Table 1 Comparison of biosignal methods
S. no. | Method | Electrodes | Placement of the signal-capturing device | Processing | Advantage disadvantage |
|---|---|---|---|---|---|
1 | Electroencephalogram (EEG) sensors | Fixed method and variable method 12 electrodes is one of the popular methods | 10–5,10–10, 10–20 methods at right ear, from front to back Frontopolar, frontal, central, parietal and occipita((o). Left are odd numbered and even are placed at the right part of the head Middle is called zero line | Wavelets. Machine learning and deep learning algorithms, signal processing methods, hybrid methods | Other fields of applications for proposed system are Human Computer Interface, medical dignosis and military field. Nonstationary and nonlinearity are drawbacks |
2 | Electrocardiogram (ECG) sensors | Twelve lead is popular. For laboratory conditions,3 leads are used, | For laboratory conditions, three lead ECG with the Right arm, left arm and left leg | NN50, SDNN, RMSSD are some of the features | improvisation in the previous research has hurdles of Age group bias, subjectivity in readings |
3 | Electromyography (EMG) | Surface Noninvasive EMG, and intramuscular | Facial EMG near the chin is popular. Low cost Myosensor is available | Methods like KNN, SVM are useful | Research is ongoing |
4 | Galvanic Skin Response sensors | Epidermal sensors | Mostly electrodes at fingers, palm, and feet. Useful in laboratory environment | AI and statistical methods can be used in combination of photoplethysmogram (PPG), EEG, and EEG | Advantage is fast response of emotions from skin. Disadvantage is the readings may deviate due to temperature and humidity |