Development and validation of preliminary fractional order impedance models for experimental pain assessment

The present study presents the development of an impedance based fractional order model that describe the dynamics of pain assessment based on experimental data. Bioimpedance spectroscopy is used to acquire real-life electrodermal responses from a healthy subject undergoing induced acute pain. The measurements register both normal epidermal values in the absence of pain and bioimpedance measurements at the presence of sudden, acute, pain. The aim is to develop a general model that describes the feeling of pain in the presence/absence of active stimulus. The complex dynamics of the acquired data suggest the usage of fractional calculus, a powerful tool that provides a versatile and efficient solution of modeling complex physical phenomena. The proposed models are obtained using constrained optimization routines and are successfully validated on the real life data.