Acquisition and analysis of cutting forces of surgical instruments for haptic simulation

Current research has focused on visual feedback for the development of virtual surgery. However, little is known about the haptic feedback required for realistic simulation. The forces necessary for the cutting of anatomical tissues were investigated for three surgical scissors: the Mayo dissection scissor, the Metzenbaum dissection scissor and the Iris scissor. Several experiments were completed in conjunction with a surgical doctor to acquire force data for analysis. This work aimed to establish the force-position relationship, find any invariant properties for tissues or scissors, and determine the frequency components present in the force signal as well as the significance of the cutting rate. General trends in the data were discovered, and necessary improvements to the experimental method for the determination of more exact quantitative measures were identified.; In general, both the measurable force magnitude and "texture" differences contribute to the difference in tactile perception between a blank run and a tissue cutting run. This is a low frequency texture, as 99% of the frequency components of the signal are below 5Hz. The force measurements were determined to be independent of the cutting speed for the Mayo and Metzenbaum scissor runs, whereas results for the Iris scissors were inconclusive. The scissor sensitivity while cutting the tissue longitudinally or transversally appears to be a function of both the tissue and the scissor. To further determine the tactile feedback required for simulation, future experiments should account for the "user grip", tissue thickness, tissue moisture content, hand orientation, and innate scissor dynamics.; A database of the collected force and position data has been created on the Internet (Site:http://www.cim.mcgill.ca/∼haptic/tissue/data.html). This data allows current force feedback devices, such as the Freedom-7, to determine the feasibility of realistic haptic simulation.