Evaluation of Two-Electrode System Configurations for Forearm Arteries Bioimpedance Measurement

Pulse wave monitoring for hemodynamic parameter acquisition, including blood pressure, constitutes a challenge for wearable device development. Hypertension as a target for such development forms a global health issue. An important aspect is the connection to the object-electrode-skin interface-from which many problems in electrical measurements originate. Finite element model simulations and experimental measurements of forearm arteries' electrical bioimpedance have been presented in this paper to evaluate the two-electrode system compared to the four-electrode system in distal and perpendicular placement relative to the artery. The four-electrode system has been reported to provide higher pulsating blood volume proportions, reaching 0.09% from the total measured impedance in distal placement, while the two-electrode system exhibits lower values (0.05%). A strong positive correlation between the simulation and experimental results appeared in distal two-electrode placement (r=0.718), while the outcome is reversed in the perpendicular approach (r=-0.539). The experimented two-electrode system configurations are applicable in wearable device development but require further analysis for the perpendicular placement.