Heuristic Optimization of Deep and Shallow Classifiers: An Application for Electroencephalogram Cyclic Alternating Pattern Detection

Entropy (Basel). 2022 May 13;24(5):688. doi: 10.3390/e24050688.

Abstract

Methodologies for automatic non-rapid eye movement and cyclic alternating pattern analysis were proposed to examine the signal from one electroencephalogram monopolar derivation for the A phase, cyclic alternating pattern cycles, and cyclic alternating pattern rate assessments. A population composed of subjects free of neurological disorders and subjects diagnosed with sleep-disordered breathing was studied. Parallel classifications were performed for non-rapid eye movement and A phase estimations, examining a one-dimension convolutional neural network (fed with the electroencephalogram signal), a long short-term memory (fed with the electroencephalogram signal or with proposed features), and a feed-forward neural network (fed with proposed features), along with a finite state machine for the cyclic alternating pattern cycle scoring. Two hyper-parameter tuning algorithms were developed to optimize the classifiers. The model with long short-term memory fed with proposed features was found to be the best, with accuracy and area under the receiver operating characteristic curve of 83% and 0.88, respectively, for the A phase classification, while for the non-rapid eye movement estimation, the results were 88% and 0.95, respectively. The cyclic alternating pattern cycle classification accuracy was 79% for the same model, while the cyclic alternating pattern rate percentage error was 22%.

Keywords: 1D-CNN; ANN; CAP; HOSA; LSTM.

Grants and funding

This research was funded by ARDITI-Regional Agency for the Development of Research Technology and Innovation, grant numbers M1420-09-5369-FSE-000001-PhD Studentship and M1420-09-5369-FSE-000002-Post-Doctoral Fellowship, co-financed by the Madeira 14-20 Program-European Social Fund. This research was funded by MITIExcell-EXCELENCIA INTERNACIONAL DE IDT&I NAS TIC, grant number M1420-01-0145-FEDER-000002, provided by the Regional Government of Madeira. This research was funded by the Fundação para a Ciência e Tecnologia I.P. (FCT) [grant 2021.07966.BD to Diogo Freitas].