Combination Blood Sampling Vacuum Syringe Centrifuge Container And Specimen Cup

Abstract

An elongated, unitary, blood sampling vacuum syringe, centrifuge container and specimen cup, for use with an ordinary tubular needle holder is described. The device includes an evacuated blood sample centrifuge container within one end and an evacuated specimen cup within the other end of a common tubular housing member. A transfer needle coaxially arranged within the housing member between the centrifuge container and the specimen cup effects transfer of the blood serum, after centrifuging, from the centrifuge container to the specimen cup through piercable diaphragm closure caps at the inner or facing ends thereof. Means is provided for breaking away of the specimen cup end of the common housing member for ready removal of the serum-filled specimen cup for use in analysis.

Description

This invention relates to medical syringes and is directed particularly to improved vacuum syringe devices combining a blood sample centrifuge container and a serum receiving specimen cup in a unitary structure.

In blood analysis for medical diagnosis or research it is frequently necessary to separate the blood serum from the cellular blood matter for independent chemical analysis. This is usually done by centrifuging a blood sample or specimen taken from the patient or donor with the use of an ordinary piston-controlled or vacuum actuated medical syringe. Because freshly drawn blood has a tendency to change in character due to enzymatic action, it is essential that separation and removal of the blood serum be effected as soon as possible after collection to ensure valid analysis. It is also important that the procedure undertaken in the centrifuging of the blood sample and removal of the serum specimen be such as to minimize any possibility of contamination. Since, in medical diagnosis, a substantial portion of the blood samples for analysis are taken in private clinics or physician's treatment facilities, and since such facilities vary over a wide range as to laboratory capability, availability and competence of technical personel, the preparation for analysis of blood sample serum is not infrequently of less than optimum quality. It should also be noted that samples obtained in this manner are frequently shipped over long distances before being subjected to chemical analysis. If the cellular blood mass is not properly and totally separated from the serum, a faulty result will be obtained by the receiving laboratory. In such cases the specimen collection agency, and not the receiving laboratory, is at fault. The medical literature as well as the publications in the field of clinical chemistry have, in the past, expressed great concern over these deficiencies and stated that the following determinations are particularly affected. Thus, it is well known that a number of changes ensue when whole blood is allowed to stand without removal of the cellular fraction. The glucose concentration diminishes rapidly, electrolytes migrate across cell membranes to establish new equilibria; phosphatases cleave intracellular organic phosphate esters, increasing the inorganic phosphorous level, and cellular enzymes may leak out causing false serum levels. When hemolysis occurs these effects become exaggerated and, in addition, complications develop with the technical aspects of certain test procedures.

The removal of the centrifuged blood serum from the blood sample for analysis was heretofore accomplished either by manually pouring the serum from the top of the container or tube into the serum specimen cup, or by vacuum withdrawal by mouth with the use of a pipette tube lowered into the blood serum for subsequent release into separate specimen cups. It can readily be understood that either of these two commonly used serum removal methods are subject to sources of contamination. These methods of separation, moreover, are readily subject to contamination of the serum by migrating blood cells unless great care is taken in the separating process. For this reason, several spinnings in a centrifuge are generally necessary in order to obtain a serum sample which lends itself to reliable and valid chemical analysis. This process of separation takes much of the technician's time and, in addition, necessitates the uneconomic use of glassware.

It is, accordingly, the principal object of this invention to provide a new and improved blood sampling vacuum syringe, centrifuge container and specimen cup that obviates the above described deficiencies of blood serum specimen preparation devices and procedures heretofore devised.

A more particular object of the invention is to provide a combination blood sampling vacuum syringe, centrifuge container and specimen cup of the character above described that will be of unitary structure including an enclosed blood sample centrifuge container and a specimen cup for use with an ordinary tubular needle holder for vacuum drawing a blood sample into the centrifuge container, and which includes means for automatically withdrawing a predetermined quantity of subsequently centrifuged blood serum in said container into the specimen cup for analysis upon the manual manipulation of the device in a simple and noncritical manner.

