Patent ID: RE44875

Claim:
A system for non-invasively monitoring concentrations of blood constituents in a living subject, said system comprising: a light source configured to be positioned at a measurement site and further configured to irradiate a fleshy medium of a living subject with radiation at a plurality of wavelengths selected for attenuation sensitivity to at least one of a plurality of blood constituent concentrations, said plurality of blood constituent concentrations including a glucose concentration; an optical detector configured to be positioned at said measurement site to detect only light which has been attenuated by said fleshy medium at said measurement site, said optical detector configured to generate an output signal indicative of an intensity of said radiation after attenuation through said fleshy medium; a pressure application device configured to be positioned at a location different from said measurement site to avoid applying direct pressure to said measurement site while causing a change in a volume of blood in the fleshy medium at said measurement site sufficient to alter said output signal to increase a likelihood of determining at least said glucose concentration, said pressure application device configured to modulate pressure on the fleshy medium at a rate above a normal heart rate range; and a signal processor responsive to said output signal to analyze said output signal to extract portions of said signal due to optical characteristics of said blood and to determine a concentration of at least one selected constituent within said subject's bloodstream ; and a pressure application device configured to be positioned at a location different from said measurement site to avoid applying direct pressure to said measurement site while causing a change in a volume of blood in the fleshy medium at said measurement site sufficient to alter said output signal to increase a likelihood that said signal processor can determine at least said glucose concentration. by analyzing an effect of the modulated pressure on the output signal.