A Hybrid Continuum Manipulator for Minimally Invasive Surgery: Design, Modeling, and Validation

Combining different types of continuum manipulators is a potential strategy to overcome the limitations of continuum manipulators. In this paper, a high-accuracy hybrid continuum manipulator (HCM) consisting of a notch continuum manipulator section and a concentric tube manipulator section is proposed. The static model of the manipulator is established, and an optimization algorithm of the manipulator has been carried out to enhance the precision of the kinematic model. This algorithm can optimize the accuracy of the model while retaining the high computational speed. Then, three different modes, namely the trajectory planning mode, operation mode, and hybrid mode are introduced to cater to distinct surgical requirements. The mechanical structure of the HCM is specifically designed to realize the modes above. The experimental results demonstrate a repetition positioning error of 0.4745 mm and an operation error of 1.7801 mm. The kinematic model error of the optimized manipulator was reduced by 77.4% compared to its pre-optimization state. Finally, the feasibility of the manipulator is demonstrated through function testing experiments. The proposed manipulator design provides a more versatile and adaptable solution to meet the diverse requirements of surgical procedures.