We have developed a method to reconcile the computation time of realistic physically based deformable models and the high refresh frequencies needed for haptic rendering. This method takes into account the sensibility of the human touch, and the characteristics of the human gesture. It is based on two asynchronous loops, one for the deformable model running at visual real-time frequency, the other for the extrapolation of the forces computed by the simulation loop. We have tried three extrapolation functions: constant, linear over time extrapolation, and the more original linear over position extrapolation, which uses the fact that the position can be read on the force feedback device anytime we need it. We found that this last method gives good results as soon as the spatial sampling of the tool movement is dense enough, or, in other words the the ratio between the simulation frequency and the tool speed is large enough. This leads us to conclude that for the speed of the surgeon's gesture, a simulation at a visual real-time frequency (about 20Hz) is enough to produce high quality force feedback (about 500Hz) thanks to the linear extrapolation over position.