invention is to provide a blood specimen collection assembly which includes an evacuated specimen receptacle normally containing an amount of testing fluid therein, which receptacle is adapted to directly receive the blood specimen withdrawn from the patient by the assembly, the assembly additionally including check valve means whereby to prevent backflow of the blood and fluid mixture from the receptacle into the bloodstream of the patient.

Another important object of this invention is to provide a blood specimen collection assembly for communication with a specimen receptacle, the assembly having a body provided with a chamber therein, a hollow needle in communication with the chamber and extending from one end of the body for penetrating a vein of the patient, valve means within the chamber shiftable to and from an open and closed condition permitting inflow of blood through the needle and a fluid outlet whereby said assembly is placed in communication with said receptacle to permit blood to be drawn through said assembly by the negative pressure exerted from the receptacle through the assembly.

Yet another object of the instant invention is the provision of a blood specimen collection assembly comprising a combination of components including check valve means within the body of the assembly, the check valve means having a ball adapted for a sealing the fluid inlet of the assembly against backflow and structure for spacing the ball from the fluid outlet during flow of blood through the assembly to the specimen receptacle.

A yet further object of the present invention is to provide a blood specimen collection assembly wherein the blood specimen is withdrawn from the patient into the specimen receptacle by means of a negative pressure exerted through the assembly by virtue of said receptacle being evacuated, the negative pressure causing shifting movement of a check valve to initially permit inflow of blood into the assembly and therethrough into the receptacle, the check valve then being permitted to shift to a closed position whereby to preclude backflow of the blood and testing mixture into the vein of the patient.

Other objects of this invention include many details of construction which will become apparent from following specification and accompanying drawing, wherein:

FIG. 1 is a fragmentary, elevational view partially in section and showing one form of the invention with a specimen receptacle and holder;

FIG. 2 is an enlarged, fragmentary, substantially central sectional view thereof with the receptacle and holder removed;

FIG. 3 is a sectional view taken along line 3 -3 of FIG. 2;

FIG. 4 is a side elevational view of another form of the invention with the specimen receptacle and holder removed;

FIG. 5 is an enlarged, fragmentary, substantially central sectional view of the assembly shown in FIG. 4; and

FIG. 6 is a sectional view taken along line 6 -6 of FIG. 5.

The blood specimen collection assembly 10 as illustrated in the embodiment of the invention shown in FIG. 1 includes, as its primary components, a body 12 having coupled therewith a specimen receptacle 14, there being a holder 16 provided for said receptacle in order that the assembly 10 may be utilized in the manner hereinafter described.

The body 12 is best illustrated in the sectional showing of FIG. 2 of the drawing, the same including a head 18 and a fitting 20, said head 18 and fitting 20 preferably being formed of compatible materials whereby the same may be fitted together in cooperating relationship whereby to define a chamber 22 therebetween, the forwardmost end of said chamber being defined by a conical sidewall 24 formed interiorly of head 18, the normally rearmost end of the chamber 22 being defined by a face 26 presented by an inner end of fitting 20.

A fluid inlet passage 28 extends through head 18 and is in communication with chamber 22, there being a hollow needle 30 carried within and extending substantially outwardly from said passage 28, which needle is penetrated into the vein of the patient during utilization of the assembly 10.

A fluid outlet passageway 32 is formed substantially centrally of fitting 20 and carries tubular member 34 which extends rearwardly or to the right of the assembly 10 viewing FIGS. 1 and 2.

In the embodiment of the invention illustrated in FIGS. 1-- 3, the chamber 22 has check valve means disposed therein, said check valve means including a shiftable ball 36 and a plurality of ball-supporting flutes 38 formed as a part of the face 26 of fitting 20. Said check valve means permits longitudinal shifting movement of the ball 36 within the passage from the full line position shown in FIG. 2 of the drawing wherein the ball is in sealing engagement with the sidewall 24 whereby to close fluid inlet needle 30 to the dotted line position of FIG. 2 wherein the ball 36 is in engagement with the outer inclined edges 40 of the flutes 38, such engagement spacing ball 36 from the mouth 42 of tubular outlet member 34 whereby blood may pass through said outlet tube 34 and into the specimen receptacle when the assembly 10 is utilized in the manner hereinafter described.

In order to permit such utilization of the assembly 10 the same is normally coupled with specimen receptacle 14, which receptacle contains a predetermined amount of testing material in the nature of a suitable liquid or powder which is intended to react with the blood in a predetermined manner in order to indicate certain desired characteristics. It is important that the blood, when mixed with such testing material, not be permitted to flow back through assembly 10 and into the bloodstream of the patient whose blood is being tested. In order to achieve this result, a negative pressure is drawn on the receptacle 14 and the open end thereof is tightly closed by a stopper 44 having a centrally disposed thin section 46, to the opposite end of receptacle 14 being permanently sealed inasmuch as the same is in the nature of a test tube or the like.

