# US 11,433,201 B2 · Methods and apparatus for treating respiratory disorders > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,433,201 B2 - Document ID: US11433201B2 - Status: Granted - Kind: B2 - Application number: 16/071,334 - Filed: 2017-02-01 - Published: 2021-07-08 - Granted: 2022-09-06 - Earliest claimed: 2016-02-02 - Assignees: ResMed Pty Ltd - Applicants: ResMed Pty Ltd - Inventors: Dinesh Ramanan - Web page: https://patentgrep.com/patent/US11433201B2 ## CPC - A61B 5/4812: {Detecting sleep stages or cycles} - A61M 16/024: {including calculation means, e.g. using a processor} - A61B 5/087: Measuring breath flow - A61B 5/4809: {Sleep detection, i.e. determining whether a subject is asleep or not} - A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)} - 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 16/0066: {Blowers or centrifugal pumps} - A61M 16/0683: {Holding devices therefor} - A61M 16/16: Devices to humidify the respiration air {(A61M16/1045 takes precedence)} - A61B 5/0871: {Peak expiratory flowmeters} - A61B 5/091: Measuring volume of inspired or expired gases, e.g. to determine lung capacity - A61B 5/097: Devices for facilitating collection of breath or for directing breath into or through measuring devices - A61B 5/4818: {Sleep apnoea} - A61M 16/0069: {the speed thereof being controlled by respiratory parameters, e.g. by inhalation} - A61M 16/0633: {with forehead support} - A61M 16/1055: {bacterial} - A61M 2016/0027: {pressure meter} - A61M 2016/003: {with a flowmeter} - A61M 2016/0036: {in the breathing tube and used in both inspiratory and expiratory phase} - A61M 2202/0208: Oxygen - A61M 2205/07: having air pumping means - A61M 2205/18: with alarm - A61M 2205/42: Reducing noise - A61M 2205/502: User interfaces, e.g. screens or keyboards - A61M 2205/52: with memories providing a history of measured variating parameters of apparatus or patient - A61M 2230/40: Respiratory characteristics - 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)} ## Abstract Methods and apparatus infer or indicate sleep stage(s) of a patient from a respiratory flow rate signal of the patient. The method may include applying a plurality of detection pathways to a signal representing a respiratory flow rate of the patient, wherein each detection pathway is configured to generate start events and end events indicating start times and end times of episodes respectively of a corresponding sleep stage, wherein each start event and each end event has a priority; and combining the start events and end events based on their priorities to produce an indication of the sleep stage of the patient. The apparatus may include a sensor configured to generate a signal representing a property of a flow of air within a patient interface; and a processor configured to implement a method of inferring a sleep stage of the patient from the signal. ## Claims ### Claim 1 A method of indicating a sleep stage of a patient, the method comprising: applying, in one or more processors, a plurality of detection pathways to a signal representing a respiratory flow rate of the patient, wherein each detection pathway is configured to generate start events and end events indicating start times and end times respectively of episodes of a corresponding sleep stage, wherein each start event and each end event has a priority; and combining, in the one or more processors, the start events and end events based on their priorities to produce an indication of a sleep stage of the patient, wherein when the start events and end events indicate a detection collision comprising contradictory sleep stages for the patient that overlap in time, resolving the detection collision by: disregarding a detection of a sleep stage, for the patient, that has a first priority in favor of a detection of a sleep stage, for the patient, that has a second priority, and producing the detection of the sleep stage that has the second priority as the sleep stage of the patient. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more processors is configured to resolve detection collisions between sleep stages detected by different detection pathways. ### Claim 3 (depends on 1) The method of claim 1, wherein the combining comprises disregarding a detected stage of a lower priority in favor of a detected sleep stage of higher priority. ### Claim 4 (depends on 1) The method of claim 1, wherein the one or more processors is configured to indicate the sleep stage from a set of stages including any two or more of: deep sleep; Long-term awake type 2; respiratory event sleep (RES); Long-term awake type 1; Short-term awake; and REM. ### Claim 5 (depends on 1) The method according to claim 1, further comprising: generating a supply of air at positive pressure to an airway of the patient; and altering a treatment pressure of the supply of air based on the indication of the sleep stage of the patient. ### Claim 6 (depends on 1) The method according to claim 1, further comprising storing the indication of the sleep stage of the patient in a hypnogram. ### Claim 7 (depends on 6) The method of claim 6 further comprising generating output, on a display, that represents the hypnogram. ### Claim 8 (depends on 1) The method according to claim 1, wherein combining the start events and end events comprises: