A measurement technique using flexible PVDF gages for characterizing the propagation of pressure waves in biological tissues is developed. We demonstrated that experimental measurements, coupled with numerical simulations, represent a promising method to obtain reliable pressure histories in biomaterials and to calibrate constitutive models for these materials. Data that can be used for such calibration include the dependence of apparent wave velocity on pressure pulse amplitude and pressure pulse attenuation (and possibly shape changes) with propagation distance. We are currently developing an appropriate nonlinear (power) viscoelastic constitutive model that we will calibrate and test using the methodology described in this paper.