Olivier Comas

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Accurate biomechanical modelling of soft tissue is a key aspect for achieving realistic surgical simulations. However, because medical simulation is a multi-disciplinary area, researchers do not always have sufficient resources to develop an efficient and physically rigorous model for organ deformation. We address this issue by implementing a CUDA-based(More)
Efficient and accurate techniques for simulation of soft tissue deformation are an increasingly valuable tool in many areas of medical image computing, such as biomechanically-driven image registration and interactive surgical simulation. For reasons of efficiency most analyses are based on simplified linear formulations, and previously almost all have(More)
We present here the state of our work on medical simulators. We have developed several patient-based training simulators for ultrasound examination and ultrasound guided needle insertion. These simulators are built upon a method already described in MMVR in 2005 that allows to automatically create new cases from a 3D medical image (CT or MRI) They use(More)
Corroboration of mechano-regulation algorithms is difficult, partly because repeatable experimental outcomes under a controlled mechanical environment are necessary, but rarely available. In distraction osteogenesis (DO), a controlled displacement is used to regenerate large volumes of new bone, with predictable and reproducible outcomes, allowing to(More)
This paper presents a new modelling technique for the deformation of thin anatomical structures like membranes and hollow organs. We show that the behaviour of this type of surface tissue can be abstracted with a modelling of their elastic resistance using shell theory. In order to apply the shell theory in the context of medical simulation, our method(More)
With 30 million interventions a year worldwide, cataract surgery is one of the most frequently performed procedures. Yet, no tool currently allows teaching all steps of the procedure without putting patients at risk. A particularly challenging stage of this surgery deals with the injection and deployment of the intra-ocular lens implant. In this paper we(More)
Previously almost all biomechanically-based time-critical surgical simulation has ignored the well established features of tissue mechanical response of anisotropy and time-dependence. We address this issue by presenting an efficient solution procedure for anisotropic viscohyperelastic constitutive models which allows use of these in nonlinear explicit(More)
This paper describes a single simulation framework to perform interactive cataract surgery simulations. Contributions includes advanced bio-mechanical models and intensive use of modern graphics hardware to provide fast computation times. Surgical devices are replicated and located in a real-time thanks to infrared tracking. Combination of a high-fidelity(More)
BACKGROUND Quality of life is a key issue for the consideration of hypertension therapy. However, reliable and sensitive evaluation methods are not available in Spain. To this end, a quality of life questionnaire has been elaborated, its yield has been evaluated, and the influence of hypertension and several associated variables on the quality of life has(More)
BACKGROUND A virtual reality (VR) neurosurgical simulator with haptic feedback may provide the best model for training and perfecting surgical techniques for transsphenoidal approaches to the sella turcica and cranial base. Currently there are 2 commercially available simulators: NeuroTouch (Cranio and Endo) developed by the National Research Council of(More)