Paracentesis modeling and VR-based interactive simulation with haptic display for clinical skill training and assessment C.S. Tzafestas*, Y. Koumpouros**, K. Birbas*** * National Technical University of Athens, School of Electrical and Computer Engineering, Division of Signals Control and Robotics, Zografou Campus, Athens 15773, Greece Phone: +30-210-7723687, Fax: +30-210-7722490, E-mail: ktzaf@softlab.ntua.gr ** ATAC – Innovative Applications, Athens, Greece *** University of Athens, Faculty of Nursing, Department of Surgery Abstract - In this paper1 we describe the development of an interactive virtual reality (VR) system that aims to realistically simulate specific paracentesis clinical procedures (particularly the procedure involved in the catheterization of the subclavian vein). Two elastostatic finite element (FE) models are developed to enable physically based simulation of the deformable tissues, particularly skin deflection during needle insertion. The first one is a two-dimensional approximation FE model, while the second one is a further simplified 1D model with inhomogeneous properties. Simulation results from both FE models are compared to real experimental data available in the literature (reporting on human skin deformation profiles) and demonstrate their applicability for realtime interactive applications under the specific constraints and assumptions of the paracentesis simulation application considered in this paper. Furthermore, a haptic feedback device is coupled with the VR-based simulation to provide the user with realistic feeling of the interaction forces applied during the simulated paracentesis procedure. The system described in this paper is developed in the frames of a research project aiming to develop a larger-scale virtual environment simulator of emergency room scenarios and protocols for clinical skill training and assessment. I. INTRODUCTION The barrier between theoretical knowledge and clinical performance is probably the biggest problem as far as education of medical doctors and nursing professionals is concerned. Efficient clinical training of healthcare professionals constitutes undoubtedly a very difficult task, which is nowadays primarily based on the close supervision and monitoring by a specialist trainer, on the patient’s consent, but also on suitable general conditions; a combination of factors which is not always attainable since the main and primary concern always remains, that _____________________________ 1This work was supported by the Greek General Secretariat for Research and Technology and the European Commission, under grant EL4-2003, Project “VRES”. of treating the patient in the best possible way. Based on the above remarks, we can say that the difficulties associated with clinical training in specific medical practice hospital environments (such as, the Emergency Rooms or the Intensive Care Units, where the ultimate degree of dexterity together with “real-time” clinical skills are needed) are more than evident. The timely and persistent adaptation of the trainee medical doctor from the theoretical education field to the clinical “hands-on” practice on the hospital environment, constitutes undoubtedly a real challenge and a primary educational objective in the Health Sciences. Training on cadavers, which is still used today for over a century now, is not always adequate to cover other than special needs, not always of primary importance in surgical education and training. The use of animals constituted an “attractive” solution for decades, but for obvious reasons, related to human ethics as well as evolving legislation issues, as well as due to the need for important investments in terms of the related infrastructure, this solution has been practically abandoned. The experience obtained from the application of flight-simulation systems for the training of pilots, in an application environment that resembles in a way the field of clinical practice (in terms of the need for rapid complex data evaluation and critical decisionmaking) has more recently increased interest towards the use of Virtual Reality (VR) technologies in the medical education field. In this paper we describe on-going work that is carried out in the frames of a research project aiming to develop a computer-assisted educational platform based on a dynamic simulation system of an emergency room (ER) hospital environment. A set of clinical protocols and real case scenarios is implemented within the ER simulator, also incorporating VR techniques for visualization and user interaction. The system will enable the user to examine (virtual clinical data examination), evaluate (vital signs, clinical findings and medical images, obtained from a database of pre-stored clinical cases) and treat the virtual patient (for instance, by commanding the execution of certain clinical procedures like medicine supply). The system is designed to support both asynchronous self-education and training in specific .....