Constrained finite element method for runtime modeling of soft tissue deformation

This paper presents a new constrained FEM (finite element method) for accurate and runtime modeling of soft tissue's mechanical deformation from measurement of local surface displacement. This method turns the modeling problem of tissue deformation with unknown loading input into a constrained estimation problem to online estimate physical tissue deformation. Based on linear FEM discretization, a constrained estimation algorithm is developed to optimally estimate unknown loading input and online calculate deformation from measurement of local surface displacement. Results of simulation and experimentation exhibit that the proposed method significantly promotes the FEM computational performance but still inherits the FEM advantage of physical accuracy.