Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports

Sweat rate magnitude is a desired outcome for any wearable sensing patch dedicated to sweat analysis. Indeed, sweat rate values can be used two-fold: self-diagnosis of dehydration and correction/normalization of other physiological metrics, such as Borg scale, VO2, and different chemical species con...

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Main Authors: Xing Xuan, Daniel Rojas, Isabel Maria Diaz Lozano, Maria Cuartero, Gastón A. Crespo
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Sensors
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Online Access:https://www.mdpi.com/1424-8220/24/22/7243
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author Xing Xuan
Daniel Rojas
Isabel Maria Diaz Lozano
Maria Cuartero
Gastón A. Crespo
author_facet Xing Xuan
Daniel Rojas
Isabel Maria Diaz Lozano
Maria Cuartero
Gastón A. Crespo
author_sort Xing Xuan
collection DOAJ
description Sweat rate magnitude is a desired outcome for any wearable sensing patch dedicated to sweat analysis. Indeed, sweat rate values can be used two-fold: self-diagnosis of dehydration and correction/normalization of other physiological metrics, such as Borg scale, VO2, and different chemical species concentrations. Herein, a reliable sweat rate belt device for sweat rate monitoring was developed. The device measures sweat rates in the range from 1.0 to 5.0 µL min<sup>−1</sup> (2 to 10 µL min<sup>−1</sup> cm<sup>−2</sup>), which covers typical values for humans. The working mechanism is based on a new direct current (DC) step protocol activating a series of differential resistance measurements (spatially separated by 800 µm) that is gradually initiated by the action of sweat, which flows along a customized microfluidic track (~600 µm in width, 10 mm in length, and 235 µm in thickness). The device has a volumetric capacity of ~16 µL and an acquisition frequency between 0.010 and 0.043 Hz within the measured sweat rate range. Importantly, instead of using a typical and rather complex AC signal interrogation and acquisition, we put forward the DC approach, offering several benefits, such as simplified circuit design for easier fabrication and lower costs, as well as reduced power consumption and suitability for wearable applications. For the validation, either the commercial sweat collector (colorimetric) or the developed device was performed. In five on-body tests, an acceptable variation of ca. 10% was obtained. Overall, this study demonstrates the potential of the DC-based device for the monitoring of sweat rate and also its potential for implementation in any wearable sweat platform.
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spelling doaj-art-b9711480e2814d919c4cfc2cc01e49662025-08-20T01:53:56ZengMDPI AGSensors1424-82202024-11-012422724310.3390/s24227243Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in SportsXing Xuan0Daniel Rojas1Isabel Maria Diaz Lozano2Maria Cuartero3Gastón A. Crespo4UCAM-SENS, Universidad Católica San Antonio de Murcia, UCAM HiTech, Avda. Andres Hernandez Ros 1, 30107 Murcia, SpainUCAM-SENS, Universidad Católica San Antonio de Murcia, UCAM HiTech, Avda. Andres Hernandez Ros 1, 30107 Murcia, SpainUCAM-SENS, Universidad Católica San Antonio de Murcia, UCAM HiTech, Avda. Andres Hernandez Ros 1, 30107 Murcia, SpainUCAM-SENS, Universidad Católica San Antonio de Murcia, UCAM HiTech, Avda. Andres Hernandez Ros 1, 30107 Murcia, SpainUCAM-SENS, Universidad Católica San Antonio de Murcia, UCAM HiTech, Avda. Andres Hernandez Ros 1, 30107 Murcia, SpainSweat rate magnitude is a desired outcome for any wearable sensing patch dedicated to sweat analysis. Indeed, sweat rate values can be used two-fold: self-diagnosis of dehydration and correction/normalization of other physiological metrics, such as Borg scale, VO2, and different chemical species concentrations. Herein, a reliable sweat rate belt device for sweat rate monitoring was developed. The device measures sweat rates in the range from 1.0 to 5.0 µL min<sup>−1</sup> (2 to 10 µL min<sup>−1</sup> cm<sup>−2</sup>), which covers typical values for humans. The working mechanism is based on a new direct current (DC) step protocol activating a series of differential resistance measurements (spatially separated by 800 µm) that is gradually initiated by the action of sweat, which flows along a customized microfluidic track (~600 µm in width, 10 mm in length, and 235 µm in thickness). The device has a volumetric capacity of ~16 µL and an acquisition frequency between 0.010 and 0.043 Hz within the measured sweat rate range. Importantly, instead of using a typical and rather complex AC signal interrogation and acquisition, we put forward the DC approach, offering several benefits, such as simplified circuit design for easier fabrication and lower costs, as well as reduced power consumption and suitability for wearable applications. For the validation, either the commercial sweat collector (colorimetric) or the developed device was performed. In five on-body tests, an acceptable variation of ca. 10% was obtained. Overall, this study demonstrates the potential of the DC-based device for the monitoring of sweat rate and also its potential for implementation in any wearable sweat platform.https://www.mdpi.com/1424-8220/24/22/7243wearable sensorsweat analysissweat ratedirect current methodmicrofluidic
spellingShingle Xing Xuan
Daniel Rojas
Isabel Maria Diaz Lozano
Maria Cuartero
Gastón A. Crespo
Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports
Sensors
wearable sensor
sweat analysis
sweat rate
direct current method
microfluidic
title Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports
title_full Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports
title_fullStr Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports
title_full_unstemmed Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports
title_short Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports
title_sort demonstration of a validated direct current wearable device for monitoring sweat rate in sports
topic wearable sensor
sweat analysis
sweat rate
direct current method
microfluidic
url https://www.mdpi.com/1424-8220/24/22/7243
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AT mariacuartero demonstrationofavalidateddirectcurrentwearabledeviceformonitoringsweatrateinsports
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