Characterizing Variability in Non-Invasive Hydration Monitoring Using Raman Spectroscopy

Area of Science:

• Biomedical Optics
• Spectroscopy
• Physiology

Background:

• Dehydration negatively impacts thermoregulation, cardiovascular function, and performance.
• Current methods for assessing hydration are often invasive or lack objectivity.
• Non-invasive tools are needed for real-time systemic hydration monitoring.

Purpose of the Study:

• To develop and validate Raman spectroscopy for non-invasive systemic hydration detection.
• To investigate the relationship between spectral features and hydration levels in vivo.
• To assess the feasibility of using Raman spectroscopy for monitoring hydration changes.

Main Methods:

• High-wavenumber Raman spectroscopy was employed.
• Validation was performed using tissue-mimicking phantoms.
• Three in vivo feasibility studies were conducted to assess spectral metrics and hydration.

Main Results:

• Raman-derived metrics, including the area under the curve (AUC) of water bands and the ratio of water to CH bands, correlated with hydration.
• A trend of decreasing water bands AUC was observed post-exercise, though with high variability.
• Multiple anatomical locations proved suitable for spectral measurements, despite inter-subject variability.

Conclusions:

• Raman spectroscopy demonstrates potential for rapid, non-invasive systemic hydration monitoring.
• Standardization of study protocols is crucial to mitigate variability and enhance detection accuracy.
• This technique could improve routine hydration management and reduce dehydration-related risks.