GB2377985A

GB2377985A - A disposable container for refrigerated animal/human tissue or fluid

Info

Publication number: GB2377985A
Application number: GB0108327A
Authority: GB
Inventors: Brian Clarke
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-03
Filing date: 2001-04-03
Publication date: 2003-01-29
Also published as: GB0108327D0

Abstract

A disposable container (dry shipper) 22 for refrigerated animal / human tissue or fluid comprises a thermally insulating outer wall 26 lined with a heat reflective material 28 to reduce thermal radiation losses and may be either attached to the interior of the outer wall 26 or loosely placed inside, a liquid refrigerant (liquid nitrogen) absorbent material 30 having one or more pockets for receiving semen containers 34 so that the refrigerant is in close proximity of the semen containers 32, an upper layer 36 of the same material as absorbent material 30 to absorb any liquid nitrogen which may be released accidentally from absorbent material 30 and a lid 24 having a lining 40 of the same heat reflective material 28. The outer wall is preferably of polystyrene which also provides structural integrity. The absorbent material may be sponge, granular, particulate, paper, tissue, wood or any chemically absorptive material or any combination of these. The preferred material is that used by florist in flower arrangements.

Description

CONTAINER FOR REFRIGERATED SEMEN In one aspect, this invention relates to a container for refrigerated semen, suitable for storing animal (e. g. cattle) semen. A particular application of the invention is the transportation of cattle semen to farms, for use in artificial insemination, but the invention is not limited exclusively to this. The container may also find use in other fields for storing refrigerated tissue or other animal or human matter.

Such refrigerated transportation containers are known in the art, and are referred to specifically as"dry shippers", for carrying semen (in individual semen holders) in an environment of liquid nitrogen Broadly speaking, a first aspect of the present invention provides a disposable dry shipper.

Such a disposable dry shipper can provide significant advantages over conventional dry shippers which are expensive and necessarily intended for use many times.

A typical prior art container is shown in Fig. I, and consists of a rigid aluminium cylinder 10 with a dual-wall structure defining a high-vacuum area 12, and a central volume 14 Silica provided in muslin bags 16 is arranged around the central volume, and retained in position by a stainless steel mesh tube 18. Individual semen holders are placed with the mesh tube 18. The container is filled with liquid nitrogen, which is absorbed by the silica, to keep the semen cool.

Such prior art containers are necessarily complicated and of sturdy construction, because liquid nitrogen is considered to be a difficult material to handle. Moreover, it is essential to keep the semen below a certain temperature (e. g. about-80 C) in order to adequately preserve the semen for use in artificial insemination.

However, such a prior art container causes difficulties when the container is used to transport semen to a farm which may be in an infected or diseased area. It is common for such an area to be effectively quarantined, so that any object which is brought to the farm cannot be removed until it has been completely disinfected. In such a case,

the above prior art container is wholly unsuitable because it is difficult to disinfect.

Moreover, the container will not be re-usable until the disinfectant has been fully purged from the silica; this can take about ten days or more.

In contrast, by using a disposable dry shipper, it is not necessary to disinfect the container after it has been used. To the best of the inventor's knowledge, disposable dry shippers have not been contemplated hitherto Moreover, the difficulties encountered with liquid nitrogen make such a disposable dry shipper counterintuitive.

In a closely related aspect, the invention provides disposable apparatus for containing one or more semen containers, the apparatus comprising:

a housing of heat insulating material ; and 0 a region containing a liquid absorbent material for holding a liquid refrigerant.

Preferably, the housing is of polystyrene. Preferably, the liquid absorbent material is of foam.

Preferably, a heat reflective material is arranged in at least one region between the housing and the liquid absorbent material The combination of a heat insulating material and a heat reflective material can provide eminently satisfactory protection against thermal losses, instead of requiring an expensive vacuum insulation.

Preferably, the liquid absorbent material is formed with one or more pockets, or recesses, for receiving one or more semen containers. Preferably, each pocket is dimensioned to receive a single semen container, such that each container is immersed, or surrounded, by the liquid refrigerant environment. This can provide

close contact between the semen container and the liquid refrigerant, to keep the 7=1 semen cool for as long as possible In a closely related aspect, the invention provides disposable apparatus for containing a plurality of semen containers, the apparatus comprising: a housing of heat insulating material; and

a region containing a liquid absorbent material for holding a liquid refrigerant, wherein the liquid absorbent material is formed with a plurality of pockets for receiving the semen containers, such that each semen container is receivable in its own pocket, to be in close contact with the liquid refrigerant environment.

