Thermal control system

Abstract

A thermal control unit for delivering temperature-controlled fluid to one or more patient therapy devices (e.g. pads, blankets, etc.) that are in contact with a patient is disclosed. The thermal control unit includes a fluid circuit with an inlet and outlet, a reservoir, a heat exchanger, a pump, and a controller. The thermal control also includes any one or more of the following: ( 1 ) an air eliminator with an air filter for filtering air vented from the fluid circuit to the ambient surroundings; ( 2 ) a plug that moves in response to changing fluid levels and that fluidly isolates the air filter from the fluid; ( 3 ) a second air filter coupled to the reservoir; ( 4 ) a check valve to prevent fluid from back flowing into the reservoir; and/or ( 5 ) a liquid filter coupleable to the reservoir to filter liquid entering or exiting the reservoir.

What is claimed is: 
     
         1 . A thermal control unit comprising:
 a fluid circuit having a fluid outlet adapted to couple to a fluid supply line and a fluid inlet adapted to couple to a fluid return line;   a removable reservoir for supplying fluid to the fluid circuit, the removable reservoir adapted to be lifted out of the thermal control unit;   a heat exchanger in the fluid circuit and adapted to change a temperature of the fluid in the fluid circuit;   a pump for circulating fluid supplied by the removable reservoir through the fluid circuit;   an air eliminator for venting air from the fluid circuit to the ambient surroundings;   a check valve positioned between the removable reservoir and the fluid circuit, the check valve adapted to prevent fluid from flowing out of the fluid circuit and into the removable reservoir; and   a controller adapted to control the heat exchanger such that a temperature of the circulating fluid is adjustable toward a desired temperature.   
     
     
         2 . The thermal control unit of  claim 1  further including an air and liquid filter coupled to the removable reservoir, the air and liquid filter adapted to filter the fluid when the fluid is poured into the removable reservoir, and to filter air escaping from the removable reservoir to the ambient surroundings. 
     
     
         3 . The thermal control unit of  claim 2  wherein the air and liquid filter has a pore size adapted to filter out particles of 0.2 microns or larger. 
     
     
         4 . The thermal control unit of  claim 2  wherein the air and liquid filter is integrated into a removable lid adapted to be selectively attached to, and detached from, the removable reservoir. 
     
     
         5 . The thermal control unit of  claim 1  further including an air filter coupled to the removable reservoir and a liquid filter coupled to the removable reservoir, the air filter adapted to filter air escaping from the removable reservoir to the ambient surroundings, and the liquid filter adapted to filter the fluid when the fluid is poured into the removable reservoir. 
     
     
         6 . The thermal control unit of  claim 1  wherein the air eliminator includes an air filter and a plug having a position that varies in response to a level of fluid in the thermal control unit, and the plug is adapted to fluidly isolate the air filter from the fluid in the thermal control unit if the level of fluid in the thermal control unit exceeds a threshold. 
     
     
         7 . The thermal control unit of  claim 6  wherein the plug is adapted to float in the fluid and to rise and fall with rising and falling levels of fluid, respectively, in the thermal control unit. 
     
     
         8 . The thermal control unit of  claim 7  wherein the plug is adapted to sealingly engage an aperture when the plug rises past a threshold height, the aperture being positioned between the air filter and the fluid. 
     
     
         9 . The thermal control unit of  claim 1  wherein the removable reservoir includes an air filter in fluid communication with an interior of the removable reservoir, the air filter adapted to filter air escaping from the interior of the removable reservoir into the ambient surroundings. 
     
     
         10 . The thermal control unit of  claim 9  wherein the air filter is integrated into a removable lid adapted to be selectively attached to, and detached from, the removable reservoir. 
     
     
         11 . A thermal control unit comprising:
 a fluid circuit having a fluid outlet adapted to couple to a fluid supply line and a fluid inlet adapted to couple to a fluid return line;   a reservoir for supplying fluid to the fluid circuit, the reservoir including a liquid filter in fluid communication with an interior of the reservoir, the liquid filter adapted to filter the fluid when the fluid is poured into the reservoir.   a heat exchanger in the fluid circuit and adapted to change a temperature of the fluid in the fluid circuit;   a pump for circulating fluid supplied by the reservoir through the fluid circuit; and   a controller adapted to control the heat exchanger such that a temperature of the circulating fluid is adjustable toward a desired temperature.   
     
     
         12 . The thermal control unit of  claim 11  wherein the liquid filter is integrated into a removable lid adapted to be selectively attached to, and detached from, the reservoir. 
     
     
         13 . The thermal control unit of  claim 12  further including an air filter integrated into the removable lid, the air filter adapted to filter air escaping from an interior of the reservoir. 
     
     
         14 . The thermal control unit of  claim 13  wherein the air filter has a pore size adapted to filter out particles of 0.2 microns or larger. 
     
     
         15 . The thermal control unit of  claim 12  further including a check valve positioned between the reservoir and the fluid circuit, the check valve adapted to prevent fluid from flowing out of the fluid circuit and into the reservoir. 
     
     
         16 . The thermal control unit of  claim 15  further comprising an air eliminator for venting air from the fluid circuit to the ambient surroundings, the air eliminator including an air filter and a plug having a position that varies in response to a level of fluid in the thermal control unit, wherein the plug is adapted to fluidly isolate the air filter from the fluid in the thermal control unit if the level of fluid in the thermal control unit exceeds a threshold. 
     
     
         17 . The thermal control unit of  claim 16  wherein the reservoir is adapted to be lifted out of the thermal control unit without leaking fluid.