Evaluation of Deep Thermal Rehabilitation System Using Resonant Cavity Applicator During Knee Experiments

This paper evaluates experiments on the knee using a new heating rehabilitation system. For effective thermal rehabilitation of osteoarthritis, it is necessary to heat the deep tissue inside the knee joint. Our new rehabilitation system is based on the re-entrant type resonant cavity applicator which was developed for deep hyperthermia treatment in our previous studies. Our experimental results using agar phantoms showed our heating system is able to heat the deep tissue inside the knee without physically contacting the surface skin. In this study, we developed a prototype applicator and experimented on a healthy human subject's knee under clinical conditions. To evaluate heating performance, we conducted heating experiments with our resonant cavity applicator and a conventional microwave diathermy system and compared the results. The experimental results of temperature increase distributions inside the human body were estimated by ultrasound imaging techniques. The estimated results from our knee experiments show that our heating system is able to heat knee tissue more deeply than microwave diathermy systems can and thus would be effective for deep thermal rehabilitation applications in clinics.