storing the start events and end events in time order; and consolidating the start events and end events into a hypnogram based on their priorities. ### Claim 9 (depends on 1) The method according to claim 1, wherein one detection pathway is a respiratory event pathway configured to generate start events and end events indicating start times and end times respectively of episodes of respiratory event sleep. ### Claim 10 (depends on 9) The method according to claim 9, wherein the respiratory event pathway is configured to generate a respiratory event sleep start event on detecting a series of respiratory events in close succession. ### Claim 11 (depends on 10) The method according to claim 10, wherein the respiratory events are one or more of apneas, hypopneas, and respiratory event-related arousal s (RERAs). ### Claim 12 (depends on 11) The method according to claim 11, wherein each hypopnea is an obstructive hypopnea. ### Claim 13 (depends on 10) The method according to claim 10, wherein the respiratory event pathway is configured to generate a respiratory event sleep end event upon not detecting a respiratory event for a timeout threshold. ### Claim 14 (depends on 1) The method according to claim 1, wherein one detection pathway is a breathing stability pathway configured to generate start events and end events indicating start times and end times respectively of episodes of one or more of: non-respiratory-event sleep, and wakefulness. ### Claim 15 (depends on 14) The method according to claim 14, wherein non-respiratory event sleep comprises one or more of: REM sleep, and deep sleep. ### Claim 16 (depends on 1) The method according to claim 1, wherein at least one of the detection pathways comprises a REM sleep detector configured to generate a REM start event on detecting short-term and medium-term variation in breath features, but long-term stability of the breath features. ### Claim 17 (depends on 1) The method according to claim 1, wherein at least one of the detection pathways comprises a sleep onset detector configured to generate a deep sleep start event on detecting a transition of breath features from highly variable to semi-stable. ### Claim 18 (depends on 1) The method according to claim 1, wherein at least one of the detection pathways comprises a wakefulness detector configured to generate start events and end events indicating start times and end times respectively of episodes of one or more of: short-term awake; and long-term awake. ### Claim 19 (depends on 18) The method according to claim 18, wherein the wakefulness detector is configured to generate a short-term awake start event on detecting large short-term variation in breath features. ### Claim 20 (depends on 19) The method according to claim 19, wherein the wakefulness detector is configured to generate a long-term awake start event on detecting large long-term variation in breath features. ### Claim 21 (depends on 20) The method according to claim 20, wherein the wakefulness detector is configured to generate start events and end events indicating start times and end times respectively of episodes of two types of long-term awake. ### Claim 22 (depends on 21) The method according to claim 21, wherein the wakefulness detector is configured to generate a long-term awake start event of a second type on detecting medium-term variability of a breath feature. ### Claim 23 (depends on 1) The method according to claim 1, wherein: one detection pathway is a respiratory event pathway configured to generate start events and end events indicating start times and end times respectively of episodes of respiratory event sleep; and one detection pathway is a breathing stability pathway configured to generate start events and end events indicating start times and end times respectively of episodes of deep sleep, and deep sleep events have a higher priority than respiratory event sleep events. ### Claim 24 (depends on 1) The method of claim 1, wherein the plurality of detection pathways include: a first detection pathway that generates a first start event and a first end event with a priority, indicating a first sleep stage of the patient during a first time frame, and a second detection pathway that generates a second start event and a second end event with a priority, indicating a second sleep stage of the patient during a second time frame, wherein the first time frame overlaps with the second time frame, and wherein the first sleep stage contradicts the second sleep stage. ### Claim 25 (depends on 24) The method of claim 24, further comprising: comparing (a) the priority of the first start event and the first end event and (b) the priority of the second start event and the second end event; disregarding the first sleep stage in favor of the second sleep stage after determining that the priority of the second start event and the second end event is higher than the priority of the first start event and the first end event; and producing an indication that the second sleep stage is detected. ### Claim 26 (depends on 1) A computer processor-readable memory storage apparatus having processor-executable instructions encoded thereon which, when executed by a processor, cause the processor to perform a method of indicating a sleep stage of a patient, the method comprising