Takehiro Hamaguchi

A Study of Bioelectrical Impedance Analysis Methods for Practical Visceral Fat Estimation

The method of bioelectrical impedance-based visceral fat estimation is in advance of other methods such as X-ray CT or MRI from the point views of cost and safety. However, it requires complex and diversity signal analysis and modeling to realize its high estimation accuracy. In response to this requirement, complication of feature attributes and simplification in selection of them to model the estimation has been proposed and evaluated in this paper. The complication of feature attributes is realized by applying priori knowledge and by employing the idea of cardinality as quantitative evaluation index. The simplification of the estimation model is realized by employing Akaike information criteria. The experiments were conducted to evaluate the proposed method and the results prove high estimation accuracy and stability of the proposed method.

Visceral Fat Estimation Method by Bioelectrical Impedance Analysis and Causal Analysis

It has been clarified that abdominal visceral fat accumulation is closely associated to the lifestyle disease and metabolic syndrome. The gold standard in medical fields is visceral fat area measured by an X-ray computer tomography (CT) scan or magnetic resonance imaging. However, their measurements are high invasive and high cost; especially a CT scan causes X-ray exposure. They are the reasons why medical fields need an instrument for viscera fat measurement with low invasive, ease of use, and low cost. The article proposes a simple and practical method of visceral fat estimation by employing bioelectrical impedance analysis and causal analysis. In the method, abdominal shape and dual impedances of abdominal surface and body total are measured to estimate a visceral fat area based on the cause-effect structure. The structure is designed according to the nature of abdominal body composition to be fine-tuned by statistical analysis. The experiments were conducted to investigate the proposed model. 180 subjects were hired to be measured by both a CT scan and the proposed method. The acquired model explained the measurement principle well and the correlation coefficient is 0.88 with the CT scan measurements.