The effects of tissue proportions on blood volume change-induced variations using bio-impedance analysis: a simulation study.

Bioimpedance Analysis (BIA) along the radial artery has been widely investigated for hemodynamic monitoring. However, its applicability to different body type populations still lacks sufficient research. The Finite Element Method (FEM) was performed on three different wrist models using ANSYS HFSS, aiming to reveal the influences of different fat and muscle proportions on the sensitivity of blood volume change-induced bioimpedance change. The simulation results confirmed that the current density in each tissue mainly depended on the conductivity of tissues. The higher conductivity of the tissue, the higher current density inside said tissue. The amounts of flowing current were decided by both volume and conductivity of tissues. Moreover, increasing the fat layer thickness from 4 mm to 6 mm raised simulated impedance from 86.82 Ω to 100.39 Ω and impedance change from 0.63 Ω to 1.55 Ω. However, a higher muscle proportion occupied more injected current from the blood and resulted in lower impedance change. Therefore, for the overweight population, the placement of BIA is recommended to avoid the muscular body parts for the acquirement of better-quality pulse waves.Clinical Relevance-This establishes the bio-impedance analysis should avoid the muscular body parts for a better blood pulse wave quality for overweight populations.