Thermal Sensor Circuit Using Thermography for Temperature-Controlled Laser Hyperthermia

Laser hyperthermia is a powerful therapeutic modality that suppresses the growth of proliferative lesions. in hyperthermia,the optimal temperature range is dependent on the disease; thus,a temperature-driven laser output control system is desirable. such a laser output control system,integrated with a thermal sensor circuit based on thermography,has been established. in this study,the feasibility of the developed system was examined by irradiating mouse skin. the system is composed of a thermograph,a thermal sensor circuit (pc and microcontroller),and an infrared laser. based on the maximum temperature in the laser-irradiated area acquired every 100 ms during irradiation,the laser power was controlled such that the maximum temperature was maintained at a preset value. temperature-controlled laser hyperthermia using the thermal sensor circuit was shown to suppress temperature fluctuations during irradiation (sd 0.14°c) to less than 1/10 of those seen without the thermal sensor circuit (sd 1.6°c). the thermal sensor circuit was able to satisfactorily stabilize the temperature at the preset value. this system can therefore provide noncontact laser hyperthermia with the ability to maintain a constant temperature in the irradiated area. © 2017 shinsuke nomura et al.