×

Methods and systems for extracting venous pulsation and respiratory information from photoplethysmographs

  • US 10,206,612 B2
  • Filed: 06/16/2015
  • Issued: 02/19/2019
  • Est. Priority Date: 01/13/2014
  • Status: Active Grant
First Claim
Patent Images

1. A method for extracting arterial, venous, blood oxygen, and respiratory information from a set of photoplethysmographic signals comprising the steps of:

  • preprocessing the set of photoplethysmographic signals;

    locating a venous signal and an arterial signal in each photoplethysmographic signal of the set of photoplethysmographic signals, using second order blind identification;

    extracting the arterial signal and the venous signal from each photoplethysmographic signal of the set of photoplethysmographic signals;

    extracting a respiratory signal using the venous signal and the arterial signal; and

    ,extracting a blood oxygen saturation from the arterial signal;

    wherein the set of photoplethysmographic signals comprises a red signal and an infrared signal;

    wherein the red signal comprises a red venous signal and a red arterial signal; and

    ,wherein the step of extracting a respiratory signal further comprises the steps of;

    determining a red signal derivative of the red signal;

    determining a red venous signal derivative for the red venous signal;

    generating a time domain window signal from the red signal derivative and the red venous signal derivative;

    generating a windowed signal from the time domain window signal and the red venous signal derivative;

    determining a maximum amplitude from the windowed signal;

    determining a venous return variation from the maximum amplitude;

    interpolating the venous return variation; and

    ,filtering the venous return variation to generate the respiratory signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×