U.S. patent application number 11/034239 was filed with the patent office on 2005-09-01 for passive, portable blood storage system.
Invention is credited to Wallace, Mark W..
Application Number | 20050188714 11/034239 |
Document ID | / |
Family ID | 34794369 |
Filed Date | 2005-09-01 |
United States Patent
Application |
20050188714 |
Kind Code |
A1 |
Wallace, Mark W. |
September 1, 2005 |
Passive, portable blood storage system
Abstract
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.
Inventors: |
Wallace, Mark W.; (Eden
Prairie, MN) |
Correspondence
Address: |
Scott M. Oldham
Hahn, Loeser & Parks LLP
Suite 300
One GoJo Plaza
Akron
OH
44311
US
|
Family ID: |
34794369 |
Appl. No.: |
11/034239 |
Filed: |
January 12, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60535844 |
Jan 12, 2004 |
|
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Current U.S.
Class: |
62/371 ;
62/457.2 |
Current CPC
Class: |
F25D 2201/14 20130101;
F25D 17/047 20130101; A61J 1/165 20130101; F25D 3/08 20130101; F25D
2303/085 20130101; F25D 2600/04 20130101; F25D 2303/0831 20130101;
F25D 2331/8014 20130101 |
Class at
Publication: |
062/371 ;
062/457.2 |
International
Class: |
F25D 003/08 |
Claims
What is claimed is:
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.degree. 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.degree. 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.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY
REFERENCE
[0001] 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 FIELD
[0002] Certain 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 INVENTION
[0003] A 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 H.sub.2O). 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.
[0004] 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.
[0005] 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.
[0006] 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 INVENTION
[0007] An 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.
[0008] 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.
[0009] 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
[0010] FIG. 1 is an exemplary illustration of an embodiment of a
portable system for storing human blood, in accordance with various
aspects of the present invention.
[0011] FIG. 2 is a schematic top view of the interior wall layer
for the system as shown in FIG. 1.
[0012] FIGS. 3A and 3B show schematic representations of the side
and bottom/top walls of the system as shown in FIG. 1.
[0013] FIG. 4 is a flow chart of an embodiment of a method of
storing blood using the system of FIG. 1, in accordance with
various aspects of the present invention.
[0014] FIG. 5 is an exemplary graph illustrating the temperature
regulating capability of the system of FIG. 1 using the method of
FIG. 2 in a hot environment, in accordance with an embodiment of
the present invention.
[0015] FIG. 6 is an exemplary graph illustrating the temperature
regulating capability of the system of FIG. 1 using the method of
FIG. 2 in a cold environment, in accordance with an embodiment of
the present invention.
[0016] FIG. 6 is an illustration of the system of FIG. 1 being used
in the field in a combat situation, in accordance with an
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 1 is an exemplary illustration of an embodiment of a
portable system 100 for storing materials at a given temperature
range over a period of time, such as human blood or other
temperature sensitive materials. The embodiment of FIG. 1 shows
various aspects of the present invention, and the system 100
generally comprises a base unit 110, having four side walls and a
bottom wall. The base unit 110 also includes a removable or
semi-removable lid 120 for sealing the base unit 110. The lid 120
may be hingedly attached to the base unit for example. The system
100 may further comprise vacuum insulation panels (or material) 130
to surround and help insulate the base unit 110 and lid 120,
although depending on the environment in which the system 100 is to
be used, panels 130 may not be needed. The vacuum insulation panels
130 have an R-value of 30 or other suitable value, and are
configured such that a top panel 135 opens up providing access to
the sealed base unit 110, in accordance with an embodiment of the
present invention. In an embodiment, the temperature stability of
the system is significantly enhanced by a pinwheel type attachment
of the insulation panels 130 to one another at the locations of the
intersection between panels 130, such as at the corners of the
enclosure formed by the panels 130. As seen in FIG. 2, the
sidewalls may have insulation panels 130 with a barrier material
forming the interior surfaces 132, or the barrier material may be
provided separate from panels 130. The barrier material forming
surface 132 is configured with pinwheel type overlapping adjacent
walls, such as by providing overlapping sections 134 arranged in a
pinwheel type configuration, with each successive overlapping
portion 134 corresponding to the corner regions of the enclosure.
The overlapping portions 134 provide more effective sealing of the
interior volume of system 100, to significantly reduce any thermal
losses or gains at these locations, to facilitate providing a
substantially uniform temperature atmosphere within system 100.
Pinwheel attachment or overlapping attachment of panels 130 or of
barrier material 132 at these intersections can reduce any edge
loss, to thereby maintain temperature stability uniformly
throughout the system 100.
[0018] 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 FIGS. 3A and 3B, examples of the walls and
top/bottom of the system 100 have a phase change material 125 in
the cavity 126. The phase change material is preferably a gel-based
material which melts and solidifies at a certain temperature and,
in doing so, is capable of storing or releasing energy. As a
result, the phase change material can be used to help maintain or
regulate the temperature of other materials (e.g., blood). In
accordance with an embodiment of the present invention, the phase
change material is designed to change phase (i.e., melt or
solidify) at approximately 1 to 10.degree. C., or more preferably
at approximately 4.degree. C. As an example, a phase change such as
deuterium oxide may be used in the base unit 110 and lid 120, but
other phase change materials could be utilized which change phase
at the desired temperatures. Using a phase change material which
changes phase at approximately 1-10 C., provides a temperature for
storing bags of human blood as an example. The base unit 110 and
lid 120 constitute a removable thermal isolation chamber (TIC). In
accordance with an embodiment of the present invention, the base
unit 110 can hold at least 4 standard units (i.e., bags) of blood.
