Iranian Journal of Medical Physics

Iranian Journal of Medical Physics

Impact of Annotation Fidelity, Temporal Grouping, and Fuzzy Model Specification on Wavelet-Based EEG Seizure Classification: A Single-Record Methodological Study

Document Type : Original Paper

Authors
1 Sabzevaruninersity of medical science
2 Sabzevar university of medical sciences
3 Hakim Sabzevari University
10.22038/ijmp.2026.97801.2730
Abstract
Introduction: Performance estimates in automated EEG seizure classification depend on label fidelity, temporal partitioning, preprocessing placement, and correct model implementation. This controlled single-record methodological study quantified the influence of these factors and was not designed to estimate patient-independent clinical performance.

Materials and Methods: A de-identified single-channel CHB-MIT record (chb01_26; 256 Hz) was analyzed. A scripted seizure crop was compared with the official 1862-1963 s annotation. Three 100-s interictal intervals and the official ictal interval were divided into 10-s temporal blocks. Level-4 wavelet statistics were classified using Gaussian naive Bayes, radial-basis-function support vector machine, and a first-order Takagi-Sugeno-Kang system. Random-window, block-preserving, and chronological evaluations used fold-wise preprocessing. An additional contiguous-block evaluation introduced a 30-s temporal exclusion buffer, and TSK rule-count sensitivity was evaluated for 3, 5, 7, and 9 rules. A factorial analysis compared db4 and sym4 wavelets, 1-, 2-, and 4-s windows, and 0% or 50% overlap.

Results: The scripted seizure segment began at 1818.4 s, and 44.3% of its samples preceded the official onset. The reconstructed dataset contained 360 windows in 40 temporal groups. Under blocked validation, Gaussian naive Bayes, support vector machine, and Takagi-Sugeno-Kang models achieved Matthews correlation coefficients (MCCs) of 0.793, 0.784, and 0.827, respectively. A 30-s temporal exclusion buffer caused marked MCC reductions, while five TSK rules had the highest mean blocked MCC among 3, 5, 7, and 9 rules tested. The highest descriptive preprocessing MCC was 0.882 (sym4, 4-s windows, 50% overlap).

Conclusion: Annotation correction, temporal-group preservation, and explicit fuzzy-model specification materially changed within-record performance estimates. The findings constitute a single-record methodological case study; multi-record patient-independent validation remains necessary before clinical generalization.
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Articles in Press, Accepted Manuscript
Available Online from 14 November 2026

  • Receive Date 30 July 2026
  • Revise Date 12 September 2026
  • Accept Date 04 October 2026