the method of claim 1. ### Claim 27 (depends on 23) Apparatus comprising: a sensor configured to generate a signal representing a property of a flow of air within a patient interface, the patient interface configured to engage with an entrance to an airway of a patient; and one or more processors coupled with the computer processor-readable memory storage apparatus of claim 23, wherein the one or more processors is configured to indicate a sleep stage of the patient from the signal according to the processor-executable instructions encoded on the computer processor-readable memory storage apparatus. ### Claim 28 (depends on 27) The apparatus of claim 27 further comprising: a pressure generator configured to generate a supply of air at positive pressure to an airway of the patient via the patient interface over an air circuit, wherein the one or more processors is/are configured to control the supply of air based on the sleep stage indicated. ### Claim 29 Apparatus comprising: a sensor configured to generate a signal representing a property of a flow of air within a patient interface, the patient interface configured to engage with an entrance to an airway of a patient; and one or more processors configured to indicate a sleep stage of the patient from the signal, wherein the one or more processors is/are configured to: apply a plurality of detection pathways to the signal, wherein each detection pathway is configured to generate start events and end events indicating start times and end times respectively of episodes of a corresponding sleep stage, wherein each start event and each end event has a priority; and combine the start events and end events based on their priorities to produce an indication of a sleep stage of the patient, wherein when the start events and end events indicate a detection collision comprising contradictory sleep stages for the patient that overlap in time, the detection collision is resolved by: a detection of a sleep stage, for the patient, that has a first priority is disregarded in favor of a detection of a sleep stage, for the patient, that has a second priority, and the detection of the sleep stage that has the second priority is produced as the sleep stage of the patient. ### Claim 30 (depends on 29) Apparatus according to claim 29, wherein the sensor is located within the patient interface and the property is pressure. ### Claim 31 (depends on 29) Apparatus according to claim 29, wherein the one or more processors is/are located within the patient interface. ### Claim 32 (depends on 29) Apparatus according to claim 29, wherein the one or more processors is/are located in a remote external computing device configured to communicate with the patient interface. ### Claim 33 (depends on 29) Apparatus according to claim 29, further comprising: a pressure generator configured to generate a supply of air at positive pressure to an airway of the patient via the patient interface over an air circuit, and a central controller configured to control the pressure generator. ### Claim 34 (depends on 33) Apparatus according to claim 33, wherein the one or more processors is/are the central controller. ### Claim 35 (depends on 33) Apparatus according to claim 33, wherein the one or more processors is/are located in a remote external computing device configured to communicate with the central controller. ### Claim 36 (depends on 33) Apparatus according to claim 33, wherein the sensor is located within the pressure generator, and the property is flow rate. ### Claim 37 (depends on 33) Apparatus according to claim 33, wherein the sensor is located within the air circuit, and the property is flow rate. ### Claim 38 (depends on 29) The apparatus of claim 29, wherein the one or more processors is configured to resolve detection collisions between sleep stages detected by different detection pathways. ### Claim 39 (depends on 29) The apparatus of claim 29, wherein to combine the start events and end events based on their priorities the one or more processors is configured to disregard a detected stage of a lower priority in favor of a detected sleep stage of higher priority. ### Claim 40 (depends on 29) The apparatus of claim 29, wherein the one or more processors is configured to indicate the sleep stage from a set of stages including any two or more of: deep sleep; Long-term awake type 2; respiratory event sleep (RES); Long-term awake type 1; Short-term awake; and REM. ### Claim 41 (depends on 29) The apparatus of claim 29, further comprising the patient interface. ### Claim 42 A system comprising: means for generating a signal representing a property of a flow of air within a means for engaging with an entrance to an airway of a patient; means for applying a plurality of detection pathways to the signal, wherein each detection pathway is configured to generate start events and end events indicating start times and end times respectively of episodes of a corresponding sleep stage, wherein each start event and each end event has a priority; and means for combining the start events and end events based on their priorities to produce an indication of a sleep stage of the patient. ### Claim 43 (depends on 42) The system of claim 42, further comprising the means for engaging with an entrance to an airway of the patient.