A NEW APROACH FOR CONTROLLINGTHERMAL DOSE IN HYPERTHERMIA TREATMENT

An optimal model based controller of the thermal dose in hyperthermia has been developed, using Pennes bio heat transfer function (which is a diffusion equation) as a plant model. Here in, a new approach is used to optimize the thermal dose of a simple scanned focused ultrasound transducer that satisfies the following aims: a)rising temperature of tumor region to 43 °c and keep it uniform during treatment . (It takes 30 to 60 minutes ) . b) keeping the temperature of normal region near its initial value . c) using the minimum amount of energy. d) obtaining the optimal open loop controller that dose not need the invasive temperature measurements. This work demonstrates that the temperature can be made much more uniform by deposing greater amount of energy at the boundary of tumor than within the interior tumor region (it demonstrates in simulation part).

Keywords:

Control , diffusion equation , hyperthermia , optimization , scanned focused Ultrasound