Capturing Electrocardiogram Signals from Chairs by Multiple Capacitively Coupled Unipolar Electrodes.

Area of Science:

• Biomedical Engineering
• Medical Instrumentation
• Signal Processing

Background:

• Conventional electrocardiogram (ECG) systems typically use bipolar electrodes for signal acquisition.
• Capacitively coupled electrodes offer a non-invasive alternative for biopotential monitoring.
• Unipolar electrode configurations can provide distinct signal characteristics compared to bipolar setups.

Purpose of the Study:

• To design and validate a prototype ECG signal acquisition system utilizing multiple unipolar capacitively coupled electrodes.
• To evaluate the feasibility of acquiring reliable ECG signals in a unipolar, multi-channel configuration.
• To develop a method for assessing and combining ECG signal quality from multiple unipolar electrodes.

Main Methods:

• Development of a prototype system with four unipolar, PCB-based capacitively coupled electrodes mounted on a chair.
• Separate amplification and sampling of biopotential signals from each unipolar electrode.
• Application of phase space reconstruction for ECG signal quality evaluation and aggregation.
• Experimental testing with clothed subjects seated in the chair.

Main Results:

• The prototype system successfully acquired ECG signals using a unipolar, multi-channel approach.
• Signal quality varied across the four unipolar channels.
• The proposed phase space reconstruction-based index effectively evaluated and aggregated ECG signal quality.
• Reliable ECG signal acquisition was demonstrated even with clothed subjects.

Conclusions:

• A unipolar capacitively coupled electrode system is a viable method for ECG signal acquisition.
• The proposed signal processing techniques enable reliable ECG monitoring in a non-conventional setup.
• This approach holds potential for developing comfortable and non-invasive cardiac monitoring devices.