A fast and robust patient specific Finite Element mesh registration technique: Application to 60 clinical cases

Abstract

Abstract. Finite Element mesh generation remains an important issue for patient specific biomechanical modeling. While some techniques make automatic mesh generation possible, in most cases, manual mesh generation is preferred for better control over the sub-domain representation, element type, layout and refinement that it provides. Yet, this option is time consuming and not suited for intraoperative situations where model generation and computation time is critical. To overcome this problem we propose a fast and automatic mesh generation technique based on the elastic registration of a generic mesh to the specific target organ in conjunction with element regularity and quality correction. This Mesh-Match-and-Repair (MMRep) approach combines control over the mesh structure along with fast and robust meshing capabilities, even in situations where only partial organ geometry is available. The technique was successfully tested on a database of 5 pre-operatively acquired complete femora CT scans, 5 femoral heads partially digitized at intraoperative stage, and 50 CT volumes of patients' heads. In the latter case, both skin and bone surfaces were taken into account by the mesh registration process in order to model the face muscles and fat layers. The MMRep algorithm succeeded in all 60 cases, yielding for each patient a hex-dominant, Atlas based, Finite Element mesh with submillimetric surface representation accuracy, directly exploitable within a commercial FE software.

From Finite Element Meshes to Clouds of Points: A Review of Methods for Generation of Computational Biomechanics Models for Patient-Specific Applications

“…Consequently, they are the most common choice when creating computational grids for biomechanical models of living tissues. 18 It has been reported in the literature that high quality tetrahedral meshes can be created using readily available mesh generators. 20,34,68 However, for continua with complicated geometry, quality control of tetrahedral meshes can be a challenge 68,92 and varies according to the mesh generation method employed.…”

Foot biomechanical modelling to study orthoses influence

“…When applying our mesh matching algorithm (Bucki et al 2010) to this foot model and to patients' medical datasets (such as CT scans), new models, including the FE model and the bony structures, can be created and can undergo FE simulation in Artisynth. This allows us to perform a patient-specific study of influence of the different orthoses and potentially to choose which is the most appropriate for a patient.…”

Soft Tissue Finite Element Modeling and Calibration of the Material Properties in the Context of Computer-Assisted Medical Interventions

“…The face soft tissues are thus modeled as a single entity, without distinctions between dermis layers, fat, muscles and mucosa. To overcome these limitations, our group has proposed a methodology called the Mesh-Match-and-Repair algorithm (Couteau et al, 2000 ;Bucki et al, 2010) consisting first, in manually defining a structured 3D mesh, in order to build one "generic" model of the face. Emphasis is given to the design of the generic mesh, so that the elements inside the mesh can be associated to anatomical entities (dermis layers, fat, muscles, mucosa…).…”