Still another object of the invention is to provide a vacuum syringe device of the above nature wherein the specimen cup has its open end hermetically sealed by means of an inwardly directed, resilient diaphragm closure cap adapted to be pierced, upon actuation of the device, by one end of a hollow transfer needle coaxially arranged within the device, the other end of said transfer needle being adapted to pierce a resilient diaphragm closure cap at the inner end of the centrifuge tube for depression down into the centrifuged serum to be evacuated into the specimen tube.

And yet another object of the invention is to provide a vacuum syringe device in the above nature including means for readily transversely severing or breaking away the specimen cup end portion of the device housing to permit easy removal of the filled serum specimen cup for laboratory analysis. Quicker and more efficient separation of serum from cells is thus achieved with less labor and a higher degree of accuracy than heretofore possible.

Yet another object of the invention is to provide a vacuum syringe device of the above nature which will be of such simple and inexpensive construction as to be readily disposable or expendable after use, while at the same time providing under a clean environment a capped blood serum containing specimen cup for interchangeable use in automatic multiple tests laboratory analyzers.

Other objects, features and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:

FIG. 1 is a longitudinal cross-sectional view of a vacuum syringe device embodying the invention shown partly inserted in a tubular needle holder preparatory to the taking of a blood sample;

FIG. 2 is a vertical cross-sectional view similar to that of FIG. 1, but showing the vacuum syringe device fully depressed pressed within the needle holder after a blood sample has been taken and further showing the blood sample which has been withdrawn into the lower or centrifuge chamber of the device;

FIG. 3 is a vertical cross-sectional view of the vacuum syringe device of FIG. 2, shown separately, after centrifuging of the blood sample, and with the centrifuge chamber pressed upwardly within its housing preparatory to removal of the centrifuged blood sample serum into the specimen cup;

FIG. 4 is a longitudinal cross-sectional view similar to that of FIG. 3 but showing the serum specimen cup depressed downwardly within its housing and with the serum specimen withdrawn therein;

FIG. 5 is a vertical cross-sectional view similar to that of FIG. 4 but showing how an upper portion of the cylindrical housing of the device can be broken away to separate the serum containing specimen cup;

FIG. 6 is a longitudinal cross-sectional view of a modified form of vacuum syringe device embodying the invention shown partly inserted in a tubular needle holder preparatory to the taking of a blood sample;

FIG. 7 is a vertical cross-sectional view similar to that of FIG. 6, but showing the vacuum syringe device fully depressed within the needle holder after a blood sample has been taken, and further showing the blood sample withdrawn into the lower or centrifuge chamber of the device;

FIG. 8 is a vertical cross-sectional view of the vacuum syringe device of FIG. 7, shown separately, after centrifuging of the blood sample and with the transfer needle and serum specimen cup pressed downwardly within their housing so that the downwardly-extending portion of the needle pierces into the centrifuge chamber just prior to removal of the centrifuged serum therefrom;

FIG. 9 is a longitudinal cross-sectional view similar to that of FIG. 8 and showing how further depression of a vacuum serum specimen cup effects piercing of the lower diaphragm cap of the specimen cup to permit vacuum withdrawal thereinto from the centrifuge chamber of the blood serum; and

FIG. 10 is a vertical cross-sectional view similar to that of FIG. 9, but showing how an upper portion of the cylindrical housing of the device can be broken away to remove the serum containing specimen cup.

