Raman Spectroscopy for Noninvasive Physiological Monitoring of Hydration

Dehydration can have severe mental and physical consequences, yet there exist no current tools for the rapid, real-time assessment of hydration status. The development of a tool for hydration monitoring is urgently needed in many communities such as the military, high-performance athletics, and geriatrics. This study aims to develop a new tool, utilizing depth resolved Raman spectroscopy, to monitor hydration in real time. We are taking a 2-armed approach to this development by collecting spectral measurements from exercising individuals and performing molecular modeling to further understand the molecular interactions we are able to probe with our in vivo Raman system. The final aim of this project is to develop a portable Raman device for implementation of this technique into clinical settings.

In Vivo Hydration Measurements on Exercising Individuals

Depth resolved Raman spectroscopy can provide information about the water contained in interstitial tissue, indicating systemic hydration. A dual excitation wavelength Raman system is being used to examine water dynamics in the high wavenumber region (2500-3800 cm^-1) and collect complementary information regarding macromolecules from the fingerprint region (500-1800 cm^-1). We are enrolling participants in an IRB-approved studies where exercise is performed for a set duration under standardized conditions, with spectral measurements and clinical standards taken prior to and following the exercise period. From our spectral measurements we are using analysis techniques to determine which spectral features are the best indicators of hydration status, while simultaneously comparing our spectral measurements with clinical hydration standards. Future directions include expanding the testing of this this monitoring technique in various exercising populations including endurance athletes, military personnel, and average exercisers.

Researchers

Faculty

Anita Mahadevan-Jansen

Post Doctoral Scholars and Graduate Students

Anna Rourke

Molecular Modeling to Understand Water Dynamics In Vivo

Raman spectroscopy fundamentally measures a quantum mechanical interaction of a photon with a molecule, thus we must understand what we are measuring at the quantum level. In order to develop this understanding for hydrated tissues, various molecular models will be made to mimic simple versions of what is happening in vivo. These models have two major focuses: superficial water (water on the skin surface, mostly composed of sweat) and interstitial water (water trapped within tissue in collagen fiber networks). These models will help us understand how the molecular dynamics change with changing hydration and how these changes affect the vibrational modes and thus the Raman spectra of water within tissue.