Haptics is the use of the sense of touch to interact with a virtual environment through force feedback and other tactile properties. It is an essential part of a medical simulator. It has been implemented in telerobotic surgery, to provide a surgeon the tactile sensations of grasping and manipulating medical instruments remotely. The design and modeling of the virtual instruments present a number of challenges, when attempting to improve their accuracy and mobility, necessary to carry out realistic surgery simulations and to support skills transfer in medical training.

A proxy is a kind of tip used to simulate a medical instrument in a virtual environment. As this paper shows, it is difficult to provide force feedback to a proxy; therefore, generally, it is represented as a static virtual instrument. This paper presents mathematical models to give haptic proxies the ability to move, collide, interlock, and grasp. Mitra and Niemeyer present an experiment where the models are successfully tested with a minimal invasive surgical trainer using two proxies.

The proposed models do not take into account the problems that can occur with mechanical parts of a medical simulator, such as motor wear and friction over time. The paper proposes considering motor speed and workspace constraints in future work.

This paper moves forward research on medical telerobotics by describing an important approach to improving collision detection and force feedback simulation, particularly their application to haptic proxies that will eventually serve to build much more accurate and realistic medical simulators.