NMR Based Device for Fluid Status Monitoring

Technology #16497

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Inventors
Professor Michael Cima
Department of Material Science and Engineering, MIT
External Link (cima-lab.mit.edu)
Matthew Li
Harvard-MIT Division of Health Sciences and Technology, MIT
Christophoros Vassiliou
Department of Electrical Engineering and Computer Science, MIT
Negar Tavassolian
The David H. Koch Institute for Integrative Cancer Research, MIT
Lina Colucci
Harvard-MIT Division of Health Sciences and Technology, MIT
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Ben Rockney
MIT Technology Licensing Officer
Patent Protection

NMR Sensor and Methods for Rapid, Non-invasive Determination of Hydration State or Vascular Volume of a Subject

US Patent Pending US 2016-0120438
Publications
A novel magnetic relaxation-based platform for hydration monitoring
Sensors Journal, IEEE , (2014) Vol. 14:8, pp. 2851-2855
1H nuclear magnetic resonance (NMR) as a tool to measure dehydration in mice
NMR in Biomedicine , (2015) Vol. 28:8, pp. 1031-1039

Applications

Portable hydration sensor

Problem Addressed

Hydration imbalance, either dehydration or over-hydration (hyponatremia), affects cognitive and physical abilities, negatively impacting cardiovascular function, compromising thermoregulation, and decreasing exercise performance.  Hydration imbalance is a critical, life-threatening problem that affects over 1.2 million people annually and represents over $44.7 billion in healthcare costs.  Dehydration is preventable and reversible, and hospitalization from fluid imbalance is preventable through monitoring and early intervention.  Though various tools and metrics exist to measure hydration state, such as body mass change, capillary refill time, plasma osmolality, and bioimpedance, there is no hydration assessment method that is fast, portable, accurate, non-invasive, and designed for outpatient settings.

Technology

This invention presents a novel method for non-invasively measuring physiological hydration state using nuclear magnetic resonance (NMR).  This technology utilizes 1H NMR, which measures the relaxivity of hydrogen in water.  Using NMR relaxivity component analysis and signal-processing methods, the amount of water in different tissue targets (e.g. intracellular, extracellular, interstitial, intravascular) can be determined.  This invention marks the first time applying NMR measurement to physiological hydration state.

Vascularization varies in different anatomical locations and tissues of the body.  Signals from the vasculature can be detected by increasing the measurement volume and focusing on a region with reduced blood velocity where excited protons do not exit the field of measurement quickly. 

While not limited to a single tissue type, fingers contain dense capillary beds with relatively small amounts of muscle mass and are particularly convenient.  Simple spin-spin relaxation (T2) measurements of the fingers correlate with the hydration state of a human and appear to be equivalent to clinically accepted yet more invasive assessments.  This novel finger NMR unit is small (please refer to the figures), making it easy for a patient to comfortably place a finger in the field of measurement.  

Advantages

  • Portable, inexpensive, easy, fast, and reliable hydration sensor
  • Potential to greatly reduce hospital spending on hydration imbalance