Design And Experiments Of Minimally Invasive Surgical Instruments Based On The Tendon-driven Configuration

The conceptual design, kinematics analysis and configuration design of a novel surgical instrument with a rotation end are presented based on the configuration of tendon-driven. On the basis of the novel surgical instrument, the rigid rod wrist is changed into a flexible wrist composed by multi-joint. Then, the multi-degree of freedom surgical instrument with a flexible wrist is studied.The following works have been accomplished.Firstly, the procedures and features of laparoscopic minimally invasive surgery are analyzed. The design requirements are carried out according to the constraint conditions of the surgical instruments. After analysis and comparison of a variety of transmission, tendon-driven is chosen and the configuration of tendon-driven is summarized. A novel surgery robot instrument and a surgery instrument with flexible wrist are proposed based on the configuration of tendon-driven.Secondly, the forward and inverse kinematics analysis are presented by D-H and vector method. The workspace is also analyzed. The structural of the novel robotic surgical instrument is designed based on tendon-driven structural. Analysis of the surgical instrument clamping force and structure optimization are carried out to ensure the reliability of surgical instrument holding operation.A flexible wrist with two degrees of freedom and a rigid driver platform are designed. According to the steel wire length variation, the mapping model between the flexible wrist and the rigid driver platform is presented by the method of mathematical modeling and programming calculation. Then, overall structure and size parameters of the instrument are optimized.Finally, a variety of experiments are carried out based on the theoretical analysis of the surgical instruments. Experimental results show that the multiple degree of freedom surgical tools are designed with good flexibility to meet the needs of minimally invasive surgery.