Human Factors in Tele-Inspection and Tele-Surgery (ARPA).
Abstract
Closed loop control of a telemanipulator such as is used for telesurgery is intolerant to loop time delay of more than 0.05 second. Such a system goes unstable, especially when force feedback is employed. The time delay inherent in modem high-bandwidth communication channels such as satellite or ISDN telephone systems is mostly attributable to required modulation/demodulation time, and can easily exceed 0.5 second. (I) This research applies a new approach, called fuzzy sliding control, to smooth out and stabilize teleoperation with time delay in the force and visual feedback. A demonstration system was built and fuzzy sliding control was evaluated relative to other control methods operating under time delay. While still not a perfect solution, it provided better stabilization than other methods. (II) This research tests the hypothesis that if video signals must be delayed due to modulation/demodulation as required by the channel, it may be better to send control signals by a faster method if possible, even if that means force feedback will not arrive in synchrony with vision or audio feedback. Experimental trials of various laparoscopic telesurgical tasks were performed with the surgeon remote from the patient and a paramedical assistant local to the patient. Results clearly showed that whenever the remote surgeon operated laparoscopic instruments (as compared to adjusting the laparoscope and letting the assistant do the actual surgery) the asynchronous feedback was better.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1998
- Accession Number
- ADA354117
Entities
People
- James M. Thompson
- Juanjuen Hu
- Thomas B. Sheridan
Organizations
- Massachusetts Institute of Technology