Abstracts
1998 Digestive Disease Week

#3588

FORCE FEEDBACK GRASPER HELPS RESTORE SENSE OF TOUCH IN MINIMALLY INVASIVE SURGERY. M. MacFarlane; J. Rosen*; B. Hannaford*; C. Pellegrini; M. Sinanan. Dept. of Surgery and Electrical Engineering*; University of Washington, Seattle, Washington.

The age of Minimally Invasive Surgery (MIS) has brought forth astounding changes in the health care field. Less pain and quicker patient recovery have been demonstrated with several types of operations that were once performed by an open technique. With these dramatic changes have also come reports of complications. The decreased sense of touch is just one of several pitfalls in MIS which may lead to complications, such as gastric perforation and liver laceration. In prior work, we have developed and demonstrated a force feedback device that allows measurement of reflected forces of various biological tissues based on their intrinsic properties. The purpose of the current study is to demonstrate the ability of this device to restore some of the lost sense of touch in MIS which is present in open surgery. To demonstrate this ability, we used eight latex materials of identical dimensions but graded compliance, and asked 10 subjects to place them in increasing/decreasing order of compliance. They used three tools (their dominant gloved hand, a standard laparoscopic babcock grasper and our force feedback device fitted with the identical babcock grasper) to rate the latex samples in a blinded fashion. These conditions thus approximated the conditions of open surgery, MIS and MIS fitted with a force sensing device in terms of feeling tissues. Five MIS skilled surgeons and five non-surgeons participated in the study. Each subject rated the eight samples four times with each tool type (total of 12 data points per subject and 120 data points for the study). The difference of the chosen order from the known order is reported as the root mean square (RMS) of the difference. Statistical significance was reported as P<0.05. The results indicate that the force feedback device is significantly better than a standard babcock grasper at rating various tissue compliance, but was not as successful as a gloved hand (RMS = 2.76; 6.23; 1.34 respectively). There was no significant difference between surgeons and non-surgeons in rating compliance. We conclude that this device, with its capability of fully interchangeable tool tips, is able to partially restore a sense of touch in MIS which has been lost as compared to open surgery. This restored ability may thus potentially result in more efficient operations with fewer complications during MIS. In addition, these force feedback capabilities can also be incorporated into surgical simulation to create a more realistic simulation for training of future MIS skilled surgeons.

Copyright 1996 - 1998, SSAT, Inc. Revised 29 June 1998.