Referring now in detail to the drawings, reference numeral 10 designates, generally, a combination blood sampling vacuum syringe, centrifuge container and specimen cup embodying the invention, the same being shown, in FIGS. 1 and 2, being used in association with a hollow needle holder 11. The needle holder 11 is of standard known construction, and may be of the type commonly used with ordinary vacuum syringes. As such, it comprises a tubular body portion 12, the upper end of which is open to receive an evacuated blood collection tube and provided with an outwardly extending, peripheral flange 13 for manual grip and control. The opposite end of the tubular body portion 12 is closed with a bottom wall portion 14 provided with an internally threaded, axial opening 15 into which a disposable hollow needle assembly 16 may be removably fitted in known fashion. The needle assembly 16 comprises an outwardly extending end 17 for insertion into the patient's vein upon the taking of a blood sample, and an inwardly extending end 18 for piercing the centrifuge chamber of the vacuum syringe device, as is hereinbelow more particularly described.

The vacuum syringe device 10 embodying the invention comprises an elongated, cylindrical housing member 19, preferably of a tough, transparent synthetic plastic material, within which is slidably fitted a blood sample centrifuge chamber 20. The centrifuge chamber 20 comprises a cylindrical tube 21, preferably of glass, hermetically sealed at the lower end by a lower diaphragm cap member 22 and, at the upper end, by an upper diaphragm cap member 23. The interior of the centrifuge chamber 20 is evacuated to effect the withdrawal of blood thereinto during use of the device as is hereinbelow more particularly described. A removable end closure cap 24, which may be of a somewhat resilient synthetic plastic material friction fitted over the lower end of the cylindrical housing member 19, retains the blood sample centrifuge chamber 20 within said cylindrical housing member. The end closure cap 24 is provided with a central opening 25 for through passage of the inwardly extending end 18 of the needle assemble 16, as is hereinbelow more particularly described. A removable abutment pin 26 extending through diametrically opposed pin openings 27, 28 in the cylindrical housing member 19 is so disposed as to constrain the evacuated blood sample centrifuge chamber 20 at its lowermost position within the cylindrical housing member 19 prior to use of the device.

A hollow transfer needle 29 is coaxially disposed within the elongated cylindrical housing member 19, being retained by a supporting disc member 30 tranversely affixed within said housing member about one-third the distance from the upper end thereof. The supporting disc member 30 also supports a hollow displacement air needle 31 extending through said supporting disc member and projecting a short distance in the downward direction. The transfer needle 29 comprises a long, downwardly extending portion 32 and a short, upwardly extending portion 33. The peripheral wall of the cylindrical housing member 19 is provided with an air vent opening 34 directly above the needle supporting disc member 30, for the purpose hereinafter appearing.

Fitted in inverted disposition within the upper end of the cylindrical housing member 19, and slidably disposed therein, is a specimen cup 35. The specimen cup 35, which is preferably integrally formed of a strong, transparent synthetic plastic material, comprises a cylindrical outer wall 36 having an outwardly extending peripheral flange 37 near its open end, and a substantially frusto-conical bottom 38 at the closed or upper end, as illustrated in the drawings. The specimen cup 35 is of a shape typical of those used in automatic blood chemistry analyzers, and therefore forms no part of the present invention in and of itself. The open end of the specimen cup 35 is fitted with a diaphragm closure cap 39 hermetically sealing said cup against a contained vacuum for the purpose hereinafter appearing.

Prior to use of the vacuum syringe device, the lower end of the capped specimen cup 35 rests against the upper end or point of the upper needle portion 33, as illustrated in FIG. 1. The upper or bottom end of the specimen cup 35 extends just short of the upper end of the cylindrical housing member 19, and said housing end is capped by a removable end cap member 40. The end cap member 40 is preferably molded of a comparatively resilient, synthetic plastic material and is so sized as to be frictionally retained in place.

