Photoplethysmography apparatus and method employing high resolution estimation of time-frequency spectra
AssigneeThe Research Foundation of State University of New York
InventorsKi H. CHON, Kilwan JU
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Abstract
A photoplethysmography apparatus and method is provided for high resolution estimating of Time-Frequency Spectra (TFS) and associated amplitudes using Variable Frequency Complex Demodulation (VFCDM), in a two-step procedure using a Time-Varying Optimal Parameter Search (TVOPS) technique to obtain TFS, followed by VFCDM to obtain even greater TFS resolution and instantaneous amplitudes associated with only specific frequencies of interest, via the combined TVOPS and VFCDM.
Claims7
A digital filtering method for estimating Time-Frequency Spectra (TFS) and amplitudes of a photoplethysmography (PPG) signal using Variable Frequency Complex Demodulation (VFCDM), the method comprising:
- obtaining a TFS of the PPG signal by performing, with a controller, the VFCDM of the PPG signal to obtain at least one VFCDM signal having improved TFS resolution and instantaneous amplitudes associated with frequencies of interest;
- and
- deriving a heart rate and a respiratory rate from the at least one VFCDM signal.
A photoplethysmography (PPG) apparatus for monitoring heart and respiratory rates, the apparatus comprising:
- a controller configured to:
- obtain a Time-Frequency Spectra (TFS) of a PPG signal by performing a Variable Frequency Complex Demodulation (VFCDM) with the PPG signal to obtain at least one VFCDM signal having improved TFS resolution and instantaneous amplitudes associated with frequencies of interest, and
- derive a heart rate and a respiratory rate from the at least one VFCDM signal.
Dependencies are inferred from the claim text.