Patent ID: 8788003
Filing Date: 2014-07-22
Classification: A61B

Abstract:
1. An apparatus for non-invasively measuring blood constituent levels within biological tissue, the apparatus comprising: at least one light source for providing a sample beam and a reference beam, the at least one light source providing at least two wavelengths of light, the at least one light source configured to direct the sample beam to the biological tissue, the at least two wavelengths of light including first and second wavelengths of light, the first wavelength of light having measurably different scattering properties sensitive to a first blood constituent relative to the second wavelength of light; a phase shifter configured to adjust phase path of the reference beam; a scanner configured to scan the sample beam over an area of the subject's tissue; an interferometer that allows comparison of a reflected sample beam from the subject tissue with the reference beam; at least one photodetector configured to generate non-image measurements from the reference beam and the reflected sample beam, the non-image measurements including at least scatter measurements of the first and second wavelengths of light; and blood constituent monitor configured to receive the non-image measurements and calculate, based on the non-image measurements, a level of a first blood constituent based at least partly on the scatter measurements of the first wavelength of light obtained at a location in the biological tissue where the scatter measurements of the second wavelength of light indicate a presence of blood-perfused tissue.