Electric heating pads and mattresses

An electric heating pad for warming a patient, the electric heating pad comprising a heated underbody support or heated mattress, the heated underbody support or heated mattress comprising:

• a heater assembly comprising:
• a flexible sheet-like heating element including a top surface, a bottom surface, an upper edge, a lower edge, and at least two side edges,
• conductive bus bars respectively attached near each of the at least two side edges of the flexible sheet-like heating element,
• a temperature control sensor attached to the flexible sheet-like heating element at a location configured to be in contact with a patient laying on the electric heating pad,
• a pressure sensor to detect a weight of a patient laying on the electric heating pad, and
• fabric side edge extensions extend from the at least two side edges of the flexible sheet-like heating element;
• a layer of polymeric foam including a top surface, a bottom surface, an upper wall, a lower wall, and at least two side walls, the layer of polymeric foam positioned under the heater assembly;
• and
• a shell covering the heater assembly and the layer of polymeric foam, the shell comprising one or more sheets of flexible material,
• wherein the heater assembly is wrapped around the top surface of the layer of polymeric foam and the at least two side edges of the flexible sheet-like heating element and the conductive bus bars lie adjacent the at least two side walls of the layer of polymeric foam,
• wherein the fabric side edge extensions are wrapped under and attached to the bottom surface of the layer of polymeric foam thereby securing the heater assembly to the layer of polymeric foam, and
• wherein the pressure sensor is configured to reduce or turn off electrical power to the flexible sheet-like heating element when the weight of the patient has not been detected by the pressure sensor for a preset period of time.

An electric heating pad for warming a patient, the electric heating pad comprising a heated underbody support or heated mattress, the heated underbody support or heated mattress comprising:

• a heater assembly comprising:
• a flexible sheet-like heating element including a top surface, a bottom surface, an upper edge, a lower edge, and at least two side edges,
• conductive bus bars respectively attached near each of the at least two side edges of the flexible sheet-like heating element,
• fabric side edge extensions extend from the at least two side edges of the flexible sheet-like heating element, and
• a fabric lower edge extension attached to the lower edge of the flexible sheet-like heating element;
• a layer of polymeric foam including a top surface, a bottom surface, an upper wall, a lower wall, at least two side walls, the layer of polymeric foam positioned under the heater assembly;
• and
• a shell covering the heater assembly and the layer of polymeric foam, the shell comprising one or more sheets of flexible material,
• wherein the heater assembly is wrapped around the top surface of the layer of polymeric foam and the at least two side edges of the flexible sheet-like heating element and the conductive bus bars lie adjacent the at least two side walls of the layer of polymeric foam,
• wherein the fabric side edge extensions are wrapped under and attached to the bottom surface of the layer of polymeric foam thereby securing the heater assembly to the layer of polymeric foam, and
• wherein the fabric lower edge extension, attached to the lower edge of the flexible sheet-like heating element, is attached to the top surface, the lower wall and the bottom surface of the layer of polymeric foam.