title: Wearable Multi-Frequency and Multi-Segment Bioelectrical Impedance Spectroscopy for Unobtrusively Tracking Body Fluid Shifts during Physical Activity in Real-Field Applications: A Preliminary Study.
abstract: Bioelectrical Impedance Spectroscopy (BIS) allows assessing the composition of body districts noninvasively and quickly, potentially providing important physiological/clinical information. However, neither portable commercial instruments nor more advanced wearable prototypes simultaneously satisfy the demanding needs of unobtrusively tracking body fluid shifts in different segments simultaneously, over a broad frequency range, for long periods and with high measurements rate. These needs are often required to evaluate exercise tests in sports or rehabilitation medicine, or to assess gravitational stresses in aerospace medicine. Therefore, the aim of this work is to present a new wearable prototype for monitoring multi-segment and multi-frequency BIS unobtrusively over long periods. Our prototype guarantees low weight, small size and low power consumption. An analog board with current-injecting and voltage-sensing electrodes across three body segments interfaces a digital board that generates square-wave current stimuli and computes impedance at 10 frequencies from 1 to 796 kHz. To evaluate the information derivable from our device, we monitored the BIS of three body segments in a volunteer before, during and after physical exercise and postural shift. We show that it can describe the dynamics of exercise-induced changes and the effect of a sit-to-stand maneuver in active and inactive muscular districts separately and simultaneously.
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan 20133, Italy. federica.villa@polimi.it.
authors.forename: Federica
authors.initials: F
authors.lastname: Villa
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan 20133, Italy. alessandro.magnani@polimi.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Magnani
authors.affiliation: Center for Space Medicine and Extreme Environments, Charité-University Medicine Berlin, Berlin 10117, Germany. martina.maggioni@charite.de.|Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan 20133, Italy. martina.maggioni@charite.de.
authors.forename: Martina A
authors.initials: MA
authors.lastname: Maggioni
authors.affiliation: Center for Space Medicine and Extreme Environments, Charité-University Medicine Berlin, Berlin 10117, Germany. martina.maggioni@unimi.it.
authors.forename: Alexander
authors.initials: A
authors.lastname: Stahn
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan 20133, Italy. susanna.rampichini@unimi.it.
authors.forename: Susanna
authors.initials: S
authors.lastname: Rampichini
authors.affiliation: Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan 20133, Italy. giampiero.merati@unimi.it.|IRCCS Fondazione Don C. Gnocchi, Milan 20148, Italy. giampiero.merati@unimi.it.
authors.forename: Giampiero
authors.initials: G
authors.lastname: Merati
authors.affiliation: IRCCS Fondazione Don C. Gnocchi, Milan 20148, Italy. pcastiglioni@dongnocchi.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Castiglioni
mesh_terms: D001823:Body Composition; D001826:Body Fluids; D017097:Electric Impedance; D015444:Exercise; D018495:Fluid Shifts; D006801:Humans
keywords: blood shift; body composition; electrical impedance; exercise