Research On Path Planning And Force Control Technology Of Robot-assisted Transcranial Magnetic Stimulation Therapy

Transcranial Magnetic Stimulation(TMS)is a noninvasive and painless method for the diagnosis and treatment of brain diseases.Compared with traditional manual operation,robot-assisted TMS treatment is more accurate,safe and reliable.When the TMS treatment robot performs the TMS target stimulation task in the unstructured environment of human-computer interaction,the patient’s treatment head is both a target and an obstacle,facing the difficulty of accurately locating the stimulation target and the unstable movement of the patient’s head leading to the treatment The problem of reduced effect,these problems hinder the popularization and application of robot-assisted transcranial magnetic stimulation technology,in view of this,this paper established a robot-assisted TMS stimulation treatment system,and carried out the research on the path planning and force control technology of TMS treatment robot.Aiming at the limitations of the traditional TMS treatment process,the requirements of the robot-assisted TMS treatment system were analyzed according to the actual clinical situation,the functional requirements and workflow of the system were clarified,the system treatment plan was formulated,and the hardware components of the system were introduced.Aiming at the problem of head stimulation target pose recognition,a target image acquisition system based on a depth camera was established to obtain the Ar Uco code of the head stimulation target mark,and the automatic recognition of the patient’s head target point pose was realized by the Ar Uco code recognition method.Aiming at the problem of automatic positioning and switching of head stimulation targets,the forward and reverse kinematics of the robotic arm was analyzed,and the layout of the robot-assisted TMS treatment system was analyzed based on the offline simulation software Robo DK,and the patient’s head,robotic arm base,and depth camera were determined.The positional relationship between them;the path planning was carried out for the initial positioning of the stimulation target and the switching between the stimulation targets,and a trajectory planning method combining joint space and Cartesian space was proposed.The path planning simulation of the TMS treatment robot treatment process was carried out by using MATLAB,and the results verified the feasibility and effectiveness of the proposed method.Aiming at the problems of following the stimulation target during the head movement and the safety of human-computer interaction,a gravity compensation method for the terminal stimulation coil and a force/position hybrid control method for the TMS treatment robot are proposed.Among them,the gravity compensation method can accurately measure the gravity load generated by the end stimulation coil itself by modeling the whole end tool and combining the least square method,so as to provide correction data for the determination of the human-computer interaction contact force;the force/position hybrid control method is Based on the basis of gravity compensation,the terminal stimulation coil follower controller is designed with the detection result of the stimulation target during head movement as input,and the position of the stimulation coil at the end of the manipulator is corrected in real time to realize the dynamics of the stimulation coil during the movement of the head stimulation target.follow.Finally,based on the experimental platform of the designed robotassisted TMS treatment system,the effect of head stimulation target following treatment was verified.During the stimulation target following therapy experiment,the maximum deviation of the following spatial position was 5.8 mm,which was less than the maximum deviation of 10 mm required by transcranial magnetic stimulation therapy.The experimental results showed that the designed system could control the manipulator to follow the target stimulation target in real time.And maintain the stability of the contact force between the stimulation coil and the patient’s head,meeting the system design requirements.