Force feedback controls of multi-gripper robotic endovascular intervention: design, prototype, and experiments.

PURPOSE Robotic endovascular intervention system (REIS) has the advantages of telemanipulation without radiation damage, precise location, and isolation of hand quiver. However, current REIS lacks a force feedback, which leads to high clinical risks. For the high operational safety of remote operations, this research proposes a force feedback control method for a novel manipulator with multi-grippers and develops a prototype to verify its expected telepresence. METHODS A high-resolution force sensor is used to acquire and transmit the intervention resistance force to the control handle. When the handle is translated or rotated, a loading mechanism composed of a servomotor, a screw pair, a spring, and friction roller generates the resistance force transmitted to the doctor's hand through the handle. A force/displacement hybrid control and PID control algorithm are used for the smaller feedback force error and lower delay. RESULTS This manipulator and its control handle are tested in the simulated catheter and vascular cases. The experiments show that force feedback precision can reach 0.05 N and the delay is not more than 50 ms, and the bandwidth is 9 Hz@-3 dB. CONCLUSION The proposed force feedback method can recreate resistance force from the intervention devices. The control model is valid with higher precision and wide bands, which has laid foundations to the application of REIS in clinic.