1- Department of Electronics and Communication Engineering, Panjab University Chandigarh, Chandigarh, India.
2- Department of Psychiatry, Cheema Medical Complex, Mohali, India.
Abstract:
Introduction: Several computer-aided diagnosis systems for depression are suggested for use by clinicians to authorize the diagnosis. EEG may be used as an objective analysis tool for identifying depression in the initial stage to avoid it from reaching a severe and permanent state. However, artifact contamination reduces the accuracy in EEG signal processing systems.
Methods: This work proposes a novel denoising method based on Empirical Mode Decomposition (EMD) ( with Detrended Fluctuation Analysis (DFA) and wavelet packet transform. Initially, real EEG recordings corresponding to depression patients are decomposed into various mode functions by applying EMD. Then, DFA is used as the mode selection criteria. Further Wavelet Packets Decomposition (WPD)-based evaluation is applied to extract the cleaner signal.
Results: Simulations were conducted on real EEG databases for depression to demonstrate the effects of the proposed techniques. To conclude the efficacy of the proposed technique, SNR and MAE were identified. The obtained results indicated improved signal-to-noise ratio and lower values of MAE for the combined EMD-DFA-WPD technique. Additionally, Random Forest and SVM (Support Vector Machine)-based classification revealed the improved accuracy of 98.51% and 98.10% for the proposed denoising technique. Whereas the accuracy of the EMD- DFA is 98.01% and 95.81% and EMD combined with DWT technique equaled 98.0% and 97.21% for the EMD- DFA technique for RF and SVM, respectively, compared to the proposed method. Furthermore, the classification performance for both classifiers was compared with and without denoising to highlight the effects of the proposed technique.
Conclusion: Proposed denoising system results in better classification of depressed and healthy individuals resulting in a better diagnosing system. These results can be further analyzed using other approaches as a solution to the mode mixing problem of the EMD approach.
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● Several computer-aided systems are suggested for diagnosing depression.
● EEG may be used as an objective analysis tool for identifying depression.
● Denoising system proposed in this study results in better classification of depressed and healthy individuals.
Plain Language Summary
Depression is a major global burden. For years, EEG-based computer-aided systems were a powerful tool for detecting neurological disorders. However, advanced healthcare facilities based on EEG for identifying depression in the early stage are required to avoid a severe and irreversible state. Thus, preprocessing is an exclusively required step in EEG signal analysis. EEG is sensitive to certain irrelevant sources as well as artifacts, like EOG and EMG. Denoising describes the procedure of removing noise present in the signal. At first, a linear digital filter-based reduction of superimposed noise on the tracings of the EEG was proposed. Then, the efficiency of the regression analysis was demonstrated for single trials of ERP signals and the average potentials. Denoising system proposed in this study results in better classification of depressed and healthy individuals and the results can be further analyzed using other approaches.
Type of Study:
Original |
Subject:
Computational Neuroscience Received: 2019/04/6 | Accepted: 2021/06/30 | Published: 2021/07/1