# US 2026/0144993 A1 · Implantable Medical Device Having an Optimized Undersensing Management > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0144993 A1 - Document ID: US20260144993A1 - Status: Published application - Kind: A1 - Application number: 19/390,899 - Filed: 2025-11-17 - Published: 2026-05-28 - Earliest claimed: 2024-11-28 - Assignees: BIOTRONIK SE & Co. KG - Applicants: BIOTRONIK SE & Co. KG - Inventors: Uwe STUERMER; Bernhard WOLF; Frank BECKER; Peter SCHNEIDER; Christian NOACK - Web page: https://patentgrep.com/patent/US20260144993A1 ## CPC - A61N 1/36585: {controlled by two or more physical parameters} - A61N 1/3704: {Circuits specially adapted therefor, e.g. for sensitivity control} - A61B 5/363: Detecting tachycardia or bradycardia - A61N 1/3621: {for treating or preventing abnormally high heart rate} - 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) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract An implantable medical device implantable in a human or animal heart that carries out the following steps during its operation: a) continuously detecting a cardiac electric signal; b) starting a coagulation timer if the detected cardiac electric signal is indicative for an atrial tachycardia; c) keeping the coagulation timer active during a temporary loss of the cardiac electric signal; and d) stopping the coagulation timer, if the following criteria are fulfilled: i) an amplitude of the cardiac electric signal of a plurality of cardiac intervals being close in time exceeds a presettable significance threshold, and ii) an atrial rate calculated from the plurality of cardiac intervals being close in time is below a predefinable threshold rate indicative for atrial tachycardia, or e) keeping the coagulation timer active for a predefined time period, if the criteria are not fulfilled. ## Claims ### Claim 1 Implantable medical device implantable in a human or animal heart, comprising a processor, a memory unit, and a detection unit configured to detect an electric signal of the same heart, wherein the memory unit comprises a computer-readable program that causes the processor to perform the following steps when executed on the processor: a) continuously detecting, with the detection unit, a cardiac electric signal; b) starting a coagulation timer if the detected cardiac electric signal is indicative for an atrial tachycardia; c) keeping the coagulation timer active during a temporary loss of the cardiac electric signal; and d) stopping the coagulation timer, if the following criteria are fulfilled: i) an amplitude of the cardiac electric signal of a plurality cardiac intervals being close in time exceeds a presettable significance threshold, and ii) an atrial rate calculated from the plurality of cardiac intervals being close in time is below a predefinable threshold rate indicative for atrial tachycardia, or e) keeping the coagulation timer active for a predefined time period, if the criteria are not fulfilled. ### Claim 2 (depends on 1) Implantable medical device according to claim 1, characterized in that the detection unit has a presettable sensing threshold, and the significance threshold is equal to or greater than 110% of the sensing threshold. ### Claim 3 (depends on 2) Implantable medical device according to claim 2, wherein the temporary loss of the cardiac electric signal is classified to be caused by a decrease of an amplitude of the cardiac electric signal below the sensing threshold. ### Claim 4 (depends on 2) Implantable medical device according to claim 2, wherein the sensing threshold is dynamically adjustable based on a peak amplitude of the cardiac electric signal. ### Claim 5 (depends on 2) Implantable medical device according to claim 2, wherein the sensing threshold is equal to or smaller than a programmed maximal sensitivity of the detection unit. ### Claim 6 (depends on 2) Implantable medical device according to claim 2, wherein a noise window is started when the amplitude of the cardiac electric signal exceeds the sensing threshold, wherein the noise window is a time period lying in a range of from 10 ms to 60 ms. ### Claim 7 (depends on 2) Implantable medical device according to claim 2, wherein an undersensing monitoring window is started if the amplitude of the cardiac electric signal exceeds the sensing threshold and no previously started undersensing monitoring window is still running, or an undersensing monitoring window is restarted if the previously started undersensing monitoring window is still running and the amplitude of the cardiac electric signal exceeds the significance threshold. ### Claim 8 (depends on 2) Implantable medical device according to claim 2, wherein the undersensing monitoring window is a time period lying in a range of an expected atrial interval, in particular in a range of from 200 ms to 800 ms. ### Claim 9 (depends on 7) Implantable medical device according to claim 7, wherein the temporary loss of the cardiac electric signal is detected when the undersensing monitoring window has elapsed. ### Claim 10 (depends on 1) Implantable medical device according to claim 1, wherein the coagulation timer is set to run for a time interval of from 12 hours to 72 hours, in particular of from 24 hours to 48 hours, in particular of 36 hours. ### Claim 11 (depends on 1) Implantable medical device according to claim 1, wherein the plurality of cardiac intervals being close in time corresponds to a first natural number n of cardiac intervals for which the criteria are fulfilled within a second number m of consecutive cardiac intervals including cardiac intervals for which the criteria are fulfilled and cardiac intervals for which the criteria are not fulfilled, wherein n lies in a range of from 18 to 22 and m lies in a range of from 23 to 28, in particular n equals 20 and m equals 24. ### Claim 12 (depends on 1) Implantable medical device according to claim 1, wherein the predefinable threshold rate indicative for a tachycardia lies in a range equal to or larger than 100 bpm. ### Claim 13 (depends on 1) Implantable medical device according to claim 1, wherein the implantable medical device comprises a stimulation unit for stimulating the human or animal heart, wherein the computer-readable program causes the processor to prevent the stimulation unit from delivering an antitachycardic therapy if the coagulation timer has elapsed. ### Claim 14 Method for operating an implantable medical device implantable in a human or animal heart, the method comprising the following steps: a) continuously detecting a cardiac electric signal; b) starting a coagulation timer if the detected cardiac electric signal is indicative for an atrial tachycardia; c) keeping the coagulation timer active during a temporary loss of the cardiac electric signal; and d) stopping the coagulation timer, if the following criteria are fulfilled: i) an amplitude of the cardiac electric signal of a plurality of cardiac intervals being close in time exceeds a presettable significance threshold, and ii) an atrial rate calculated from the plurality of cardiac intervals being close in time is below a predefinable threshold rate indicative for atrial tachycardia, or e) keeping the coagulation timer active for a predefined time period, if the criteria are not fulfilled. ### Claim 15 Method for treating an atrial tachycardia of a patient in need of such treatment, the method comprising the following steps: a) continuously detecting a cardiac electric signal; b) starting a coagulation timer if the detected cardiac electric signal is indicative for an atrial tachycardia; c) keeping the coagulation timer active during temporary loss of the cardiac electric signal; d) stopping the coagulation timer, if the following criteria are fulfilled: i) an amplitude of the cardiac electric signal of a plurality of cardiac intervals being close in time exceeds a presettable significance threshold, and ii) an atrial rate calculated from the plurality of cardiac intervals being close in time is below a predefinable threshold rate indicative for atrial tachycardia, or e) keeping the coagulation timer active for a predefined time period, if the criteria are not fulfilled; and f) applying an antitachycardic pacing only if the coagulation timer is active.