Patent ID: 7657292

Claim:
A method for assessing an extracellular water metric in a subject, said method comprising: using at least one sensor: emitting light of at least one wavelength toward a tissue site of interest, wherein a portion of the emitted light is reflected by the tissue site of interest; detecting at least one wavelength of the light reflected by the tissue site of interest from a position about one millimeter to about five millimeters from the tissue site of interest; emitting light of at least one wavelength toward a reference tissue site, wherein a portion of the emitted light is reflected by the reference tissue site; detecting at least one wavelength of the light reflected by the reference tissue site from a position about one millimeter to about five millimeters from the reference tissue site; and using a processor: processing detected reflected light from the tissue site of interest and detected reflected light from the reference tissue site to compute the extracellular water metric, wherein the hydrostatic pressure of the tissue site of interest differs from the hydrostatic pressure of the reference tissue site.