# US 12,109,007 B2 · Sensing for heart failure management > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,007 B2 - Document ID: US12109007B2 - Status: Granted - Kind: B2 - Application number: 18/492,038 - Filed: 2023-10-23 - Published: 2024-02-15 - Granted: 2024-10-08 - Earliest claimed: 2019-05-03 - Assignees: Medtronic, Inc. - Applicants: Medtronic, Inc. - Inventors: Alfonso Aranda Hernandez; Richard Cornelussen; Mirko de Melis; Richard Sutton; Berthold Stegemann - Web page: https://patentgrep.com/patent/US12109007B2 ## CPC - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/076: {Permanent implantation} - A61B 5/349: Detecting specific parameters of the electrocardiograph cycle - A61B 5/686: {Permanently implanted devices, e.g. pacemakers, other stimulators, biochips (A61B5/6861 takes precedence)} - A61B 5/6861: {Capsules, e.g. for swallowing or implanting} - A61B 5/6869: {Heart} - 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 5/02405: {Determining heart rate variability} - A61B 5/0816: {Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00)} - A61B 5/1116: {Determining posture transitions} - A61B 5/1118: {Determining activity level} - A61B 5/282: Holders for multiple electrodes (for introduction into the body A61B5/287) - A61B 2562/0219: Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches - A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract In some examples, determining a heart failure status using a medical device comprising one or more sensors includes determining a first value of a heart beat variability metric of a patient while an activity state of a patient satisfies an inactivity criterion based on a signal received from the one or more sensors, and determining, within a predetermined period of time after further determining that the activity state of the patient no longer satisfies the inactivity criterion, a second value of the heart beat variability metric while the activity state of the patient no longer satisfies the inactivity criterion based on the signal. A difference between the first value of the heart beat variability metric and the second value of the heart beat variability metric may be determined and the heart failure status of the patient may be determined based on the difference. ## Claims ### Claim 1 A system for determining a heart failure status of a patient using a medical device, the system comprising: the medical device, wherein the medical device comprises one or more sensors; and processing circuitry configured to: determine a first value of at least one heart beat variability metric of the patient while an activity state of the patient satisfies at least one inactivity criterion based on at least one signal received from the one or more sensors; determine, in response to and within a predetermined period of time after the activity state of the patient no longer satisfies the at least one inactivity criterion, a second value of the at least one heart beat variability metric while the activity state of the patient no longer satisfies the at least one inactivity criterion based on at least one signal received from the one or more sensors, the predetermined period of time being less than thirty minutes; and generate the heart failure status of the patient, based, at least in part, on the first value of the at least one heart beat variability metric and the second value of the at least one heart beat variability metric, to be output at an output device for medical intervention that is based on the heart failure status. ### Claim 2 (depends on 1) The system of claim 1, wherein the processing circuitry is configured to generate the heart failure status of the patient based, at least in part, on a comparison of the first value of the at least one heart beat variability metric to the second value of the at least one heart beat variability metric. ### Claim 3 (depends on 2) The system of claim 2, wherein the processing circuitry is configured to compare the first value of the at least one heart beat variability metric to the second value of the at least one heart beat variability metric to determine the comparison. ### Claim 4 (depends on 2) The system of claim 2, wherein the processing circuitry is configured to generate the heart failure status of the patient based on the comparison between of the first value of the at least one heart beat variability metric to the second value of the at least one heart beat variability metric by at least determining whether the comparison between the first value of the at least one heart beat variability metric and the second value of the at least one heart beat variability metric satisfies a heart beat variability comparison threshold value that is associated with a change in the heart failure status of the patient. ### Claim 5 (depends on 1) The system of claim 1, wherein the at least one signal comprises at least one first signal, and wherein the processing circuitry is configured to determine that the activity state of the patient satisfies at least one inactivity criterion based on at least one second signal received from the one or more sensors. ### Claim 6 (depends on 5) The system of claim 5, wherein the processing circuitry is configured to determine, after determining the first value of the at least one heart beat variability metric, that the activity state of the patient no longer satisfies the at least one inactivity criterion based on at least one third signal received from the one or more sensors. ### Claim 7 (depends on 1) The system of claim 1, wherein the processing circuitry is configured to generate the heart failure status of the patient based on the difference by at least determining a possibility that the patient will experience an adverse medical event based on the difference. ### Claim 8 (depends on 1) The system of claim 1, wherein the at least