# US 11,896,386 B2 · Coherence-based method, apparatus, and system for identifying corresponding signals of a physiological study > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,386 B2 - Document ID: US11896386B2 - Status: Granted - Kind: B2 - Application number: 15/997,282 - Filed: 2018-06-04 - Published: 2018-12-06 - Granted: 2024-02-13 - Earliest claimed: 2017-06-02 - Assignees: Nox Medical Ehf - Applicants: Nox Medical Ehf - Inventors: Sveinbjörn Höskuldsson; Jón Skírnir Ágústsson - Web page: https://patentgrep.com/patent/US11896386B2 ## CPC - A61B 5/4818: {Sleep apnoea} - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/02405: {Determining heart rate variability} - A61B 5/02416: {using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence)} - A61B 5/113: occurring during breathing - A61B 5/1135: {by monitoring thoracic expansion} - A61B 5/117: Identification of persons (methods or arrangements for recognising patterns, e.g. fingerprints, G06F18/00, G06V40/00; identification of persons by analysing their voice or speech G10L17/00) - A61B 5/318: Heart-related electrical modalities, e.g. electrocardiography [ECG] - A61B 5/4806: {Sleep evaluation (A61B5/4821 takes precedence; devices for inducing sleep A61M21/02)} - A61B 5/7221: {Determining signal validity, reliability or quality (preventing, reducing or removing noise induced by motion artefacts A61B5/7207; noise originating from a therapeutic or surgical apparatus A61B5/7217)} - 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} - G06F 21/32: using biometric data, e.g. fingerprints, iris scans or voiceprints - A61B 5/0245: by using sensing means generating electric signals, {i.e. ECG signals} - A61B 5/086: {by impedance pneumography} - A61B 5/1455: using optical sensors, e.g. spectral photometrical oximeters - A61B 5/4815: {Sleep quality} - A61B 5/7267: {involving training the classification device} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method, apparatus, and system for determining a correspondence of physiological data obtained in a physiological study of a subject. The method includes extracting a first signal from the physiological study. A second signal from the physiological study is also extracted. The first signal and the second signal are obtained by one or more biometric sensors. Data of the first signal and data of the second signal are stored on a memory storage. A coherency value is determined between components of the extracted first signal and components of the extracted second signal. And the correspondence of the physiological study data is determined based on the determined coherency value. ## Claims ### Claim 1 A method for determining whether a first signal and a second signal of a physiological study originate from a same intended subject, the method comprising: extracting the first signal from the physiological study, the physiological study being a sleep study, the first signal being a respiratory inductance plethysmography (RIP) signal obtained in the sleep study; extracting the second signal from the physiological study, the second signal being a pulse-measuring signal obtained in the sleep study, and data of the RIP signal and data of the pulse-measuring signal being stored on a memory storage; determining a coherency value between components of the RIP signal and components of the pulse-measuring signal; determining whether the RIP signal and the pulse-measuring signal originate from the same intended subject based on the determined coherency value; and wherein determining the coherency value includes sampling a first frequency band of the RIP signal, sampling a second frequency band of the pulse-measuring signal, and determining whether a synchronous relationship exists between components of the first frequency band of the RIP signal and the second frequency band of the pulse-measuring signal, wherein the first frequency band and the second frequency band include heart rate and/or harmonics of the heart rate and/or respiratory rate and/or harmonics of the respiratory rate in the subject during the physiological study, wherein in a case that the RIP signal and the pulse-measuring signal are determined to originate from the same intended subject, data of the physiological study is indicated to be usable for diagnosing a sleep disorder of the intended subject or determining that the intended subject does not suffer from a sleep disorder, and in a case the case that the RIP signal and the pulse-measuring signal are determined to not originate from the same intended subject, data of the physiological study is indicated to be falsified. ### Claim 2 (depends on 1) The method according to claim 1, further comprising determining a presence within the first signal and the second signal of a trigger signal portion of a same physiological origin. ### Claim 3 (depends on 1) The method according to claim 1, wherein the second signal includes a photoplethysmography signal, an electrocardiogram (ECG) signal, an accelerometer signal, a pulse oximeter, a pulse plethysmography signal, a pulse meter signal, and/or an audio signal. ### Claim 4 (depends on 1) The method according to claim 1, wherein the step of determining the coherency value is based on a determination of a coherency between a first frequency component of the first signal and a second frequency component of the second signal. ### Claim 5 (depends on 1) The method according to claim 1, further comprising identifying a further common physiological event present in both the first signal and the second signal. ### Claim 6 (depends on 1) The method according to claim 1, further comprising identifying a further common physiological event present in both the first signal and the second signal, wherein the common physiological event includes one or more, or coupling between, body movement, brain activity, skin conductance, muscle tone, eye movement, or sound. ### Claim 7 (depends on 1) The method according to claim 1, wherein the step of determining the coherency value includes measuring a coupling strength of common harmonics between the first signal and the second signal, and determining whether at least some components of the first signal and the second signal originate from a common physiological origin. ### Claim 8 (depends on 1) The method according to claim 1, wherein the second signal is a photoplethysmography signal, and the first frequency band and the second frequency band include the heart rate and harmonics of the heart rate in the subject during the physiological study. ### Claim 9 (depends on 1) The method according to claim 1, wherein the first frequency band and the second frequency band include heart rate and harmonics of the heart rate in the subject during the physiological study. ### Claim 10 (depends on 1) The method according to claim 1, wherein the second signal is a plethysmography signal. ### Claim 11 (depends on 1) The method according to claim 1, wherein the first frequency band and the