Considering now the operation of the vacuum syringe device 10, the same will first be fitted loosely in a typical needle holder 11 as described above preparatory to insertion of the outwardly extending end portion 17 of the needle assembly 16 in the distended vein of the patient giving the blood sample. As illustrated in FIG. 2, immediately upon insertion of the needle the blood sample centrifuge chamber 20 will become filled with blood, indicated at B, drawn in under the influence of the contained vacuum. The vacuum syringe device 10 will thereupon be withdrawn from the needle holder 11, and the lower diaphragm cap 22, being of a resilient material such as natural or synthetic rubber, will seal off the contained blood upon its separation from the inwardly extending needle portion 18. The blood containing vacuum syringe device 10 is now ready for centrifuging to separate the blood cell mass from the serum, such separation being illustrated in FIG. 3 by the cell mass C shown in the lower end portion of the centrifuge chamber 20, and the blood serum, designated S, at the upper end portion of said centrifuge chamber. As illustrated by reference character D in FIGS. 3, 4 and 5, after centrifuging there will be a rather sharp plane of demarcation between the dense blood cell mass C and the serum S.

FIGS. 3 and 4 further illustrate how the blood serum S in the blood sample centrifuge chamber 20 is transfered to the specimen cup 35. To this end, the end closure cap 24 will next be removed from the lower end of the cylindrical housing member 19 and the finger or a suitable pushing device, such as a pencil, will be used to push the centrifuge chamber 20 up against the underside of the supporting disc member 30 so that the lower end portion 32 of the transfer needle 29 passes through the upper diaphragm cap 23 of said centrifuge chamber and deep into the blood serum S contained therein. In this connection, it is to be noted that the abutment pin 26, which normally prevents upward movement of the centrifuge chamber 20 prior to centrifuging of a blood sample, must first be removed. The head at one end of the pin 26 permits easy manual withdrawal. After the centrifuge chamber 20 has been pushed home against the underside of the fixed supporting disc member 30, the upper end cap 40 on the cylindrical housing member 19 will be removed and the specimen cup 35 will be pushed in inwardly, (see FIG. 4), so that its lower end seats against the top of the supporting disc member 30. In so doing, the short upper end portion 33 of the hollow transfer needle 29 will be made to pierce the diaphragm closure cap 39 whereupon, under the influence of the contained vacuum, blood serum S will be drawn upwardly into the specimen cup 35. The hollow displacement air needle 31, which also pierces the upper diaphragm cap 23 of the blood sample centrifuge chamber 20 upon its being pushed into seating engagement against the underside of the supporting disc member 30 as described above, serves as a flow path for displacement air upon removal of blood serum S to the specimen cup 35 as described above. To insure free flow of atmospheric air into the air needle 31, the side wall of the cylindrical housing member 19 will preferably be provided with a small vent opening 34 located directly above the supporting disc member 30 (see FIG. 1).

With reference to FIG. 4, the length of the lower end portion 32 of the hollow transfer needle 29 will be such, with respect to the proportions of the blood sample centrifuge chamber 20, as to extend somewhat short of the plane of separation or demarcation D between the centrifuged blood serum S and the blood cell mass C. With such spacing, eddy currents in the serum S occasioned by swift inflow at the lower end of the needle portion 29 will be far enough removed from the blood cell mass to obviate any possibility of contamination of serum S being drawn into the specimen cup 35. As an additional precaution against the setting up of such strong eddy currents at the tip end of the transfer needle end portion 29 as might conceivably cause blood cell mixing or contamination of the specimen serum, a side-wall portion of said needle portion is preferably apertured, near the lower end thereof as indicated at 41, to serve as an auxiliary passageway for the flow of serum S into said needle. The aperture 41 has the effect of reducing the velocity of serum flow through the pointed hollow end of the needle, thereby lessening any possibility of disturbance of blood cells in the vicinity of the plane of demarcation or separation D.

