Biosignal Extraction Using Dual Interfacing Units for Motion Artifact Removal
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Solution Overview
Problem
Existing biosignal measuring systems face challenges in accurately detecting and isolating biosignals from noise, particularly motion artifacts, due to the similarity in frequency bands between biosignals and noise signals, which complicates filtering and results in poor signal-to-noise ratio (SNR) characteristics.
Innovation Solution
The proposed biosignal measuring apparatus employs a dual interfacing unit system with one unit detecting biosignals and another detecting noise, using electrolytes or metals for effective connection and adaptive filtering to isolate and correct noise, thereby enhancing SNR. This system includes differential amplifiers and adaptive filters to remove noise from the biosignal, improving signal clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single interfacing unit is used to detect biosignals, then the device structure is simple, but motion artifacts and noise cannot be effectively separated from the biosignal
Solution Approach 1:
The interfacing unit is segmented into a first interfacing unit for detecting biosignals and a second interfacing unit for detecting motion artifacts and noise. This segmentation allows independent detection of signal and noise components, enabling effective noise removal while maintaining measurement precision.
Solution Approach 2:
A connecting unit is introduced as an intermediary component to electrically connect the second interfaces of the second interfacing unit. This mediator enables the second interfacing unit to function as a complete noise detection system, facilitating noise artifact removal without significantly increasing overall device complexity.
2Measurement precision
If traditional filtering methods are used to remove noise, then the device structure remains simple, but the signal-to-noise ratio remains poor due to frequency band similarity between biosignals and noise
Solution Approach 1:
The noise component is extracted separately using the second interfacing unit, which is specifically configured to detect motion artifacts and noise. The extracted noise signal is then removed from the biosignal through differential amplification and adaptive filtering, significantly improving the signal-to-noise ratio.
Solution Approach 2:
An adaptive filter is implemented that uses the noise signal from the second interfacing unit as feedback to dynamically adjust filtering parameters. This feedback mechanism enables the system to adaptively remove noise while preserving the biosignal, achieving high signal-to-noise ratio with moderate system complexity.
3Reliability
If electrolytes are used in the second interfaces, then connection quality between skin and interfaces is improved, but the device structure becomes more complex
Solution Approach 1:
Electrolytes are applied locally at the interface between the second interfaces and the skin, specifically where electrical contact is needed. This localized application improves connection quality and signal detection reliability without requiring electrolytes throughout the entire device, thus limiting the increase in device complexity to only the necessary interface regions.
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
The apparatus effectively extracts biosignals with improved SNR characteristics by accurately detecting and removing noise, enhancing the accuracy of biosignal measurement and diagnosis.
Implementation Method 1
the second interfaces include electrolytes, and the connecting unit includes an electrolyte configured to connect the electrolytes of the second interfaces
Implementation Method 2
the electrolytes are hydrogels. These are a particularly useful electrolytes with adhesion properties
Implementation Method 3
the biosignal extracting unit is further configured to remove a result obtained from performing differential amplification on the outputted signals from the second interfacing unit from a result obtained from performing differential amplification on the first signals outputted from the first interfacing unit
Implementation Method 4
the adaptive filter being configured to adaptively filter a signal output from the second differential amplifier based on the extracted biosignal
Data Source
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AI summary
A biosignal measuring apparatus and a method of measuring a biosignal is provided. A biosignal measuring apparatus includes a first interfacing unit including two or more first interfaces configured to detect first signals form a subject, a second interfacing unit including two or more second interfaces and a connecting unit, the second interfaces being configured to detect noise from the subject, the connecting unit being configured to connect the second interfaces, and a biosignal extracting unit configured to extract a biosignal from the first signals by using signals output from the second interfacing unit.