Smith Predictor-Based Robot Control for Ultrasound-Guided Teleoperated Beating-Heart Surgery

Abstract

Abstract-Performing surgery on fast-moving heart structures while the heart is freely beating is next to impossible. Nevertheless, the ability to do this would greatly benefit patients. By controlling a teleoperated robot to continuously follow the heart's motion, the heart can be made to appear stationary. The surgeon will then be able to operate on a seemingly stationary heart when in reality it is freely beating. The heart's motion is measured from ultrasound images and thus involves a non-negligible delay due to image acquisition and processing, estimated to be 150 ms that, if not compensated for, can cause the teleoperated robot's end-effector (i.e., the surgical tool) to collide with and puncture the heart. This research proposes the use of a Smith predictor to compensate for this time delay in calculating the reference position for the teleoperated robot. The results suggest that heart motion tracking is improved as the introduction of the Smith predictor significantly decreases the mean absolute error, which is the error in making the distance between the robot's endeffector and the heart follow the surgeon's motion, and the mean integrated square error.

GPC-based teleoperation for delay compensation and disturbance rejection in image-guided beating-heart surgery

“…systems where both the image acquisition and processing delays and the surgical robot's dynamics must be accounted for. It expands on the work previously done by Ginhoux et al [13] and Bowthorpe et al [15], by aiming to develop a teleoperated system guided by ultrasound images that follows the heartbeat-induced motion of the POI for procedures performed on the exterior surface or interior of the heart. Hence, the image acquisition and processing delay is significantly larger than that in [13] where a 500 Hz camera as opposed to a 28 Hz ultrasound scanner is used.…”

“…However, ultrasound images only track the heartbeatinduced motion as the ultrasound probe must remain in contact with the patient's skin and will therefore move in synchrony with the respiratory-induced motion. On the bright side, ultrasound images can be acquired in real-time, tens of times per second, can visualize through blood, and are used in [15], [16], [17] for annuloplasty and pericardial effusion.…”

“…Ginhoux et al used Generalized predictive control (GPC) to follow the periodic respiratory-induced motion and an adaptive disturbance predictor to follow the heartbeat-induced motion [13]. Bowthorpe et al used a Smith predictor to stabilize the surgical system in the presence of long image processing and acquisition delays of approximately 150 ms to track the heartbeat-induced motion [15].…”

“…Hence, the image acquisition and processing delay is significantly larger than that in [13] where a 500 Hz camera as opposed to a 28 Hz ultrasound scanner is used. Importantly, by using a generalized predictive controller instead of a Smith predictor as in [15], disturbances originating from the heart's backand-forth motion can be rejected directly by the controller.…”

Remote Lab for Robotics Applications

“…Robotic toys today are very common, it is possible to find from assistive robots to support feeding to people with limitations [1] to assistant robots of physical activity for adolescents [2], which are part of the great variety of developments found in the state of the art. The presentations of the robotic agents are very varied, until reaching critical support points, as intermediaries in teleoperations [3]. This type of applications allows to see the incidence of the robots in the activities of the man and his improvement of the quality of life.…”