Analysis, Design and Validation of a Portable Power-Bank-Powered Thermoelectric Cooling System for Clinical Rehabilitation

Cryotherapy is widely used in rehabilitation, yet existing devices face significant limitations. Conventional icebucket solutions lack portability and precise temperature control. Emerging TEC-based systems enable accurate temperature regulation but typically require high power and AC supply, as conventional designs treat the human body as a constant heat source and size systems for peak thermal load. This paper challenges this static assumption by studying the dynamic characteristics of body heat load during cryotherapy. Theoretical analysis reveals that three physiological mechanisms-vasoconstriction, reduced local metabolism, and thermal insulation layer formationsynergistically reduce heat load as skin temperature decreases. Heat load drops from approximately 34 W to 14 W (theoretical 60% reduction; experiments show >70%). This reduction enables system design based on time-averaged rather than peak load, making consumer-grade power banks sufficient for therapeutic cryotherapy. A thermodynamic model incorporating human thermoregulatory response is developed and reasonably agrees with experimental measurements. Based on these findings, a portable TEC-based cryotherapy system powered by a 25000 mAh power bank is designed and validated through human trials. Results demonstrate that skin temperature reaches 11.9 °C within the therapeutic range, with battery life exceeding 50 minutesconfirming that portable battery-powered cryotherapy is thermally feasible when human thermoregulatory dynamics are considered.