Apparatus For Taking Multiple Samples Of Biological Liquid

Abstract

Apparatus for taking samples of biological liquid and in particular human blood comprises an elongate body having a longitudinally extending central passageway connected at one end to a hypodermic needle. Branch channels extend respectively from the central passageway to individual test tubes which are supported by their upper ends along the lower side of the body. The test tubes are sealed so as to remain in sterile condition and means is provided for selectively venting air from the test tubes and controlling flow of liquid from the central passageway to the individual test tubes so that they can be filled successively or as desired. The test tubes are removable from the body for carrying out the several tests or analyses for which the samples are intended.

Description

FIELD OF INVENTION

The present invention relates to apparatus for the selective sampling of biological liquid and more particularly blood and especially human blood with a view to obtaining by a single sampling a plurality of separate samples or specimens intended for different tests or analyses.

BACKGROUND OF INVENTION

At present blood samples are customarily taken by means of a large capacity syringe. In order to carry out different biological analyses it is desirable to have some samples without coagulants and others with coagulants or different preservatives. This operation is still frequently effected in an archaic manner by a single operation comprising traditional withdrawal of a sample by a hypodermic syringe and its division in apparatus difficult to protect from outside contaminants and under conditions disagreeable for the patient.

SUMMARY OF THE INVENTION

The apparatus in accordance with the present invention avoids these difficulties and objections by delivering samples of the blood or other biological liquid through conduits to individual test tubes for receiving samples for the several tests or analyses to be performed. The samples are taken under conditions in which they are protected from all outside contamination. Moreover, the apparatus, by avoiding choice of anticoagulants by the operator, makes it possible for the sampling to be carried out by persons who are not highly specialized or skilled.

The invention accordingly provides apparatus for taking samples of biological liquid from an organism and more particularly samples of blood from a patient with a view to making a plurality of analyses of such liquid characterized in that it comprises an elongate body which is traversed longitudinally by a main canal connected at one of its extremities to a hypodermic needle. The body is provided on the side which is normally down during use, with a plurality of individual means for holding test tubes by their upper extremities. The main canal has branches leading to the individual test tubes and means for directing the biological liquid into the test tubes to fill them. Moreover, means which preferably controllable is provided to permit the escape of air initially contained in the test tubes as the test tubes are being filled.

The invention thus permits in a single sampling operation the successive filling of each of the test tubes. When an upstream test tube has been filled to the desired amount, it is sufficient for the operator merely to actuate the respective closing means to disconnect it from the main channel whereupon the liquid is directed to a downstream test tube of which the individual closing means is in open position.

Before the sampling, certain of the test tubes contain reagents for analysis which are not required for the test being made, can be disconnected from the circuit so that only those test tubes corresponding to the desired analyses are maintained in position to receive samples and are successively disconnected from the circuit when the quantity of liquid in them is considered sufficient.

All manipulation of multiple test tubes which are delicate for the operator and dangerous for the subject is thus avoided. The individual test tubes used in the apparatus of the present invention are placed on the support and are maintained in a sterile condition up to and during the sampling.

Other characteristics and advantages of the invention will appear from the following description of three preferred embodiments of the invention which are shown by way of nonlimiting example in the accompanying drawings in which:

FIG. 1 is a longitudinal section of apparatus in accordance with the invention;

FIG. 2 is a cross section taken on the line II--II of FIG. 1;

FIG. 3 is a cross section identical with that of FIG. 2 but showing the test tube in active position to receive a sample;

FIG. 4 is a longitudinal section of a second form of apparatus in accordance with the invention;

FIG. 5 is a perspective view showing in detail a valve member of the embodiment of FIG. 4;

FIG. 6 is a longitudinal section of a third embodiment of sampling apparatus in accordance with the present invention;

FIG. 7 is a cross section of the apparatus along the line VII--VII in FIG. 6; and,

FIG. 8 is a side elevation of a valve member of the apparatus of FIG. 6.

