Apparatus For Separating And Injecting Blood Component

Abstract

The device comprises a system of blood-taking and decanting pockets interconnected by tubes, a storage pocket, the dimensions of which correspond to the amount of component to be injected, a filter and injection means in this storage pocket. The device is particularly useful for separating by cryo-precipitation and for injecting into a patient the factor VIII used against haemophilia.

Description

The present invention relates to a method and apparatus for separating, isolating and injecting certain blood components. More particularly, the invention relates to a device comprising a system of flexible pockets interconnected by means of tubes and intended to take up blood components and to separate them, especially by decanting.

In one known device, blood is taken from the donor's vein and is stored in a first blood-taking pocket, where it undergoes a first treatment for initial separation. One of the components is then transferred to a second pocket in the system for a second separation treatment. One of the elements separated after this second treatment is passed to a final pocket where it is stored.

The element thus separated and intended to be injected into a patient is taken from this storage pocket by means of a hollow needle which is used to pierce the pocket. In the case of a blood component containing agglomerated elements, however, the device just described has disadvantages, since the agglomerated particles may obstruct the passage in the hollow needle or may enter the patient's vein and create circulation problems. Incidents of this kind generally occur where the blood component has been separated by cryo-precipitation, since agglomerated elements still remain after thawing. In order to avoid such incidents, it is usual to dilute the component in a solution, especially an isotonic solution, before injecting it into the patient. This operation is usually carried out in an adjacent pocket into which the constituent taken is introduced by means of the hollow needle.

For the purpose of overcoming these disadvantages, it is also known to filter the blood before injecting it into the patient. A transfusion device of this kind is described in U.S. Pat. No. 2,702,034 filed on July 20, 1950. The filter chamber, usually of large capacity, is integrated into the means of transfusion and the dead volume of the latter therefore makes it impossible to use it for injecting small quantities.

Finally it is very difficult to remove the liquid from the storage pocket in a perfectly sterile manner in order to dilute it in the isotonic solution and inject it, while eliminating any risk of contamination of the element to be injected.

It is an object of this invention to provide a method and an apparatus to overcome these disadvantages and difficulties. The method in accordance with the present invention consists in the following steps:

THE COMPONENT IS TRANSFERRED IN A STERILE MANNER TO A STORAGE POCKET CONNECTED TO THE SYSTEM OF BLOOD-TAKING AND DECANTING POCKETS, THE POCKET COMPRISING AN INTERNAL FILTER AND HAVING DIMENSIONS CORRESPONDING TO THE AMOUNT OF COMPONENT ISOLATED;

THE STORAGE POCKET IS SEPARATED FROM THE SYSTEM OF BLOOD-TAKING AND DECANTING POCKETS, AND

THE COMPONENT IS KEPT IN THE STORAGE POCKET UNTIL IT IS INJECTED INTO THE PATIENT'S VEIN.

According to one embodiment of the invention, before the component just isolated is transferred to the storage pocket, it is mixed with a rinsing solution, especially an isotonic solution, which dilutes, in part, the agglomerated elements; this rinsing solution is contained in a pocket connected in a sealed and sterile manner to the system of blood-taking and decanting pockets.

The apparatus made in accordance with the present invention consists of a storage pocket containing a filter and having dimensions corresponding to the quantity of component isolated. The arrangement of the filter within the storage pocket is essential, since it produces a device which is particularly compact and easy to use, in which dead volumes are greatly limited. This is essential if the quantities of component extracted from the blood are very small.

According to another embodiment of the invention, the storage pocket also comprises injection means adapted to the end of the filter. The purpose of this arrangement is to avoid contamination of the components in the storage pocket at the time of their injection, but this highly compact arrangement of the injection means also helps to greatly limit dead volumes.

According to another embodiment of the apparatus of the invention, the isotonic solution is kept, prior to use, in the storage pocket. Thus the storage pocket, which comprises a filter and injection means, contains a solution of the blood component already diluted and ready to be injected.