In a further closely related aspect, the invention provides a method comprising using a disposable container comprising polystyrene and a liquid absorbing material, to transport semen in a liquid nitrogen environment, and disposing of the container after said use An embodiment of the invention is now described, by way of example only, with reference to the accompanying further drawings, in which:

(Fig I is a schematic sectional view showing a prior art dry shipper), zn Fig. 2 is a schematic sectional view showing the components of an embodiment of the present invention; and Fig. 3 is a schematic sectional view along the line Ill-Ill of Fig. 2.

Referring to Figs 2 and 3, a disposable dry shipper 20 is illustrated for transporting semen, in particular animal semen, in a refrigerated condition. The dry shipper 20 is especially suitable for transporting cattle semen (for example, bull semen) to farms for use in artificial insemination The dry shipper 20 is in the form of an open container body 22, and a lid 24.

The container body comprises an outer wall 26 made of a thermally insulating material; polystyrene is preferred as this is an inexpensive, lightweight material with excellent thermal insulation properties. Typically, the wall thickness is about 2-10 cm, although other thicknesses may be used as desired. The function of the outer wall 26 is to provide thermal insulation to reduce thermal conduction losses. In this embodiment, the outer wall 26 also provides the structural integrity of the container.

If desired, the outer wall may also be formed with, or support, one or more handles (not shown) by which the container may be carried.

The outer wall 26 is lined with a heat reflective material 28. Any suitable heat p. Tt reflective material may be used, but a reflective Mylar film is currently preferred The function of the reflective layer is to reduce thermal radiation losses The reflective layer 28 may be attached to the outer wall 26, or it may be placed loosely inside the outer wall 26, as desired A loose or separable arrangement may be more convenient and less expensive to manufacture The interior volume of the container 22 contains liquid absorbent material 30, which is capable of absorbing a liquid refrigerant. A suitable refrigerant is, for example, liquid nitrogen The liquid absorbent material 30 is formed to have openings, recesses or pockets 32 for receiving semen containers (one of which is shown schematically at 34) The function of the liquid absorbent material 30 is to hold the refrigerant liquid in the interior of the container 22, and in close proximity to the semen containers 34.

The liquid absorbent material may be any suitable material, including a foamed material ; or sponge; or a granular or particulate material (for example cat litter); or paper, tissue, or wood; or a chemically-absorptive material such as so-called super- absorbents; or any combination of the above This list is merely a list of examples, and is not exhaustive. It is preferred that the material be relatively inexpensive so that the dry shipper can be disposed of after use. It is also preferred that the material be relatively lightweight

(T A particularly preferred material is the foam commonly known as Oasis This is normally used by florists as a base for flower arrangements. This material has excellent liquid holding properties, is relatively easy to shape (to form the pockets 32, for example, by simple punching), and is lightweight and inexpensive. Moreover, after the pockets 32 have been formed, they will retain their shape unaided.

In this embodiment, individual pockets 32 are provided for receiving the semen containers 34, one per pocket. This can improve the thermal coupling between each

semen container 34 and the liquid refrigerant environment. In particular, the thermal coupling may be improved over that attained in the prior art arrangement of Fig. 1.

In use, the semen containers 34 are inserted into the pockets 32 before any liquid refrigerant is loaded. Thereafter, liquid refrigerant, typically liquid nitrogen, is poured into the open container body 12 to be absorbed by the liquid absorbent material 30.

Initially, the container body 12 and its contents will be at room temperature.

However, the liquid nitrogen (at -196OC) will rapidly cool the contents A certain amount of the liquid nitrogen will evaporate as the contents cool Therefore, the liquid nitrogen should be continued to be added, or topped up, until the evaporation has stabilised.

pu-tam It will be appreciated that, particularly when Oasis is used as the liquid absorbent

material 30, the amount of cooling required to lower the temperature of this material is considerably less than when a metal is present in the interior volume (as in the prior art arrangement of Fig. !). Therefore, liquid nitrogen wastage can be reduced.

Z :) ZD Once the evaporation has stabilised, the excess liquid nitrogen (i. e. any excess which has not been absorbed by the liquid absorbent material 30) is poured away. It is undesirable to have free liquid nitrogen in the container, as this could splash out and

risk causing an accident I Thereafter, an upper layer of a liquid absorbent material 36 is placed in the mouth of the container body 22 to cover the contents The upper layer 36 may be of the same' material as the liquid absorbent material 30. However, it is preferred that the upper layer 36 be at least partly compressible. The function of the upper layer 36 is to absorb any liquid nitrogen which may be released accidentally from the liquid absorbent material 30.

Finally, a lid 38 is placed over the upper layer 36 The lid 38 is of an insulating material, for example, the same material as that of the outer wall 26 of the body 22. the lid is also lined with a heat reflective material 40 in the same manner as the heat reflective material 28 of the container body 22.

