SYSTEM FOR ANALYZING OXIMETRY DATA

• US 20140039283A1
• Filed: 07/31/2013
• Published: 02/06/2014
• Est. Priority Date: 07/31/2012
• Status: Active Grant

• Current Assignee: The Periodic Breathing Foundation, LLC
• Original Assignee: The Periodic Breathing Foundation, LLC
• Inventors: Daly, Robert W.
• Granted Patent: US 10,631,738 B2
• Time in Patent Office: Days
• US Class Current: 600/324
• 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 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

A method and system for the analysis of a patient'"'"'s oximetry data to detect sleep-disordered breathing is provided. The system employs an algorithm to reliably detect patient arousals and correlate those with accelerated heart rate and oxygen saturation levels in a manner that detects sleep-disordered breathing via the respiratory mask. Initially a timing channel is formed based on a plethsmography signal using an optical finger sensor. Based on the pleth waveform, a respiratory wave form is prepared that represents respiration rate. An arousal mask is applied to the signal based on attenuations in the pleth signal. Once arousals are identified the time required for changes to propagate from the lungs to the blood gas is subtracted from the onset time of the arousal. As a result if the timing agrees with dropping oxygen saturation or falling arterial pH then the arousal is indicated as a chemoreflex related arousal.

Claims

1. A method of diagnosing disordered breathing from a pleth signal:

recording a pleth signal including a heart rate that varies over time;

using said variation in heart rate to identify a time based respiratory pattern that is recorded as a continuous waveform;

identifying attenuations in said pleth signal as arousal events and recording a time of each arousal event;

subtracting a time constant from the time related to each arousal event to determine a delay time related to each arousal event;

reviewing said respiratory pattern at each of said delay times to determine if there are changes in said respiratory pattern corresponding to each of said arousal events; and

recording each of said arousal events that correlate with changes in said respiratory pattern.

2. The method of claim 1, wherein said pleth signal is recorded using a pulse oximeter.

3. The method of claim 1, wherein said changes in said respiratory pattern are a reduction or slowing in respiration rate.

4. The method of claim 1, wherein said changes in said respiratory pattern are changes in respiratory amplitude.

5. The method of claim 1, wherein the time constant is the time delay between actually taking a breath and the actual registering of a change in blood gasses at carotid sensors.

6. The method of claim 1, further comprising:

identifying said arousal events that correlate with changes in said respiratory pattern as being chemo-reflex related arousals.

7. The method of claim 6, further comprising:

reviewing an oxygen saturation reading at or slightly after the time of each arousal, wherein arousals having a rising saturation reading are disregarded and arousals having dropping saturation readings are confirmed as chemo-reflex related.

8. The method of claim 1, further comprising:

reviewing an oxygen saturation reading at or slightly after the time of each arousal, wherein arousals having a rising saturation reading are disregarded and arousals having dropping saturation readings are identified as chemo-reflex related.

9. The method of claim 1, further comprising:

generating a graphed array of each of said recorded arousals to identify whether a pattern of arousal exists over time.

10. A method of diagnosing disordered breathing:

recording a pleth signal using a pulse oximeter, said pleth signal including a heart rate that varies over time;

using said variation in heart rate to identify a time based respiratory pattern that is recorded as a continuous waveform;

identifying attenuations in said pleth signal as arousal events and recording a time of each arousal event;

subtracting a time constant that represents the time delay between actually taking a breath and the actual registering of a change in blood gasses at carotid sensors from the recorded time of each arousal event to determine a delay time related to each arousal event;

reviewing said respiratory pattern at each of said delay times to determine if there are changes in said respiratory pattern corresponding to each of said arousal events; and

recording each of said arousal events that correlate with changes in said respiratory pattern.

11. The method of claim 10, wherein said changes in said respiratory pattern are a reduction or slowing in respiration rate.

12. The method of claim 10, wherein said changes in said respiratory pattern are changes in respiratory amplitude.

13. The method of claim 10, further comprising:

identifying said arousal events that correlate with changes in said respiratory pattern as being chemo-reflex related arousals.

14. The method of claim 13, further comprising:

reviewing an oxygen saturation reading at or slightly after the time of each arousal, wherein arousals having a rising saturation reading are disregarded and arousals having dropping saturation readings are confirmed as chemo-reflex related.

15. The method of claim 10, further comprising:

reviewing an oxygen saturation reading at or slightly after the time of each arousal, wherein arousals having a rising saturation reading are disregarded and arousals having dropping saturation readings are identified as chemo-reflex related.

16. The method of claim 10, further comprising:

generating a graphed array of each of said recorded arousals to identify whether a pattern of arousal exists over time.