The invention will now be described in greater detail in conjunction with two forms of embodiment given by way of examples only, and illustrated in the attached drawings, wherein:

FIG. 1 shows a side elevational view of the device according to the invention;

FIG. 2 shows a side elevational view of the storage pocket, partly broken away and to an enlarged scale; and

FIG. 3 shows a side elevational view of another embodiment of the device according to the invention.

Illustrated in FIG. 1 is a device which comprises a first flexible pocket 1 made of transparent synthetic material. Opening into this pocket is the end of a flexible tube 3 made of weldable synthetic material, the other end thereof being integral with a hollow needle 4 protected by a sleeve 5.

Opening into pocket 1 is one end of a tube 8 made of weldable synthetic material, the other end of which is integral with one arm of a three-way union 9, the other two arms of which are connected respectively, through tubes 11 and 12, to flexible pockets 6 and 10. Pocket 10 is connected through a tube 13 to a storage pocket 14 made of two sheets of synthetic material welded together by their edges. Pocket 14 contains a filter 17 and injection means consisting, more particularly, of a tube 23 comprising an injection needle 15 protected by a cap 16.

Filter 17, seen in FIG. 2, consists of a piece of fabric in the form of a sleeve, one end thereof being held by the weld at the bottom of the pocket, while the other end accommodates a ferrule 18 to which it is attached by the weld joining together the two sheets of which the pocket is made.

In one particular configuration of the invention, ferrule 18 has an internal wall 19 intended to be pierced by a hollow needle 20 integral with a sleeve 21 connected to the injection needle by means of a tube 23.

A description will now be given of the method of using the device illustrated in FIGS. 1 and 2. Hollow needle 4 is inserted into the patient's vein. After the blood has been collected in pocket 1, tube 3 is flattened in the vicinity of the pocket and its walls are welded together in order to close it off. The remainder of the tube, which is no longer in use, is then cut off.

The plasma is separated from the blood in some way, for example by centrifuging, after which the plasma is passed through tubes 8 and 11 into pocket 6, tube 12 being closed off by means of a clamp.

The plasma in pocket 6 is subjected to a treatment, such as cryo-precipitation, in order to separate an element (such as factor VIII) used against haemophilia. After tube 8 has been closed off, the element of the blood to be separated is decanted, through tubes 11 and 12, into pocket 10 which contains an isotonic solution to be mixed with the element. This mixture is then transferred to pocket 14 through tube 13.

Another way of using the present device consists in passing the plasma contained in pocket 1 through tubes 8 and 12 into pocket 10, tube 11 being closed off, for example by means of a clamp. The component contained in the plasma (more particularly factor VIII which is used against haemophilia) is separated by cryo-precipitation in pocket 10. The unprecipitated fraction of the plasma is transferred to pocket 6 through tubes 11 and 12, after tube 8 has been closed off, for example with a clamp. The isotonic solution, which in this configuration of the invention, is contained in storage pocket 14, is transferred to pocket 10 where it is used to dilute the component separated by cryo-precipitation. Pocket 10 is carefully rinsed with this solution, and the mixture of isotonic solution and component is transferred to pocket 14 through tube 13.

Tube 13 is then flattened and welded and pocket 14 is then separated from pocket 10 by cutting the tube. The blood elements in pockets 1 and 6 are then retained for specific purposes, while the component in pocket 14 may be kept therein until it is required for use.

At the time of use, sleeve 21 is pushed into ferrule 18 in a manner such that needle 20 pierces wall 19, after which needle 15 is inserted into the patient's vein and the component in its isotonic solution is injected directly by rolling up pocket 14 in order to force the liquid through tube 23. The agglomerated elements cannot pass through filter 17 and they therefore remain in pocket 14. Dead volumes are limited to a minimum since pocket 14 is small in size and the useful volume thereof corresponds substantially to the volume of component placed in solution for injection into the patient; moreover, the filter means is integrated into the storage pocket. A device of this kind also prevents contamination and ensures storage and injection under completely sterile conditions.

