Development of virtual reality tools for arthroscopic surgery training. (Développement d'outils de réalité virtuelle pour l'enseignement de la chirurgie arthroscopique)

The minimally invasive approach of arthroscopy means less pain and faster recovery time for patients compared to open surgery. However, it implies a high difficulty of performance. Therefore, surgeon should remain at a high level of technical and professional expertise to perform such operations. Surgeon’s skills are being developed over years of surgical training on animals, cadavers and patients. Nowadays, cadavers and animal specimens present an ethical problem also the practice on real humans is usually risky. For surgeons to reach a high level, new and alternative ways of performing surgical training are required. Virtual reality technology has opened new realms in the practice of medicine. Today, virtual reality simulators have become one of the most important training methods in the medical field. These simulators allow medical students to examine and study organs or any structure of the human body in ways that were not possible few years earlier. Similarly, the surgeon as well as the medical student can gain a valuable experience by performing a particular surgery with an anatomical accuracy and realism as it is actually performed in the real world. Thus, they can practice on virtual operation before they proceed and operate on real patients. In this thesis, a virtual reality training simulator for wrist arthroscopy is introduced. Two main issues are addressed: the 3-D reconstruction process and the 3-D interaction. Based on a sequence of CT images a realistic representation of the wrist joint is obtained suitable for the computer simulation. Two main components of the computer-based system interface are illustrated: the 3-D interaction to guide the surgical instruments and the user interface for haptic feedback. In this context, algorithms that model objects using the convex hull approaches and simulate real time exact collision detection between virtual objects are presented. A force feedback device, coupled with a haptic algorithm, is used as a haptic interface with the computer simulation system. This leads in the development of a low cost system with the same benefits as professional devices. In this regard, the wrist arthroscopy can be simulated and medical students can learn the basic skills required with safety, flexibility and less cost.