Telerobotic Surgery: An Intelligent Systems Approach to 
Mitigate the Adverse Effects of Communication Delay

Frank M. Cardullo
State University of New York
Binghamton, New York
USA

It is interesting to note that in the late 1980s, after its inception the 
utilization of laparoscopic cholecystectomy grew rapidly. However, minimally 
invasive surgery (MIS) for other operations has not experienced the same 
pattern of growth. It appears that the reason is that in general laparoscopic 
procedures are hard to learn, perform and master. Robotic surgery appears to 
be the solution. In a sense this robot is a telemanipulator under the control 
of the surgeon. The robotic system provides a stable video platform, added 
dexterity and in some cases a stereoscopic view of the surgical field.

Since proximal robotic surgery seems to be maturing the next logical step in 
surgical care is to extend to remote applications of robotic surgery. The main 
impediment to the availability of this technology is the communications delay 
associated with long distance signal transmission. This delay is inevitable 
and a consequence of the propagation speed of electromagnetic radiation.

It is well known that system delays will cause a deterioration of the 
human-machine system performance and ultimately an unstable system. It is 
observed that when delays become long, human operators will adopt a move and 
wait strategy. The move and wait strategy is unacceptable in tightly closed 
loop applications such as robotic surgery. To quote Dr. Richard Satava, 
"During my development of the initial telesurgery systems through the Advanced 
Biomedical Technology program at DARPA, there was principal focus on the 
systems integration but the program was not able to resolve the latency issue 
This is an area which has had much speculation but little hard data, resulting 
in the off-hand dismissal of very remote telesurgery." 

Since the delay can not be eliminated, in order to accomplish this objective, 
the only solution is to mitigate the effects of the delay on the surgeon 
performing the operation. We have developed an innovative approach, which is 
to have the surgeon operate through a simulator running in real-time. The use 
of a simulator enables the surgeon to operate in a virtual environment free 
from the impediments of telecommunication delay. The simulator functions as a 
predictor and periodically the simulator state is corrected with "truth" data. 
The figure below illustrates the general approach.

Since, in robotic surgery, the surgeon is already in a synthetic environment 
the introduction of a simulator does not significantly alter the physician's 
perceptual stimuli. The operating station containing the control inceptors and 
the visual displays is the same as that used to control the surgical robot in 
the conventional configuration. 

The paper discusses the approach in the context of an intelligent machine. 
There are a number of intelligent components from the image processing - to 
the intelligent controller - to the simulator providing an environment in 
which the surgeon can operate with smooth continuous motion - to the creation 
of augmented reality with haptic feedback to the surgeon.