Stability Analysis Of The Continuum Mechanism Of The Laryngeal Surgery

Because of the high stiffness, the end effector's high flexibility, and the structure being easy to scale, the continuum mechanism is very suitable for the operation of the human body.As a result of the narrow laryngeal minimally invasive surgery space and the existence of operation process of fibrillation and other factors, which has a great impact on the operation safety and precision,so the research on continuum structure has great value in academic and medical application.This thesis will be focused on the research of larynx surgery continuum structures.From the comprehensive analysis of the basic research of relevant technologies at home and abroad, the design scheme of the continuum mechanism into four modules is put forward,in view of the difficulty of the operation of the throat.In this paper,this thesis designed a universal drive bending mechanism, an end actuator, six joint bending mechanism, four bending segment mechanism, and design the three-dimensional structure of institutions.The main body of the continuum mechanism adopts the universal drive bending mechanism as compensation and drive mechanism.This new type of continuum structure has 32 degrees of freedom,the end effector's movement controlled by line drive,which can enable it complete the operation with high difficulty and high precision in the marrow and long place of larynx.This thesis analyzes the stiffness of a single component in a continuum structure,for the reason of the existence of fibrillation in laryngeal surgery.Based on ANSYS software, this thesis sets up a static finite element model of the interval disc, four joints and six joints, and carry on the static analysis, to prove that the designed structure can bear the stress of the throat theoretically. Based on Workbench ANSYS software,this thesis established the dynamic model of the universal driving bending mechanism and carry out the free modal and constrained modal analysis,to study the overall dynamic characteristics of the mechanism under the constraint.Based on Workbench ANSYS software,we establish the dynamic model of the disk and end effector and carry out constrained modal analysis,to determine the range of the natural frequency of each component,which provides the guarantee conditions for the operation of the fibrillation.According to the deformation error of flexible rod in continuum mechanism,this thesis established the deformation curve equation of continuum structure, and derive the kinetic energy expression.Then, the potential energy of the mechanical system is derived based on theexisting formula.On the basis of this, this thesis established the dynamic model of continuum structure.Based on ANSYS Workbench software, this thesis established the finite element model of the whole body of continuum mechanism in order to study the range of natural frequencies of the whole machine to avoid the frequency preserve and resonance,which provides a theoretical basis for the development of physical prototype and animal experiment.