Preliminary study of the robotic couch for prostate cancer in proton/heavy ion therapy

In the process of proton/heavy ion radiotherapy, the position of patients requires dynamic adjustment to improve the accuracy of proton/heavy ion radiation. For flexible adjustment of patient's pose at radiotherapy, a six DOF (Degree of Freedom) proton /heavy ion robotic couch for prostate cancer is design, which is a 3-RPS-R&&PP series- parallel hybrid mechanism. During the radiotherapy, the prostate of patient is unfixed in consideration of instability of prostate affected by the lower limbs posture, hence, a lower limb adjustment mechanism on therapy couch is designed. Analyses the kinematics of the radiotherapy bed, the inverse position formula and position constraint equation of the mechanism are established. The workspace simulation of the mechanism is carried out using the polar coordinate search method and MATLAB software, and the results meet the requirements of the robotic bed. This design is considered as the foundation of further study.