No abstract

In this paper, a simulation environment is described for balloon dilation during percutaneous transluminal angioplasty. It means simulating tool/tissues interactions involved in the inflation of a balloon by considering patient specific data. In this context, three main behaviors have been identified: soft tissues, crush completely under the effect of the balloon, calcified plaques, do not admit any deformation but could move in deformable structures and blood vessel wall and organs, try to find their original forms. A deformable soft tissue model is proposed, based on the Enhanced ChainMail method to take into account tissues deformation during dilatation. We improved the original ChainMail method with a "forbidden zone" step to facilitate tool/tissues interactions. The simulation was implemented using five key steps: 1) initialization of balloon parameters; 2) definition of the data structure; 3) dilatation of the balloon and displacement approximation; 4) final position estimation by an elastic relaxation; and 5) interpolation step for visualization. Preliminary results obtained from patient CT data are reported.

International audienceTackling transluminal angioplasty planning, the aim of our work is to bring, in a patient specific way, solutions to clinical problems. This work focuses on realization of simple simulation scenarios taking into account macroscopic behaviors of stenosis. It means simulating geometrical and physical data from the inflation of a balloon while integrating data from tissues analysis and parameters from virtual tool-tissues interactions. In this context, three main behaviors has been identified: soft tissues crush completely under the effect of the balloon, calcified plaques, do not admit any deformation but could move in deformable structures, the blood vessel wall undergoes consequences from compression phenomenon and tries to find its original form. We investigated the use of Chain-Mail which is based on elements linked with the others thanks to geometric constraints. Compared with time consuming methods or low realism ones, Chain-Mail methods provide a good compromise between physical and geometrical approaches. In this study, constraints are defined from pixel density from angio-CT images. The 2D method, proposed in this paper, first initializes the balloon in the blood vessel lumen. Then the balloon inflates and the moving propagation, gives an approximate reaction of tissues. Finally, a minimal energy level is calculated to locally adjust element positions, throughout elastic relaxation stage. Preliminary experimental results obtained on 2D computed tomography (CT) images (100x100 pixels) show that the method is fast enough to handle a great number of linked-element. The simulation is able to verify real-time and realistic interactions, particularly for hard and soft plaques