EP0597070B1

EP0597070B1 - Removal of blood product from a container

Info

Publication number: EP0597070B1
Application number: EP93912084A
Authority: EP
Inventors: Michel Joie; Jean-Claude Bernes; Alphonse Heremans; Ermenegildo Lavezzo
Original assignee: Baxter International Inc
Current assignee: Baxter International Inc
Priority date: 1992-05-29
Filing date: 1993-03-23
Publication date: 1998-04-29
Anticipated expiration: 2013-03-23
Also published as: JPH06509968A; DE69318255D1; DE69318255T2; EP0597070A4; EP0597070A1; WO1993024371A1

Abstract

A method for removing a frozen liquid (14) form a plastic container (12) without thawing the liquid is provided comprising the steps of: breaking an interfacial bond between the frozen liquid and plastic container by cutting the container along a circumference (20) thereof between a first and second end of the container; and removing the frozen liquid from the resultant cut container. An apparatus for removing liquid from a plastic container without thawing same is also provided. The apparatus includes a body (16) defining an interior for receiving the container. The body includes within the interior at least one cutting member (32) that is so constructed and arranged that it cuts the container along a circumference thereof when the container is received within the body. Additionally, the apparatus includes means (52) for removing the frozen liquid from the container.

Description

BACKGROUND OF THE INVENTION

The present invention relates to removing a frozen liquid, such as a blood product, from a plastic container.

Of course, it is known in the medical industry to collect blood from human donors and store same in a plastic container. Such blood can either be directly infused, as whole blood replacement to patients, or broken down into its various components, such as plasma, red blood cells, and platelets. By breaking blood down into its components, this allows the blood product to be used more efficiently to replace the necessary component the patient may need.

It is also known to store blood components, such as plasma, in sterile, flexible plastic containers. This allows small quantities of plasma, usually a pint or less, to be stored until a sufficient quantity of plasma is collected for processing into the various components. After enough of the frozen plasma has been accumulated for a batch, the frozen slugs of plasma can be removed from the plastic containers and processed through the necessary equipment.

In using the frozen slugs of plasma, it is important that the frozen plasma is quickly removed from the plastic containers after the containers are taken from the cold storage. Premature thawing of the frozen slugs of plasma allows precipitates, which are produced during the freezing process, to go back in the solution, thus reducing the processing yield.

Recently, examination of frozen plastic containers including plasma demonstrates that at target processing temperatures of -40°C, an interfacial bond is created between the plastic container and the plasma. It is believed that this bond may be created by water that is absorbed into the matrix of the polymer during the autoclaving process. At the low temperatures involved in the storage of plasma (-40°C), a physical bond is formed between the plasma and the residue moisture in the polymer of the container. As this residue moisture level varies, so also can the strength of the physical bond.

One possible method for removing the frozen plasma from the container is through the utilization of heat. However, the utilization of heat to break the bond can damage the plasma due to temperature fluctuations that can denature the proteins. Some typical previous practices to retrieve frozen plasma from polymer containers either required product preconditioning in the -10/-20°C range, or required a skin thaw process. It is also known to use a low temperature shock (-80°C) to weaken the container and break it by heavy shaking. Disadvantages with these processes, aside from the concerns with temperature fluctuations also include the fact that these techniques require a two-step process.

One previous method of opening such a container included cutting or slicing off one end of the container after such processing. The disadvantage of such a process is that it tends to be a slow operation that permits excessive thawing of the frozen product. This reduces the yield of the processing operation. Further, the manual cutting process can expose the frozen plasma product to human contact which can cause contamination of the plasma being processed and may create some risks for the operator.

U.S. Patent No. 3,939,623 discloses a plasma collection system in which frozen plasma is thawed before the plasma containers are cut open. The containers are carried on a conveyor passed a cutting tool that cuts open the container and allows the liquid contents to fall into a collection vessel. A disadvantage of the system is that the premature thawing reduces the process yield and therefore the system is not suitable for removing frozen slugs of plasma.

