Passive, portable blood storage system
A passive, portable system and a method for storing blood are disclosed. The system comprises a sealable thermal isolation chamber which is preconditioned at a certain temperature for a predefined period of time. The thermal isolation chamber includes cavities of a phase change material which help to maintain the temperature of bags of human blood that are placed into the thermal isolation chamber for storage during transit. The thermal isolation chamber is surrounded by vacuum insulation panels and the vacuum insulation panels, encompassing the thermal isolation chamber, is placed into a durable carrying bag. The thermal isolation chamber is reusable along with the vacuum insulation panels and bag.
This application claims priority to provisional U.S. patent application Ser. No. 60/535,844 filed on Jan. 12, 2004, which is incorporated herein by reference in its entirety.
TECHNICAL FIELDCertain embodiments of the present invention relate to the portable storage of materials within a temperature range, such as for the storage of human blood in the field. More particularly, certain embodiments of the present invention relate to a portable system that maintains a predetermined temperature range for materials kept therein, such as bags filled with human blood, over a long period of time and without requiring a source of power.
BACKGROUND OF THE INVENTIONA variety of materials are desirably maintained in a predetermined temperature for various purposes. For example, sensitive materials such as human blood are often stored in non-portable, powered refrigeration units to keep the blood at a temperature that will keep the blood from going degrading and becoming unusable. When the blood needs to be removed from a refrigeration unit and transported for use in the field (e.g., military combat situations, car accident victims, etc.) it is often transported in an insulated container which may or may not contain, for example, ice (i.e., frozen H2O). However, such portable methods of transportation often allow the temperature of the blood to fluctuate more than desired and do not typically keep the temperature of the blood within the desired range for a long enough period of time. Other materials are also desirably maintained at a predetermined temperature in environments which do not allow refrigeration or the like.
As an alternative, a portable or semi-portable container with an internal active power and temperature regulation system to regulate the temperature within the container can be used. The active power system may include a battery or a fuel cell and a refrigerant system which adds to the complexity and weight of the container and may not have a desired level of reliability (e.g., the battery may discharge at a faster rate than desired). Another alternative is to use an external power source, such as a gasoline powered generator or external battery, which plugs into a temperature regulation system of the container in order to regulate the temperature within the container. This requires transporting the external power source along with the container.
It is desired to have a lightweight, highly reliable, portable container which maintains the temperature of bags of human blood over a relatively long period of time such that the blood can be administered to patients many hours after it was first placed into the container.
Further limitations and disadvantages of conventional, traditional, and proposed approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTIONAn embodiment of the present invention comprises a portable system for storing materials at a predetermined temperature range, such as human blood. The system comprises a base unit, having a plurality of closed walls and an open side, into which bags of human blood or other materials are placed. The closed walls of the base unit include internal cavities containing a phase change material. The system also includes a lid having an internal cavity containing the phase change material. The lid fits onto the open side of the base unit to seal the base unit when storing the bags of human blood. The system further comprises a vacuum insulation material surrounding the base unit and lid and an outer carrying bag surrounding the vacuum insulation material.
Another embodiment of the present invention comprises a method for storing materials, such as human blood. The method comprises preconditioning a thermal isolation chamber at a preconditioning temperature for a predefined period of time. The thermal isolation chamber comprises a base unit and a lid. The base unit has a plurality of walls and an open side. The closed walls of the base unit and the lid include internal cavities containing a phase change material which changes phase at about a predetermined storage temperature. The method also includes placing at least one bag of human blood into the base unit. The method further comprises placing a lid onto the open side of the base unit to seal the base unit. The method also includes surrounding the sealed base unit with a vacuum insulation material and placing the sealed base unit, surrounded by the insulation material, into a carrying bag.
These and other advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
In accordance with an embodiment of the present invention, the base unit 110 and lid 120 have internal cavities containing a phase change material. The walls and top/bottom of the system 100 may define a continuous cavity or discrete cavities may be provided if desired. As shown in
The system 100 also includes a durable carrying bag 140 to hold the sealed base unit, which may be surrounded by the vacuum insulation panels 130. The carrying bag 140 may be made of durable nylon and include a zipper 145 and an adjustable strap 146, in accordance with an embodiment of the present invention. Other perishable medical supplies may be stored in the system 100 as well, in accordance with various embodiments of the present invention.
