Patient-specific finite element model of the buttocks for pressure ulcer prevention - linear versus non-linear modelling

摘要

The linear model underestimates the internal stresses in all but one case, yet the error is smaller than 5% of the nonlinear reference value. This indicates that linear modelling of the buttocks soft tissues might be suitable for a real-time personalised ulcer prevention strategy using a von Mises-based indicator of the level of tissue damage. The presented modelling method seems well suited for handling individual morphologies although some limitations exist. First, it is difficult to acquire an unconstrained 'resting shape' of the buttocks. Initial stresses should thus be taken into account to gain accuracy. Second, our model overestimates the buttocks stiffness as it only considers the gluteal muscles and ignores the fat layer. This parameter should be integrated within the model as it affects the outcome of the analysis.