A medical robot for needle placement therapy in liver cancer

Hepatocellular carcinoma （HCC） is the second most common malignancy in China. As microwave ablation （MWA） is an effective method for liver cancer, a robotic surgical system with ultrasound-directed was designed to assist surgeons on positioning the needles. This robotic system includes a surgical robot with 5 degrees of freedom, a workstation for path-planning and image processing, a conventional 2D ultrasound device, and an electromagnetic （EM） tracking system. Surgery space, clinical operation requirements and optimal mechanical structure are the key factors to be considered in designing a medical robot suitable for use by surgeons. Based on the mechanics of the needle placement robot, we have conducted detailed kinematic analysis, including a combined numerical algorithm and coordinate mapping. Finally, the feasibility of the needle placement robot has been validated by experiment.