Rourke-Funderburg Anna S, Elstub Laura J, Voss Trevor, Liao Richard L, Masson Laura E, Mahadevan-Jansen Anita
Vanderbilt Biophotonics Center, Vanderbilt University, Nashville, Tennessee, USA.
Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.
Appl Spectrosc. 2025 Aug;79(8):1228-1241. doi: 10.1177/00037028241307043. Epub 2024 Dec 26.
Significant dehydration can increase thermoregulatory and cardiovascular strain and impair physical and cognitive performance. Despite these negative effects, there are currently no objective, non-invasive tools to monitor systemic hydration. Raman spectroscopy is an optical modality with the potential to fill this gap because it is sensitive to water, provides results quickly, and can be applied non-invasively. In this work, high wavenumber Raman spectroscopy has been developed toward detection of systemic hydration via validation with tissue-mimicking phantoms, followed by three in vivo feasibility studies to investigate the relationship between spectral features and systemic hydration. The area under the curve (AUC) of the water bands and the ratio of water bands to CH bands are Raman-derived metrics that can be used to describe systemic hydration. Here, we determined a trend in decreasing water bands AUC after exercise, although the magnitude of the change was highly variable. In investigating the sources of variability, we identified significant inter-subject variability and a failure of current clinical standards to benchmark our developed technique against. Despite the high variability, we found that multiple anatomical locations were suitable for collecting the spectral measurements. While the high degree of variability may confound the use of Raman spectroscopy for non-invasive hydration monitoring, when implementing additional study standardization, significant differences ( <.05) in spectral metrics can be identified before and after exercise. Raman spectroscopy can allow for rapid, non-invasive detection of systemic hydration, which would improve routine hydration monitoring and reduce the incidence of negative side effects associated with dehydration.
严重脱水会增加体温调节和心血管负担，并损害身体和认知能力。尽管有这些负面影响，但目前尚无客观、非侵入性的工具来监测全身水合状态。拉曼光谱是一种光学方法，有潜力填补这一空白，因为它对水敏感、能快速给出结果且可用于非侵入性检测。在这项工作中，通过用仿组织体模进行验证，已开发出高波数拉曼光谱用于检测全身水合状态，随后进行了三项体内可行性研究，以探究光谱特征与全身水合状态之间的关系。水带的曲线下面积（AUC）以及水带与CH带的比率是可用于描述全身水合状态的拉曼衍生指标。在此，我们确定了运动后水带AUC下降的趋势，尽管变化幅度差异很大。在研究变异性的来源时，我们发现个体间存在显著差异，且当前临床标准无法作为我们所开发技术的基准。尽管变异性很高，但我们发现多个解剖部位都适合进行光谱测量。虽然高度变异性可能会混淆拉曼光谱在非侵入性水合监测中的应用，但在实施额外的研究标准化时，运动前后的光谱指标可发现显著差异（<0.05）。拉曼光谱能够实现对全身水合状态的快速、非侵入性检测，这将改善日常水合监测，并降低与脱水相关的负面副作用的发生率。
