A Stereo-Guided Biomechanical Model for Volumetric Deformation Analysis

A framework for soft tissue deformation recovery is presented and tested on both simulated and real data. The core of the approach is a volumetric deformable model based on the biomechanics of the material. Often, e.g. in medical applications, the deformation is very complex and dependent on many factors. In such cases, in order to reliably estimate the deformation, the model has to be guided by the available, typically limited, data. We propose the use of stereo cameras for guidance, where the reconstructed surface is used as a boundary condition for the partial differential equations that define the model. By integrating the model deformation and surface reconstruction algorithms, we avoid the correspondence problem and reduce the impact of surface specularities. The approach is applied to the problem of brain shift brain deformation that occurs during the surgery. A partial validation using intraoperative magnetic resonance images suggests that the error introduced by the brain shift can be reduced almost to the image resolution.