A parallel manipulator as a haptic interface solution for amniocentesis simulation

The education of surgical students in the practical gesture needs to find new pedagogical tools. Some operations such as amniocentesis, require specific training. The medical simulation allows learning step by step, with an increasing difficulty in the exercises. To improve the realism of the simulation, a haptic feedback is sometimes important. We introduce a novel haptic display specially designed for a pedagogical simulator of amniocentesis. The main problem is to keep the needle free, as in reality, and so to place the interface in the body of the manikin. All the gestures are simulated: ultrasound scanning, the choice of a point of insertion of the puncture, the crossing through the different abdominal tissues. A mechanical model based on a finite element formulation gives a force feedback tensor. The force feedback interface consists of a parallel manipulator with three degrees of freedom (DOF). The interface is operated thanks to a needle connected to the mechanical structure of the manipulator