FIG. 3 shows blood-taking pocket 1 with its means for taking blood, namely hollow needle 4 protected by cap 5. This pocket is connected, through tube 32, to a second pocket 30 which is connected in turn, through a tube 33, to a third pocket 31 and, through a tube 34, to a storage pocket 14. This latter pocket comprises a filter 17 integral with a ferrule 18 as described in connection with FIG. 2, the ferrule being integral with a sterile access port 35, and the end of the ferrule being adaptable to the injection means.

The method of using this device to isolate and inject a component containing agglomerated elements will now be described.

The blood taken from the subject's vein is subjected to initial fractionation in pocket 1, more particularly by centrifuging. The plasma is transferred, through tube 32, to pocket 30, after which the tube is heat sealed or welded and cut off. The plasma in pocket 30 is again fractionated, more particularly by cryo-precipitation, in order to isolate those components which are present in very small quantities in human blood and which possess therapeutical properties. After being thawed out, the liquid fraction of the plasma is transferred, through tube 33, to pocket 31, during which transfer tube 34 is closed off, for example with a clamp. After tube 32 has been closed off, the rinsing solution in storage pocket 14 is passed, through tube 34, into pocket 30 which contains the component separated by cryo-precipitation. The mixture thus obtained is again transferred to pocket 14, where it is retained after tube 34 has been welded and cut off. During this latter operation, sterile air trapped in pocket 14 is evacuated through tube 34, so that pocket 14 is completely filled. In order to inject the solution containing the component into the patient's vein, a catheter containing a tube of very small cross section is connected to pocket 14. This catheter is fitted to ferrule 18 in access port 35 after the port has been opened under sterile conditions. The liquid is then injected by compressing pocket 14. The agglomerated elements are retained in pocket 14 by filter 17. Moreover, there is no risk of introducing air into the patient's vein, since care is taken to remove the air from pocket 14 before it is sealed. Moreover, the dead volume of the injection tube is as small as possible, and almost the entire amount of the solution contained in the storage pocket is injected. Finally, the injection means may be disconnected from access port 35 in pocket 14 and connected to a new pocket. It is thus possible to inject into the patient's vein as many doses as may be required, with no fear of the fine injection tube becoming blocked.

It is to be understood that the invention is not restricted in interpretation except by the scope of the following claims.

Claims

I claim:

1. In an apparatus for sampling and fractionating blood components including a plurality of sampling and fractionating pockets interconnected by tubing, a means for sequentially isolating, storing and intravenously injecting into a patient a blood component present in small amounts in the blood and liable to contain agglomerated elements,

said means comprising:

a distinct storage pocket for said component,

the inlet of said storage pocket being connected by sectionable tubing to said plurality of sampling and fractionating pockets,

the outlet of said storage pocket being sealed and having means for being equipped with injection means;

a filter means for preventing the injection of the agglomerated elements incorporated inside said storage pocket between said inlet and said outlet; said storage pocket being of dimensions substantially corresponding to the quantity of the component separated.

2. An apparatus according to claim 1, wherin said filter means consists of a tubular length of a filter fabric in the form of a sleeve running longitudinally inside said storage pocket,

one end of said sleeve being held closed at the bottom of said storage pocket,

the other end surrounding an outlet ferrule, said other end and said ferrule being held at the top of said storage pocket.

3. An apparatus according to claim 1, wherein said storage pocket is composed of two sheets having sides welded together; said filter means consisting of a tubular length of a filter fabric in the form of a sleeve running longitudinally inside said storage pocket,

one end of said sleeve being held closed between said sheets by the weld at the bottom of said storage pocket,

the other end surrounding an outlet ferrule, said other end and said ferrule being held between said sheets by the weld at the top of said storage pocket.

4. An apparatus according to claim 2, wherein said injection means is integral with said outlet ferrule.

5. An apparatus according to claim 2, wherein said outlet ferrule is further surrounded by a sterile access port, said injection means being adaptable to said access port.