Study On Control Strategy And Its Application For Cryosuegery&Radiofrequency Alternating Tumor Ablation

Cryosurgery, also known as low-temperature treatment, creates ultra-lowtemperature around the lesion region, and destroys the structure of the targettissue, so as to achieve the goal of treatment. In the rapid freezing process,intracellular ice crystals quickly forms inside the tumor cells, while in there-warming process, the crystallization can occur again. The tiny ice crystalsformed in the crystallization and re-crystallization will destroy the tumor cells.At the same time, a inhibit tumor immune response is also believed to havebeen stimulated in the process.In the field of physical therapy, Radiofrequency Ablation technique(RFA) research and practice have been relatively mature. RFA technique hasbeen widely used in the treatment of skin disease, nerve pain treatment, thetreatment of atria fibrillation. In tumor therapy field, FRA is also consideredwith great prospects, and given extensive attention in the research and clinicalpractice. Its accuracy and small damage to the normal surrounding tissue,applied to the treatment of liver cancer, lung cancer, kidney cancer, prostatecancer, and other diseases.However, experiments show that cryosurgery alone may not be able to killcancer cells, and because of instability in the flow of liquid nitrogen andphase change will be difficult to control the process of refrigeration; and RFAtreatment also has some flaws: energy may be weakened due to the flow ofthe blood, the border of the cancer treatment is hard to control, etc. But if wecombine these two methods, which means to adopt a cryosurgery and RFAalternating therapy, there could have a better curative effect in tumor ablation. In this paper, we present a new cryosurgery and RFA alternating tumortherapy system and its power control strategy, experiments in vitro organ andanimal have proved that the method can basically meet the designrequirements.