Heart Sound Detection Using Activity Transition Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Patients with congestive heart failure (CHF) face challenges in monitoring their heart function post-physical activity due to impaired cardiovascular recovery, which can lead to delayed heart sound detection and inaccurate heart failure status indications, especially when mechanical sensors used for activity monitoring interfere with heart sound detection.

Innovation Solution

A system that includes a sensor interface circuit and a signal processing circuit to detect physical activity level transitions and classify heart sound characteristics, providing a surrogate for heart sound parameters and improving heart failure status monitoring by distinguishing heart sounds associated with pre-transition activity levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mechanical sensor is used to monitor both physical activity and heart sounds, then activity monitoring capability is improved, but heart sound detection accuracy deteriorates due to mechanical acceleration masking heart sounds

Engineering Contradiction:

Improvedual-use sensor capabilityVSAvoidheart sound detection accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the sensor data processing by creating separate analysis pathways: one for activity detection and one for heart sound detection. The processor identifies activity intervals separately from heart sound intervals, allowing each type of data to be analyzed with appropriate parameters and thresholds, thereby resolving the interference between the two functions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by detecting physical activity levels before attempting to detect heart sounds. The system first determines if the subject is engaged in physical activity, then selectively processes heart sound data only during periods when activity is minimal, preventing acceleration artifacts from corrupting the heart sound signal

Inventive Principle:

Principle #10Preliminary action

2Duration of action of stationary object

If heart sounds are monitored during physical activity, then continuous monitoring capability is improved, but detection reliability deteriorates due to activity interference

Engineering Contradiction:

Improvecontinuous monitoring durationVSAvoidheart sound detection reliability

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent implements periodic action by continuously monitoring activity levels and periodically attempting heart sound detection only during low-activity intervals. The system cycles through activity detection, identifies suitable detection windows, performs heart sound analysis during those windows, and repeats the process, ensuring reliable detection without requiring constant monitoring

Inventive Principle:

Principle #19Periodic action

3Loss of information

If heart sound parameters are logged at multiple activity levels, then diagnostic information quality is improved, but data accuracy deteriorates when activity masks heart sounds

Engineering Contradiction:

Improveheart sound parameter informationVSAvoidheart sound parameter accuracy

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The patent applies local quality by making the data logging strategy adaptive to local conditions (activity levels). Rather than uniformly logging at all times, the system selectively logs heart sound parameters only during low-activity intervals where detection reliability is high, while still providing comprehensive diagnostic coverage across multiple activity levels by capturing data during appropriate windows

Inventive Principle:

Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the ability to monitor heart failure status by accurately determining heart sound characteristics post-activity, reducing interference from physical activity and providing timely indications for heart failure, potentially replacing the need for dobutamine stress tests.

Implementation Method 1

a sensor configured to sense both physical activity of a subject and an acoustic physiologic heart sound of the subject

Methodology Applied

Scientific EffectMechanical vibration: Vibration

Implementation Method 2

an acoustic physiologic heart sound of the subject

Methodology Applied

Scientific EffectAcoustic wave detection: Sound

Data Source

PatentUS10595734B2Diagnostic and optimization using exercise recovery data

Publication Date: 2020.03.24 CARDIAC PACEMAKERS INC

AI summary

An apparatus, such as a cardiac function management system can detect heart sounds following a sensed transition in physical activity level, such as from an elevated physical activity level to rest. A technique can include systems, methods, machine-readable media, or other techniques that can include identifying a physical activity level transition, receiving a heart sound signal, determining characteristics of the heart sound and subject physiologic activity to provide an indication, such as a heart failure status indication.