A novel five degrees of freedom (dof) haptic device is designed and developed as part of a medical training simulator. It consists of a 2-dof, 5-bar linkage and a 3-dof spherical joint. All dof are active. To reduce mechanism moving mass and inertia, all actuators are placed at the base. The transmission system is implemented using tendon drives with capstans. A great effort was placed in developing an optimum haptic mechanism, i.e. one with the best mechanical design under given kinematical. operational and constructional constraints. The device is suitable for the accurate application of small forces and moments. The above described haptic device is part of a medical training simulator for urological minimal invasive operations. The haptic mechanism is responsible for the haptic information exchange between the user and the virtual environment. The training simulator includes also a virtual reality tissue model that presents graphically the virtual human tissue and its deformation and calculates according to a fast and simple mathematical model the forces and torques applied to the user. The third part of the simulator is the control system, which controls and coordinates the other two. Simulators employing haptic devices are being used for the training in various medical operations. To be able to represent interaction between endoscopes and tissues, these simulators require relatively accurate models of tissue behavior. One way to obtain these models is to rely upon the experience of specialist surgeons. Therefore, the question that arises is whether we can use this experience to produce reliable force models for simulators. The study is implemented using a haptic mechanism with a single degree of freedom. The aim is to experimentally evaluate the extent to which the experience of a specialist can justifiably be used as a guide for defining the force model in a simulator.

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• Vlachos, K. and Papadopoulos, E. “Analysis and Experiments of a Haptic Tele-Manipulation Environment for a Microrobot Driven by Centripetal Forces,” ASME Journal of Computing Sciences and Information in Engineering, Special Issue on Haptics, Tactile and Multimodal Interfaces, vol. 8, no. 4, December, 2008.

• Papadopoulos, E., Tsamis, A., and Vlachos, K. “Development of a Real-time Visual and Force Environment for a Haptic Μedical Training Simulator,” Artificial Life and Robotics, Vol. 12, no 1, 2008, pp. 307-316.

• Vlachos, K. and Papadopoulos, E., “A Transparency Maximization Methodology for Haptic Devices,” IEEE/ASME Transactions of Mechatronics, Vol. 11, No. 2, June 2006, pp. 249-255.

• Vlachos K., Papadopoulos, E. and Mitropoulos, D., “Design and Implementation of a Haptic Device for Urological Operations,” IEEE Transactions on Robotics and Automation, Vol. 19, No. 5, October 2003, pp. 801-809.

• Vlachos, K., Vartholomeos, and Papadopoulos, E. “A Haptic Tele-Manipulation Environment for a Vibration-Driven Micromechatronic Device,” Proc. 2007 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM ’07), September 4-7, 2007, ETH Zurich, Switzerland.

• Vlachos, K. and Papadopoulos, E., “Endpoint-Side Optimization of a Five Degree-of-Freedom Haptic Mechanism,”Proc.13th IEEE Mediterranean Conference on Control and Automation, June 27-29, 2005, Limassol, Cyprus.

• Papadopoulos, E., Vlachos K., and Mitropoulos, D., “Design of a 5-dof Haptic Simulator for Urological Operations,” Proc. IEEE International Conference on Robotics and Automation (ICRA’ 02), Wachington, DC, May 11-15, 2002.