Camera-Based ECG Reconstruction from Skin Color for Arrhythmia Detection

Solution Overview

Problem

Existing ECG measurement methods require contact electrodes and large instruments, limiting their use for widespread heart rhythm monitoring and arrhythmia detection in daily life, especially for asymptomatic patients.

Innovation Solution

A method for reconstructing ECG signals through imaging using remote photoplethysmography (rPPG) to extract heart rhythm information from skin color variations, combined with neural networks for feature extraction and fusion, enabling non-contact, mobile heart rhythm monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If contact electrode-based ECG instruments are used, then measurement precision is improved, but device complexity and ease of operation deteriorate

Engineering Contradiction:

ImproveECG signal measurement precisionVSAvoidinstrument size and complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical contact electrode system with an optical imaging system. Instead of using physical electrodes that require skin contact and complex signal acquisition hardware, the invention uses camera-based imaging to capture skin color variations caused by blood volume changes during heartbeat, thereby eliminating the need for contact electrodes and simplifying the device structure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces skin color variation as an intermediary parameter to indirectly measure ECG signals. Rather than directly measuring electrical heart signals through contact electrodes, the system uses optical imaging to detect color changes in the skin caused by blood volume pulsations, which correlate with heart rhythm, thereby avoiding direct electrical contact and reducing device complexity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If contact electrode-based ECG instruments are used, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:

ImproveECG signal measurement precisionVSAvoidmobility and ease of use

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical contact electrode system with an optical imaging system. Instead of using physical electrodes that require skin contact and complex signal acquisition hardware, the invention uses camera-based imaging to capture skin color variations caused by blood volume changes during heartbeat, thereby eliminating the need for contact electrodes and simplifying the device structure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent makes the imaging device universal by enabling it to perform both standard imaging functions and ECG signal detection. The same camera system can capture images for medical diagnosis while simultaneously extracting heart rhythm information through color variation analysis, eliminating the need for separate specialized ECG equipment and improving ease of operation

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If traditional ECG monitoring is used, then arrhythmia detection accuracy is improved, but loss of time increases

Engineering Contradiction:

Improvearrhythmia detection accuracyVSAvoidtime for heart rhythm tracking and diagnosis

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent enables preliminary detection of arrhythmias by continuously monitoring heart rhythm through imaging in real-time. Instead of waiting for symptoms to manifest and then undergoing diagnostic testing, the system can detect abnormal heart patterns early in their occurrence, allowing for timely intervention before serious health issues develop

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent enables continuous heart rhythm monitoring through the imaging system, which can operate continuously without requiring patient movement to different locations or repeated testing. This continuous monitoring allows for comprehensive arrhythmia detection over extended periods, improving both accuracy and reducing the time loss associated with intermittent monitoring

Inventive Principle:

Principle #20Continuity of useful action

4Measurement precision

If contact electrode-based ECG instruments are used, then measurement precision is improved, but adaptability deteriorates

Engineering Contradiction:

ImproveECG signal measurement precisionVSAvoidapplicability in daily life

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical contact electrode system with an optical imaging system. Instead of using physical electrodes that require skin contact and complex signal acquisition hardware, the invention uses camera-based imaging to capture skin color variations caused by blood volume changes during heartbeat, thereby eliminating the need for contact electrodes and simplifying the device structure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from direct electrical signal detection to optical color variation detection. This parameter change enables the system to work in diverse environments and situations where contact electrodes would be impractical, such as during physical activity, in different positions, or without requiring specialized equipment, thereby improving adaptability to daily life

Inventive Principle:

Principle #35Parameter changes

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

Enables early detection of arrhythmias without contact electrodes, allowing users to monitor their heart rhythm freely and receive timely alerts, reducing the need for prolonged hospital stays and medical resources.

Implementation Method 1

photoplethysmography (PPG) is used to obtain cardiac function information for blood oxygen detection

Methodology Applied

Scientific EffectPhotoplethysmography: Absorption (EM radiation)

Data Source

PatentUS20250285739A1Method for Reconstructing ECG signals through Imaging for Arrhythmia Detection and Its Detection System

Publication Date: 2025.09.11 NAT CHENG KUNG UNIV

AI summary

Method for reconstructing ECG signals through imaging for arrhythmia detection and its detection system, wherein the method for reconstructing ECG signals through imaging for arrhythmia detection involves receiving images of the human skin, which contain color changes on the skin surface caused by heartbeats and heart rhythms. The method comprises performing noise reduction on these color changes and analyzing the color variations to extract a remote photoplethysmographic (rPPG) signal that corresponds to the heart rates and heart rhythms. Frequency domain analysis is conducted to identify the frequency features within the rPPG signal, and feature extraction is performed on these frequency characteristics to obtain a photoplethysmographic (PPG) signal. The PPG signal undergoes feature extraction to derive time domain features and frequency domain features, which are then fused to output a reconstructed ECG signal. Finally, the waveform characteristics of the reconstructed ECG signal are interpreted, allowing for the identification of classifications corresponding to arrhythmias based on these waveform features.