Body Composition in Nutritional Assessment: Bioimpedance Analysis Revisited

Electrical Bioimpedance (EBI) has the possibility to assess tissue composition of the human body non-invasively. After many years in clinical research use without the expected breakthrough in clinical practice, the basics of its application to nutritional assessment are revisited. New signal processing and analysis approaches of EBI measurements are being tested and validated with the goal of increasing the robustness of the application of EBI for clinical body composition analysis. This investigation includes EBI pre-processing techniques, signal analysis, and the use of novel textile electrodes.

Underlying problem

Electrical Bioimpedance (EBI) is the Technology of choice for non-invasive assessment of body fluid distribution. Despite of its widely acceptance among nutrition clinics, its performance depends on several factors like the skin-electrode interface. The use of Ag/AgCI electrodes with a reduced contact surface often produces elevated electrode polarization impedances, especially with elder patients that present a non-uniform and flat epidermis. Such combination makes the acquisition of EBI measurements a challenge. EBI measurements taken in this situation most often produces wrong estimations of the fluid distribution parameters.

Clinical benefits

The development of measurement approach that facilitates the acquisition of EBI measurements and ensures the goodness of the EBI measurements and its estimations would improve the overall performance and reliability of the EBI method for Body Composition Assessment (BCA). If the level reach of reliability is high enough this would enable the development of Home Monitoring applications based in BCA and EBI.

Medical concept

Textile Technology has progressed considerably in the field of conductive textiles, as a result conductive fabrics for producing Textile Electrodes (Textrodes) are available. Textrodes embedded in garments has shown encouraging performance when measuring wrist-to-ankle measurements of EBI, therefore a properly designed garment with integrated Textrodes would facilitate the acquisition of the measurements, producing more reliable measurements and consequently more reliable estimators for BCA.

Project description and objective

A Textrode garment has been produced by the Smart Textile Prototype Factory for performing 4-electrode Wrist-to-ankle EBI spectroscopy measurements. The garments (10 units) will be tested in healthy volunteers and elder patients. Its measurement and estimation performance will be assessed as well as its usability.

The main goal is to obtain a more reliable EBI approach enabled by the use of Textrodes. Secondary goals are to facilitate the work related to the acquisition of the EBI measurements and learn how mature is this Textrode approach for its integration in Home Monitoring applications.

People:

Prof. Ingvar Bosaeus
Enheten för klinisk nutrition
Sahlgrenska University Hospital

Fernando Seoane
School of Engineering
University of Borås