Real-time smart multisensing wearable platform for monitoring sweat biomarkers during exercise

Abstract

Sweat secreted by the human eccrine sweat glands can provide valuable biomarker information during exercise in hot and humid conditions. Real-time noninvasive biomarker recordings are therefore useful for evaluating the physiological conditions of an athlete such as their hydration status during endurance exercise. In this work, we describe a platform that in-cludes different sweat biomonitoring prototypes of cost-effective, smart wearable devices for continuous biomonitoring of sweat during exercise. One prototype is based on conformable and disposable soft sensing patches with an integrated multisensor array requiring the integration of different sensors and printed sensors with their corresponding functionalization protocols on the same substrate. The second is based on silicon based sensors and paper microfluidics. Both platforms integrate a multi-sensor array for measuring sodium, potassium, and pH in sweat. We show preliminary results obtained from the multi-sensor prototypes placed on two athletes during exercise. We also show that the machine learning algorithms can predict the percentage of body weight loss during exercise from biomarkers such as heart rate and sweat sodium concentration collected over multiple subjects.

Analytical Assessment of Sodium Isfet Based Sensors for Sweat Analysis

“…The ISFETs showed good performance Na + quantification in sweat samples, being feasible their integration in compact electronic wearable devices [42,43]. As future work, the ISFETs will be integrated in a CMOS fabricated chip for real-time, continuous monitoring of analytes on-body, allowing correction of interferences using deep learning approaches [44].…”

Dual-Gate Organic Thin-Film Transistor and Multiplexer Chips for the Next Generation of Flexible EG-ISFET Sensor Chips

“…With the continuous growth of OTFT technology and the development of new approaches for avoiding crosstalk, we may expect to see an increase in the number of analogue multiplexer applications that use OTFTs in the future [ 111 , 112 ].…”

Multisensing Wearables for Real-Time Monitoring of Sweat Electrolyte Biomarkers During Exercise and Analysis on Their Correlation With Core Body Temperature

“…Three healthy athletes volunteered to participate in this study. The printed sensor patch was tested on two subjects (Subject 1: 46 years old, 175 cm, 63.1 kg, HRmax of 178 bpm, MAP of 350 W, and VO 2 max of 67 mL/kg/min; Subject 2: 25 years old, 179 cm, 70.0 kg, HRmax of 183 bpm, MAP of 390 W, and VO 2 max of 60 mL/kg/min), who were also involved in a previous study [21], while the ISFET sensor patch was tested on another subject (Subject 3: 37 years old, 182 cm, 72.0 kg, HRmax of 181 bpm, MAP of 408 W, and VO 2 max of 61 mL/kg/min). They provided their written informed consent and the study was approved by the ethical commission of the Canton of Vaud Switzerland on May 10 th , 2021 (Protocol No.…”

“…These measurements were performed together with the continuous recording of other physiological and sweat biomarkers such as heart rate (HR), core body temperature (core body T), and regional sweat rate (RSR). A short description of the wearable sensor technology was previously presented in [21]. This previous work presented results from the prediction of the percentage of body weight loss by applying various linear and nonlinear machine learning (ML) algorithms to the various physiological biomarker measurements in a thirtysubject study.…”

“…This task was used in several studies but based on physiological biomarkers such as heart rate and skin temperature [22]. We apply the ML algorithms described in [21], [23] on the real-time sweat biomarker measurements from the printed patch, and compare the root mean square error (RMSE) of the prediction with values obtained by using other physiological biomarkers. We also compute the correlation values of the sweat biomarkers with other physiological biomarkers collected during this hour-long session and compare the biomarker readings with those from a commercial device and ISFETs.…”