Structural design and analysis of pneumatic prostate seed implantation robot applied in magnetic resonance imaging environment.

Abstract

The method of MRI (Magnetic Resonance Imaging) image-guided robot for prostate seed implantation has developed rapidly in recent years. During the operation, although the puncture effect guided by MRI is very good, it is difficult for conventional robots driven by motors to work normally in this environment, which reduces the accuracy of seed implantation and affects the treatment effect. First, this paper designs a pneumatic prostate seed implantation robot that is compatible with MRI; the robot is composed of an execution module and an adjustment module, and can complete the positioning and adjustment of the robot's needle entry point, the pose adjustment of the puncture needle and the completion of seed implantation in the MRI space; meanwhile, the statics simulation analysis of its key components is carried out. Then, the kinematics analysis was carried out according to the designed robot structure, and the relationship between the posture of the needle tip and the change of the pneumatic cylinder was obtained; meanwhile, using MATLAB 2020 software, combined with the method of Monte Carlo random number sampling, the simulation analysis of the workspace was carried out. Finally, an experimental prototype is constructed to conduct puncture accuracy experiments, workspace experiments and performance comparison tests in MRI environment. The statics simulation results verify that the key components of the robot designed in this paper can meet the strength requirements of the robot. The simulation results of the workspace meet the requirements of space surgery for prostate seed implantation under the guidance of MRI environment. The puncture accuracy experimented to verify that increasing the puncture speed can improve the seed implantation accuracy, and the puncture deviation of the robot is less than the average deviation of the doctor's actual operation by 6.5mm. The working space experiment shows that the pitch range is -23.3°~27.8°, the movement range in the X direction is 0~210mm, the movement range in the Y direction is 0~101mm, and the lifting range in the Z direction is 0~81mm, which meets the workspace requirements under MRI. The performance comparison test results in the MRI environment show that the robot is well compatible with MRI instruments. The pneumatic prostate seed implantation robot designed in this paper has a reasonable structure and stable dynamic performance output, and can perform precise surgical operations in the MRI strong magnetic environment. The research work in this paper provides a design reference for the related research on the positioning accuracy of minimally invasive puncture surgery guided by MRI images.