Heart Sound Detection Using Multi-Axis Accelerometer Signals

Solution Overview

Problem

Traditional cardiac rhythm management devices rely on electrical signals for heart sound detection, which increases complexity, cost, and power consumption, and are susceptible to signal noise and errors.

Innovation Solution

A system that uses multiple heart sound signals from different axes to produce a composite heart sound signal without relying on electrical signals, applying coefficients to reduce signal-to-noise ratio and improve processing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional CRM devices use electrical signals for heart sound detection, then detection capability is achieved, but device complexity, cost, and power consumption increase

Engineering Contradiction:

Improveheart sound detection capabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces electrical signal-based heart sound detection with a mechanical vibration detection system using accelerometers. The accelerometer senses mechanical vibrations of the heart directly through contact with the heart surface, converting mechanical energy to electrical signals for processing. This substitution eliminates the need for complex electrical signal conditioning circuits while maintaining detection capability, thereby reducing device complexity and power consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If traditional CRM devices use electrical signals for heart sound detection, then detection capability is achieved, but power consumption increases

Engineering Contradiction:

Improveheart sound detection capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces electrical signal-based heart sound detection with a mechanical vibration detection system using accelerometers. The accelerometer senses mechanical vibrations of the heart directly through contact with the heart surface, converting mechanical energy to electrical signals for processing. This substitution eliminates the need for complex electrical signal conditioning circuits while maintaining detection capability, thereby reducing device complexity and power consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If electrical signals are used for heart sound detection, then detection is achieved, but susceptibility to signal noise and electromagnetic interference increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidsignal noise and electromagnetic interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electrical signal-based heart sound detection with a mechanical vibration detection system using accelerometers. The accelerometer senses mechanical vibrations of the heart directly through contact with the heart surface, converting mechanical energy to electrical signals for processing. This substitution eliminates the need for complex electrical signal conditioning circuits while maintaining detection capability, thereby reducing device complexity and power consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an accelerometer as an intermediary device between the heart and the detection system. The accelerometer acts as a mechanical transducer that converts mechanical heart vibrations into electrical signals, serving as a mediator that isolates the detection system from direct electrical interference while accurately capturing heart sound information through mechanical means.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Productivity

If multiple heart sound signals from different axes are combined, then processing efficiency improves, but signal-to-noise ratio decreases

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidsignal-to-noise ratio

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent combines multiple heart sound signals from different accelerometer axes (x, y, z) to create a composite heart sound signal. By merging the signals from multiple measurement angles and orientations, the system captures comprehensive heart vibration information while the signal processing algorithms maintain the signal-to-noise ratio through coherent integration of the multi-axis data, thereby improving processing efficiency without sacrificing detection reliability.

Inventive Principle:

Principle #5Merging (Combining)

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

This approach reduces the need for amplification and filtering, decreases power consumption, and enhances battery life while providing accurate heart sound detection with lower susceptibility to electromagnetic interference.

Implementation Method 1

the first signal can include heart sound information from a first axis of an accelerometer, and the second signal can include heart sound information from a second axis of the accelerometer

Methodology Applied

Scientific EffectAccelerometer: Accelerometer

Data Source

PatentEP3684260B1Devices and methods for heart sound detection

Publication Date: 2023.01.25 CARDIAC PACEMAKERS INC

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AI summary

This document discusses, among other things, systems and methods to produce a composite heart sound signal of a patient using a first signal including heart sound information over a first physiologic interval and a second signal including heart sound information over the first physiologic interval.