# US 2021/0330983 A1 · Dynamic patient-specific filtering of an activity signal within a beating heart > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0330983 A1 - Document ID: US20210330983A1 - Status: Published application - Kind: A1 - Application number: 17/369,711 - Filed: 2021-07-07 - Published: 2021-10-28 - Earliest claimed: 2014-11-25 - Assignees: Medtronic, Inc. - Applicants: Medtronic, Inc. - Inventors: Todd J. Sheldon; Wade M. Demmer; Karen J. Kleckner; Douglas A. Peterson; Paul R. Solheim - Web page: https://patentgrep.com/patent/US20210330983A1 ## CPC - A61N 1/36542: {controlled by body motion, e.g. acceleration} - A61N 1/36067: {Movement disorders, e.g. tremor or Parkinson disease (stimulating motor muscle A61N1/36003)} - A61N 1/36128: {Control systems} - A61N 1/36135: {using physiological parameters} - A61N 1/36139: {with automatic adjustment} - A61N 1/36585: {controlled by two or more physical parameters} - A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators} - 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 An implantable medical device includes an activity sensor, a pulse generator, and a control module. The control module is configured to determine activity metrics from the activity signal and determine an activity metric value at a predetermined percentile of the activity metrics. The control module sets a lower pacing rate set point based on the activity metric value at the predetermined percentile. ## Claims ### Claim 1 An implantable cardiac device comprising: a housing configured to be implanted within a heart of a patient; an accelerometer positioned within the housing, the accelerometer configured to generate an accelerometer signal; a control circuit configured to: determine, based on the accelerometer signal, an activity metric over a time period; filter, from the activity metric determined over the time period, a portion of the activity metric expected to correspond to heart motion when the patient is at rest; determine, based on the filtered activity metric, a pacing set point; and cause a pulse generator to generate pacing pulses at the pacing set point. ### Claim 2 (depends on 1) The implantable cardiac device of claim 1, wherein the control circuit is configured to determine the activity metric over the time period by determining a plurality of activity counts over the time period. ### Claim 3 (depends on 2) The implantable cardiac device of claim 2, wherein the control circuit is configured to filter the portion of the activity metric by filtering from the plurality of activity counts a non-zero number of activity counts expected to correspond to when the patient is at rest. ### Claim 4 (depends on 3) The implantable cardiac device of claim 3, wherein the filtered activity counts are expected to correspond to heart motion when the patient is at rest. ### Claim 5 (depends on 3) The implantable cardiac device of claim 3, wherein the control circuit is configured to filter the non-zero number of activity counts from the plurality of activity counts by filtering activity counts that do not exceed a percentile of the plurality of activity counts. ### Claim 6 (depends on 5) The implantable cardiac device of claim 5, wherein the percentile is approximately 15%. ### Claim 7 (depends on 1) The implantable cardiac device of claim 1, wherein the control circuit is configured to determine the pacing set point by determining a lower rate set point that comprises a lowest pacing rate for pacing the heart. ### Claim 8 (depends on 1) The implantable cardiac device of claim 1, wherein the time period comprises a pacing set point adjustment interval. ### Claim 9 (depends on 8) The implantable cardiac device of claim 8, wherein the adjustment interval comprises a 24-hour time period. ### Claim 10 (depends on 1) The implantable cardiac device of claim 1, wherein the control circuit is configured to cause the pulse generator to generate pacing pulses at the pacing set point despite activity data received from the accelerometer that would otherwise call for pacing at a higher rate than the pacing set point. ### Claim 11 A method comprising: determining, by a control circuit of an implantable cardiac device based on an accelerometer signal, an activity metric over a time period, wherein the implantable cardiac device comprises a housing configured to be implanted within a heart of a patient, and wherein the implantable cardiac device comprises an accelerometer positioned within the housing, the accelerometer configured to generate the accelerometer signal; filtering, by the control circuit from the activity metric determined over the time period, a portion of the activity metric expected to correspond to heart motion when the patient is at rest; determining, by the control circuit based on the filtered activity metric, a pacing set point; and causing, by the control circuit, a pulse generator to generate pacing pulses at the pacing set point. ### Claim 12 (depends on 11) The method of claim 11, further comprising determining, by the control circuit, the activity metric over the time period by determining a plurality of activity counts over the time period. ### Claim 13 (depends on 12) The method of claim 12, further comprising filtering, by the control circuit, the portion of the activity metric by filtering from the plurality of activity counts a non-zero number of activity counts expected to correspond to when the patient is at rest. ### Claim 14 (depends on 13) The method of claim 13, wherein the filtered activity counts are expected to correspond to heart motion when the patient is at rest. ### Claim 15 (depends on 13) The method of claim 13, further comprising filtering, by the control circuit, the non-zero number of activity counts from the plurality of activity counts by filtering activity counts that do not exceed a percentile of the plurality of activity counts. ### Claim 16 (depends on 15) The method of claim 15, wherein the percentile is approximately 15%. ### Claim 17 (depends on 11) The method of claim 11, further comprising determining, by the control circuit, the pacing set point by determining a lower rate set point that comprises a lowest pacing rate for pacing the heart. ### Claim 18 (depends on 11) The method of claim 11, wherein the time period comprises a pacing set point adjustment interval. ### Claim 19 (depends on 11) The method of claim 11, further comprising causing, by the control circuit, the pulse generator to generate pacing pulses at the pacing set point despite activity data received from the accelerometer that would otherwise call for pacing at a higher rate than the pacing set point. ### Claim 20 A non-transitory computer-readable medium configured to store instructions that, when executed, cause one or more processors to: determine, based on an accelerometer signal generated by an accelerometer positioned within a housing of an implantable cardiac device, an activity metric over a time period, wherein the housing is configured to be implanted within the heart of the patient; filter, from the activity metric determined over the time period, a portion of the activity metric expected to correspond to heart motion when the patient is at rest; determine, based on the filtered activity metric, a pacing set point; and cause a pulse generator to generate pacing pulses at the pacing set point.