User-Interface for Teleoperation with Mixed-Signal Haptic Feedback

Haptic feedback for minimally invasive surgery is a widely debated topic, especially force sensors for this kind of application are thoroughly researched. The current state-of-the-art includes several realization options, but none of them are suitable to be integrated in small diameter instruments. In this work, we present a new approach for the generation of haptic feedback by using two separate feedback mechanisms for spatial kinesthetic and unidirectional tactile feedback in a tele-operation system with a parallel kinematic slave robot and the design of the corresponding user interfaces. Kinesthetic forces are measured with proximal sensors in the robot kinematic and displayed with a delta-type kinematic mechanism. Tactile signals are acquired with an acceleration sensor placed closely at the tip of the robot manipulator and conveyed open-loop by a vibrating cylinder to the user's palm. Kinesthetic forces up to 15 N can be displayed up to a frequency of 50 Hz. The tactile interface displays accelerations up to 15 m/s for frequencies from 50 Hz to 1000 Hz. The combination of the two interfaces allows the display of high-fidelity haptic feedback with greatly reduced requirements on the interface components.