Method and apparatus for measuring and treating shivering during therapeutic temperature control

Abstract

Methods and apparatus for the prevention and treatment of shivering encountered during therapeutic temperature regulation are disclosed that utilize an active system of counterwarming such that the timing and intensity of warmth provided to selected body areas is regulated dynamically in response to such factors as the extent of cooling applied to the core, the degree of shivering encountered, and patient temperature. Additionally, methods and apparatus are disclosed for the measurement and quantification of shivering for use in this and other applications.

We claim: 
     
         1 . A method for treating shivering in a subject in the course of therapeutic temperature regulation comprising applying active counterwarming for inhibition of shivering. 
     
     
         2 . The method of  claim 1  wherein applying active counterwarming operates in a feedback system. 
     
     
         3 . The method of  claim 1  wherein the therapeutic temperature regulation comprises applying core cooling to the subject. 
     
     
         4 . The method of  claim 1  wherein counterwarming is applied in response to quantified shivering. 
     
     
         5 . The method of  claim 1  wherein counterwarming is applied in response to change in the core temperature of the subject. 
     
     
         6 . The method of  claim 3  wherein counterwarming is applied in response to the amount of core cooling being applied. 
     
     
         7 . The method of  claim 1  wherein counterwarming is applied in response to a combination of one or more of quantified shivering, change in core temperature of the subject, or applied core cooling. 
     
     
         8 . A method for applying active counterwarming to a subject during therapeutic temperature regulation of the subject, the therapeutic temperature regulation including cooling to reduce the core temperature of the subject, comprising regulating application of warming to one or more selected sites on the subject's body. 
     
     
         9 . The method of  claim 8  wherein the selected site includes a body area not used for cooling the core. 
     
     
         10 . The method of  claim 8  wherein applying counterwarming includes one or a combination of any of: changing the temperature of warming applied to all treated body regions, changing the temperature of warming applied to specific treated body regions, changing the pattern of warming applied to selected treated body regions. 
     
     
         11 . Apparatus for applying active counterwarming to a subject, comprising apparatus for quantifying shivering in a subject and apparatus for warming selected areas of the patient's body. 
     
     
         12 . Apparatus for applying active counterwarming to a subject during therapeutic temperature regulation of the subject, comprising apparatus for quantifying shivering in the subject and apparatus for warming selected areas of the subject's body, and further comprising apparatus for cooling the patient to lower the core temperature. 
     
     
         13 . The apparatus of  claim 12  wherein the apparatus for cooling the subject comprises a temperature set point feedback device operatively connected to cooling apparatus, and a core temperature sensor operatively connected to the temperature set point feedback device. 
     
     
         14 . The apparatus of  claim 12  wherein the cooling apparatus comprises one or more of a cooling blanket, cooling pads, and an endovascular cooling catheter. 
     
     
         15 . The apparatus of  claim 12  wherein the apparatus for warming selected areas of the body includes counterwarming elements, and a counterwarming controller operatively connected to the counterwarming elements and configured and adapted to adjust the warming applied to the counterwarming elements. 
     
     
         16 . The apparatus of  claim 15  wherein the counterwarming controller is operatively connected to one or a combination of two or more of: a core temperature sensor; a core cooling controller; and the apparatus for quantifying shivering. 
     
     
         17 . The apparatus of  claim 15  wherein the counterwarming elements include heating apparel. 
     
     
         18 . The apparatus of  claim 15  wherein the counterwarming elements include one or more of: heated mittens, heated booties, heated ear muffs, heated blankets, and heated pads. 
     
     
         19 . The apparatus of  claim 15  wherein the counterwarming elements are heated by means for heat transfer. 
     
     
         20 . The apparatus of  19  wherein the means for heat transfer comprise one or more of a circulating warm liquid, or insulated electrical heating coils. 
     
     
         21 . The apparatus of  15  wherein the counterwarming elements include apparatus configured for infusion of a suitable warm sterile liquid into the external auditory canals of both ears of the patient. 
     
     
         22 . A method for isolating a first signal from a combined signal containing first and second signals, wherein the second signal includes recurring epochs of a stereotyped waveform, by: digitally sampling the combined signal at a suitable sample rate; storing in memory a number of epochs of the combined signal; averaging the stored epochs of the combined signal to obtain an average of the recurring epochs of the stereotyped second signal waveform; and, using a microprocessor, subtracting the average recurring epoch from each of at least a subset of the epochs of the combined signal and storing the results, containing isolated first signal epochs substantially free of second signal features, in memory.