# US 11,298,076 B2 · Methods and systems for alerting practitioners to physiological conditions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,076 B2 - Document ID: US11298076B2 - Status: Granted - Kind: B2 - Application number: 16/119,770 - Filed: 2018-08-31 - Published: 2018-12-27 - Granted: 2022-04-12 - Earliest claimed: 2008-02-19 - Assignees: Covidien LP - Applicants: Covidien LP - Inventors: James Ochs; Scott Amundson; Keith Batchelder - Web page: https://patentgrep.com/patent/US11298076B2 ## CPC - A61B 5/4818: {Sleep apnoea} - A61B 5/002: {Monitoring the patient using a local or closed circuit, e.g. in a room or building (A61B5/0017 takes precedence)} - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/14551: {for measuring blood gases} - A61B 5/14552: {Details of sensors specially adapted therefor} - A61B 5/7246: {using correlation, e.g. template matching or determination of similarity} - 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)} - A61B 5/7405: {using sound} - A61B 5/742: {using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339)} - A61B 5/746: {Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms} - A61B 5/7475: {User input or interface means, e.g. keyboard, pointing device, joystick} - A61M 16/0051: {with alarm devices} - A61M 16/021: {operated by electrical means (A61M16/202 – A61M16/205 take precedence)} - A61M 16/06: Respiratory or anaesthetic masks - G08B 21/0453: {worn on the body to detect health condition by physiological monitoring, e.g. electrocardiogram, temperature, breathing (detecting, measuring or recording for diagnostic purposes A61B5/00)} - A61B 5/02416: {using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence)} - A61B 5/14542: {for measuring blood gases (A61B5/14551 takes precedence)} - A61B 5/1455: using optical sensors, e.g. spectral photometrical oximeters - A61M 2205/18: with alarm - A61M 2205/50: with microprocessors or computers - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - 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)} - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## Abstract Embodiments of the present disclosure provide systems and methods for monitoring a patient to produce a signal representing a blood oxygen concentration. The signal may be analyzed to determine the presence of one or more sleep apnea events, and an integral of the signal may be calculated if the signal is outside of a set range or threshold. A practitioner may choose to be informed of the presence of sleep apnea events if the blood oxygen concentration is less then a preset limit, if an upper limit has been reached for an integral representing the severity of the oxygen deprivation over time, or anytime sleep apnea events may be present in the signal. ## Claims ### Claim 1 A system, comprising: a processor configured to: determine a presence of a plurality of oxygen desaturation patterns in a photoplethsymograph (PPG) signal; determine that a first oxygen desaturation pattern of the plurality of oxygen desaturation patterns is qualified based on a qualification function; adjust the qualification function in response to determining that the first oxygen desaturation pattern is qualified; determine that a second oxygen desaturation pattern of the plurality of oxygen desaturation patterns is qualified based on the adjusted qualification function, wherein the adjusted qualification function is less stringent than the qualification function, and wherein the second oxygen desaturation pattern is not qualified based on the qualification function but is qualified based on the adjusted qualification function; and trigger a sleep apnea alarm in response to the determination that the first oxygen desaturation pattern and the second oxygen desaturation pattern are qualified. ### Claim 2 (depends on 1) The system of claim 1, wherein the processor is configured to count consecutive qualified desaturation patterns and to trigger the sleep apnea alarm in response to a count above a predetermined alarm count threshold. ### Claim 3 (depends on 2) The system of claim 2, wherein the processor is configured to adjust the qualification function in response to the count of the consecutive desaturation patterns being above a predetermined qualification count. ### Claim 4 (depends on 1) The system of claim 1, wherein the qualification function is based on: a slope ratio between the fall slope and the rise slope of a desaturation pattern; a magnitude of the desaturation pattern between a rise peak and a fall peak; a fall slope of the desaturation pattern between a fall peak and a nadir; a path length ratio of the desaturation pattern; a difference between consecutive desaturation patterns; or a combination thereof. ### Claim 5 (depends on 1) The system of claim 1, comprising a PPG sensor configured to generate the PPG signal. ### Claim 6 (depends on 1) The system of claim 1, wherein the processor is configured to increase an air pressure supplied by the