Power controlling strategy for cryosurgery & RF alternating thermal therapy system

Cryosurgery treatment and Radiofrequency Ablation (RFA) are both effective method of physical therapy for tumor, but both of them have some disadvantages. Some occasional findings in the biological experimental phenomenon show that the alternative use of cryosurgery and RFA may have a better curative effect in the tumor ablation. We developed a joint system, trying to combine the freezing and heating process together, to verify the above-mentioned phenomenon, and proposed a new tumor physical therapy method. Because of the high and rapid changing tissue impedance caused by the freezing process, we developed a new control strategy based on the improved fuzzy control theory to adapt to this new treatment modality. The experimental results show that the stability of this system can be effectively ensured by the power control strategy.