Haptic Rendering of Deformable Surfaces in Medical Training

Haptic systems applied to medical simulation and training can provide users with crucial kinaesthetic and tactile info otherwise impossible to convey. As the typical objects involved in this kind of simulation are very often deformable tissues, one of the main challenges in this area is the perceptually believable reproduction of these structures through haptic rendering techniques. In this paper we propose the use of a colour or grey scale bitmap to associate local deformability info to the geometry. This approach allows the visual-haptic engine to modulate the resistance to compression exerted by the simulated tissues based to a local parameter. By using multiple layers of textures or animated textures, locally non-linear or even dynamic behaviours can be simulated with a low computational load. Preliminary experiments based on a Immersion Cyberforce hand-based haptic device are encouraging.