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MANUAL AND AUTOMATIC PROBE CALIBRATION

  • US 20090270703A1
  • Filed: 04/24/2009
  • Published: 10/29/2009
  • Est. Priority Date: 06/07/1995
  • Status: Active Grant
First Claim
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1. A method to obtain physiological data relating to a physiological parameter without knowing precise operating wavelengths of one or more light emitting devices in an oximeter sensor, the method comprising:

  • driving a first light emitting device with a first drive current to generate a first light energy having a first wavelength;

    transmitting the first light energy through a medium under test to result in a first attenuated light energy;

    driving the first light emitting device with a second drive current to generate a second light energy having a second wavelength, wherein the second drive current has a different current level than the first drive current, the first wavelength and the second wavelength fall within a first predetermined range of operating wavelengths, and a difference between the first wavelength and the second wavelength is approximately equal to a preselected wavelength shift;

    transmitting the second light energy through the medium under test to result in a second attenuated light energy;

    driving a second light emitting device with a third drive current to generate a third light energy having a third wavelength, wherein the third wavelength falls within a second predetermined range of operating wavelengths and is distinct from the first wavelength and the second wavelength;

    transmitting the third light energy through the medium under test to result in a third attenuated light energy; and

    calculating the physiological parameter based on the first attenuated light energy, the second attenuated light energy, the third attenuated light energy, and the preselected wavelength shift.

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