METHODS AND SYSTEMS FOR DETERMINING EFFECTIVENESS OF RESPIRATION IN INDIVIDUALS

• US 20160338597A1
• Filed: 01/13/2015
• Published: 11/24/2016
• Est. Priority Date: 10/11/2013
• Status: Active Grant

• Current Assignee: Xhale Assurance, Inc. (Koninklijke Philips N.V.)
• Original Assignee: Xhale, Inc.
• Inventors: Melker, Richard J, Tan, Huwei, Cohen, Sean
• Granted Patent: US 10,729,334 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• 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 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/0826 Detecting or evaluating apnoea events A61B5/4818 takes precedence
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/0878 using temperature sensing means
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/6819 Nose
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61M 16/1005 with O2 features or with parameter measurement

Abstract

The present invention relates to systems and methods for comparing photoplethysmography (PPG) signals from an individual with signals from a secondary respiration sensor secured to the individual to determine whether effective respiration has occurred or whether the individual has apnea, hypopnea, or other respiratory distress.

Claims

1. A method of monitoring the effectiveness of respiration in an individual, comprising

determining whether a respiratory attempt in the individual occurred within a predefined time period based on photoplethysmography (PPG) signals obtained from a PPG sensor secured to the individual;

determining whether a ventilation occurred within the predefined time period using a secondary respiration sensor; and

comparing the determination of the respiratory attempts based on the PPG signals with the determination of the ventilation based on the secondary respiration sensor to assess whether the individual'"'"'s respiratory attempts are effective.

2. The method of claim 1, wherein the secondary respiration sensor comprises at least one of a thermistor, capnometer, nasal flow sensor, differential pressure transducer, and a nasal pressure sensor.

3. The method of claim 1, wherein if a respiratory attempt is determined to have occurred based on the PPG signals and ventilation is determined to have occurred based on the secondary respiration sensor, then the effective respiratory attempt is used to calculate the respiration rate of the individual.

4. The method of claim 1, wherein if a respiratory attempt is determined to have occurred but ventilation is determined to have not occurred, then a predetermined action is effected.

5. The method of claim 4, wherein the predetermined reaction comprises initiating an alarm.

6. The method of claim 4, wherein the predetermined reaction comprises administering oxygen.

7. The method of claim 4, further comprising determining whether the individual'"'"'s blood oxygen saturation has decreased to a predefined level, and if so, effecting a predetermined reaction.

8. The method of claim 7, wherein the predetermined reaction comprises initiating an alarm.

9. The method of claim 1, further comprising calculating a first respiration rate based on the respiratory attempts determined from the PPG signals, calculating a second respiration rate based on breaths determined from the secondary respiration sensor, and comparing the first and second respiration rates to determine whether the individual is suffering from hyperpnoea, apnea or hypopnea.

10. The method of claim 9, wherein if the individual is determined to be suffering from hyperpnea, apnea or hypopnea, a predetermined reaction is effected.

11. The method of claim 10, wherein the predetermined reaction comprises initiating an alarm.

12. A system for monitoring respiration comprising

a microprocessor configured to compare PPG signals from a PPG sensor secured to an individual with signals from a secondary respiration sensor secured to the individual, to determine at least one of (a) whether ventilation has occurred, (b) whether the patient has central apnea, and (c) whether the patient has obstructive apnea.

13. The system of claim 13, wherein the microprocessor is further configured to isolate an AC and a DC component signal of the PPG signals, use the isolated AC and/or DC component signal to determine whether a respiratory attempt in the individual has occurred.

14. The system of claim 14, wherein the microprocessor is configured to determine whether a respiratory attempt has occurred based on the PPG signals;

to determine whether the ventilation has occurred based on the secondary respiration sensor signals; and

to compare the determination of the respiratory attempt based on the PPG signals with the determination of ventilation based on the secondary respiration sensor to assess whether an effective respiratory attempt has occurred.

15. The system of claim 15, wherein a predetermined reaction is effected if the respiratory attempt is determined to not have been effective.

16. The system of claim 16, wherein the predetermined reaction comprises initiating an alarm.

17. The system of claim 16, wherein the predetermined reaction comprises directing the system to administer oxygen to the individual.

18. The system of claim 16, wherein the microprocessor further determines whether the individual'"'"'s blood oxygen saturation has decreased a predefined percentage, and the predetermined reaction is effected if the respiratory attempt is determined to not have been effective and the blood oxygen saturation has decreased a predefined percentage.

19. The system of claim 19, wherein the predefined percentage is in a range of 3 and 10%.