haptic device

Based on the kinematic design of the Delta robot, which was originally developed at EPFL, the sigma.7 is a high-precision seven degrees-of-freedom haptic device commercialized by Force Dimension. Based on a parallel structure, the system is composed of three main arms that join together at the end-effector. The articulated arms are actuated by three custom designed high-torque motors. The main distinctions of its mechanism are its low inertia, high stiffness and wide range of forces. An interesting property of its kinematics model is the fact that the end-effector plate always remains parallel to the base of the device independently of its position, consequently allowing rotation motions of the user handle to be decoupled from any translations. The device also included a gripper with force-feedback capabilities. The sigma.7 haptic device is currently being integrated into a number of surgical consoles designed to control medical robot tools. .

The sigma.7 haptic interface for MiroSurge: A new bi-manual surgical console.
A. Tobergte, P. Helmer, U. Hagn, P. Rouiller, S. Thielmann, S. Grange, A. Albu-Schäffer, F. Conti, G. Hirzinger. IROS 2011, San Francisco, September 2011.