Structure Design And Analysis Of MRI-Compatible Robot Based On Flexible Shaft Transmission

At present, as the most advanced medical imaging technology in the world, magnetic resonance imaging(MRI) has been widely used in medical field because of its excellent imaging quality and provides a new therapeutic method for minimally invasive surgery. But the magnetic field of MRI and the limited space raise a serious of demands to the driving mode and structure of invasive robot guided by MRI. This thesis aims at designing a minimally invasive surgery robot that can meet the requirements of magnetic compatibility and work by the guidance of MRI, and its driving system. Then some analyses and experiments have done on them.Firstly, the basic requirements for the design of the robot is analyzed based on the breast biopsy. On this basis,this thesis design a complete full range of multi needle breast biopsy robot motion attitude using the idea of modularizati on and the virtual prototype of the robot is constructed using Cero2.0.Secondly, several common driving schemes are analyzed, and the external motor drive scheme is selected as the driving mode of robot according to the characteristics of the MRI robot. The flexible shaft is selected as the main transmission parts considering the characteristics of driving mode of external electric motor. Flexible shaft has be designed and checked based on working environment, and its transmission effect is verified by experiment.Then, the kinematics and the inverse kinematics problem was analyzed with the method of D-H series mechanism of robot and parallel mechanism was analyzed by ZYZ type Euler angle. The workspace of the parallel part is analyzed by the analytic method. The workspace of the robot is solved by the method of Monte Carlo simulation using Matlab software.Finally, the parts of the robot which is under the larger force and the force is concentrated are analyzed about static analysis, including the biopsy needle, the upper support rails, and so on. The conclusion is drawn: the analysis of the components of the maximum stress and deformation values are in the acceptable range and the rationality of the design of the robot is proved.