Blood sampling device

Abstract

A device for taking samples of blood is composed of a tube closed at one end, a ferrule solid with a needle fitting onto the open end of the tube and sealing it except for at least one air outlet hole and the aperture of the needle, and a stopper or cap fitting exclusively onto the ferrule in such a way as to seal the hole or holes as well as the aperture of the needle.

Description

The present invention is concerned with devices or assemblies used for taking samples of blood from living creatures, particularly animals, for the purpose of analysis or other studies.

Until now tubes were used for this purpose, onto which a needle can be fitted and which are corked when the sample has been taken in order to send or convey it to the laboratory.

Devices are also known which comprise a vacuum tube, threaded and closed by a pierceable stopper, which cooperates with a ferrule, also threaded, through which the needle passes so that after being inserted in the vein the needle pierces the stopper when the ferrule is screwed onto the tube.

In all these devices or assemblies the needle is withdrawn from the tube, which is then sealed by some means or another for transportation.

Consequently the needle is separated from the tube containing the sample and may therefore possibly be used again and again. There is thus no means of ensuring that a blood sample is not contaminated by being obtained by means of a needle which has already been used before.

Hence, there is danger of falsifying the results of the analysis and also of giving rise to contamination of one individual by a needle which has already been used on another individual, who may himself be ill.

This danger is especially great in the treatment of animals when, for instance, blood samples have to be taken from a whole herd.

For instance, in the event of an infection of brucellosis, a disease characterized by the presence of a raised blood agglutinin level, if the same needle is used for several animals, traces of agglutinin in the needle due to a sick animal, added to the non-specific agglutinin of a healthy animal, may falsify the analysis of the blood of the latter and cause it to be regarded as sick. In such a case the animal may be slaughtered and classified as unfit for consumption. This represents a considerable loss.

Inversely this needle may then contaminate a healthy animal.

The object of the invention is to remedy this defect by means of a blood sampling device in which the tube can be sealed with the needle remaining in place so that the recipient of the sample may be certain that the needle has only been used once.

To this end the object of the invention is a blood sampling device characterized by the fact that it comprises a tube closed at one end, a ferrule solid with a needle which can be fitted to the open end of the tube so as to seal it except for at least one air outlet and the aperture of the needle, and a stopper or cap which fits exclusively on to the ferrule in such a way as to close the said orifice or orifices as well as the needle aperture.

It follows therefore that if the recipient of the sample received the unit complete, that is to say the sealed tube closed by the ferrule carrying the needle and the cap fitted onto the ferrule, he can be quite certain that the needle has only been used for this one sample.

Such a device is therefore particularly useful to meet the requirements of the public services if they should have to impose regulations or standards of hygiene in the veterinary field.

According to one form of execution of the invention the ferrule comprises a cylindrical body, along the axis of which is fixed the needle, a cylindrical skirt which extends in the reverse direction of the point of the needle and made so as to fit tightly in the open end of the tube, a peripheral flange extending in the opposite direction to the skirt and forming a circular groove around a central boss which holds the needle, and in the bottom of the groove are pierced axially the said air escape hole or holes.

The said circular groove is made to receive, with a tight fit, the open end of a stopper in the form of a cap which covers the needle in such a way that the rim of the said open end seals tightly at the same time the said air outlet or outlets.

Other characteristics of the invention will become clear from the description which follows on the basis of the annexed drawing, which is given purely as an example, and in which:

FIG. 1 is a side elevation, partially in cross section of a unit in accordance with the invention;

FIG. 2 is a partial view with the cap which protects the needle removed;

FIG. 3 is a cross section along the line 3--3 of FIG. 2;

FIG. 4 is similar to FIG. 1 and shows a variant;

FIG. 5 is a cross section along the line 5--5 of FIG. 4.

In accordance with the example of execution shown in FIGS. 1 to 3 a blood sampling device in accordance with the invention is composed of a cylindrical tube 1, open at one end and forming the body of the assembly, a ferrule carrying a needle 3 solid with it and a cap 4 fitted into the support 2.

The ferrule 2 carrying the needle 3 is of overall cylindrical shape. It comprises a cylindrical skirt 5, of an external diameter about equal to the internal diameter of the tube 1 to enable it to be fitted with friction into the end of the tube in a watertight manner.

The needle 3 is fixed in the centre of the ferrule 2 in a boss 6 and extends in the opposite direction to the skirt 5.

The ferrule 2 forms a shoulder 7 between the skirt and the needle so as to rest upon the edge of the end of tube 1. Moreover the ferrule 2 is extended in the opposite direction to the skirt 5 in such a way as to form a rim 8 forming a circular groove 9 with the centre boss 6.

One or more holes 10 pass axially through the ferrule 2 and is or are pierced in the bottom of the groove 9 around the boss 6 (FIG. 3).

Into the circular groove 9 is fitted with friction and in a watertight manner the open end 11 of the cap 4, the thickness of the wall of the cap at this end being about equal to the width of the groove 9.

It is understood that when the cap is fitted into the groove of the ferrule, watertightness is assured between its external surface and the internal wall of the groove and also between the surface of the end of the cap and the bottom of the groove, thus sealing the hole or holes 10 and also the aperture of the needle.

It will be observed that the assembly can be sterilised, the sterile needle being protected by the cap.

When it is desired to take a sample of blood, one only has to remove the cap 4 in order to use the device.

As the tube can only be closed by the stopper provided that the ferrule 2 is fitted onto the tube, the presence of the needle assures the recipient of the blood sample that the needle has been used only once, to obtain the sample contained in the tube.

FIG. 4 shows a variant in which the cap 4a has a skirt 12 which covers externally the junction of the ferrule 2a and the tube 1a.

In this example the boss 6a and the rim 8a are aligned at the same height and the groove is omitted.

The closing of the holes 10a is effected by the surface of a shoulder 13 of the cap 4a.

The skirt can with advantage include a locking device 14 cooperating with a complementary device 15 provided on the external surface of the body 1a.

If required, the lower edge of the skirt can be provided with a safety band (not shown) which has to be torn to enable the cap 4a to be removed, so as to provide a guarantee of the so-called "inviolable" type.

The tube is made with advantage, for example, of crystal polystyrene and the cap can be made of polyethylene.

Claims

What we claim is:

1. A blood sampling device comprising a tube closed at one end and open at the opposite end, a closure plug mounted in the open end, said plug having an air vent hole therein, and a second hole, a hollow needle fixedly supported in the second hole and extending above said tube, said needle having a central bore which communicates with the interior of the tube, and a cap positioned over the needle and the vent hole and in sealing engagement with the plug, said cap sealing said vent hole from said needle bore, external said tube.

2. The device of claim 1 in which the cap is in direct sealing engagement with the plug surface surrounding said vent hole so that the vent hole is covered at one opening by the cap.

3. The device of claim 1 in which the plug includes a circular groove which extends to one opening of the vent hole, and in which the cap is securely held in place in the circular groove of the plug.

4. The device of claim 2 in which the plug includes a circular groove which extends to one opening of the vent hole, and in which the cap is securely held in place in the circular groove of the plug.

5. The device of claim 1 in which the tube includes a locking device and the cap includes a mating locking device for secure engagement to said locking device of said tube.

6. The device of claim 2 in which the tube includes a locking device and the cap includes a mating locking device for secure engagement to said locking device of said tube.