Heated under-body warming systems

Abstract

A heated underbody supports including heated mattresses, heated mattress overlays and heated pads, and methods of using heated underbody supports, for therapeutic warming. The heated underbody supports include a heater assembly and a layer of compressible support material. The heater assembly includes a flexible heating element , first and second bus bars, and a temperature sensor. The flexible heating element is a conductive fabric which can be adapted to stretch into a 3-dimensional compound curve without wrinkling or folding while maintain electrical conductivity, and wherein the heating element is adapted to return to the planar shape when pressure is removed. The flexible heating element may include a fabric which is coated with a conductive or semi-conductive polymer. The heated underbody support may also include a water resistant shell which may encase the heater assembly and the compressible support material.

1 . A heated underbody support comprising a heated mattress, heated mattress overlay, or heated pad, the heated underbody support comprising:
 a heater assembly comprising:
 a flexible heating element comprising a sheet of conductive fabric having a top surface, a bottom surface, a first edge and an opposing second edge, a length, and a width, wherein the sheet is comprised of threads separately and individually coated with an electrically conductive or semi-conductive material, and wherein the coated threads of the fabric are able to slide relative to each other such that the sheet is flexible and stretchable; 
 a first bus bar extending along the entire first edge of the heating element, the first bus bar adapted to receive a supply of electrical power; 
 a second bus bar extending along the entire second edge of the heating element; and 
 a temperature sensor; and 
   a layer of compressible material adapted to conform to a person's body under pressure from a person resting upon the support and to return to an original shape when pressure is removed, the layer located beneath the heater assembly and having a top surface and an opposing bottom surface, a length, and a width, wherein the length and width of the layer are approximately the same as the length and width of the heater assembly.   
     
     
         2 . The heated underbody support of  claim 1  wherein the conductive or semi-conductive material comprises polypyrrole. 
     
     
         3 . The heated underbody support of  claim 1  wherein the compressible material comprises a foam material. 
     
     
         4 . The heated underbody support of  claim 1  further comprising a water resistant shell encasing the heater assembly, the shell comprising an upper shell and a lower shell that are sealed together along their edges to form a bonded edge, wherein the heater assembly is attached to the shell only along one or more edges of the heater assembly. 
     
     
         5 . The heated underbody support of  claim 1  wherein the compressible material comprises one or more flexible air filled chambers. 
     
     
         6 . The heated underbody support of  claim 1  wherein the heating element has a planar shape when not under pressure, wherein, in response to pressure, the heating element is adapted to stretch into a 3 dimensional compound curve without wrinkling or folding while maintaining electrical conductivity, and wherein the heating element is adapted to return to the planar shape when pressure is removed. 
     
     
         7 . A heated underbody support comprising a heated mattress, heated mattress overlay, or heated pad, the heated underbody support comprising:
 a heater assembly comprising:
 a flexible heating element comprising a sheet of conductive fabric having a top surface, a bottom surface, a first edge and an opposing second edge, a length, and a width; 
 a first bus bar extending along the first edge of the heating element, the first bus bar adapted to receive a supply of electrical power; 
 a second bus bar extending along the second edge of the heating element; and 
 a temperature sensor; 
 wherein the heating element has a planar shape when not under pressure, 
 wherein, in response to pressure, the heating element is adapted to stretch into a 3-dimensional compound curve without wrinkling or folding while maintaining electrical conductivity, and wherein the heating element is adapted to return to the planar shape when pressure is removed; and 
   a layer of compressible material which conforms to a patient's body under pressure and returns to an original shape when pressure is removed, wherein the layer of compressible material is located beneath the heater assembly.   
     
     
         8 . The heated underbody support of  claim 7  wherein the flexible heating element comprises a fabric coated with a conductive or semi-conductive material, the conductive or semi-conductive material comprising a carbon fiber or metal containing polymer or ink. 
     
     
         9 . The heated underbody support of  claim 7  wherein the flexible heating element comprises a fabric coated with a conductive or semi-conductive material, the conductive or semi-conductive material comprising a polymer. 
     
     
         10 . The heated underbody support of  claim 7  wherein the compressible material comprises a foam material. 
     
     
         11 . The heated underbody support of  claim 7  wherein the heater assembly is attached to the top surface of the layer of compressible material. 
     
     
         12 . The heated underbody support of  claim 7  further comprising a water resistant shell encasing the heater assembly, the shell comprising an upper shell and a lower shell that are sealed together along their edges to form a bonded edge. 
     
     
         13 . The heated underbody support of  claim 12  wherein one or more edges of the heater assembly are sealed into the bonded edge. 
     
     
         14 . The heated underbody support of  claim 12  wherein the heater assembly is attached to the upper layer of water resistant shell material. 
     
     
         15 . The heated underbody support of  claim 12  wherein the heater assembly is attached to the shell only along one or more edges of the heater assembly. 
     
     
         16 . The heated underbody support of  claim 12  further comprising an electrical inlet, wherein the inlet is bonded to the upper shell and the lower shell and passes between them at the bonded edge. 
     
     
         17 . The heated underbody support of  claim 7  wherein the compressible material comprises one or more flexible air filled chambers. 
     
     
         18 . The heated underbody support of  claim 7  wherein the heating element has a first Watt density when in a planar shape and a second Watt density when stretched into a 3 dimensional compound curve, and wherein the first Watt density is greater than the second Watt density. 
     
