# US 10,499,858 B2 · Detection of worsening heart failure events using heart sounds > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,499,858 B2 - Document ID: US10499858B2 - Status: Granted - Kind: B2 - Application number: 16/133,911 - Filed: 2018-09-18 - Published: 2019-01-17 - Granted: 2019-12-10 - Earliest claimed: 2015-10-08 - Assignees: Cardiac Pacemakers, Inc. - Applicants: Cardiac Pacemakers, Inc. - Inventors: Pramodsingh Hirasingh Thakur; Qi An - Web page: https://patentgrep.com/patent/US10499858B2 ## CPC - A61B 7/04: Electric stethoscopes - A61B 5/02028: {Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction} - A61B 5/7275: {Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor} - 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)} - A61N 1/3627: {for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy} - A61N 1/36514: {controlled by a physiological quantity other than heart potential, e.g. blood pressure (controlled by two or more physical parameters A61N1/36585)} - A61N 1/37235: {Aspects of the external programmer} - A61N 1/3962: {in combination with another heart therapy} - A61N 1/39622: {Pacing therapy} - A61N 1/3987: {characterised by the timing or triggering of the shock} - H04L 67/12: specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks - 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) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Systems and methods for detecting events indicative of worsening using heart sounds are disclosed. A system can include a signal sensor circuit to sense a heart sound (HS) signal. The system can detect at least first and different second HS components using the HS signal, and generate respective first and second HS metrics. The system can determine a trend indicator for the first or second HS metric, and selectively generate one or more composite HS metrics using the first and second HS metrics, according to the trend indicator indicating a growing or decay trend. The system can include a heart failure (HF) event detector to produce a HF status using the composite HS metrics, and output an indication of the HF status, or deliver therapy according to the HF status. ## Claims ### Claim 1 A system, comprising: a metric generator circuit configured to receive cardiac acceleration information of a patient, and to generate a first signal metric and a different second signal metric using the received cardiac acceleration information; and a blending circuit configured to generate a composite metric using (1) a ratio of the second signal metric to the first signal metric or (2) a product of the first and second signal metrics; and a cardiac event detector circuit configured to detect a heart failure (HF) status using a combination of (1) at least one of the first or second signal metric and (2) the composite metric. ### Claim 2 (depends on 1) The system of claim 1, wherein the cardiac acceleration information includes cardiac acceleration information from an accelerometer. ### Claim 3 (depends on 2) The system of claim 2, wherein the first and second signal metrics include respectively first and second heart sound metrics. ### Claim 4 (depends on 3) The system of claim 3, wherein the first heart sound metric includes an intensity of an S1 or an S2 heart sound, and the second signal metric includes an intensity of an S3 or S4 heart sound. ### Claim 5 (depends on 1) The system of claim 1, wherein the cardiac event detector circuit is configured to: generate the composite metric using the ratio of the second signal metric to the first signal metric if the first signal metric is decreasing over time; or generate the composite metric using the product of the first and second signal metrics if the first signal metric is increasing over time. ### Claim 6 (depends on 5) The system of claim 5, wherein the first signal metric includes an S1 heart sound amplitude, the second signal metric includes an S3 or S4 heart sound amplitude, and the processor circuit is configured to: generate the composite metric using a ratio of the S3 or S4 heart sound amplitude to the S1 heart sound amplitude if the S1 heart sound amplitude has a decay trend; or generate the composite metric using a product of the S3 or S4 heart sound amplitude and the S1 heart sound amplitude if the S1 heart sound amplitude has a growth trend. ### Claim 7 (depends on 1) The system of claim 1, wherein the cardiac event detector circuit is configured to receive physiologic information of the patient different from the received cardiac acceleration information, and to detect the HF status further using the received physiologic signal. ### Claim 8 (depends on 7) The system of claim 7, wherein the received physiologic information includes one of a thoracic impedance signal, a respiration signal, a physical activity signal, or a pressure signal. ### Claim 9 (depends on 1) The system of claim 1, wherein the first signal metric includes an S1 heart sound amplitude, wherein the second signal metric includes an S3 heart sound amplitude, wherein the composite metric includes a ratio of S3 heart sound amplitude to S1 heart sound amplitude (S3/S1), and wherein the cardiac event detector circuit is configured to detect the HF status using the ratio of S3/S1 and the S3 heart sound amplitude. ### Claim 10 (depends on 1) The system of claim 1, wherein the metric generator circuit is configured to determine a cardiac contractility indicator, and wherein the cardiac event detector is configured to detect a HF event with cardiac contractility compensation, or a HF event without cardiac contractility compensation, using the determined cardiac contractility. ### Claim 11 (depends on 10) The system of claim 10, wherein the metric generator circuit is configured to generate an S1 heart sound amplitude using the received cardiac acceleration information, and to determine the cardiac contractility indicator using the generated S1 heart sound amplitude. ### Claim 12 (depends on 10) The system of claim 10, wherein the metric generator circuit is configured to measure a systolic timing interval using the received cardiac acceleration information, and to determine the cardiac contractility indicator using the measured systolic timing interval. ### Claim 13 (depends on 10) The system of claim 10, wherein the metric generator circuit is configured to measure a cardiac contractility indicator using received physiologic information of the patient different than the received cardiac acceleration information. ### Claim 14 A method, comprising: receiving cardiac acceleration information of a patient; generating a first signal metric and a different second signal metric using the received cardiac acceleration information; generating a composite metric using (1) a ratio of the second signal metric to the first signal metric or (2) a product of the first and second signal metrics; and detecting a heart failure (HF) status using a combination of (1) at least one of the first or second signal metric and (2) the generated composite metric. ### Claim 15 (depends on 14) The method of claim 14, wherein the cardiac acceleration information includes one or more heart sounds of the patient, and the first and second signal metrics include respectively first and second heart sound metrics. ### Claim 16 (depends on 14) The method of claim 14, comprising determining a trend indicator of the first signal metric, wherein generating composite metric includes using the ratio of the second signal metric to the first signal metric if the first signal metric is decreasing over time, or using the product of the first and second signal metrics if the first signal metric is increasing over time. ### Claim 17 (depends on 16) The method of claim 16, wherein the first signal metric includes an S1 heart sound amplitude, the second signal metric includes an S3 or S4 heart sound amplitude, and wherein generating the composite metric includes using a ratio of the S3 or S4 heart sound amplitude to the S1 heart sound amplitude if the S1 heart sound amplitude has a decay trend, or using a product of the S3 or S4 heart sound amplitude and the S1 heart sound amplitude if the S1 heart sound amplitude has a growth trend. ### Claim 18 (depends on 14) The method of claim 14, comprising: receiving physiologic information of the patient different from the received cardiac acceleration information, wherein detecting the HF status further includes using the received physiologic information. ### Claim 19 (depends on 14) The method of claim 14, comprising: determining a cardiac contractility indicator of the patient; and detecting a HF event with cardiac contractility compensation, or a HF event without cardiac contractility compensation, using the determined cardiac contractility indicator. ### Claim 20 A system, comprising: means for receiving cardiac acceleration information of a patient; means for generating a first signal metric and a second signal metric different than the first signal metric using the received cardiac acceleration information; means for generating a composite metric using (1) a ratio of the second signal metric to the first signal metric or (2) a product of the first and second signal metrics; and means for detecting a heart failure (HF) status using a combination of (1) at least one of the first or second signal metric and (2) the generated composite metric.