second frequency band include respiratory rate and harmonics of the respiratory rate in the subject during the physiological study. ### Claim 12 (depends on 1) The method according to claim 1, wherein the respiratory inductance plethysmography (RIP) signal is obtained by one or more RIP belts, and wherein the method further comprises detecting during the physiological study whether the one or more RIP belts becomes disconnected from the intended subject. ### Claim 13 (depends on 1) The method according to claim 1, further comprising monitoring of the intended subject during the physiological study with a camera to confirm that the first signal and the second signal are obtained from the intended subject of the physiological study. ### Claim 14 A system to determine whether a first signal and a second signal of a physiological study originate from a same intended subject, the system comprising: one or more processors; and one or more memory storages, wherein the one or more memory storages have stored thereon the data of the physiological study, wherein the one or more processors are configured to perform the following extract the first signal from the physiological study, the physiological study being a sleep study, the first signal being a respiratory inductance plethysmography (RIP) signal obtained in the sleep study; extract the second signal from the physiological study, the second signal being a pulse-measuring signal obtained in the sleep study, and data of the RIP signal and data of the pulse-measuring signal being stored on the one or more memory storage devices; determine a coherency value between components of the extracted RIP signal and components of the pulse-measuring signal; and determine whether the RIP signal and the pulse-measuring signal originate from the same intended subject based on the determined coherency value, wherein the one or more processors determines the coherency value by sampling a first frequency band of the RIP signal, sampling a second frequency band of the pulse-measuring signal, and determining whether a synchronous relationship exists between components of the first frequency band of the RIP signal and the second frequency band of the pulse-measuring signal, wherein the first frequency band and the second frequency band include heart rate and/or harmonics of the heart rate and/or respiratory rate and/or harmonics of the respiratory rate in the subject during the physiological study, wherein in a case that the RIP signal and the pulse-measuring signal are determined to originate from the same intended subject, the one or more processors indicates data of the physiological study to be usable for diagnosing a sleep disorder of the intended subject or determining that the intended subject does not suffer from a sleep disorder, and in a case that the RIP signal and the pulse-measuring signal are determined to not originate from the same intended subject, the one or more processors indicates data of the physiological study to be indicated to be falsified. ### Claim 15 (depends on 14) The system according to claim 14, wherein the one or more processors are further configured to determine a presence within the first signal and the second signal of a trigger signal portion of a same physiological origin. ### Claim 16 (depends on 14) The system according to claim 14, wherein the second signal includes a photoplethysmography signal, an electrocardiogram (ECG) signal, an accelerometer signal, a pulse oximeter, a pulse plethysmography signal, a pulse meter signal, or an audio signal. ### Claim 17 (depends on 14) The system according to claim 14, wherein the one or more processors are further configured to determine the coherency value based on a determination of a coherency between a first frequency component of the first signal and a second frequency component of the second signal. ### Claim 18 (depends on 14) The system according to claim 14, wherein the one or more processors are further configured to identify a further common physiological event present in both the first signal and the second signal. ### Claim 19 (depends on 18) The system according to claim 18, wherein the common physiological event includes one or more, or coupling between, body movement, brain activity, skin conductance, muscle tone, eye movement, or sound. ### Claim 20 (depends on 14) The system according to claim 14, wherein the one or more processors are further configured to determine the coherency value by measuring a coupling strength of common harmonics between the first signal and the second signal, and determining whether at least some components of the first signal and the second signal originate from a common physiological origin. ### Claim 21 One or more non-transitory computer-readable mediums having stored thereon executable instructions that when executed by one or more processors configure a computer system to perform a method for determining whether a first signal and a second signal of a physiological study originate from a same intended subject based, including the following: extract the first signal from the physiological study, the physiological study being a sleep study, the first signal being a respiratory inductance plethysmography (RIP) signal obtained in the sleep study; extract the second signal from the physiological study, the second signal being a pulse-measuring signal obtained in the sleep study, and data of the RIP signal and data of the pulse-measuring signal being stored on the one or more memory storage device; determine a coherency value between components of the RIP signal and components of the pulse-measuring signal; and determine whether the RIP signal and the pulse-measuring signal originate from the same intended subject based on the determined coherency value, wherein the one or more processors determines the coherency value by sampling a first frequency band of the RIP signal, sampling a second frequency band of the pulse-measuring signal, and determining whether a synchronous relationship exists between components of the first frequency band of the RIP signal and the second frequency band of the pulse-measuring signal, wherein the first frequency band and the second frequency band include heart rate and/or harmonics of the heart rate and/or respiratory rate and/or harmonics of the respiratory rate in the subject during the physiological study, wherein in a case that the RIP signal and the pulse-measuring signal are determined to originate from the same intended subject, the one or more processors indicates data of the physiological study to be usable for diagnosing a sleep disorder of the intended subject or determining that the intended subject does not suffer from a sleep disorder, and in a case the case that the RIP signal and the pulse-measuring signal are determined to not originate from the same intended subject, the one or more processors indicates data of the physiological study to be indicated to be falsified.