Calibration of the fat and muscle hyperelastic material parameters for the assessment of the internal tissue deformation in relation to pressure ulcer prevention

Abstract

Our group aims at proposing a protocol for evaluating the subject-specific risk for sacral pressure ulcer (PU). The idea is to model the way soft tissue will be deformed under the external pressure and to compute internal strains. It has been indeed showed that high strains can create deep tissue injuries (Ceelen et al., 2008). Because of the clinical constraints, we propose to use Ultrasound (US) to build the subject-specific biomechanical model of the sacral soft tissue as an alternative to 3D MR imaging (because of cost, time and accessibility). This paper focuses on the way such a subject-specific model will be designed and more specifically on the methodology we propose for estimating the constitutive parameters of the internal sacral soft tissue, namely the adipose tissue and the muscle. The values of these parameters have indeed a strong influence on the computed internal strains