Study Of Needle-holding Robot For Ultrasound-guided Percutaneous Microwave Ablation Of Liver Tumor

Many studies of recent years have shown that ultrasound-guided percutaneous microwave ablation of liver tumor is minimal invisive, safe and effective in treatment of liver tumor. In this method, microwave needle was inserted into target tumor under ultrasound guidance to achieve eradication or substantial tumor destruction by direct application of thermal therapies to a specific focal tumor.The most important two steps of microwave ablation is to insert and place microwave needle in the tumor precisely and keep the relative position of microwave needle to the the tumor stable. During the procedure of tumor ablating, the position of microwave needle may change because of motion and deformation of patient liver during respiratory cycle, weight of microwave needle and accessory cable. Currently, an experienced physician is arranged as assistant specially for stable holding of microwave needle manually. However, this method depends too much on the experience of physicians, leads to waste of manpower resources and even results in reduction of treatment effect. In order to decrease influence of human factor during holding of microwave needle and free the two hands of needle-holding assistant, a needle-holding robot was developed and studied to take the place of assistant to fulfill stable holding of microwave needle, thus in turn makes ultrasound-guided percutaneous microwave ablation of liver tumor a more objective, controllable and standardized treatment which could be widely applied more easily.The treatment procedure of ultrasound-guided percutaneous microwave ablation was introduced and relative issues concerning about stable holding of microwave needle during ablating was analyzed first. Then in order to provide design parameters of needle-holding robot, spatial disposition of interventional operating room was analyzed and moving data sets of microwave needle during ablating was achieved by using magnetic tracking system. A needle-holding robot was developed according to the technical character and specific clinical requirements of ultrasound-guided percutaneous microwave ablation of liver tumor. After safety, stability and flexibility of the robot was validated and holding efficacy was contrasted with needle-holding assistant through in vivo animal experiments, initial clinical application was performed in 20 patients.In this dissertation, a needle-holding robot was developed, in vivo animal experiments and initial clinical application were performed. This project demonstrates that needle-holding robot is feasible, safe and effective when used to hold microwave needle in ultrasound-guided percutaneous microwave ablation of liver tumor and may play a more important role after improved and optimized. Thus microwave ablation technique could be more reasonable, standardized, controllable and more easy to gain wide applications.