Design and Study of Particle Implantation Robot for Prostate Cancer Based on Imitating the Human Arm

Abstract

In the clinical treatment of prostate cancer, radioactive particle implantation surgery by a puncture robot is a safe and effective therapeutic approach. During surgery, patients are generally required to remain in the lithotomy position, within a limited and narrow working space for the complex procedure. However, the existing prostate particle implantation robots have poor motion flexibility, excessively large volume, complex inverse kinematics, and difficulty in control. Therefore, a prostate particle implantation robot based on imitating the human arm is proposed and designed in this paper. First, in accordance with the surgical requirements of prostate particle implantation and the bionics principle, the relevant physical parameters of the human arm are measured via X‐ray imaging, and the overall structure of the robot is designed. Kinematic analysis and the establishment of the spatial model for the main components of the robot—a robotic arm based on imitating the human arm (abbreviated as RAIHA robot)—are carried out to obtain the constraint conditions of each arm link in the working space and the constraint conditions between the joint angle of each arm and the driving force of the servo electric cylinder. Third, the objective optimization function for the RAIHA robot parameters is established based on the kinematic model and constraint conditions, and both the genetic algorithm (GA) and the NSGA‐Ⅱ‐based multiobjective optimization algorithm are used to optimize the RAIHA robot and its related structural parameters. Meanwhile, Matlab2017a/Simulink software is used to simulate the optimization results and verify their feasibility. Finally, to verify the effectiveness of the prostate particle implantation robot designed in this paper, a physical prototype is developed, and experiments are conducted to verify the rotational position of each arm joint, the influence of gravity torque on the angular position error of rotary joints, and the performance of terminal attitude control. The results show that the prostate particle implantation robot designed in this paper can not only well meet the task requirements of prostate implanting surgery in the human lithotomy position, but also overcome the influence of its own heavy moment, with the gravity torque self‐compensated by about 55.2%. Moreover, the robot exhibits excellent attitude adjustment performance and flexible movement, it ensures the stability of motion control for the terminal puncture needle. The robot structure designed in this paper can stably and accurately perform multiposture movements of the terminal puncture needle, reduce energy consumption, and meet the requirements of surgical tasks that demand a wide range of motion within the narrow yet effective maneuvering space at the human lithotomy site. The research work in this paper provides a theoretical reference for the design and development of puncture robots.