Research On Physical Modeling And Implantation Scheme Of Cochlear Perimodiolar Electrode

In recent years,with the development of virtual reality technology,it is possible to design perimodiolar electrode implantation scheme using a virtual implantation simulation platform of perimodiolar electrode.In this thesis,the composite spring mass model of perimodiolar electrode was established,and the collision detection algorithm for virtual implantation of perimodiolar electrode was designed.On this basis,the virtual implantation simulation platform of perimodiolar electrode was built,the perimodiolar electrode implantation scheme based on the Stanley algorithm was proposed on this platform.The main work is as follows:Firstly,the physical modeling method of perimodiolar electrode based on composite spring mass model was proposed.The composite spring mass model of perimodiolar electrode was established,and the sensitivity and modeling simulation analysis of the model were carried out.The analysis results show that in the virtual environment,the virtual-volumetric spring plays an important role in simulating and maintaining the preset shape of perimodiolar electrode,and the physical modeling method of perimodiolar electrode in this thesis is feasible.Secondly,a simplified scala tympani model was established and its hierarchical bounding box tree was constructed.Based on this tree,the collision detection algorithm for virtual implantation of perimodiolar electrode was designed.On this basis,combined with the composite spring mass model of perimodiolar electrode,the virtual implantation simulation platform of perimodiolar electrode was built.The feasibility and real-time performance of the collision detection algorithm for virtual implantation of perimodiolar electrode and the authenticity of the interaction between perimodiolar electrode and scala tympani model was verified by the platform.Then,based on the virtual implantation simulation platform of perimodiolar electrode,the perimodiolar electrode implantation scheme based on the Stanley algorithm was proposed,and the implantation simulation experiment of perimodiolar electrodes was carried out based on the scheme.The maximum contact arc length between the perimodiolar electrode and the scala tympanic wall is 1.0654 mm,the final implantation depth of the perimodiolar electrode is 16.6 mm,and the implantation angle is 322.2°.The experimental results show that the perimodiolar electrode implantation scheme based on the Stanley algorithm can avoid the largescale contact between the perimodiolar electrode and the scala tympanic wall,and realize the effective use of the perimodiolar electrode.Finally,based on the virtual implantation simulation platform of perimodiolar electrode,physical modeling simulation experiment of perimodiolar electrode and simulation comparison experiment of perimodiolar electrode implantation based on different implantation schemes were carried out.The mean absolute percentage error between the local deformation angles of the simulated and measured sets of mass points is 3.88%,and the Wilcoxon sign rank test shows that there is no significant difference between them The contact arc length generated by the implantation scheme based on the Stanley algorithm is 94% less than that of the implantation scheme based on the scala tympanic centerline.The composite spring mass model of perimodiolar electrode in this thesis has authenticity in virtual environment,and the perimodiolar electrode implantation scheme based on the Stanley algorithm has obvious advantage reducing implant damage.