Interface[s] Montréal

Immersion and Virtual Reality

Carl-Éric Aubin, Benoît Ozell

École Polytechnique de Montréal, Dep. Mechanical Engineering & CHU Sainte-Justine

Surgical Simulator for the Virtual Prototyping of the Surgical Instrumentation of the Scoliotic Spine

View the presentation [In French]

The use of surgical instruments on the spines of patients who have scoliolytic deformations is a complex procedure which involves several parameters to plan and control (the determination of which vertebrae to operate on, the choice of which type of implant and their localization, surgical manoevers, etc.). The objective is to develop user-friendly and reliable tools for conceiving and testing different types of surgical strategies before carrying out the actual surgery.

The surgical simulator (baptized S3 for Spine Surgery Simulator) will be realized in several stages:
1) based on calibrated X-rays of a patient, biomechanical 3D modeling of the patient’s spine takes into account the geometric and mechanical properties of spinal tissues and helps to simulate different surgical steps/stages ;
2) A user-friendly software interface which allows a surgeon to define each step of a surgical procedure. This interface is related to the simulation model, in order to permit interactive practicing of the planned surgical procedure.

Two versions have been developed:

- the first on a PC computer (for a rapid simulation of the surgical intervention) integrates menus and windows, thus allowing for the manipulation of the patient-model and for specifying each step of the surgical procedure.

- The second version of the simulator has been integrated into an immersive interface in conditions of virtual reality. The images of the operating room and of the patient are projected and updated in real time on four walls. With the help of stereoscopic glasses and a 3D mouse, the surgeon can interact with the operation scene virtually and carry out various manipulations involved in the surgical intervention. The validation we are working on consists of simulating already existing surgical interventions and comparing the digital results with real-life post-operative results.

Once the validation is complete, the S3 Simulator will enable the testing and refinement of several different surgical strategies and then an iterative refinement BEFORE the actual strategy, as well as optimizing the actual surgical intervention (financed by CRNSG and Medtronic Sofamor-Danek).

Picture form the work of A. Plouznikoff, C.E. Aubin, B. Ozell and H. Labelle

Carl-Éric Aubin, received the B.Eng and Ph.D. degrees in mechanical engineering from the École Polytechnique de Montréal, Montreal. He is Full Professor at École Polytechnique in the Department of Mechanical Engineering and at the Biomedical Engineering Institute, and Researcher at the Research Center of Sainte-Justine University Hospital, Montreal. He is also Director of the Biomechanical Modeling & Computer Assisted Surgery Lab. Since 2001, he has held the Canada Research Chair on CAD Innovations in Orthopedic Engineering. His research interests include orthopedic biomechanics, computer modeling of the spine and thorax, pathomechanism of musculoskeletal deformities, computer assisted surgery as well as experimental evaluation and biomechanical simulations of orthotics and surgical corrections.

Benoît Ozell received his bachelor’s degree in Mathematics and Computer Science from Université de Montréal in 1981. He received his Master in Applied Mathematics in 1984 and his Ph.D. in Mechanical Engineering in 1995 from École Polytechnique de Montréalde Montréal. He worked as Research Associate in the CASTOR project at École polytechnique de Montréal from 1984 to 1992 in grid generation and CFD flow visualisation. He started as Research Professional at CERCA (Center for Research on Computation and its Applications) in 1992 focusing on scientific visualization. In 1999, he became Professor at the Department of Computer Engineering of École polytechnique de Montréal. Benoît Ozell was Affiliated Professor at CERCA until its closing in 2003. He is member of CERCA Management Committee, and responsible for the Scientific Visualization research program at that Center. His expertise lies in scientific visualization and computer graphics. His research is focused on distributed numerical visualization and collaborative virtual environments in immersion.