MPCNN: A Novel Matrix Profile Approach for CNN-based Sleep Apnea
  Classification
Hieu X. Nguyen Duong V. Nguyen Hieu H. Pham Cuong D. Do
Sleep apnea (SA) is a significant respiratory condition that poses a major
global health challenge. Previous studies have investigated several machine and
deep learning models for electrocardiogram (ECG)-based SA diagnoses. Despite
these advancements, conventional feature extractions derived from ECG signals,
such as R-peaks and RR intervals, may fail to capture crucial information
encompassed within the complete PQRST segments. In this study, we propose an
innovative approach to address this diagnostic gap by delving deeper into the
comprehensive segments of the ECG signal. The proposed methodology draws
inspiration from Matrix Profile algorithms, which generate an Euclidean
distance profile from fixed-length signal subsequences. From this, we derived
the Min Distance Profile (MinDP), Max Distance Profile (MaxDP), and Mean
Distance Profile (MeanDP) based on the minimum, maximum, and mean of the
profile distances, respectively. To validate the effectiveness of our approach,
we use the modified LeNet-5 architecture as the primary CNN model, along with
two existing lightweight models, BAFNet and SE-MSCNN, for ECG classification
tasks. Our extensive experimental results on the PhysioNet Apnea-ECG dataset
revealed that with the new feature extraction method, we achieved a per-segment
accuracy up to 92.11 \% and a per-recording accuracy of 100\%. Moreover, it
yielded the highest correlation compared to state-of-the-art methods, with a
correlation coefficient of 0.989. By introducing a new feature extraction
method based on distance relationships, we enhanced the performance of certain
lightweight models, showing potential for home sleep apnea test (HSAT) and SA
detection in IoT devices. The source code for this work is made publicly
available in GitHub: https://github.com/vinuni-vishc/MPCNN-Sleep-Apnea.