system in response to triggering the sleep apnea alarm. ### Claim 7 (depends on 1) The system of claim 1, wherein the processor is configured to adjust the qualification function to qualify desaturation patterns having maximum oxygen saturations above a threshold. ### Claim 8 A system, comprising: a photoplethsymograph (PPG) sensor configured to generate a PPG signal; and a patient monitor comprising: a processor configured to: receive the PPG signal from the PPG sensor; determine a presence of one or more oxygen desaturation patterns in a photoplethsymograph (PPG) signal; determine that a first oxygen desaturation pattern of the one or more oxygen desaturation patterns is indicative of sleep apnea based on at least a predetermined range or a predetermined threshold; increase a count of consecutive desaturation patterns in response to determining that the first oxygen desaturation pattern is indicative of sleep apnea based on the predetermined range or the predetermined threshold, wherein the first oxygen desaturation pattern is within a predetermined time period; adjust a qualification function based on the count of consecutive desaturation patterns; determine that a second oxygen desaturation pattern is indicative of sleep apnea, and wherein the second oxygen desaturation pattern is not qualified based on the qualification function but is qualified based on the adjusted qualification function; and provide an indication of sleep apnea in response to determining that both the first oxygen desaturation pattern and the second oxygen desaturation pattern are indicative of sleep apnea. ### Claim 9 (depends on 8) The system of claim 8, comprising a display coupled to the processor, wherein the processor is configured to provide the indication of sleep apnea as a visual indicator on the display. ### Claim 10 (depends on 8) The system of claim 8, comprising a mask operatively coupled to the processor, wherein the processor is configured to increase an air pressure supplied by the system via the mask in response to providing the indication of sleep apnea. ### Claim 11 (depends on 8) The system of claim 8, comprising a network interface operatively coupled to the processor and configured to send the indication of sleep apnea to a device located on a local area network. ### Claim 12 (depends on 8) The system of claim 8, wherein the first oxygen desaturation pattern and the second oxygen desaturation pattern are part of a cluster of the one or more oxygen desaturation patterns in the PPG signal. ### Claim 13 (depends on 8) The system of claim 8, wherein the processor is configured to: determine a value for an integral in response to a determination that the PPG signal is outside of a PPG range or a PPG threshold; compare the value of the integral to an integral threshold; and provide the indication of sleep apnea based on a result of the comparing and the determination that first oxygen desaturation pattern and the second oxygen desaturation pattern are indicative of sleep apnea. ### Claim 14 A method, comprising: determining, via the processor, a presence of one or more oxygen desaturation patterns in a photoplethsymograph (PPG) signal; adjusting, via the processor, a qualification function in response to a determination that a first oxygen desaturation pattern of the one or more oxygen desaturation patterns is indicative of sleep apnea; determining, via the processor, that a second oxygen desaturation pattern of the plurality of oxygen desaturation patterns is indicative of sleep apnea, and wherein the second oxygen desaturation pattern is not qualified based on the qualification function but is qualified based on the adjusted qualification function; determining, via the processor, a presence of a cluster based on determining that both the first oxygen desaturation pattern and the second oxygen desaturation pattern are indicative of sleep apnea; determining, via the processor, a value for an integral in response to a determination that the PPG signal is outside of a PPG range or a PPG threshold; and providing, via the processor, an indication of sleep apnea in response to the cluster detection and the value being above a combined alarm limit associated with cluster detection. ### Claim 15 (depends on 14) The method of claim 14, wherein the combined alarm limit is lower than an integral alarm threshold associated with no cluster detection. ### Claim 16 (depends on 14) The method of claim 14, wherein the indication of sleep apnea is an alarm. ### Claim 17 (depends on 14) The method of claim 14, wherein the indication of sleep apnea is displayed on a display. ### Claim 18 (depends on 14) The method of claim 14, comprising increasing, via the processor, an air pressure supplied by a system in response to the indication of sleep apnea. ### Claim 19 (depends on 14) The method of claim 14, comprising: generating, via a PPG sensor, the PPG signal; and receiving, via the processor, the PPG signal from the PPG sensor.