The lid 38 preferably does not make a hermetic seal with the container body 12. It is important that any nitrogen gas generated by the slowly evaporating liquid nitrogen be allowed to escape If the gas is not allowed to escape, the container would be likely to burst under the pressure of gas With the above construction, it has been found that the semen can be kept at the desired temperature (e. g. below at about-80 C) for a period of between 7 and 12 hours This is more than adequate to enable the semen to be transported from a central refrigerated location to, for example, a farm requiring the semen for artificial insemination It is believed that such excellent thermal properties are a result of : the outer wall 26 of insulating material, the lining 28 of reflective material, and the use of a liquid absorbent material 30 in intimate contact with each of the semen holders Of course, it is not essential that all of the these features be used in every embodiment It will be appreciated that the invention enables the use of a non-evacuated outer wall (in contrast to the prior art arrangement of Fig. 1). Therefore, the apparatus can be very much simpler in construction It will also be appreciated that, particularly in the illustrated embodiment, there is no direct heat-conducting path for thermal losses from the interior of the container to the exterior. This can reduce thermal losses by conduction along such a direct path (compared, for example, to the heat conducting path provided by the stainless steel mesh tube 18 in the prior art arrangement of Fig. 1).

The apparatus can be manufactured very inexpensively, meaning that it can be disposable at the place of delivery. This avoids all of the problems associated with disinfecting the apparatus, and re-using the apparatus, as in the prior art. Moreover, the invention is especially suitable for transporting semen to areas which are considered to be at risk of infection or disease, from which it is preferable not return the apparatus after use.

It will be appreciated that the foregoing description is merely an example, and that 0 many modifications may be made using the scope and/or principles of the present invention. Features believed to be of importance are defined in the appended claims.

However, the Applicant claims protection for any novel feature or idea described herein and/or illustrated in the drawings, whether or not emphasis has been placed thereon.

Claims

CLAIMS I A disposable dry shipper for containing refrigerant liquid and one or more semen containers
2 Disposable apparatus for containing one or more semen containers, the apparatus comprising a housing of heat insulating material; and

a region containing a liquid absorbent material for holding a liquid refrigerant 4 :) ZD
3 Apparatus according to claim 2, wherein the housing is of polystyrene
4 Apparatus according to claim 2 or 3, wherein the liquid absorbent material is formed with one or more pockets for receiving a semen container
5 Apparatus according to claim 4, wherein the liquid absorbent material is formed with a plurality of pockets for receiving a plurality of semen containers
6 Apparatus according to claim 4 or 5, wherein the shape of each pocket is defined structurally stably in, or by, the liquid absorbent material.
7 Apparatus according to claim 2 or any claim dependent thereon, wherein the 0 liquid absorbent material comprises a foam.
8 Apparatus according to claim 7, wherein the foam is an open cell foam
9. Apparatus according to claim 7 or 8, wherein the foam is so-called Oasis foam.
10 Apparatus according to claim 2 or any claim dependent thereon, further comprising heat reflective material arranged in at least one region between the housing and the liquid absorbent material.

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11. Apparatus according to any preceding claim, having a non-evacuated heat In insulating wall 12 Apparatus according to any preceding claim, further comprising liquid

refrigerant received by the liquid absorbent material ZD 13. Apparatus according to claim 12, wherein the liquid refrigerant is liquid nitrogen.

0 14 A method comprising using a disposable container comprising polystyrene and a liquid absorbing material, to transport semen in a liquid nitrogen environment, and dispostng of the container after said use.

15 Disposable apparatus for containing a plurality of semen containers, the in apparatus comprising a housing of heat insulating material ; and a region containing a liquid absorbent material for holding a liquid refrigerant, wherein the liquid absorbent material is formed with a plurality of pockets for receiving the semen containers, such that each semen container is receivable in its own pocket, to be in close contact with the liquid refrigerant environment.

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16 A disposable dry shipper for containing refrigerant liquid, for storing and/or transporting animal or human tissue or fluid 17. Disposable apparatus for containing animal or human tissue or fluid in a refrigerated condition, the apparatus comprising a housing of heat insulating material ; and a region containing a liquid absorbent material for holding a liquid refrigerant.

18 Disposable apparatus for containing one or more semen containers in a refrigerated condition, and/or a method of use, being substantially as hereinbefore described with reference to Figs 2 and 3 of the accompanying drawings.

11 Apparatus according to claim 10, wherein the heat reflective material is of Mylar p-t 12 Apparatus according to claim 2, or any claim dependent thereon, further comprising a lid removably placeable over a mouth of the housing.

13 Apparatus according to claim 12, further comprising an absorbent upper layer placeable beneath the lid.

14. Apparatus according to claim 13, wherein the absorbent upper layer is of sponge material.