METHODS FOR DETECTION OF RESPIRATORY EFFORT AND SLEEP APNEA MONITORING DEVICES

• US 20160120465A1
• Filed: 07/31/2015
• Published: 05/05/2016
• Est. Priority Date: 11/07/2012
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Somnarus Inc.
• Inventors: Parfenova, Maria A., Parfenov, Alexandr S., Zobnin, Yuri P., Konstantinov, Nikolay V.
• Granted Patent: US 10,383,570 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/16 Details of sensor housings or probes; Details of structural supports for sensors A61B2560/0462 takes precedence
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• 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 5/0295 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 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/6819 Nose
• CPC Class Codes: A61B 5/688 using adhesives
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms

Abstract

A sleep apnea diagnostic system includes a housing that is configured to be attached to near the nose of a patient'"'"'s face to sense physiological information of a patient. The housing includes sensors to sense the physiological information. The physiological information may be, for example, air flow through the nose or the mouth or both. The physiological information further may be, for example, blood volume. The sleep apnea diagnostic system includes at least one processor in the housing or external to the housing or both to analyze the physiological information to determine whether the patient has experienced irregular or abnormal respiratory activity and to detect respiratory effort. The analysis may be real time or delayed.

Claims

1. A sleep apnea monitoring device comprising:

a housing shaped to fit the contours of the patient'"'"'s face;

at least one pair of photosensors positioned to detect blood volume in the face of the patient;

at least one air-flow sensor positioned to detect airflow during breathing of the patient;

a memory disposed in the housing and configured to store physiological information related to the detected blood volume and store physiological information related to detected airflow during breathing;

a controller disposed in the housing and configured to control the at least one pair of photosensors to detect blood volume, to control the at least one airflow sensor to detect airflow, and to control the memory to store physiological information related to the detected blood volume and store physiological information related to detected airflow during breathing, during a predefined monitoring period.

2. The sleep apnea device according to claim 1 further comprising an accelerometer positioned to detect patient'"'"'s movements and sleep time.

3. The sleep apnea device according to claim 1 wherein the housing includes tubing that protrudes from the housing and having a distal end mounted to the air-flow sensors.

4. The sleep apnea device according to claim 1 wherein the housing is shaped to fit the skin surface of the patient'"'"'s nose, upper lip, and the area of maxillary sinuses.

5. The sleep apnea device according to claim 1 wherein the housing further comprises an adhesive on a surface thereof configured to be contentiously affixed to the patient during at least the monitoring period.

6. The sleep apnea device according to claim 1 wherein the housing is made of a flexible bio-compatible polymer.

7. The sleep apnea device according to claim 1 wherein the pair of the photosensors emit and measure absorption of light wavelengths typically absorbed by oxygenated and desoxygenated hemoglobin.

8. The sleep apnea device according to claim 1 wherein the housing further comprises a power source configured to provide power during at least the monitoring period.

9. The sleep apnea device according to claim 1 wherein at least one airflow sensor measures oronasal breathing.

10. The sleep apnea device according to claim 1, further comprising a processor configured to obtain peripheral plethysmography data from the stored physiological information, the processor is further configured to analyze a DC component of the plethysmography data to identify respiratory events and to identify respiratory effort during respiratory event by detecting changes in the DC portion of the plethysmography and by estimating and subtracting the effect of the autonomous nervous system during an onset of respiratory event.

11. The sleep apnea device according to claim 10, wherein the processor further is configured to obtain peripheral plethysmography data from the stored physiological information related to the detected blood oxygen saturation levels.

12. The sleep apnea device according to claim 10, wherein the processor further is configured to obtain peripheral plethysmography data from the stored physiological information related to the detected airflow during breathing.

13. The sleep apnea device according to claim 10, wherein the processor is further configured to obtain plethysmography data from the detected physiological data before, during and after a respiratory event by generating measure of vascular tone for each plethysmography pulse wave before and during an respiratory event, and wherein the processor is further configured to estimate the effect of autonomous nervous system on the intensity variation during the respiratory event by generating a change in the measure of vascular tone during the respiratory event based on changes in the detected physiological data.

14. A method for detection of respiratory effort during a respiratory event, the method comprising:

identifying a respiratory event;

obtaining peripheral plethysmography data; and

identifying respiratory effort during the respiratory event by;

detecting changes in a DC component of the plethysmography data during an onset of the respiratory event,

estimating effect of autonomous nervous system on the DC component of the plethysmography data during the respiratory event; and

subtracting the effect of the autonomous nervous system from the plethysmography data to obtain the respiratory effort.

15. The method for detection of respiratory effort during a respiratory event according to claim 14, wherein respiratory event is apnea or hypopnea.

16. The method for detection of respiratory effort during a respiratory event according to claim 14, wherein peripheral plethysmography data is collected with a photosensor.

17. The method for detection of respiratory effort during a respiratory event according to claim 14, wherein peripheral plethysmography data is collected with a pressure sensor.

18. The method for detection of respiratory effort during a respiratory event according to claim 14, wherein peripheral plethysmography data is collected with an impedance sensor.

19. The method for detection of respiratory effort occurring during a respiratory event according to claim 14, wherein the respiratory efforts are detected by applying a frequency filter to the plethysmography signal.

20. The method for detection of respiratory effort occurring during a respiratory event according to claim 14, wherein the respiratory efforts are detected by applying a Fourier analysis to the plethysmography signal.