Faculty of Electrical Engineering, Mathematics & Computer Science, Delft University of Technology, Mekelweg 4, Delft 2628 CD, The Netherlands.
Faculty of Industrial Design Engineering, Delft University of Technology, Landbergstraat 15, Delft 2628 CE, The Netherlands.
Anal Chem. 2022 May 10;94(18):6893-6901. doi: 10.1021/acs.analchem.2c01052. Epub 2022 Apr 29.
Sweat sensors allow for new unobtrusive ways to continuously monitor an athlete's performance and health status. Significant advances have been made in the optimization of sensitivity, selectivity, and durability of electrochemical sweat sensors. However, comparing the performance of these sensors in detail remains challenging because standardized sweat measurement methods to validate sweat sensors in a physiological setting do not yet exist. Current collection methods, such as the absorbent patch technique, are prone to contamination and are labor-intensive, which limits the number of samples that can be collected over time for offline reference measurements. We present an easy-to-fabricate sweat collection system that allows for continuous electrochemical monitoring, as well as chronological sampling of sweat for offline analysis. The patch consists of an analysis chamber hosting a conductivity sensor and a sequence of 5 to 10 reservoirs that contain level indicators that monitor the filling speed. After testing the performance of the patch in the laboratory, elaborate physiological validation experiments (3 patch locations, 6 participants) were executed. The continuous sweat conductivity measurements were compared with laboratory [Na] and [Cl] measurements of the samples, and a strong linear relationship ( = 0.97) was found. Furthermore, sweat rate derived from ventilated capsule measurement at the three locations was compared with patch filling speed and continuous conductivity readings. As expected from the literature, sweat conductivity was linearly related to sweat rate as well. In short, a successfully validated sweat collection patch is presented that enables sensor developers to systematically validate novel sweat sensors in a physiological setting.
汗液传感器可以实现对运动员的性能和健康状态进行连续、非侵入式监测的新方法。在电化学汗液传感器的灵敏度、选择性和耐用性的优化方面已经取得了重大进展。然而，由于目前还没有标准化的汗液测量方法来验证生理环境下的汗液传感器，因此详细比较这些传感器的性能仍然具有挑战性。目前的采集方法，如吸收垫技术，容易受到污染且劳动强度大，这限制了可以随时间采集的样本数量，无法进行离线参考测量。我们提出了一种易于制造的汗液采集系统，它可以实现连续的电化学监测，以及按时间顺序对汗液进行采样以供离线分析。该贴片由一个分析室组成，其中包含一个电导率传感器和一系列 5 到 10 个储液器，储液器中装有液位指示器，用于监测填充速度。在实验室中测试了该贴片的性能后，我们进行了详细的生理验证实验（3 个贴片位置，6 名参与者）。将连续的汗液电导率测量与实验室中对样本的 [Na] 和 [Cl] 测量进行了比较，发现两者之间存在很强的线性关系（=0.97）。此外，还将三个位置的通风胶囊测量得到的出汗率与贴片的填充速度和连续电导率读数进行了比较。正如文献中所预期的那样，汗液电导率与出汗率也呈线性关系。总之，我们成功验证了一种汗液采集贴片，它使传感器开发人员能够在生理环境中系统地验证新型汗液传感器。
