Method and system for detection of respiratory variation in plethysmographic oximetry

• US 8,128,569 B1
• Filed: 12/05/2008
• Issued: 03/06/2012
• Est. Priority Date: 12/06/2007
• Status: Active Grant

• Current Assignee: Los Angeles Biomedical Research Institute At Harbor-Ucla Medical Center (University of California)
• Original Assignee: Los Angeles Biomedical Research Institute At Harbor-Ucla Medical Center (University of California)
• Inventors: Mason, Gregory R., Criley, John M.
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): JANG, CHRISTIAN YONGKYUN
• Application Number:
  US12/315,813
• Time in Patent Office: 1,187 Days
• Field of Search: 600/484
• US Class Current: 600/484
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle

Abstract

A method and system for detection of respiratory variation in pulse oximetry are provided. In one embodiment, the method includes detecting a pattern consistent with a respiratory cycle of a waveform representing cardiac oscillations and identifying an abnormality based on the pattern. The method further includes triggering an alarm in response to identifying an abnormality. A system is further provided including a database and a module. The database to store data representing a physiological condition of a patient over a period of time, wherein the data comprises data corresponding to respiratory activity and data corresponding to cardiac oscillations, wherein the data corresponding to respiratory activity comprises a first waveform and the data corresponding to the cardiac oscillations comprises a second waveform; and a module for detecting a pattern of the second waveform consistent with a cycle of a first waveform and detecting an abnormality in the pattern, wherein when an abnormality is detected an alarm is triggered to alert a health care provider of the abnormality.

Claims

1. A method comprising:

detecting a pattern corresponding to a respiratory cycle of a waveform representing cardiac oscillations; and

identifying, using a module, pulsus paradoxus based on the pattern by determining a value from the pattern based on an average offset of wave bases of the waveform from a baseline and an average amplitude of wave peaks of the waveform from a best-fit line to the wave bases,

wherein the respiratory cycle is determined by impedance plethysmography using an electrocardiogram (ECG).

2. The method of claim 1, wherein the waveform representing cardiac oscillations is a plethysmographic waveform.

3. The method of claim 1, further comprising:

sounding an alarm in response to identifying pulsus paradoxus.

4. The method of claim 1, wherein the pattern is established after determining an average distance of the respiratory cycle from at least two consecutive respiratory cycles.

5. A method comprising:

detecting a pattern corresponding to a respiratory cycle of a waveform representing cardiac oscillations; and

identifying, using a module, pulsus paradoxus based on the pattern by determining a value from the pattern based on an average offset of wave bases of the waveform from a baseline and an average amplitude of wave peaks of the waveform from a best-fit line to the wave bases.

6. The method of claim 5, wherein the waveform representing cardiac oscillations is a plethysmographic waveform.

7. The method of claim 5, further comprising:

sounding an alarm in response to identifying pulsus paradoxus.

8. The method of claim 5, wherein the pattern is established after determining an average distance of the respiratory cycle from at least two consecutive respiratory cycles.