A State-of-the-Art Design: Applying Forward Kinematics to Improve Patient Positioning in Radiosurgery

Abstract

This paper presents a comprehensive study on the application of forward kinematics in the development and control of an innovative Patient Positioning System (PPS) for radiosurgery treatment. The proposed PPS, consisting of a linear rail system, a linkage system, and a tabletop, synergizes to enable precise human body positioning.The standout feature of our PPS is the linkage system, equipped with four linkage arms—three active and one passive. Together, these arms facilitate diverse motions, allowing for rotation, translation, and inclination of the endpoint, thereby providing unmatched precision and versatility. Forward kinematics profoundly enhances the design and operational capabilities of the robotic linkage and the positioning system as a whole.In addressing the positional challenges posed by the PPS’s robotic components, remarkable accuracy has been achieved in the system’s kinematic modeling. A crucial aspect of our findings revolves around the error analysis. By applying single and dual loop control methods, significant advancements have been made in minimizing positional errors, thereby enhancing the PPS’s accuracy and reliability. Detailed insights into the error, including the Heat Matrix, will be discussed in-depth within the paper, following a robust experimental validation using MATLAB and a comparative assessment with CAD model measurements.