With reference to FIG. 4, means is provided for quickly and simply removing the filled specimen cup 35 for independent storage, transport and analysis. To this end, the outer peripheral wall of the cylindrical housing member 19, at a position immediately above the supporting disc member 30, is provided with an annular groove 42 defining a weakened wall zone permitting lateral breakaway upon the imposition of a gentle manually applied twisting and/or pulling motion at opposite sides of said groove, as illustrated in FIG. 5. The separated upper portion of the cylindrical housing 19 can thereafter readily be withdrawn from the specimen cup 35, and the filled specimen cup removed from the upper end portion 33 of the transfer needle 29 for independent use as described above. The diaphragm closure cap 39 enclosing the upper end of the specimen cup 35, being of a resilient material such as natural or synthetic rubber, will seal itself upon withdrawal from the transfer needle to prevent spillage or contamination of the contained specimen prior to use in analysis. The diaphragm closure cap 39 can be readily manually removed if necessary for sampling of the specimen during subsequent analysis.

FIGS. 6 through 10 illustrate a modified form of the above described invention, differing therefrom principally in that the disc member 30a supporting the hollow transfer needle 29a is slidably disposed in the elongated cylindrical housing member 19a instead of being fixed therein. Since this second embodiment otherwise differs only slightly from the embodiment of FIGS. 1 through 5 described above, only such differences, and their effects upon the use and operation of the vacuum syringe device, will now be detailed herein.

Referring to FIG. 6, it will be noted that in the second form of the invention the removable abutment pin 26 and its associated pin openings 27 and 28 described above in the first embodiment are omitted, and that the piercing needle point at the lower end of the hollow transfer needle 29a abuts directly against the outer surface of the upper diaphragm cap 23a. The upper needle point of the hollow transfer needle 29a similarly abuts directly against the outer surface of the diaphragm closure cap 39a associated with specimen cup 35a. As a salient feature of construction of the embodiment of the invention illustrated in FIGS. 6 through 10, it is to be noted that the thickness and/or quality of the central zone 43 of the lower diaphragm cap 22a to be pierced is such as to be more readily pierced upon relative axial movement of its associated needle end portion 18 than the central zone 44 of the upper diaphragm cap 23a to be pierced by relative axial movement of the lower end of the hollow transfer needle 29a. In addition, the central zone 45 of the diaphragm closure cap 39 will be of such thickness and/or quality as to be pierced only by a relatively greater axial force imposed by the transfer needle 29a than that required to pierce the upper diaphragm cap 23a. Thus, referring to FIG. 7 and considering the operation of the vacuum syringe device, it will be noted that downward pressure of the device 10a upon the taking of a blood sample from a patient as described above in connection with the description of operation of the embodiment of the invention illustrated in FIGS. 1 through 5, will result in the piercing only of the lower diaphragm cap 22a to enable the withdrawal of a blood sample into the centrifuge chamber 20a. The sample-containing vacuum syringe device is then ready for centrifuging, after which, as illustrated in FIG. 8, the housing upper end cap 19a will be removed to permit pushing inwardly upon the specimen cup 35a by use of the finger or suitable implement, such as an ordinary pencil. FIG. 8 illustrates how under such pushing action, the lower end of the transfer needle will penetrate the upper diaphragm cap 23a of the blood sample centrifuge chamber 20a to its fullest extent, i.e., to the extent limited only by the moving of the needle supporting disc member 30a into seating engagement upon the upper diaphragm cap 23a. Thereafter, because of the buttressing effect upon the underside of the supporting disc member 30a imposed by the capped centrifuge chamber 20a, further downward force upon the specimen cup 35a will result, finally, in the piercing of the specimen cup diaphragm closure cap 39a, as illustrated in FIG. 9, to effect evacuation of centrifuged blood serum S into said specimen cup in the same manner and for the same purpose as described above in connection with the operation of the first form of the invention illustrated in FIGS. 1 through 5.

As in the embodiment of the invention illustrated in FIGS. 1 through 5, the second embodiment of the invention illustrated in FIGS. 6 through 10 is similarly provided with means for quickly and easily separating the serum-containing specimen cup from the used vacuum syringe device. To this end, the outer peripheral wall of the cylindrical housing member 19a, at a position immediately above the transfer needle supporting disc member 30a in its final position of use as illustrated in FIG. 9, is provided with an annular groove 46 defining a weakened wall zone permitting lateral breakaway upon the imposition of a manually applied twisting and/or pulling motion at opposite sides of said groove, (see FIG. 10).

