Design and Modeling of a Spring-Based Continuum Manipulator for Minimally Invasive Surgery

Minimally invasive surgery (MIS) has gained significant attention from both patients and doctors for its less trauma, less pain, and faster recovery. Robot-assisted MIS has proven effective in reducing doctors' fatigue and improving surgical precision. MIS robots require more degrees of freedom of motion within limited dimensions to complete accurate, stable and safe surgery in a constrained working space. This paper proposes a spring-based continuum manipulator for MIS. The manipulator's length can be adjusted automatically. Its simple structure makes it easy to miniaturize. In addition, it includes a central channel for instrument replacement. The stiffness of the manipulator is analyzed, and a constant curvature kinematic model for the manipulator is developed. The effectiveness of the proposed constant curvature kinematics model was verified through experiments, and the motion performance experiments of the manipulator were conducted.