Patent ID: 6018674
Filing Date: 2000-01-25
Classification: A61B

Abstract:
A photoplethysmographic measurement system for use in determining a value for at least one blood analyte level comprising:an emitter which emits a plurality of light beams through a portion of said tissue wherein each of said light beams is transmitted through said tissue for a discrete time interval and wherein each of said light beams has a distinct spectral content characterized by a center wavelength;a fast response detector which generates a time-division multiplexed signal indicative of light transmitted through said tissue wherein said signal has a first signal portion indicative of the light transmitted by a first light beam of said plurality of light beams and a second signal portion indicative of said ambient light levela preamplifier wherein said first signal portion and said second signal portion may be amplified at substantially different gainswherein said fast response detector is selected so as to minimize the effect of the first signal portion on the second signal portion when said second signal portion is amplified at a substantially greater gain than said first signal portion; anda microprocessor wherein a computer program is executed which contains a test routine to determine whether the detector has an acceptable decay time.