Patent Document ID: 6073037
Application ID: 09131944
Patent Status: 1

Claim One:
1. A method of determining pH in pulsatile blood in a human utilizing spectra which contains histidine information, said method comprising steps of: a) generating light at three or more different wavelengths, said wavelengths being in the range of 1000 nm to 2500 nm; b) irradiating blood containing tissue with said wavelengths so that there is differential attenuation of at least some intensities of said wavelengths, said wavelength dependent differential attenuation being a function of said blood containing tissue, including histidine in said blood containing tissue; c) measuring at least a portion of said intensities of said wavelengths emerging from said blood containing tissue; d) using the presence of blood pulsations in said blood containing tissue and said measured intensities to obtain blood specific spectral information; and e) estimating said value of said blood pH from said blood specific spectral information by utilizing wavelength dependent differential attenuation derived from said histidine.