UK Patent GB 2044220B (corresponds to U.S. Patent No. 4,253,458) discloses a method and a multiple-bag collection apparatus in which plasma can be collected, separated from the blood cells, frozen, and then removed from its container while frozen, if desired, on an automated basis. The method comprises freezing the plasma to block form in the container, cutting the shoulder portion away from the rest of the container, after the plasma has frozen, to define an open, cut end, and expelling the plasma in frozen block form from the container through the open end, by collapsing the opposed walls towards each other, the side edges of the opposed walls, which define side edges of the container, diverging towards the opened end of the container in the collapsed configuration of the container.

UK Patent GB 2141723B discloses a polyester composition and collapsible container made therefrom for use in the medical field for storing blood and blood components. The container can be used in the method disclosed in the U.S. Patent No. 4,253,458.

European Patent No. 057189 provides an apparatus for removing the contents of a compressible container comprising a compression member including a pair of plates relatively movable between an open spaced apart position to receive the container, and a closed position to compress the container to discharge its contents, an operating member for moving the plates from the open position to the closed position, and a retention member cooperatively associated with the plates to retain the container therebetween during the compression.

SUMMARY OF THE INVENTION

The present invention provides an apparatus and process by which a frozen liquid, such as a frozen blood product, can be removed from a plastic container. Pursuant to the present invention, the container can be processed at storage temperatures (approximately -40'C) without an intermediate preconditioning step.

The present invention provides a method of removing frozen liquid from a plastics container having first and second ends and a length therebetween, without thawing the frozen liquid, the method comprising the steps of cutting the container along a circumference thereof and removing the frozen liquid from the resultant cut container,
characterised in that the container is cut around its circumference and along the length of the container to break an interfacial bond between the frozen liquid and the container.

The invention also resides in apparatus for removing a frozen liquid from a plastics container without thawing the frozen liquid, the apparatus comprising at least one cutting member (32,34) for cutting a container along a circumference thereof,
characterised by a body (16) having an interior for receiving the container, and means (26) for effecting relative rotation of the cutting member (32,34) and the container within the interior to provide a cut around the circumference and along the length of the container to break any interfacial bond between the frozen liquid and the container.

In each of these claims, the precharacterising part is based on US-A-4253458.

The cutting member may be rotated around the container, or the container may be rotated relative to the cutting member.

Additional features and advantages of the present invention are described in, and will be apparent from, the detailed description of the presently preferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates a perspective cross-sectional view of an embodiment of a portion of the apparatus of the present invention.

Figure 2 illustrates a top elevational view of a cross-section of the apparatus of Figure 1 along lines II-II of Figure 1.

Figure 3 illustrates a top elevational view of a cross-section of the apparatus of Figure 1 taken along lines III-III of Figure 1.

Figure 4 illustrates a container after it has been cut pursuant to an embodiment of the present invention.

Figure 5 illustrates the container after it has been cut pursuant to a further embodiment of the present invention.

Figure 6 illustrates an embodiment of a further stage of the apparatus of the present invention.

Figure 7 illustrates a further embodiment of a method for removing the plastic container from the frozen product.

Figure 8 illustrates a further embodiment of a method for removing the plastic container from the frozen liquid.

Figure 9 illustrates a further embodiment of the method for removing the plastic container from the frozen product.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Apparatus including two work stations or stages is provided: a cutting-debonding mechanism; and a slug expelling station. Although, for the sake of clarity, these stations are illustrated separately it should be noted that these stations can be part of one apparatus.

Referring now to Figure 1, a perspective view of the cutting-debonding stage 10 of the apparatus is illustrated. As set forth in detail hereinafter, a container 12 including a frozen blood product 14 enters the device 10 in a frozen state and exists the device in a state in which the interfacial bond between the blood product and container has been broken as well as the container cut.

