Self-powered steady-state skin-cooling support surfaces

• US 20070135878A1
• Filed: 12/12/2005
• Published: 06/14/2007
• Est. Priority Date: 06/13/2003
• Status: Active Grant

• Current Assignee: Charles Lachenbruch, Roger Lachenbruch
• Original Assignee: Charles Lachenbruch, Roger Lachenbruch
• Inventors: Lachenbruch, Charles, Lachenbruch, Roger
• Granted Patent: US 7,727,267 B2
• Time in Patent Office: Days
• US Class Current: 607/108
• CPC Class Codes: A47C 21/046 without active means, e.g. with openings or heat conductors
• CPC Class Codes: A47C 27/002 Mattress or cushion tickings or covers bed linen, blankets or counterpanes A47G9/02
• CPC Class Codes: A47C 27/085 of liquid type, e.g. filled with water or gel
• CPC Class Codes: A47C 7/742 for ventilating or cooling A47C31/116 takes precedence
• CPC Class Codes: A61F 2007/0001 Body part
• CPC Class Codes: A61F 2007/0056 for cooling
• CPC Class Codes: A61F 2007/0058 evaporating on or near the spot to be cooled
• CPC Class Codes: A61F 2007/0244 with layers
• CPC Class Codes: A61F 2007/0292 using latent heat produced or absorbed during phase change of materials, e.g. of super-cooled solutions
• CPC Class Codes: A61F 7/10 Cooling bags, e.g. ice-bags
• CPC Class Codes: A61G 7/057 Arrangements for preventing bed-sores or for supporting patients with burns, e.g. mattresses specially adapted therefor ventilation openings in mattresses A47C21/042; pneumatic or hydraulic mattresses A47C27/08

Abstract

A refrigerant-containing bladder or container is positioned underneath the body. Heat absorbed from the body vaporizes the refrigerant, which expands to cooler remote regions of the bladder. Heat is then withdrawn from the edges of the container by thermally conductive pathways that distribute heat from this container to a cooler area that is not underneath the body. The cooled refrigerant condenses, and is returned to the regions of the device that are under or adjacent to the central and warmest parts of the body. The heavier and warmer portions of the body force the bladder to the lowest point. Alternatively, heat is transferred from the body via a specific highly thermally conductive layer or layers of material(s) that is (are) soft, pliable, and comfortable to sit or lie on. This layer joins conductive materials that are configured to transport heat and diffuse it to the cooler environment.

Claims

1. A thermally conductive support surface for a human, comprising:

a) a thermally conductive cushion comprising a plurality of thermally conductive fibers; and

b) a thermal diffuser that communicates with said thermally conductive fibers,

wherein thermal conductivity of said thermally conductive cushion is greater than eight (8) watts per meter-degree Kelvin.

2. A thermally conductive support surface for a human as described in claim 1, wherein said thermally conductive cushion is centrally disposed within said support surface, and said thermal diffuser is present on a periphery of said support surface.

3. A thermally conductive support surface for a human described in claim 1, wherein said thermal diffuser comprises metal.

4. A thermally conductive support surface for a human as described in claim 1, further comprising a mattress, and wherein said thermally conductive cushion is centrally disposed on said mattress, and said thermal diffuser is present on a periphery of said mattress.

5. A thermally conductive support surface for a human as described in claim 1, wherein said plurality of thermally conductive fibers extend beyond a side of said thermally conductive cushion and communicate with said thermal diffuser.

6. A thermally conductive support surface for a human as described in claim 5, wherein said plurality of thermally conductive fibers that extend beyond a side of said thermally conductive cushion extend perpendicularly away from a longitudinal axis of said thermally conductive cushion, and wherein said plurality of thermally conductive fibers communicate with said thermal diffuser.

7. A thermally conductive support surface for a human as described in claim 1, wherein said plurality of thermally conductive fibers extend vertically downward from a top surface of said thermally conductive cushion.

8. A thermally conductive support surface for a human as described in claim 1, wherein said plurality of thermally conductive fibers comprises bundles of individual thermally conductive fibers.

9. A thermally conductive support surface for a human as described in claim 1, wherein at least a portion of said diffuser is remote from said thermally conductive cushion.

10. A thermally conductive support surface for a human as described in claim 1, wherein said plurality of thermally conductive fibers has thermal conductivity of greater than eight (8) watts per meter-degree Kelvin.

18. A thermally conductive support surface for a human as described in claim 1, further comprising a thermoelectric module, wherein said thermoelectric module removes heat from said thermally conductive diffuser.

20. A thermally conductive support surface for a human as described in claim 1, wherein said cushion comprises an envelope and wherein a portion of said thermally conductive fibers are contained within said envelope.

11. A thermally conductive support surface for a human, comprising:

a) a thermally conductive cushion comprising a plurality of thermally conductive fibers; and

b) a thermal diffuser that communicates with said thermally conductive fibers, wherein thermal conductivity for said thermally conductive cushion is a function of thickness of said thermally conductive cushion according to the following table;

Minimum Thickness TMaximum Thickness TConductivityRequiredRequired(W/m-K)(m)(cm)(m)(cm)400.0007500.0750.75075.00600.0005000.0500.50050.00800.0003750.0380.37537.501000.0003000.0300.30030.001250.0002400.0240.24024.001500.0002000.0200.20020.002000.0001500.0150.15015.003000.0001000.0100.10010.005000.0000600.0060.0606.0010000.0000300.0030.0303.0020000.0000150.0020.0151.5050000.0000060.0010.0060.60100000.0000030.0000.0030.30

12. A thermally conductive support surface for a human, comprising:

a) a bladder comprising a pocket within a proximal portion of said bladder, said bladder comprising a distal region that is remote from said pocket;

b) a refrigerant that is contained within said bladder, wherein said refrigerant has a boiling point that is not greater than 36 degrees Celsius, wherein a portion of said refrigerant that is in a liquid form collects in said pocket, and wherein body heat is transferred to said liquid, whereupon a portion of said liquid vaporizes and transfers to said distal region;

c) a thermally conductive diffuser that communicates with said distal region and transfers heat from said refrigerant in said distal region.

13. A thermally conductive support surface for a human as described in claim 12, wherein said bladder comprises two compartments, wherein each compartment does not permit transfer of refrigerant to a remaining compartment, and wherein each compartment comprises a pocket and a distal region.

14. A thermally conductive support surface for a human as described in claim 12, wherein the total area of the diffuser is not less than 0.25 times as large as the surface area of a heat source that contributes said body heat to said refrigerant.

15. A thermally conductive support surface for a human as described in claim 12, wherein the resulting support surface is powered by a user'"'"'s body heat.

16. A thermally conductive support surface for a human as described in claim 12, wherein the resulting support surface is powered by a difference between said user'"'"'s body heat and heat that is present in an environment that surrounds said support surface.

17. A thermally conductive support surface for a human as described in claim 12, wherein the refrigerant is not transported within said bladder by a pump.

19. A thermally conductive support surface for a human as described in claim 12, further comprising a thermoelectric module, wherein said thermoelectric module removes heat from said thermally conductive diffuser.