The Haptic Scissors: Cutting in virtual environments

The "Haptic Scissors" is a device that creates the sensation of cutting in virtual environments. The scissors have two degrees of freedom of motion and force feedback, one for cutting (single blade rotation) and one for translation. An algorithm was developed to simultaneously display translational and cutting forces for a realistic cutting simulation. In previous work, we used filtered data from cutting biological tissues to create "haptic recordings" of the cutting experience. Here, we consider two cutting models: one based on real tissue data and one that is analytical. The model based on real tissue is a segmented linear empirical model of the original data. Experimental results show that users cannot differentiate between these models and the haptic recordings created earlier. The analytical model uses a combination of friction, assumed material properties, and user motion (position and velocity) to determine the displayed cutting forces.