To this end, the device 10 includes an elongated body 16 having an entry opening 18 and an exit opening 20. As illustrated in Figure 2, the elongated body 16 defines an interior 28 having a perimeter 20 that allows the frozen blood product containers 12 to be received but prevents the container 12 from rotating either side-to-side or end-over-end as it travels through the elongated body 16. Accordingly, the container 12, as it moves from the entry opening 18 to the exit opening 20, maintains a relatively constant lateral position with respect to the elongated member 16.

The device 10 includes a rotatable drum 26 that is preferably constructed so that it can rotate in a clockwise manner. Of course, if desired, the drum 26 can be oriented so that it rotates in a counterclockwise manner. In the preferred embodiment illustrated, the rotatable drum 26 is located at approximately the middle of the elongated member 16. Thus, the rotatable drum 26 divides the elongated member 16 into an upper half 28 and a lower half 30. However, the rotatable drum 26 can be located so as to be closer to either the entry opening 18 or the exit opening 20 of the elongated member 16, if desired.

Coupled to the rotatable drum 26, in the preferred embodiment illustrated, are two cutting

members

32 and 34. The cutting

members

32 and 34 are biased into an interior channel 36, located between the upper half 28 and lower half 30 of the elongated member 16 by biasing members 38. In the preferred embodiment, the biasing members 38 are springs. As illustrated, the cutting

members

32 and 34 can be rotatable rigid wheels 41 having a cutting surface. Other cutting surfaces, however, can be utilized, such as blades, knives, and the like.

As illustrated in Figure 3, the cutting

members

32 and 34 are so constructed and arranged that they are biased into the interior channel 36 and contact a surface 40 of the container 12 as the container passes from the elongated member 16 entry opening 18 to the exit opening 20. This causes the cutting

members

32 and 34 to cut the container 12 as the container passes through the elongated member 16. At the same time, it has been found that the cutting

members

32 and 34 will break the interfacial bond between the frozen plasma and the container 12.

Preferably, the cutting

members

32 and 34 are oriented at an angle a with respect to the horizontal plane, and thereby the surface 40 of the container 12 as the container 12 passes through the elongated member 16. This causes, as illustrated in Figures 4 and 5, the cutting

members

32 and 34 to create helical cuts 43 in the container 12a. The combination of the angle a and the rotation of the cutting 32 and 34 around the container 12 creates a "screwing" effect that forces the container to move axially into the rotatable drum 26. During the cutting process, the shear stress caused by the cutting

members

32 and 34 penetrating the container 12 results in the desired debonding effect.

Of course, if desired, cuts other than helical cuts can be made in the container 12. Likewise, if desired, only one cutting or more than two cutting members can be utilized.

Figure 4 illustrates, by way of example, a one-turn helical cut 43 in the container 12a. By way of example, Figure 5 illustrates a two-turn helical cut 43 in the container 12a.

It should also be noted that although in the preferred embodiment illustrated, the container 12 remains in a relatively fixed lateral position and the rotatable drum 26, and thereby the cutting

members

32 and 34, rotate thereabout, if desired, the cutting members can be fixed and the container can be rotated with respect to the cutting

members

32 and 34.

As illustrated, as a container 12a exits the elongated member 16, it has been cut along a circumference and length thereof. The container 12a is then fed to an expelling station 50. As used herein, expelling station 50 means a station wherein the frozen blood product is removed from the cut container 12a. The container 12a is fed by the lower half 30 of the elongated member 16 directly to the expelling station 50 in the position it was fed into the entry opening, i.e., top end first.

Referring now to Figure 6, an embodiment of the expelling station 50 is illustrated. In the illustrated embodiment, two

opposed rollers

52 and 54 are provided that rotate in opposing directions.

In use, an end 56 of the cut container 12a is fed between the

rollers

52 and 54. The

rollers

52 and 54 are motorized and have surfaces 58 that are designed to grip the container. Therefore, the cut container 12a is grabbed by the

rollers

52 and 54. At least one of the rollers is spring loaded so that the space between the rollers can open slightly. This allows the cut container 12a to be pulled therethrough. At the same time, the

rollers

52 and 54 expel the frozen plasma 14 from the container. Although not illustrated, a bin or other receptacle for receiving and collecting the plasma will be located at this stage.

