Determination of a physiological parameter

摘要

Methods and systems are provided for transmitting and receiving photon density waves to and from tissue, and processing the received waves using wavelet transforms to identify non-physiological signal components and/or identify physiological conditions. A pulse oximeter may receive the photon density waves from the tissue to generate a signal having phase and amplitude information. A phase signal may be proportional to a scattering by total particles in the tissue, and an amplitude signal may correlate to an absorption by certain particles, providing information on a ratio of different particles in the tissue. Processing the phase and amplitude signals with wavelet transforms may enable an analysis of signals with respect to time, frequency, and magnitude, and may produce various physiological data. For example, non-physiological noise components may be identified, and certain physiological conditions may be identified by processing scalograms of the original signals with patterns corresponding to certain physiological conditions.

主权项

1. A monitor, comprising:
a display; a connector port configured to receive a signal generated in response to propagation of photon density waves through tissue; and data processing circuitry configured to:
derive a phase signal and a plethysmography signal from the received signal, wherein changes the phase signal are indicative of changes in photon scattering and changes in the plethysmography signal are indicative of changes in absorption of photons by the tissue;apply a continuous wavelet transform to the phase signal and to the plethysmography signal to generate a phase signal scalogram and a plethysmography signal scalogram, respectively;compare the phase signal scalogram and the plethysmography signal scalogram;identify temporal correlations between changes in photon scattering and changes in absorption of photons by the tissue based on the comparison of the phase signal scalogram and the plethysmography signal scalogram;distinguish physiological and non-physiological components of the signal based on the temporal correlations between changes in photon scattering and changes in absorption of photons by the tissue, wherein physiological components are identified at temporal locations where changes in photon scattering correlate to changes in absorption of photons by the tissue, and non-physiological components are identified at temporal locations where changes in photon scattering do not correlate to changes in absorption of photons by the tissue;generate patient physiological data based on at least the physiological components of the signal; anddisplay the patient physiological data on the display.