Real-time haptic simulation of soft tissue deformation

In early years developments in robotic, haptic and virtual reality systems have attended considerations on simulators as a tool of medical training. A kind of haptic medical training problem is to convey the feeling of touch of a biological soft tissue through haptic interface to user, to this aim in this paper real-time modeling and implementation of soft tissue deformation in haptic robotic interface are presented. Soft tissue deformation during contact of tool is modeled through finite element method (FEM). At the beginning equation of motion for whole object is extracted and is discretized by FEM and Central Difference explicit numerical scheme. In the simulations, linear material property for soft tissue, linear and non-linear strain-displacement relations are considered; it is deduced that employing non-linear strain-displacement relations in models increases accuracy as well as keeps calculation amount proper for real-time simulation. Moreover, simulation results are validated with commercial FEM software with same boundary conditions. At the end the real-time models are implemented in the haptic robotic interface. There was realistic force feedback transferred to user in simulations.