Shape Detecting And Control Of The Soft Surgical Robot

Minimally invasive surgery can not only reduce the patients' pain,but can solve the problem of the shortage of medical resources to some extent because of its quicker recovery and shorter hospital stay.At present,the minimally invasive surgery systems mainly rely on import in China,which are costly and lager volume.The end-effectors of the system are made of hard materials like metal which have big risks.For the above reasons,the utilization rate of the minimally invasive surgical instruments is low.Soft robot is a new kind of robot which is inspired by the mollusk or animal parts.Common characteristics of these animals or animal tissue are soft and there is no bone inside them,which is used to support the body.Relying on muscle's flexible movement,they can move,grab and predation.Follows these characteristics,soft robots made of silicon and cables can achieve movements similar to octopus are movements.Aiming at the problems existing in the systems of minimally invasive surgery,combined with the advantages of the soft robots,we are developing a soft robot system for minimally invasive surgery.This article is about the research revolves around the soft surgical robot system.According to the requirements of the clinical surgery,the mechanical structure of the existing soft robot surgical system is improved and the drive device and mechanical structure is combined together to realize the modularization design.The humanmachine operation interface is designed to display the important data and camera information for the doctors to be easy to timely judge the running state of the robot.The interface has alarm function at the same time.When the system is judged to be abnormal,the interface will automatically alarm and take emergency measures to reduce the surgical risks at utmost.In order to cooperate with the interface,the slave computer program is designed to perform the master computer instructions and report the running status to the master computer.Feasibility and safety of the operation system is verified by animal experiments,the chest and lung biopsy,surgical ligation of the auricle and cardiac ablation surgery on beating heart not only illustrates the extensive application of operation system,but to illustrate the feasibility and safety of the operation system.As the shape of the soft robot manipulator cannot be obtained when the soft robot manipulator inserted into the body,the doctor may take wrong measures when controlling the tip of the soft robot manipulator to come to the target point only relying on the camera information.To conquer this problem,a shape detecting algorithm is presented.The fiber Bragg gratings are embedded into the soft robot manipulator to sense the shape change of the soft robot manipulator.Then,the curvature and torsion of the soft robot manipulator at the sensor position can be calculated by the sensor data.By the interpolation algorithm,the curvature and torsion of the whole manipulator can be obtained,then,the central line shape of the soft robot manipulator can be obtained by the shape estimation algorithm.The experiments are presented to illustrate the efficiency of the algorithm.At last,shape control of the soft robot is studied.Refer to the shape control on continuum robots,combining with the characteristics of soft robots,a shape control algorithm on soft robot is proposed.The shape description parameters are obtained based on the assumption of constant curvature.Then,the relations between the shape description parameters and the length of the driven cables is obtained through the kinematics and the shape control algorithm is designed.To verify the control algorithm,several experiments have been done and some typical results are presented.