A Wearable Open-Domain Bioimpedance Sensor for Noninvasive Assessment of Deep Abdominal Fat Distribution

Abnormal accumulation of visceral adipose tissue (VAT) is a major risk factor for metabolic syndrome and cardiovascular disease. However, existing methods remain limited in their ability to provide noninvasive, dynamic, and quantitative assessment of local fat distribution. In this study, we propose a wearable open-domain bioimpedance sensor for abdominal fat distribution assessment. The system integrates a multichannel bioimpedance acquisition platform with a flexible electrode array featuring a triangular-beam architecture. The measured signals were analyzed using three-dimensional difference open-domain reconstruction, from which a deep-region conductivity feature, σ̅d, was extracted to indirectly characterize deep fat distribution. In an exploratory study involving 10 volunteers, the EIT-derived feature σ̅d exhibited a negative association with the VAT estimates reported by a commercial body-composition analyzer, although the relationship varied between the female and male groups. These preliminary observations support the feasibility of extracting deep-fat-related electrical information from body-surface measurements.