In an embodiment, the TIC may be usable in environments in which
varying pressure could be encountered, such as in military
operations wherein the system 100 could be deployed in higher
altitudes or underwater. In such circumstances, it may be desirable
to equalize pressure relative to the contents of the TIC. In such
an embodiment, one or more equilibration ports 122 may be provided
in the TIC, to allow equilibration with the outside atmosphere. The
port(s) 122 may be a small air port having a Tyvek (or other
suitable material) cover there over, which will allow gaseous
exchange with the outside atmosphere, but prevent liquid exchange
therethrough. Any suitable port system to allow equilibration
between the TIC and outer atmosphere is contemplated. As merely an
example, an equilibration port 122 may be provided in the top and
bottom portions of the TIC.
[0019] 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.
[0020] FIG. 4 is a flow chart of an embodiment of a method 200 of
storing blood using the system 100 of FIG. 1, in accordance with
various aspects of the present invention. In step 210, a thermal
isolation chamber is preconditioned at a preconditioning
temperature for a predefined period of time. The thermal isolation
chamber comprises a base unit and a lid where the base unit has a
plurality of closed walls and an open side. The closed walls of the
base unit and the lid include a phase change material incorporated
therewith which changes phase at about a predetermined storage
temperature or temperature range. In step 220, at least one bag of
blood is placed into the base unit. In step 230, the lid is placed
onto the open side of the base unit to seal the base unit. In step
240, the sealed base unit is surrounded with a vacuum insulation
material. In step 250, the sealed base unit, surrounded by the
insulation material, is placed into a carrying bag.
[0021] In accordance with an embodiment of the present invention,
the base unit 110 and lid 120 is preconditioned to a temperature of
-20.degree. C. for 6 hours for hot weather applications or to
+4.degree. C. for 2 hours for cold weather applications, before
being integrated with the vacuum insulation panels 130 and the bag
140. As shown in FIGS. 3A and 3B, the internal cavities 127 of the
base unit 110 and the lid 120 may also include thermal isolation
members or fences 115, which may be provided so as to be exposed to
the phase change material within the cavities of the base unit 110
and top 120. The members or fences 115 may be continuous layers of
material, such as a thermally conductive material, which may also
have a trigger material therewith. For example, the members 115 may
be a light gauge aluminum material, which is coated with an
aluminum oxide or other suitable material. The layers 115 are
desirably dimensioned to be larger than the adjacent cavity and
associated phase change material, so as to be exposed adjacent all
of the phase change material. The phase change material 125 is
therefore filled to a point such as at 129, such that the members
115 are in contact with the phase change material over their
extent. As shown in these embodiments, the members 115 in the
sidewalls as shown in FIG. 3A may be flat, and disposed
approximately in the center of the cavity 127. For the bottom and
top members of the system 100, the member 115 may have a
corrugated, triangulated configuration. The coating with aluminum
oxide or other suitable trigger material used in combination with
the phase change material, may then be exposed to the phase change
material throughout the cavities, to facilitate causing phase
changes at a desired temperature or temperature range. This tends
to maintain desired phase change characteristics throughout the
side, bottom and top walls of the system 100. The thermal isolation
fences thus help to dispense conductivity over the face of the
walls of the base unit 110 and lid 120, in accordance with an
embodiment of the present invention. Also, a trigger agent, such as
an amount of aluminum oxide for use with a deuterium oxide phase
change material, may be used within the phase change material to
stimulate the phase change material to change phase at the desired
temperature or temperature range.
[0022] 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.
[0023] FIG. 4 is an exemplary graph 300 illustrating the
temperature regulating capability of the system 100 of FIG. 1 using
the method 200 of FIG. 2. In this example for use in a hot
environment, as the graph 300 shows, in a sustained +105.degree. F.
(+40.degree. C.) environment, bags of human blood are held at a
constant temperature (about 4.degree. C.) for over 60 hours and
remain adequately chilled after 80 hours.
[0024] FIG. 5 is an exemplary graph 400 illustrating the
temperature regulating capability of the system 100 of FIG. 1 using
the method 200 of FIG. 2 in a cold environment. In accordance with
an embodiment of the present invention, as the graph 400 shows, in
a sustained subzero -9.degree. F. (-23.degree. C.) environment,
bags of human blood are held at a constant temperature (about
4.degree. C.) for over 60 hours, remaining above +1.degree. C.
after 96 hours.
[0025] 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.degree. C. to +40.5.degree. C., keeping the blood
contents between +1.degree. C. and +10.degree. C.
[0026] FIG. 6 is an illustration of the system 100 of FIG. 1 being
used in the field in a combat situation, in accordance with an
embodiment of the present invention. In FIG. 5, an army medical
person 510 is administering a pint of blood 515 to a wounded
soldier 520. The portable system 100 is seen sitting on the ground
next to the wounded soldier 520.
[0027] 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.
[0028] 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.
[0029] 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.
* * * * *