Tactile feedback is present during minimally invasive surgery

Background: The applications of minimally invasive surgery (MIS) and laparo scopy are rapidly expanding. Despite this expansion, our understanding of t he importance of haptic feedback during laparoscopic surgery is incomplete. Although many surgeons believe that the use of minimally invasive techniqu es eliminates force feedback and tactile sensation (haptics), the importanc e of haptics in MIS has not been fully evaluated. There is considerable int erest in the development of simulators for MIS even though the importance o f force feedback remains poorly understood. This study was designed to dete rmine the ability of experienced surgeons to interpret haptic feedback with respect to texture, shape, and consistency of an object. Study Design: A randomized, single-blinded study was designed. Twenty surge ons were presented objects in a random order, with participants blinded as to their identity. Inspection by direct palpation, conventional instruments , and laparoscopic instruments was performed on all objects. Statistic anal ysis of the data was performed using chi-square analysis and, when appropri ate, a Fischer exact probability test. Results: Direct palpation was associated with the highest accuracy for shap e identification and was superior to both conventional instruments (p < 0.0 01) and laparoscopic instruments (p<0.001). Fine texture analysis with eith er a conventional instrument or a laparoscopic instrument was superior to d irect palpation (p < 0.05). Finally, the three methods of analysis were com parable for consistency analysis. Conclusions: These data indicate that laparoscopic instruments do, in fact, provide surgeons with haptic feedback. Interpretation of the texture, shap e, and consistency of objects can be performed. In some situations, laparos copic instruments appear to amplify the haptic information available. Our o ngoing work is directed at further defining force interactions. (J Am Coil Surg 1939;189:349-355, (C) 1999 by the American College of Surgeons).