Control algorithms for active relative motion cancelling for robotic assisted off-pump coronary artery bypass graft surgery

Use of intelligent robotic tools promises an alternative and superior way of performing off-pump coronary artery bypass graft (CABG) surgery. In the robotic-assisted surgical paradigm proposed, the conventional surgical tools are replaced with robotic instruments which are under direct control of the surgeon through teleoperation. The robotic tools actively cancel the relative motion between the surgical instruments and the point-of-interest on the beating heart, in contrast to traditional off-pump CABG where the heart is passively constrained to dampen the beating motion. As a result, the surgeon operates on the heart as if it were stationary. We call the proposed algorithm "active relative motion cancelling (ARMC)" to emphasize the active cancellation. In the paper, a model-based intelligent ARMC algorithm is proposed to achieve effective motion cancellation. This is followed by an analysis of local motion of the heart collected using a sonomicrometry system to determine the specifications for ARMC system. Finally, the experimental results of the algorithm implemented on two 1-DOF robotic test-bed systems are reported