In order to permit utilization of the assembly 10, the holder 16, which is tubular in nature, having an open right-hand end viewing FIG. 1 (not shown) is provided at its opposite end with a closure wall 48 having a central aperture 50 which is threaded to complementally engage the threads 52 carried exteriorly of fitting 20. Thus, holder 16 may be coupled with the assembly 10 by interengagement of the threads thereof and the receptacle 14 can then be telescoped into the holder 16, it being noted that holder 16 could be provided with a pair of oppositely disposed finger-engaging flanges (not shown) whereby to permit the user of the complete assembly to easily grasp the holder 16 and exert, as by pressing thereupon with his thumb, a longitudinally directed force upon the receptacle 14. When such force is directed against the receptacle 14, the same, as it is being telescoped into the holder 16, will cause the central section 46 of stopper 44 to move into initial engagement with the sharpened end 54 of the tubular outlet member 34 whereby to cause end 54 to slightly penetrate section 46.

When the assembly has been prepared as by bringing the various components into the relative engagement hereinabove described, the patient's arm is prepared as by placing a constricting band thereabout and a venipuncture is made below the band with the tip of needle 30. Receptacle 14 is then pushed further into the holder 16 thereby causing section 46 to be fully punctured by tubular member 34 and thereby place the evacuated receptacle 14 in communication with assembly 10 through said member 34, chamber 22 and needle 30 and thus into communication with the vein of the patient. The evacuated nature of receptacle 14 causes the negative pressure therein to be created through the assembly 10 thereby shifting ball 36 from the full line to the dotted line position of FIG. 2, thence opening fluid inlet 56 of chamber 22 and permitting flow of blood through needle 30 into the chamber 22 and thence outwardly through mouth 42 into tubular member 34 and into the specimen receptacle 14 where it mixes with the testing material.

When receptacle 14 is sufficiently full of the blood specimen, the constricting band is released and the needle 30 removed from the vein of the patient, Release of the constricting band creates a negative pressure in the area above the band's former position and this pressure is transferred through the assembly 10. In the past, when collection devices of this nature were not provided with any check valve means, it was a simple matter to accidentally allow some of the blood and testing material mixture to be drawn back through the assembly and into the patient's bloodstream under the negative vein pressure, often resulting in serious illness or death. With the present invention, however, the negative pressure created by releasing the constricting band draws ball 36 toward wall 24 and thereby seals inlet 56, precluding backflow of the blood and testing material mixture into the vein of the patient.

The embodiment of the invention illustrated in FIGS. 4-- 6 of the drawing is generally similar in nature to that of FIGS. 1-- 3 and is likewise adapted to be coupled with a specimen receptacle and holder, although the same are not shown in FIGS. 4-- 6.

Thus there is provided an assembly 110 having a body 112 comprised of a head 118 and a fitting 120, the same being coupled together whereby to cooperated to define a chamber 122, the normally forwardmost portion of said chamber being defined by a conical sidewall 124 and the rearmost end of said chamber being defined by a face 126 of fitting 120. A passage 128 is provided through head 118 and receives a needle 130. Likewise, fitting 120 has a central passage 132 therethrough which carries a tubular member 134.

Check valve means is disposed in the passage 122 and includes a shiftable ball 136 which is movable between the full line and dotted line position of FIG. 5. A coil spring 140 normally urges ball 136 toward sidewall 124 thereby closing the fluid inlet 156. When a negative pressure is exerted through the assembly 110 the ball is caused to move from its dotted line position against spring 140 and toward the fluid outlet mouth 142, the ball being retained in a position spaced from said mouth by the spring 140, thereby permitting blood to flow through the assembly as by moving through needle 130, chamber 122 and tubular member 134 and thence into the specimen receptacle which has been suitably coupled with the assembly 110.

In either form of the invention the assembly safely and sufficiently precludes any backflow of the blood and testing material into the blood stream of the patient inasmuch as the check valve means is positioned in the flow path ahead of the point of mixture of the blood with the testing material. Thus, at any time that the constricting band about the patient's arm is released, it will cause shifting movement of the ball to a closed, sealing condition thereby effectively and fully precluding the flow of any of the blood and testing material mixture back through the assembly from the specimen receptacle 14 into the bloodstream of the patient.

Claims

I claim:

1. A blood specimen collection assembly comprising:

a partially evacuated specimen receptacle;

a body having a chamber provided with a fluid inlet at one end and a fluid outlet at the opposite end, said chamber having a conical sidewall adjacent said fluid inlet and a plurality of radially spaced flutes adjacent said fluid outlet, surrounding said outlet and extending into said chamber;

a hollow needle extending from said one end of the body and in fluid communication with the chamber through said inlet;

a fitting closing said opposite end of the chamber and having said fluid outlet formed therein, said fluid outlet being in communication with said receptacle; and

check valve means in said chamber to permit flow of fluid through said chamber in one direction only, said check valve means including a ball larger in diameter than said fluid inlet and shiftable from a position in engagement with said conical wall whereby to close said fluid inlet and a position supported by said flutes in spaced relationship from said fluid outlet whereby to permit flow of fluid through said chamber, out of said outlet and into said receptacle.