Temperature sensor assemblies for electric warming blankets

Abstract

An electric warming blanket for warming patients during surgery and other medical procedures includes a flexible heater and a temperature sensor assembly coupled thereto; a first layer of water resistant material coupled to a second layer of water resistant material, about a perimeter of the heater, forms a substantially hermetically sealed space for the heater and the temperature sensor assembly. The blanket may further include a thermal insulation layer disposed between the temperature sensor assembly and the first layer of water resistant material. The temperature sensor assembly may provide input of an average temperature over a portion of a surface area of the heater to a temperature controller, when the heater and sensor assembly are coupled to the controller.

1 .- 16 . (canceled) 
     
     
         17 . An electric warming blanket for warming patients during surgery and other medical procedures, comprising:
 a flexible heater including a first side, a second side, opposite the first side, and a first edge and a second edge, opposite the first edge, the heater having a substantially uniform watt density output across a surface area of the first and second sides, when the heater is electrically powered;   a pair of bus bars for powering the heater, a first of the pair of bus bars being coupled to the one of the first side and the second side of the heater, along the first edge thereof, and a second of the pair of bus bars being coupled to one of the first side and the second side of the heater, along the second edge thereof;   a temperature sensor assembly coupled to the first side of the heater at a first location on the first side between the first and second bus bars, the temperature sensor assembly including a first temperature sensor, a second temperature sensor and a heat spreader, the heat spreader extending over the first location between the first side of the heater and the first and second temperature sensors, and the first and second temperature sensors detecting approximately the same temperature; and   a first layer of water resistant material extending completely over the first side of the heater and the temperature sensor assembly, and a second layer of water resistant material extending completely over the second side of the heater, the first and second layers being coupled together along a seal zone that extends about a perimeter edge of the blanket to form a substantially hermetically sealed space for the heater and the temperature sensor assembly.   
     
     
         18 . The blanket of  claim 17 , wherein:
 the temperature sensor assembly provides input of the detected temperature to a means for controlling a supply of power to the bus bars based on the detected temperature; and   the second temperature sensor of the assembly provides input to a means for cutting the supply of power based on the detected temperature.   
     
     
         19 . The blanket of  claim 17 , wherein:
 the temperature sensor assembly provides input of the detected temperature to a means for controlling a supply of power to the bus bars based on the detected temperature; and   the second temperature sensor of the assembly provides input to trigger an alarm.   
     
     
         20 . The blanket of  claim 17 , wherein the heat spreader has a surface area that is no greater than approximately four square inches. 
     
     
         21 . The blanket of claim of  claim 17 , wherein the heat spreader comprises a metal foil. 
     
     
         22 . The blanket of  claim 21 , wherein the metal is copper. 
     
     
         23 . The blanket of  claim 17 , wherein the heat spreader has a thickness of approximately 0.001 inch. 
     
     
         24 . The blanket of  claim 17 , further comprising:
 at least one super over-temperature sensor coupled to the heater between the first and second bus bars at another location spaced apart from the first location;   wherein the at least one super over-temperature sensor is adapted to interrupt a supply of power to the first and second bus bars and/or to activate an alarm at a prescribed temperature that exceeds a normal operating range.   
     
     
         25 . The blanket of  claim 24 , wherein the at least one super over-temperature sensor comprises a plurality of super over-temperature sensors wired in series with one another. 
     
     
         26 . The blanket of  claim 25 , wherein one of the plurality of super over-temperature sensors is located in proximity to one of the first and second bus bars. 
     
     
         27 . The blanket of  claim 24 , wherein the at least one super over-temperature sensor is adapted to activate an alarm at the prescribed temperature. 
     
     
         28 . The blanket of  claim 24 , wherein the prescribed temperature is between approximately 45° C. and approximately 60° C. 
     
     
         29 . The blanket of  claim 17 , further comprising a first layer of flexible electrically insulating material extending between the temperature sensor assembly and the first side of the heater. 
     
     
         30 . The blanket of  claim 29 , wherein:
 the first layer of flexible electrically insulating material is laminated to the first side of the heater; and   the temperature sensor assembly is bonded to the first layer of flexible electrically insulating material.   
     
     
         31 . The blanket of  claim 29 , further comprising a layer of thermal insulation extending over the entire first side of heater, between the first and second bus bars, and over the temperature sensor assembly, the first layer of water resistant material also extending over the layer of thermal insulation. 
     
     
         32 . The blanket of  claim 17 , further comprising a layer of thermal insulation extending over the entire first side of heater and over the temperature sensor assembly, the first layer of water resistant material also extending over the layer of thermal insulation. 
     
     
         33 . The blanket of  claim 17 , wherein:
 the first location on the first side of the heater is located within a first temperature zone of the surface area of the heater, the first temperature zone being defined by a contacting portion of the second side of the heater, the contacting portion being in conductive contact with a patient when the blanket is placed over the patient; and   the surface area of the heater further includes a second temperature zone, the second temperature zone being defined by a non-contacting portion of the second side of the heater, the non-contacting portion not being in conductive contact with the patient when the blanket is placed over the patient.   
     
     
         34 . The blanket of  claim 33 , further comprising a temperature controller, the temperature controller being adapted to control a supply of power to the first and second bus bars, according to the detected temperature, in order to maintain a temperature of first temperature zone lower than a higher temperature of the second temperature zone. 
     
     
         35 . The blanket of  claim 33 , further comprising:
 at least one super over-temperature sensor coupled to the heater between the first and second bus bars at another location spaced apart from the first location;   wherein the at least one super over-temperature sensor is adapted to interrupt a supply of power to the first and second bus bars at a prescribed temperature that exceeds a normal operating range.   
     
     
         36 . The blanket of  claim 35 , wherein the prescribed temperature is between approximately 45° C. and approximately 60° C.