Real-Time ECG Denoising via Multi-Stage Filtering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Real-time processing of electrocardiogram (ECG) signals is challenging due to corruption by artifacts like high-frequency noise and baseline wander, which limits their utility in clinical evaluation.

Innovation Solution

A multi-stage filtering approach involving baseline wander removal, Savitzky-Golay de-noising, and threshold-fit smoothing is applied to ECG signals in real-time, with adjustable filtering based on noise detection and user input, using computing devices like smartphones and laptops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If filtering techniques are applied to remove noise from ECG signals, then signal readability is improved, but the width and amplitudes of critical ECG features are modified

Engineering Contradiction:
Improvesignal readabilityVSAvoidfeature accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The filtering process is divided into multiple sequential stages: baseline wander removal, high-frequency noise removal, and low-amplitude noise removal. Each stage targets specific noise components while preserving different aspects of the ECG signal, allowing progressive enhancement without excessive distortion of critical features

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different filtering techniques are applied to different frequency ranges and signal components. The first filtering stage removes baseline wander (low frequency), the second removes high-frequency noise, and the third removes low-amplitude high-frequency noise. This localized approach ensures that each filtering operation addresses specific noise types while minimizing impact on preserved signal features

Inventive Principle:
Principle #3Local quality

2Productivity

If real-time processing of ECG signals is implemented, then clinical utility is improved, but processing complexity increases

Engineering Contradiction:
Improveclinical utilityVSAvoidprocessing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The real-time processing system is segmented into three distinct filtering stages that can be independently implemented and optimized. This modular architecture allows the complex processing task to be distributed across multiple simpler computational modules, making real-time implementation more manageable

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Baseline wander removal is performed as a preliminary step before high-frequency noise removal. This preliminary action prepares the signal for subsequent filtering stages by eliminating low-frequency components that could interfere with later processing, thereby simplifying the overall real-time computation required

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS9681814B2Devices and methods for real-time denoising of electrocardiograms
Publication Date: 2017.06.20 ALIVECOR INC
  • US9681814B2 patent drawing
  • US9681814B2 patent drawing
  • US9681814B2 patent drawing

AI summary

Apparatuses and methods (including methods of using such apparatuses) for de-noising electrocardiograms (ECGs) by manually or automatically adjusting the amount of filtering of an ECG signal. For example, real-time ECG signals may be filtered by combining in a weighted fashion an unfiltered portion of an ECG (or a filtered portion of the same ECG) with the same portion of the ECG that has been filtered. The weighting may be adjusted manually and/or automatically. Also described herein are methods for real-time filtering of ECG signals using a combination of filtering techniques including filtering to correct baseline wander, Savitzky-Golay denoising, and threshold smoothing. Multiple filtering techniques may be combined in a weighed manner to provide signal de-noising.