Chételat, O.; Rapin, M.; Bonnal, B.; Fivaz, A.; Sporrer, B.; Rosenthal, J.; Wacker, J. Remotely Powered 2-Wire Cooperative Sensors for Bioimpedance Imaging Wearables. Preprints2024, 2024072368. https://doi.org/10.20944/preprints202407.2368.v1
APA Style
Chételat, O., Rapin, M., Bonnal, B., Fivaz, A., Sporrer, B., Rosenthal, J., & Wacker, J. (2024). Remotely Powered 2-Wire Cooperative Sensors for Bioimpedance Imaging Wearables. Preprints. https://doi.org/10.20944/preprints202407.2368.v1
Chicago/Turabian Style
Chételat, O., James Rosenthal and Josias Wacker. 2024 "Remotely Powered 2-Wire Cooperative Sensors for Bioimpedance Imaging Wearables" Preprints. https://doi.org/10.20944/preprints202407.2368.v1
Abstract
Bioimpedance imaging aims to generate a 3D map of the resistivity and permittivity of biologi-cal tissue from multiple impedance channels measured with electrodes applied to the skin. When the electrodes are distributed around the body (for example, by delineating a cross-section of the chest or a limb), bioimpedance imaging is called electrical impedance tomography (EIT) and results in 2D functional images. Conventional EIT systems rely on individually cabling each electrode to master electronics in a star configuration. This approach works well for rack-mounted equipment; however, the bulkiness of the cabling is unsuitable for a wearable system. Previously presented cooperative sensors solve this cabling problem using active (dry) elec-trodes connected via a two-wire parallel bus. The bus can be implemented with two unshielded wires or even two conductive textile layers, thus replacing the cumbersome wiring of the con-ventional star arrangement. Prior research demonstrated cooperative sensors for measuring bi-oimpedances, successfully realizing a measurement reference signal, sensor synchronization, and data transfer though still relying on individual batteries to power the sensors. Subsequent research using cooperative sensors for biopotential measurements proposed a method to re-move batteries from the sensors and have the central unit supply power over the two-wire bus. Building off our previous research, this paper presents this method applied to the measurements of bioimpedances. Two different approaches are discussed, one using discrete, commercially available components, and the other with an application specific integrated circuit (ASIC). Initial experimental results reveal that both approaches are feasible, but the ASIC approach offers ad-vantages for medical safety, as well as lower power consumption and smaller size.
Keywords
Bioimpedance imaging; electrical impedance tomography (EIT), active electrode; dry electrode; cooperative sensor; wearables; medical device; cardiopulmonary diseases; respiratory diseases; COPD.
Subject
Engineering, Electrical and Electronic Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
