# US 12,599,328 B2 · Method to detect noise in a wearable cardioverter defibrillator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,599,328 B2 - Document ID: US12599328B2 - Status: Granted - Kind: B2 - Application number: 18/383,011 - Filed: 2023-10-23 - Published: 2024-02-15 - Granted: 2026-04-14 - Earliest claimed: 2019-08-09 - Assignees: West Affum Holdings DAC - Applicants: West Affum Holdings Dac - Inventors: Jaeho Kim - Web page: https://patentgrep.com/patent/US12599328B2 ## CPC - A61B 5/282: Holders for multiple electrodes (for introduction into the body A61B5/287) - A61B 5/349: Detecting specific parameters of the electrocardiograph cycle - A61B 5/6802: {Sensor mounted on worn items} - A61B 5/6805: {Vests, e.g. shirts or gowns} - 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 5/746: {Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms} - A61N 1/046: {Specially adapted for shock therapy, e.g. defibrillation} - A61N 1/0484: {Garment electrodes worn by the patient} - A61N 1/3625: {External stimulators} - A61N 1/3904: {External heart defibrillators [EHD]} - 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 one embodiment, a method to detect noise levels in electrocardiogram (ECG) signals is described. The method includes connecting to at least three sensing electrodes and obtaining a signal from each of the at least three sensing electrodes. The method also includes defining at least three channels between the at least three electrodes. The method includes calculating a morphological similarity value of at least one combination of the at least three channels based at least in part on the obtained signal from each of the at least three sensing electrodes and determining a noise level based at least in part on the calculated morphological similarity value. ## Claims ### Claim 1 A wearable cardioverter defibrillator (WCD) system, comprising: a support structure wearable by a patient; a processor; and a discharge circuit configured to discharge stored electrical charge through a body of the patient, the discharge circuit in communication with the processor, wherein the processor is configured to: receive signals from at least three sensing electrodes that include a first sensing electrode located at a first location on the patient, a second sensing electrode located on a second location of the patient, and a third sensing electrode located on a third location of the patient, the at least three sensing electrodes configured to monitor electrical activity of a heart of the patient; obtain, during the monitoring, a first signal from the first sensing electrode, wherein the first signal is based on a cardiac rhythm measured by the first sensing electrode at the first location during a first time period; obtain, during the monitoring, a second signal from the second sensing electrode, wherein the second signal is based on the cardiac rhythm measured by the second sensing electrode at the second location during the first time period; obtain, during the monitoring, a third signal from the third sensing electrode, wherein the third signal is based on the cardiac rhythm measured by the third sensing electrode at the third location during the first time period; define, during the monitoring, at least three channels between the at least three sensing electrodes; calculate, during the monitoring, a morphological similarity value of at least one combination of the at least three channels by comparing the first signal with at least one of the second signal or the third signal; and determine, during the monitoring, a noise level based, at least in part, on the morphological similarity value calculated for the at least one combination of the at least three channels, wherein the noise level is used, at least in part, in determining that the patient has experienced an event of arrhythmia. ### Claim 2 (depends on 1) The WCD system of claim 1, wherein the processor is further configured to: establish correlating channels based, at least in part, on the at least three channels, wherein the correlating channels have a similar morphological similarity value when no noise is present in electrocardiogram (ECG) signals; and calculate a morphological similarity value of each of the correlating channels. ### Claim 3 (depends on 2) The WCD system of claim 2, wherein the processor is further configured to: determine when the morphological similarity value of each of the correlating channels meets or exceeds a predetermined threshold. ### Claim 4 (depends on 3) The WCD system of claim 3, wherein the predetermined threshold is equal to or above 0.2. ### Claim 5 (depends on 3) The WCD system of claim 3, wherein the processor is further configured to: analyze at least one of the first signal, the second signal, or the third signal for a shockable heart rhythm when the morphological similarity value is above the predetermined threshold. ### Claim 6 (depends on 1) The WCD system of claim 1, wherein the processor is further configured to: suspend an electrocardiogram (ECG) shockable analysis of the first signal, the second signal, and the third signal when feature coefficient correlation (FCC) values are below a predetermined analysis threshold. ### Claim 7 (depends on 6) The WCD system of claim 6, where the processor is further configured to: obtain an additional signal from each of the at least three sensing electrodes after the first time period has elapsed; and calculate a second morphological similarity value of at least one combination of the at least three channels based, at least in part, on the additional signal obtained from each of the at least three sensing electrodes. ### Claim 8 (depends on 7) The WCD system of claim 7, wherein the processor is further configured to: issue a noise alert to a person when the second morphological similarity value does not meet or exceed a predetermined threshold. ### Claim 9 (depends on 1) The WCD system of claim 1, wherein calculating the morphological similarity values includes calculating feature correlation coefficient (FCC) values. ### Claim 10 (depends on 1) The WCD system of claim 1, wherein the first time period is a fixed duration of between 3 and 15 seconds. ### Claim 11 (depends on 10) The WCD system of claim 10, wherein the fixed duration is 5 seconds. ### Claim 12 (depends on 1) The WCD system of claim 1, wherein the processor is further configured to assign individual predetermined noise thresholds for each pair of the at least three channels, based on a correlation level associated with positions of the at least three sensing electrodes. ### Claim 13 (depends on 1) The WCD system of claim 1, wherein the processor is further configured to suspend the calculation for a predetermined time period when the morphological similarity value falls below a noise threshold, and wherein the predetermined time period is between 5 seconds and 5 minutes. ### Claim 14 (depends on 1) The WCD system of claim 1, wherein the processor is further configured to determine a correlation between available electrode channels to define the at least three channels.