Physiological measurement calibration
AssigneeMasimo Corporation
InventorsPrashanth Iyengar, Jerome Novak, Prashanth Rengaswamy Chandran
Life of this patent
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Abstract
The present disclosure provides a calibration system and method for calibrating a physiological measurement based on a variable that affects the measurement. The variable can be a related physiological measurement. The technique can be implemented to obtain robust calibrations with minimal test data and computational effort.
Claims20
A physiological monitoring system configured to provide an improvement of a patient's total hemoglobin (“SpHb”) measurements by making the measurements less sensitive to unrelated physiological changes, the system comprising:
- an input of an electronic physiological monitor, said input configured to receive one or more signals responsive to light attenuated by body tissue of the patient, the one or more signals output from a light detector configured to detect said attenuated light;
- and
- one or more physiological hardware processors of the electronic physiological monitor, the one or more processors configured to use the one or more signals to electronically determine an improved SpHb hemoglobin measurement based on calibration information which decorrelates SpHb measurements from changes in the patient's perfusion, the calibration information determined based at least in part on at least two groups of correlated measurements of the patient's SpHb and perfusion index.
A method of improving a patient's SpHb measurements of a physiological measurement system, the improved SpHb measurements being less sensitive to unrelated physiological changes, the method comprising:
- using one or more emitters of the physiological measurement system, emitting light of a plurality of wavelengths into a patient's tissue;
- using one or more detectors of the physiological measurement system, detecting the light after attenuation by the patient's tissue;
- obtaining one or more signals based on the attenuated light detected by the detector;
- and
- processing the one or more signals using one or more signal processors of the physiological measurement system to electronically:
- obtain a first group of correlated measurements comprising measurements of the patient's SpHb and a first related physiological parameter, wherein the first group of correlated measurements is based at least in part on one or more attenuation ratios of absorption energies associated with each known wavelength of the light,
- obtain a second group of correlated measurements comprising measurements of the patient's SpHb and the first related physiological parameter, wherein the patient's SpHb measurement is substantially the same and wherein the first related physiological parameter is manipulated and the patient's SpHb is held the same,
- combine the first and second groups of correlated measurements with similar measurements from other patients to determine calibration information useful for decorrelating SpHb measurements from the first related physiological parameter, and
- based on the calibration information, configure the physiological parameter measurement system to obtain a decorrelated SpHb measurement.
Dependencies are inferred from the claim text.