In vivo experimental testing and model identification of human scalp skin.

A comprehensive experimental/numerical procedure is formulated and validated for the in vivo characterization of the mechanical properties of human skin and the simulation of reconstructive surgery. The procedure uses in vivo experimental tests on undermined skin flaps, which can be performed during surgery, a numerical model formulated within the framework of nonlinear finite strain elasticity and a nonlinear parameter identification technique for the calibration of the model from indirect measurements. The procedure is applied to characterize the scalp skin tested in Raposio and Nordstro¨m (Skin Res. Technol. 4 (1998) 94). The skin is treated as a time independent, isotropic and hyperelastic membrane and the problem is solved through a finite element discretization. The study highlights that the model parameters can be determined with good accuracy using displacement measurements of a few points in the domain.