It should also be noted that other methods for expelling the frozen plasma from the container can be used. These include, as illustrated in Figure 7, grasping the container 12 at an end 62 and unwinding the plastic from the frozen plasma 14. This process can either be manual or using an automated process.

Additionally, as illustrated in Figure 8, each

end

56 and 62 of the container 12a can be grasped and pulled causing the plastic container to separate from the frozen plasma 14. Again, this can be a manual or automated process.

Illustrated in Figure 9 is a further embodiment of the expelling station 150. As illustrated, the container 12a can be fed between two

plates

64 and 66. The expelling station 150 includes a clamp 69. One end 56 of the container 12a is secured between the clamp 69. To expel the plasma, one or both of the

plates

64 and 66 can be movable toward each other. As the

plates

64 and 66 are moved toward each other, because the end 56 of the container 12a is secured, the frozen plasma 14 is expelled from the container (illustrated by the arrow).

It is important to note that because the container 12a has been cut helically along a length thereof pursuant to the method of the present invention, the interfacial bond between the plastic container 12 and the frozen blood 14 is broken. This allows a variety of methods and means for expelling the frozen liquid product 14 from the plastic container 12.

The present invention also provides, in addition to the apparatus, a method for removing the frozen blood product 14 from the plastic container 12. The method allows the product to be removed without a preconditioning temperature state. Accordingly, the frozen blood product 14 can be taken directly from storage and removed from the plastic container 12.

Claims

A method of removing frozen liquid from a plastics container having first and second ends and a length therebetween, without thawing the frozen liquid, the method comprising the steps of cutting the container along a circumference thereof and removing the frozen liquid from the resultant cut container,
characterised in that the container is cut around its circumference and along the length of the container to break an interfacial bond between the frozen liquid and the container.
The method of Claim 1 wherein the container (12) is cut helically.
The method of Claim 1 or 2, including the step of rotating at least one cutting member (32) around the container to cut the container (12).
The method of Claim 3, including the step of moving the container (12) axially of the circumferential path of the cutting member (32), while the container is being cut.
The method of any preceding claim including the step of removing the frozen liquid from the container (12) by passing the cut container through means (52,54;64,66) that expels the frozen liquid from the cut container.
The method of Claim 5 comprising removing the frozen liquid from the cut container (12) by passing the cut container between a pair of rollers (52,54).
The method of Claim 5 comprising removing the frozen liquid from the cut container by using a pair of plates (64,66).
The method of any one of Claims 1 to 4, including the step of removing the frozen liquid from the cut container (12) by pulling on at least one end of the cut container to remove the container from the frozen liquid.
The method of any one of Claims 1 to 4, including the step of removing the frozen liquid from the cut container (12) by unwinding the cut container from the frozen liquid.
Apparatus for removing a frozen liquid from a plastics container without thawing the frozen liquid, the apparatus comprising at least one cutting member (32,34) for cutting a container along a circumference thereof,
characterised by a body (16) having an interior for receiving the container, and means (26) for effecting relative rotation of the cutting member (32,34) and the container within the interior to provide a cut around the circumference and along the length of the container to break any interfacial bond between the frozen liquid and the container.
The apparatus of Claim 10, wherein said means for effecting relative rotation comprises drive means (26) operable to drive the cutting member (32,34) around the interior of the body.
The apparatus of Claim 10 or 11, wherein the body (16) has an inlet opening (18) and an outlet opening (20) for a container to pass through the body, with the cutting member (32,34) located between the openings.
The apparatus of Claim 11 or 12, wherein the cutting member (32,34) is oriented at an angle (a) so as to create a helical cut in the container (12).
The apparatus of any one of Claim 10 to 13, wherein the body (16) includes two cutting members (32,34).