Vision-based variable impedance control with oscillation observer for respiratory motion compensation during robotic needle insertion: a preliminary test

Abstract

Background: To reduce the radiation exposure of patients and physicians during needle-based procedures, robotic needle insertion systems have been widely developed. However, during robotic needle insertion, the respiratory motion of the patient can cause serious injury.

Methods: A vision-based variable impedance control algorithm was introduced to compensate for the respiratory motion. The algorithm controls the robot so that the applied forces and moments on the needle are zero. Also, an oscillation observer was introduced to ensure patient safety. A preliminary test was performed using a seven degrees of freedom (7-DOF) robot and a phantom.

Result: It was found that the proposed algorithm greatly decreases damage to the phantom due to respiratory motion. Also, the proposed oscillation observer was able to ensure robot stability.

Conclusions: The proposed control scheme allows the robot to compensate for the respiratory motion to ensure patient safety during a needle-based procedure.

Keywords: respiratory motion compensation; robotic needle insertion; variable impedance control.