     
         19 . The heated underbody support of  claim 7  wherein the temperature sensor for monitoring a temperature of the heating element in located in contact with the heating element in a substantially central location upon which a patient would be placed during normal use of the support. 
     
     
         20 . The heated underbody support of  claim 7  further comprising a power supply and a controller for regulating a supply of power to the first bus bar. 
     
     
         21 . A heated underbody support comprising a heated mattress having a first end and a second end, the heated underbody support comprising:
 a heater assembly comprising:
 a flexible heating element comprising a sheet of conductive fabric having a top surface, a bottom surface, a first edge and an opposing second edge, a length, and a width; 
 a first bus bar extending along the first edge of the heating element; 
 a second bus bar extending along the second edge of the heating element; 
 at least one temperature sensor; 
 the first bus bar is adapted to receive electrical power from a power supply; 
 wherein the heating element has a planar shape when not under pressure, 
 wherein, in response to pressure, the heating element is adapted to stretch into a 3-dimensional compound curve without wrinkling or folding while maintain electrical conductivity, and wherein the heating element is adapted to return to the planar shape when pressure is removed; 
   a layer of compressible material which conforms to a patient's body under pressure and returns to an original shape when pressure is removed, wherein the layer of compressible material is located beneath the heater assembly;   an inflatable chamber positioned under the layer of compressible material; and   a flexible, water resistant cover that encases the heater assembly, the layer of compressible support material and the inflatable chamber.   
     
     
         22 . The heated underbody support of  claim 21  further comprising one or more additional inflatable chambers positioned under the layer of compressible material, wherein each of the inflatable chambers are elongated and have a longitudinal axis and are positioned side-by-side one another with their longitudinal axes extending substantially from the first end to the second end of the support. 
     
     
         23 . The heated underbody support of  claim 21  further comprising one or more additional inflatable chambers, wherein the inflatable chambers can each be inflated and deflated independently while the support is in use. 
     
     
         24 . The heated underbody support of  claim 21  further comprising one or more additional inflatable chambers, wherein the inflatable chambers can all be inflated and deflated simultaneously as a group while the support is in use. 
     
     
         25 . The heated underbody support of  claim 21  further comprising one or more additional inflatable chambers, wherein the inflatable chambers can be inflated and deflated in two or more groups while the support is in use. 
     
     
         26 . The heated underbody support of  claim 25  wherein the inflatable chambers can be inflated and deflated in two groups while the support is in use, and wherein the inflatable chambers are in alternating groups such that each inflatable chamber is in a different group from each inflatable chamber which is beside it. 
     
     
         27 . The heated underbody support of  claim 21  further comprising one or more additional inflatable chambers, each of the inflatable chambers belonging to one of two or more groups, and further comprising separate conduits to each group, each conduit providing independent fluid communication one groups of inflatable chambers for independently introducing or removing air from that group of inflatable chambers. 
     
     
         28 . The heated underbody support of  claim 27  further comprising:
 a pressure sensor for measuring an actual internal air pressure of the groups of inflatable chambers; and 
 a controller including a comparator for comparing a desired internal air pressure for each group of inflatable chambers with the actual internal air pressure of each group inflatable chambers, the controller operatively connected to each of the conduits and to an air pump, the controller further including a pressure adjusting assembly for adjusting the actual internal pressure; 
 wherein the controller is adapted to cause inflation or deflation of each group of inflatable chambers to adjust the actual internal air pressure of each of the group of inflatable chambers toward the desired internal air pressure. 
 
     
     
         29 . The heated underbody support of  claim 27  wherein each inflatable chamber within each inflatable chamber is in fluid connection with every other inflatable chamber of its own group so that each air pressure changes in one inflatable chamber redistribute to all of the other inflatable chambers in the same group; and
 wherein the an interface pressure is maintained on a top surface of each group of chambers at a location which supports a patient's body during normal use, the interface pressure being below a capillary occlusion pressure threshold of 32 mm Hg. 
 
     
     
         30 . The heated underbody support of  claim 21  further comprising a shell comprising two sheets of flexible surrounding the heater assembly, the shell comprising a water resistant plastic film or fiber reinforced plastic film, wherein the two sheets are sealed together near the edges of the heater assembly. 
     
     
         31 . The heated underbody support of  claim 21  including a power supply and controller for regulating the supply of power to the first bus bar. 
     
     
         32 . A method of warming a person comprising:
 positioning the person on a heated underbody support comprising a heated mattress, heated mattress overlay, or heated pad, the heated underbody support comprising:
 a heater assembly comprising:
 a flexible heating element comprising a sheet of conductive fabric having a top surface, a bottom surface, a first edge and an opposing second edge, a length, and a width; 
 a first bus bar extending along the first edge, the first bus bar adapted to receive a supply of electrical power; 
 a second bus bar extending along a second edge; 
 a temperature sensor near the heating element; 
 wherein the heating element has a planar shape when not under pressure, and 
 wherein, in response to pressure from the person positioned on the support, the heating element stretches into a 3 dimensional compound curve without wrinkling or folding while maintain electrical conductivity; 
 
 a layer of compressible material located beneath the heater assembly; and 
 a flexible water resistant shell encasing the heater assembly; 
   activating the support; and   directing the support to maintain a desired temperature.