Haptic User Interface for a Telerobotic System – Design based on a Network Model

Abstract

Loss of haptic feedback is one major drawback of telerobotic surgery systems. For this reason tasks of passive input devices can be taken over by haptic user interfaces. The main objective of this paper is the development of a haptic user interface with a kinematic structure matching the slave robot's kinematic structure. In addition, we focus on the detailed design and characterization of a haptic input device concerning the grasping degree of freedom. Requirements of the user interface are derived by analyzing the medical application and the structure of the slave robot. Since the user interface and the input device are supposed to provide realistic haptic feedback, static and dynamic behavior of the device is of interest. Electromechanical analogies help to design the dynamic behavior of the haptic input device. A characterization of static and dynamic behavior validates our design process. The implementation of the input device in the overall user interface is shown.The designed user interface, allows controlling the slave robot in three dimensions, rotation along the axis of the main kinematic chain and grasping. The user interfaces kinematic structure is taking the kinematic constrains of the slave kinematic into account. The input device can be handled similar as a forceps with three point precision grip, similar to a common surgical procedure without robotic assistance. The user interface provides haptic feedback in all directions of the kinematic structure.