While we have illustrated and described herein only two forms in which our invention can conveniently be embodied in practice, it is to be understood that these forms are given by way of example only and not in a limiting sense. The invention, in brief, comprises all the embodiments and modifications coming within the scope and spirit of the following claims.

Claims

What we claim as new and desire to secure by Letters Patent is:

1. For use with a conventional tubular blood sampling needle holder, a combination holder, centrifuge container and specimen cup comprising, in combination, an elongated tubular housing member, an evacuated tubular centrifuge container member slidably disposed within one end of said housing member and having a needle pierceable diaphragm closure cap member at each end, an evacuated specimen cup member slidably disposed in the other end of said housing member in axially spaced relation with respect to said centrifuge container member, the inner end of said specimen cup member having a needle pierceable diaphragm closure cap member, a hollow transfer needle pointed at each end, means supporting said transfer needle in longitudinal disposition within said housing member between said centrifuge container member and said specimen cup member for sequentially piercing the inner diaphragm closure cap of said centrifuge container member and the diaphragm closure cap of said specimen member upon relative axial movement, within said housing member, of said centrifuge container member and said specimen cup member with respect to said transfer needle.

2. The invention as defined in claim 1, wherein said tubular housing member, said centrifuge container member and said specimen cup member are cylindrical in shape.

3. The invention as defined in claim 1, including releasable means for constraining said centrifuge container member against inwardly sliding movement with respect to said housing member.

4. The invention as defined in claim 3, wherein said transfer needle supporting means comprises means retaining said transfer needle in fixed relative disposition within said housing member.

5. The invention as defined in claim 4, including a side-wall aperture in said transfer needle near the pointed end thereof facing said centrifuge container member.

6. The invention as defined in claim 5, including auxiliary means for venting the centrifuge container member through the inner diaphragm closure cap of said centrifuge container member upon the piercing thereof by said transfer needle.

7. The invention as defined in claim 5, wherein said housing member is provided with a peripheral weakened wall zone in the vicinity of the inner end of said specimen cup member to permit manual breakaway severing of an end portion of said housing member, for easy removal of said specimen cup member after being pierced by said transfer needle.

8. The invention as defined in claim 7, wherein said tubular housing member, said centrifuge container member and said specimen cup member are cylindrical in shape.

9. The invention as defined in claim 8, wherein said transfer needle is coaxially disposed within said housing member.

10. The invention as defined in claim 1, wherein the needle pierceable portion of said inner diaphragm closure cap member of said centrifuge container member is of lesser thickness than that portion of the diaphragm closure cap of said specimen cup and therefore offers less resistance to being pierced by said transfer needle than said diaphragm closure cap of said specimen cup member.

11. The invention as defined in claim 10, wherein the needle pierceable portion of said outer diaphragm closure cap member of said centrifuge member is of lesser thickness than that portion of the inner diaphragm closure cap of said centrifuge container and therefore offers less resistance to being pierced by said transfer needle than said inner diaphragm closure cap of said centrifuge container member.

12. The invention as defined in claim 10, wherein said tubular housing member, said centrifuge container member and said specimen cup member are cylindrical in shape, and wherein said transfer needle is coaxially disposed within said housing member.

13. The invention as defined in claim 12, including auxiliary means for venting the centrifuge container member through the inner diaphragm closure cap of said centrifuge container member upon the piercing thereof by said transfer needle.

14. The invention as defined in claim 13, including a side-wall aperture in said transfer needle near the pointed end thereof facing said centrifuge container member.

15. The invention as defined in claim 13, wherein said housing member is provided with a peripheral weakened wall zone in the vicinity of the inner end of said specimen cup member to permit manual breakaway severing of an end portion of said housing member for easy removal of said specimen cup member after being pierced by said transfer needle.