Tactile feedback is present during minimally invasive surgery

Background: The applications of minimally invasive surgery (MIS) and laparoscopy are rapidly expanding. Despite this expansion, our understanding of the importance of haptic feedback during laparoscopic surgery is incomplete. Although many surgeons believe that the use of minimally invasive techniques eliminates force feedback and tactile sensation (haptics), the importance of haptics in MIS has not been fully evaluated. There is considerable interest in the development of simulators for MIS even though the importance of force feedback remains poorly understood. This study was designed to determine 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 surgeons 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 analysis of the data was performed using chi-square analysis and, when appropriate, a Fischer exact probability test. Results: Direct palpation was associated with the highest accuracy for shape identification and was superior to both conventional instruments (p < 0.001) and laparoscopic instruments (p<0.001). Fine texture analysis with either a conventional instrument or a laparoscopic instrument was superior to direct palpation (p < 0.05). Finally, the three methods of analysis were comparable for consistency analysis. Conclusions: These data indicate that laparoscopic instruments do, in fact, provide surgeons with haptic feedback. Interpretation of the texture, shape, and consistency of objects can be performed. In some situations, laparoscopic instruments appear to amplify the haptic information available. Our ongoing work is directed at further defining force interactions. (J Am Coil Surg 1939;189:349-355, (C) 1999 by the American College of Surgeons).