The sampling apparatus shown by way of example in FIGS. 1, 2 and 3 comprises an elongated body 1 formed for example of metal or plastic and having a longitudinally extending main canal 2 communicating at one end with a hypodermic needle 3 either directly as shown in the drawings or by a flexible conduit. As seen in FIGS. 2 and 3 the body portion 1 is generally rectangular in cross section. On its lower side the body 1 is provided with a plurality of recesses 4 adapted to receive individual test tubes 5 which are held by their upper ends in the recesses.

Each of the recesses 4 communicates with the main canal 2 by a branch channel 6. The cross section of the branch channels 6 is such as not to permit the counter-current passage of air from the test tube when the test tube is being filled with the liquid being sampled. To permit the escape of air, each of the recesses 4 is provided with a lateral passage 7 which extends through to a side of the body 1 so as to communicate with the atmosphere. To control the flow of liquid into the test tube, each of the test tubes 5 is movable in the respective recess 4 between an upper position as shown in FIG. 2 and a lower position as shown in FIG. 3. When the test tube is in the upper position as shown in FIG. 4, it closes the air passage 7 so that air is not permitted to escape from the test tube and hence liquid cannot enter the test tube through the branch channel 6. When the test tube 5 is in the lower position as illustrated in FIG. 3, air is permitted to escape through the lateral passage 7 and hence liquid can enter the test tube through the branch channel 6.

Prior to the taking of a sample, the body 1, hypodermic needle 3 and test tubes 5 are sterilized. The test tubes are assembled in the body 1, preferably in their upper position as shown in FIGS. 1 and 2. They are thus maintained in sterile condition. Moreover, the test tubes may contain, prior to sampling, the appropriate reagents and notably the anticoagulants necessary in the case of apparatus used for sampling blood. When the hypodermic needle has been inserted into the subject, the blood or other liquid being sampled flows through the hypodermic needle 3 into the main channel 1 and from the main channel through a branch channel into the respective test tubes. The test tubes are preferably filled successively. Thus, the test tube nearest the needle is first positioned in the lower position shown in FIG. 3 so as to receive liquid from the main channel 1 through the corresponding branch channel 6. When a sufficient amount of liquid has been received in the first test tube, it is moved to its upper position as shown in FIG. 2 so as to block the air escape passage 7 and thereby prevent further liquid from entering the test tube. The liquid is thereupon directed to the branch passageway of the next downstream test tube positioned in its lower position to receive liquid. The test tubes may thus be filled one after the other to the desired extent. The test tubes are suitably numbered or otherwise identified so that each can be designated for a particular test or analysis. If a particular test is not to be made on the liquid being sampled, the corresponding test tube can be left in its upper closed position so that it does not receive liquid. The upper ends of the test tubes fit frictionally in the respective recesses 4 of the body 1 so as to be held securely in the recesses and to remain in the position to which they are moved in controlling the flow of liquid into the respective test tube. When the sampling has been completed, the entire apparatus is taken to the laboratory where the test tubes can be removed and appropriate analyses or tests are carried out on the individual samples thus collected.

The embodiment of apparatus shown in FIG. 4 likewise comprises an elongate body 1 having a longitudinally extending main canal 2 which is of capillary cross sectional dimensions. The body 1 is also provided at its lower side with a plurality of recesses 4 for receiving the upper ends of test tubes 5. Each of the recesses 4 communicates with the main canal 2 by a transverse channel 8 which is perpendicular to the main canal and extends all of the way from the recess 4 to the upper side of the body 1. Moreover, each of the recesses 4 is provided with an air escape passage 9 of small cross section which extends from the top of the recess into the main canal 2 at a point downstream of the corresponding transverse channel 8.

The test tube 5 is filled by liquid flowing down from the main canal 2 through the transverse channel 8 while the air escapes through the small passage 9. Communication of the main channel 2 with the atmosphere is provided by an auxiliary transverse passage 10 which is located at the end of the main canal 2 remote from the hypodermic needle 3 and opens to the upper face of the rectilinear body 1.

