The Application Of Wearable Hot And Cold Therapy Belt In Postoperative Rehabilitation Of TKA

Knee osteoarthritis(KOA)is a chronic disease that causes serious problems to patients’ health and life,and total knee arthroplasty(TKA)is the best treatment for patients in the middle and late stages.Clinical studies have shown that alternating hot and cold therapy after surgery can significantly relieve postoperative pain,but the market for physical therapy products is mainly based on a single thermal therapy for health care.Therefore,this study will use the semiconductor cooling device to design a hot and cold physiotherapy belt to solve the problems and shortcomings of the current hot and cold therapy.The design of the hot and cold physiotherapy belt is divided into two parts.The first part is the thermoregulator design.In this project,the finite element method(ANSYS)is used to simulate the working performance of the semiconductor cooling device,select the cooling device model suitable for weak heat dissipation,and select the corresponding cooling fan and cooling fins according to the numerical calculation.According to the above selection calculation,a thermoregulator-fabric-knee skin tissue model is established in ANSYS to analyze the heat transfer under different temperatures and different inner and outer fabrics,which provides the theoretical basis and design basis for the design of the wearable hot and cold physiotherapy device.Based on the above simulation and analysis,the temperature control system of the physiotherapy belt is designed,using STM32 as the microcontroller of the temperature control system,monitoring the temperature of the semiconductor cooler through the digital temperature sensor,and realizing the temperature control of the semiconductor cooler based on the Proportion-Integration-Differentiation(PID)algorithm.The second part is the design of the fixed fabric bandage.The second part is the design of the fixed fabric bandage,first of all,research more than 30 knee products on the market,analyze the design principles of rehabilitation products,and introduce the design elements of the fabric bandage.From the structure,size,fabric and appearance of the four parts of the fabric bandage shape design and make prototype model.Finally,the design of the hot and cold bandage was evaluated using a combination of subjective and objective methods,including the verification of the cooling/heating function of the bandage by using a thermometer to measure the temperature at five points every 2 minutes to verify the working effect of the bandage by comparison,and the results showed that the difference between the temperature at each point and the simulated value was small and within a reasonable margin of error;the verification of the pain relief function was verified by the WOMAC score and the NRS score.The results showed that the improvement was less obvious after 5 days of use and very obvious after 10 days of use;the subjective evaluation of the product design experiment used a questionnaire to comprehensively evaluate the physical therapy belt,and the overall score was high,4.9,indicating that the design of the physical therapy belt basically met the expected goal.