In accordance with an embodiment of the present invention, the base unit 110 and lid 120 is preconditioned to a temperature of −20° C. for 6 hours for hot weather applications or to +4° C. for 2 hours for cold weather applications, before being integrated with the vacuum insulation panels 130 and the bag 140. As shown in
The system 100 is a passive system in that it does not require an internal or external power source such as a battery, fuel cell, or generator. Also, the system 100 does not require any kind of active refrigeration system once it is preconditioned.
In accordance with an embodiment of the present invention, the system 100 carries at least 4 units (i.e., bags) of red blood cells for a period of at least 48 hours in an ambient temperature range of −20° C. to +40.5° C., keeping the blood contents between +1° C. and +10° C.
In accordance with an embodiment of the present invention, the physical dimensions of the exterior of the system 100 are approximately 10″ length, 9″ width, and 10″ depth. The dimensions of the interior (i.e., the inside of the TIC base unit 110 are approximately 6″ length, 5″ width, and 6″ depth. Other dimensions may be suitable for other particular applications and are contemplated herein.
In summary, a combat-portable, passive system safely stores blood and other perishable medical supplies over a long period of time in climates ranging from very cold temperatures to very hot temperatures. The layered design (i.e., TIC, vacuum insulation, bag), and the equilibrium mechanism achieved by the layered design, reduce the risk of total product failure.
While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims
1. A portable system for storing human blood, said system comprising:
- a base unit, having a plurality of closed walls and an open side, into which containers of human blood are placed, and wherein said closed walls of said base unit include a phase change material positioned therein, the phase change material having phase change characteristics to substantially maintain a temperature of between 2-6° C.;
- a lid including a phase change material, and wherein said lid fits onto said open side of said base unit to seal said base unit when storing said containers of human blood; and
- an outer carrying bag surrounding said base unit and lid.
2. The system of claim 1 wherein said base unit and said lid constitute a thermal isolation chamber.
3. The system of claim 1, further comprising at least one equilibrium port for equalizing pressure of the interior of the system relative to the exterior atmosphere.
4. The system of claim 1, wherein the walls of said base unit and said lid include cavities of said base unit and said lid include cavities in which said phase change material is provided.
5. The system of claim 4, further comprising a thermal isolation member associated with each of said cavities positioned adjacent said phase change material therein.
6. The system of claim 5, wherein said thermal isolation members comprise a sheet member having a trigger material provided therein, the trigger material facilitating control of the phase change characteristics of said phase change material.
7. The system of claim 1, further comprising a trigger material to which said phase change material is exposed to facilitate control of the phase change characteristics of said phase change material.
8. The system of claim 1, wherein the interior of the walls of said base unit are covered with an insulating material wherein the insulating material is overlapped at the intersection of the walls.
9. The system of claim 7, wherein the overlapped portions are provided in a pinwheel-type configuration.
10. The system of claim 1, further comprising insulating panels surrounding the base unit and lid.
11. The system of claim 1, wherein the temperature is maintained within the range of 2-6° C. for at least forty-eight hours.
12. The system of claim 1, further comprising at least one cavity in which the phase change material is positioned.
13. The system of claim 12, further comprising at least one thermal isolation member within the cavity.
14. The system of claim 13, wherein the at least one thermal isolation member is provided with a trigger material thereon, which is in contact with the phase change material.
15. The system of claim 13, wherein the thermal isolation member is configured to be flat or corrugated.
16. A method for storing human blood, said method comprising:
- preconditioning a thermal isolation chamber at a preconditioning temperature for a predefined period of time, said thermal isolation chamber comprising a base unit and a lid, said base unit having a plurality of closed walls and an open side, and wherein said closed walls of said base unit and said lid include internal cavities containing a phase change material which changes phase within a predetermined storage temperature range;
- placing at least one container of human blood into said base unit;
- placing said lid onto said open side of said base unit to seal said base unit;
- surrounding said sealed base unit with a vacuum insulation material; and
- placing said sealed base unit surrounded by said insulation material into a carrying bag.
Type: Application
Filed: Jan 12, 2005
Publication Date: Sep 1, 2005
Inventor: Mark Wallace (Eden Prairie, MN)
Application Number: 11/034,239