Each of the secondary transverse channels 8 is provided with a valve member 11 controlling the flow of liquid into the corresponding test tube. The valve member 11 is shown as comprising a valve stem 11a which has a sliding close fit in the corresponding passage 8 and is provided with an operating button 11b at its upper end. Each valve stem 11a is provided with a transverse opening or window 12 which is preferably circular. The valve member is movable longitudinally between a lower closed position in which a lower portion of the valve stem 11a closes the passage 8 leading from the main canal 2 to the respective test tube holding recess 4 and an open position in which the lower end of the valve stem is above the main canal 2 so that liquid can flow from the main canal 2 through the transverse channel 8 into the respective test tube. When the valve member is in its lower position, the window 12 is in alignment with the main channel 2 and permits flow of liquid through the window to a downstream test tube. The hole 12 in the valve member 11 is preferably of a diameter equal to that of the main canal 2. If desired, the valve member can be moved to an intermediate position in which the valve stem blocks both the main canal and also the branch channel to the respective test tube. This might be done for example to assure that all of the liquid for the time being goes to an upstream test tube.

The apparatus shown in FIGS. 4 and 5 is used in substantially the same manner as described with respect to that shown in FIG. 1 to 3 except that flow of liquid to the individual test tubes is controlled by means of the valve members 11 rather than by the position of the test tubes, all of which remain seated in their uppermost positions. As previously described, the test tubes can contain suitable reagents as desired and can be filled one after the other to the desired extent by suitable manipulation of the respective valve members 11 which fit frictionally in the respective channels so as to stay at the positions to which they are moved. The test tubes can be filled in any desired order and any of them can be left empty if it is so desired.

A third form of apparatus is shown in FIGS. 6, 7 and 8. In this embodiment an elongate body 1 for supporting the test tubes 5 is traversed longitudinally by a central conduit 13 which is open at both ends. On opposite sides of the conduit 13 the upper portion of the body 1 is provided with longitudinally extending parallel recesses 14 and 15. A flexible conduit 16 at one end of the body 1 joins the central conduit 13 with a hypodermic needle 17.

On the side which normally faces downwardly when the apparatus is in use the body 4 is provided with a plurality of downwardly projecting cylindrical projections or tubular sleeve portions 18 which are of a size to fit into the upper end of and hold a test tube 5. A circular groove 19 is provided in the lower face of the body 1 around the upper portion of each of the cylindrical projections 18 to receive the upper edge of the test tube and permit a tight closing of the test tube. Communication between the central conduit 13 and the interiors of the cylindrical projections 18 is effected by an opening 20 of a conical top portion 21 of the recess formed inside of the cylindrical projection. Through this opening 20 each of the tubular test tube holders 18 communicates directly with the central conduit 13.

Each of the test tube holders 18 is provided near its lower end with two outwardly projecting circumferential ribs 22 and 23 which are spaced a short distance apart to provide an intervening groove between them. At one side of the tubular part 18 there is provided an axially extending groove 24 which is formed in the outer surface of the tubular member and extends from its lower conical end approximately halfway up the length of the tubular part. These notches extend down to the lower end portions of the tubular members 18 and are all disposed on the sides toward the needle 17 in the same longitudinal median plane of the apparatus.

The ribs 22 and 23 are in a position to guide the respective test tube and to hold it in an upper position in which the upper edge of the test tube is seated in the circular groove 19 or in a lower position in which the upper part of the test tube uncovers an upper portion of the groove 24. When the test tube is in its upper position, the upper end of the test tube is closed and air cannot escape from the interior of the test tube. There is thus formed a cushion of air which prevents entry of liquid into the test tube. When the test tube is in its lower position, the upper portion of the groove 24 is uncovered so that air is permitted to escape from the test tube and hence liquid can enter.

