In-vivo viscoelastic properties estimation in subcutaneous adipose tissue by integration of poroviscoelastic-mass transport model (pve-MTM) into wearable electrical impedance tomography (w-EIT)

Abstract

In-vivo viscoelastic properties have been estimated in human subcutaneous adipose tissue (SAT) by integration of poroviscoelastic-mass transport model (pve-MTM) into wearable electrical impedance tomography (w-EIT) under the influence of external compressive pressure The pve-MTM predicts the ion concentration distribution by coupling the poroviscoelastic and mass transport model to describe the hydrodynamics, rheology, and transport phenomena inside SAT. The w-EIT measures the time-difference conductivity distribution in SAT resulted from the ion transport. Based on the integration, the two viscoelastic properties which are viscoelastic shear modulus of SAT and relaxation time of SAT are estimated by applying an iterative curve-fitting between the normalized average ion concentration distribution predicted from pve-MTM and the experimental normalized average ion concentration distribution derived from w-EIT. The in-vivo experiments were conducted by applying external compressive pressure on human calf boundary to induce interstitial fluid flow and ion movement in SAT. As a result, the value of was range from 4.9–6.3 kPa and the value of was range from 27.50–38.5 s with the value of average goodness-of-fit curve fitting R 2 > 0.76. These values of and were compared to the human and animal tissue from the literature in order to verify this method. The results from pve-MTM provide evidence that and play a role in the predicted value of