Haptics and Supervisory Control in Telesurgery

This paper reviews several interrelated experiments related to the improvement of systems by which to perform simple surgical procedures remotely using closed circuit video/audio and telerobotic manipulator devices over ISDN telephone communication channels. The realities of such technology include the existence of several second time delays, severe constraints on feedback bandwidth, and the lack of some desirable degrees of freedom for manipulation. Experiments were done to determine what sensory-motor tasks should be performed by the surgeon directly in a master-slave mode with haptic (position-force) feedback, what tasks should be programmed into and subsequently performed by a computer at the site of the patient, and what tasks should be performed by an untrained assistant (non-surgeon) physically located with the patient with the second-by-second supervisory guidance of the remote surgeon. Experiments were also done to find ways to ameliorate the instability in force feedback caused by the time delay. For each mode the paper identifies compromises in telepresence and sensory- motor performance and tradeoffs between speed and accuracy. Based on experimental results, recommendations are made for ways to improve telesurgery systems now being developed.