A sealing plunger 25 is slidable for its whole length in the interior of the central conduit 13. The plunger is provided at regular intervals throughout its length with circular ribs 25a forming sealing rings which assure a good separation between the test tubes and fluid tightness with respect to the atmosphere. The spacing of the sealing rings 25 is equal to the spacing of the test tubes along the body 1. The inner end of the plunger 25 has a conical point 26 while the other end extends beyond the body 1 and is provided with an enlarged head 27 which serves as a hand grip for operation of the plunger.

The operation of the apparatus shown in FIGS. 6 to 8 is essentially the same as that of the apparatus shown in the preceding figures. With the first test tube (nearest the hypodermic needle) in its lower position so that air can escape and with the plunger 25 positioned so that its inner end is between the entrances to the first and second test tubes, liquid will flow from the central conduit 13 into the first test tube. When this has been filled to the desired amount it is raised to its upper closed position and the plunger is withdrawn sufficiently to permit liquid to flow to a downstream test tube. In this manner the test tubes can be filled successively or otherwise as desired.

While the invention has been described with reference to the preferred embodiments illustrated in the drawings it will be understood that it is in no way limited to these embodiments and that various modifications of form and material may be made. The various features of the three embodiments shown in the drawings are mutually interchangeable insofar as they are compatible and other modifications may be made within the spirit of the invention.

Claims

What we claim and desire to secure by letters patent is:

1. Apparatus for taking samples of a biological liquid and particularly human blood to obtain a plurality of separate samples for different analyses, comprising an elongated body having a longitudinally extending central passageway, a hypodermic needle connected with said central passageway at one end of said body, a plurality of test tubes, means for removably mounting said test tubes by their upper ends in depending position under said body with the upper ends of the test tubes closed by said body, said mounting means comprising means for slidably gripping the upper end of each test tube for movement between an upper position and a lower position and venting means comprising a vent passage which is closed by the test tube when in its upper position and opened when the test tube is in its lower position, and branch passageways leading from said central passagewy to said test tubes respectively, whereby the individual test tubes can be filled successively to the desired extent with samples of liquid supplied through said needle, central passageway and the respective branch passageways by selectively manually lowering individual test tubes to corresponding lower positions on said mounting means to allow displacement of air in the lowered test tubes by fluid.

2. Apparatus according to claim 1, in which said branch passageways are of such small cross section that flow of liquid therethrough prevents the escape of air from the test tubes through said branch passageways.

3. Apparatus according to claim 1, in which said mounting means comprises a plurality of recesses in the lower side of said body, each recess receiving the upper end of one of said test tubes.

4. Apparatus for taking samples of a biological liquid and particularly human blood to obtain a plurality of separate samples for different analyses, comprising an elongated body having a longitudinally extending central passageway, a hypodermic needle connected with said central passageway at one end of said body, a plurality of test tubes, means for removably mounting said test tubes by their upper ends in depending position under said body with the upper ends of the test tubes closed by said body, said mounting means comprising means for slidably gripping the upper end of each test tube for movement between an upper position and a lower position and venting means comprising a vent passage which is closed by the test tube when in its upper position and opened when the test tube is in its lower position, branch passageways leading from said central passageway to said test tubes respectively and a plunger longitudinally slidable in said central passageway to selected positions to admit a flow of liquid from the central passageway through the branch passageways to the respective test tubes, whereby the individual test tubes can be filled successively to the desired extent with samples of liquid supplied through said needle, central passageway and the respective branch passageways.

5. Apparatus according to claim 4, in which said branch passageways are of such small cross section that flow of liquid therethrough prevents the escape of air from the test tubes through said branch passageways.

6. Apparatus according to claim 4, in which said mounting means comprises a plurality of tubular projections projecting down from the lower side of said body, each of said projections fitting into the upper end of one of said test tubes.

7. Apparatus according to claim 6, in which a circular groove in said body around the upper end of each of said projections receives the upper edge of each of said test tubes to provide a seal.

8. Apparatus according to claim 6, in which each of said projections has a circular external rib near its lower end and an axially extending groove in its outer face extending from the lower end of the projection to a point part way up the projection.