one inactivity criterion comprises a value of least one of a patient activity level, a patient posture, a time of day, a patient heart rate, or a patient respiration rate. ### Claim 9 (depends on 1) The system of claim 1, wherein the at least one heart beat variability metric comprises a corresponding at least one of a T-wave alternans metric, a PR duration metric, a short-term variability metric, or a phase-rectified signal averaging metric. ### Claim 10 (depends on 1) The system of claim 1, wherein the medical device is an implantable medical device configured for implantation within the patient, the implantable medical device comprising a housing configured for subcutaneous implantation, and the one or more sensors are positioned on or within the housing. ### Claim 11 (depends on 1) The system of claim 1, wherein the processing circuitry is further configured to: transmit the heart failure status of the patient to a remote computer; receive, from the remote computer, instructions for medical intervention based on the heart failure status of the patient; and transmit the instructions for medical intervention to a user interface. ### Claim 12 An implantable medical device comprising: one or more sensors; and processing circuitry configured to: determine a first value of at least one heart beat variability metric of the patient while an activity state of the patient satisfies the at least one inactivity criterion based on at least one signal received from the one or more sensors; determine, in response to and within a predetermined period of time after the activity state of the patient no longer satisfies the at least one inactivity criterion, a second value of the at least one heart beat variability metric while the activity state of the patient no longer satisfies the at least one inactivity criterion based on the at least one signal received from the one or more sensors, the predetermined period of time being less than thirty minutes; and generate the heart failure status of the patient, based, at least in part, on the first value of the at least one heart beat variability metric and the second value of the at least one heart beat variability metric, to be output at an output device for medical intervention that is based on the heart failure status. ### Claim 13 (depends on 12) The implantable medical device of claim 12, wherein the processing circuitry is configured to generate the heart failure status of the patient based, at least in part, on a comparison of the first value of the at least one heart beat variability metric to the second value of the at least one heart beat variability metric. ### Claim 14 (depends on 13) The implantable medical device of claim 13, wherein the processing circuitry is configured to compare the first value of the at least one heart beat variability metric to the second value of the at least one heart beat variability metric to determine the comparison. ### Claim 15 (depends on 13) The implantable medical device of claim 13, wherein the processing circuitry is configured to generate the heart failure status of the patient based on the comparison between of the first value of the at least one heart beat variability metric to the second value of the at least one heart beat variability metric by at least determining whether the comparison between the first value of the at least one heart beat variability metric and the second value of the at least one heart beat variability metric satisfies a heart beat variability comparison threshold value that is associated with a change in the heart failure status of the patient. ### Claim 16 (depends on 13) The implantable medical device of claim 13, wherein the at least one signal comprises at least one first signal, and wherein the processing circuitry is configured to determine that the activity state of the patient satisfies at least one inactivity criterion based on at least one second signal received from the one or more sensors. ### Claim 17 (depends on 16) The implantable medical device of claim 16, wherein the processing circuitry is configured to determine, after determining the first value of the at least one heart beat variability metric, that the activity state of the patient no longer satisfies the at least one inactivity criterion based on at least one third signal received from the one or more sensors. ### Claim 18 (depends on 12) The implantable medical device of claim 12, wherein the processing circuitry is configured to generate the heart failure status of the patient based on the difference by at least determining a possibility that the patient will experience an adverse medical event based on the difference. ### Claim 19 (depends on 12) The implantable medical device of claim 12, wherein the at least one inactivity criterion comprises a value of least one of a patient activity level, a patient posture, a time of day, a patient heart rate, or a patient respiration rate. ### Claim 20 (depends on 12) The implantable medical device of claim 12, wherein the at least one heart beat variability metric comprises a corresponding at least one of a T-wave alternans metric, a PR duration metric, a short-term variability metric, or a phase-rectified signal averaging metric. ### Claim 21 (depends on 12) The implantable medical device of claim 12 further comprising a housing configured for subcutaneous implantation, and the one or more sensors are positioned on or within the housing. ### Claim 22 (depends on 12) The implantable medical device of claim 12, wherein the processing circuitry is further configured to: transmit the heart failure status of the patient to a remote computer; receive, from the remote computer, instructions for medical intervention based on the heart failure status of the patient; and deliver therapy to the patient based on the instructions for medical intervention.