Study On Preoperative Path Planning Of Robotic Cochlear Implantation Of Perimodiolar Electrode

Cochlear implantation of perimodiolar electrode is the most successful medical treatment for hearing impairment.However,due to the complex structure of the cochlea and the fragile structure of the perimodiolar electrode,electrode and cochlea damage are easily caused during implantation.The robot has the advantages of high precision and high stability for cochlear implant.In this paper,a multi-rigid model of perimodiolar electrode is established for the requirements of cochlear implantation.The initial implantation path planning scheme of the perimodiolar electrode was designed,and the path optimization was performed based on the harmony search algorithm.Finally,the feasibility of the implantation path was verified by simulation and experiment.This study provides reference for preoperative path planning of robotic cochlear implantation of perimodiolar electrodeFirstly,the shape of the perimodiolar electrode is analyzed,and the shape variation characteristic of the perimodiolar electrode is obtained through experiments.According to its characteristics and structural characteristics,it is decomposed into multi-segment rigid bodies for modeling.The Fourier series compensation fitting algorithm of perimodiolar electrode is proposed to fit the joint angle variation increment to establish the plane multi-rigid body model of the perimodiolar electrode.The results show that the method not only ensures the initial state of the perimodiolar electrode model is consistent with the actual,but also accurately reflects the electrode change trend.Secondly,the human cochlea plane model is established.According to the actual implantation situation,the characteristics of the cochlear implantation are analyzed,the evaluation index is established and the initial implantation scheme of the perimodiolar electrode is designed.The harmony search algorithm is used to optimize the implantation path point of the perimodiolar electrode tip,the robot attitude and the guide wire extraction state to obtain an optimized implantation path.Then,according to the two implanting algorithms,the simulation environment is built and the round window and cochleostomy implantation simulation experiments are carried out.The simulation results show that the cochleostomy implantation path of perimodiolar electrode based on the harmony search algorithm has the best effect and the implantation depth up to 14.9 mm.The touching arc length of the perimodiolar electrode and the cochlea is 29.27% lower than that of the round window implantation,which is 31.69% lower than the initial implant path.The final implant state basically fits with the shape of the human cochlea and meets the expected implantation requirements.Finally,the test system is set up with ABB robot,pre-bend electrode holder,CCD camera and PC.The host computer interface design is completed and the robot implant path is verified by experiment.The results show that cochleostomy path planning of the perimodiolar electrode based on the harmony search method can reduce the probability of contact with the cochlea wall during implantation and achieve the implantation depth requirement.The final state of the perimodiolar electrode is substantially matched to the cochlea shape.