# US 2016/0256644 A1 · Methods and devices for the detection of hypopnoea > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0256644 A1 - Document ID: US20160256644A1 - Status: Published application - Kind: A1 - Application number: 15/156,471 - Filed: 2016-05-17 - Published: 2016-09-08 - Earliest claimed: 2009-06-05 - Assignees: ResMed Limited - Applicants: ResMed Limited - Inventors: Jeffrey Peter Armitstead - Web page: https://patentgrep.com/patent/US20160256644A1 ## CPC - A61M 16/0069: {the speed thereof being controlled by respiratory parameters, e.g. by inhalation} - A61B 5/087: Measuring breath flow - A61B 5/4818: {Sleep apnoea} - A61B 5/725: {using specific filters therefor, e.g. Kalman or adaptive filters (specific diagnostics methods using using bioelectric or biomagnetic signals A61B5/316)} - A61B 5/7278: {Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals} - A61B 5/7282: {Event detection, e.g. detecting unique waveforms indicative of a medical condition (cough events A61B5/0823; seizures A61B5/4094; sleep apnoea A61B5/4818)} - A61M 16/0003: {Accessories therefor, e.g. sensors, vibrators, negative pressure} - A61M 16/024: {including calculation means, e.g. using a processor} - A61M 16/0666: {Nasal cannulas or tubing (devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02)} - A61M 16/0875: {Connecting tubes} - A61M 2016/003: {with a flowmeter} - A61M 2016/0039: {in the inspiratory circuit} - A61M 2205/3334: Measuring or controlling the flow rate - A61M 2205/505: Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches - A61M 2230/205: partial oxygen pressure (P-O2) - A61M 2230/40: Respiratory characteristics - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Automated methods provide hypopnea detection for determining a hypopnea event and/or a severity of a hypopnea event. In some embodiments, a calculated short-term variance of a measured respiratory flow signal are compared to first and second proportions of a calculated long-term variance of the measured flow signal. A detection of the hypopnea may be indicated if the first measure falls below and does not exceed a range of the first and second proportions during a first time period. In some embodiments, a hypopnea severity measure is determined by automated measuring of an area bounded by first and second crossings of a short-term measure of ventilation and a proportion of a long-term measure. The detection methodologies may be implemented for data analysis by a specific purpose computer, a detection device that measures a respiratory airflow or a respiratory treatment apparatus that provides a respiratory treatment regime based on the detected hypopneas. ## Claims ### Claim 1 A hypopnea detection apparatus comprising: a controller having at least one processor to access data representing a measured flow of breathable gas, the controller being further configured to control: a detection of an hypopnea event from the data representing the measured flow of breathable gas; a determination of a measure indicative of obstruction coincident with the hypopnea event in the data representing the measured flow; and a classification of the detected hypopnea event as obstructive or central based on the determining of the measure indicative of obstruction. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the determination detects partial obstruction and the classification comprises scoring an obstructive hypopnea event. ### Claim 3 (depends on 2) The apparatus of claim 2 wherein the controller is further configured to control a detection of an absence of a breath and the classification comprises scoring a central hypopnea event. ### Claim 4 (depends on 2) The apparatus of claim 2 wherein the controller is further configured to detect an absence of a breath coincident with a further detected hypopnea event and to refrain from scoring the further detected hypopnea event based on the detected absence of a breath. ### Claim 5 (depends on 1) The apparatus of claim 1 further comprising: a flow generator configured to produce a breathable gas for a patient at a pressure above atmospheric pressure; and a flow sensor, wherein the controller is further configured to measure the flow of breathable gas with the flow sensor and to control the flow generator to produce the breathable gas according to a pressure therapy regime based on the classification of the detected hypopnea event. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the determination detects a breathing cycle and the classification comprises scoring an obstructive hypopnea event. ### Claim 7 (depends on 1) The apparatus of claim 1 wherein the determination detects flow limitation and the classification comprises scoring an obstructive hypopnea event. ### Claim 8 (depends on 2) The apparatus of claim 2 wherein the controller is further configured to control a detection of a patency condition of a respiratory airway and wherein the classification comprises scoring a central hypopnea event. ### Claim 9 (depends on 2) The apparatus of claim 2 wherein the controller is further configured to detect a patency condition of a respiratory airway coincident with a further detected hypopnea event and to refrain from scoring the further detected hypopnea event based on the detected patency condition of the respiratory airway. ### Claim 10 A method for detecting a hypopnea comprising: in a controller having at least one processor, the controller configured to receive a signal from a sensor indicating a measured flow of breathable gas: accessing data representing the measured flow of breathable gas; detecting a hypopnea event from the data representing the measured flow of breathable gas; determining a measure indicative of obstruction coincident with the hypopnea event in the data representing the measured flow; and classifying the detected hypopnea event as obstructive or central based on the determining of the measure indicative of obstruction. ### Claim 11 (depends on 10) The method of claim 10 wherein the determining comprises detecting partial obstruction and the classifying comprises scoring an obstructive hypopnea event. ### Claim 12 (depends on 11) The method of claim 11 further comprising controlling, with the controller, a detection of an absence of a breath and wherein the classifying comprises scoring a central hypopnea event. ### Claim 13 (depends on 11) The method of claim 11 further comprising detecting, in the controller, an absence of a breath coincident with a further detected hypopnea event and refraining from scoring the further detected hypopnea event based on the detected absence of a breath. ### Claim 14 (depends on 10) The method of claim 10 further comprising: producing, with a flow generator, a breathable gas for a patient at a pressure above atmospheric pressure; and measuring, with the controller, the flow of breathable gas with the sensor, the sensor comprising a flow sensor; and controlling, with the controller, the flow generator to produce the breathable gas according to a pressure therapy regime based on the classifying of the detected hypopnea event. ### Claim 15 (depends on 10) The method of claim 10 wherein the determining comprises detecting a breathing cycle and the classifying comprises scoring an obstructive hypopnea event. ### Claim 16 (depends on 10) The method of claim 10 wherein the determining comprises detecting flow limitation and the classifying comprises scoring an obstructive hypopnea event. ### Claim 17 (depends on 11) The method of claim 11 further comprising controlling, with the controller, a detection of a patency condition of a respiratory airway and wherein the classifying comprises scoring a central hypopnea event. ### Claim 18 (depends on 11) The method of claim 11 further comprising detecting a patency condition of a respiratory airway coincident with a further detected hypopnea event and refraining from scoring the further detected hypopnea event based on the detected patency condition of the respiratory airway. ### Claim 19 A method for detecting a hypopnea from a measured flow of breathable gas, the method comprising: in a controller having at least one processor, the controller configured to receive a signal from a sensor indicating the measured flow of breathable gas: accessing data representing the measured flow of breathable gas; determining a long-term measure of ventilation from the measured flow; determining a short-term measure of ventilation from the measured flow; determining a threshold as a proportion of the long-term measure of ventilation; measuring an area bounded by first and second crossings of the short-term measure of ventilation and the threshold; and detecting the hypopnea with the measured area. ### Claim 20 (depends on 19) The method of claim 19 wherein the measuring the area comprises integrating a difference between the threshold and the short-term measure of ventilation during a time period from when the short-term measure falls below the threshold to when the short-term measure exceeds the threshold.