Summary
Objectives: This study examines the suitability of recurrence plot analysis for the problem of
central sleep apnea (CSA) detection and delineation from ECG-derived respiratory (EDR)
signals.
Methods: A parameter describing the average length of vertical line structures in recurrence
plots is calculated at a time resolution of 1 s as ‘instantaneous trapping time’.
Threshold comparison of this parameter is used to detect ongoing CSA. In data from
26 patients (duration 208 h) we assessed sensitivity for detection of CSA and mixed
apnea (MSA) events by comparing the results obtained from 8-channel Holter ECGs to
the annotations (860 CSA, 480 MSA) of simultaneously registered polysomnograms.
Results: Multivariate combination of the EDR from different ECG leads improved the detection
accuracy significantly. When all eight leads were considered, an average instantaneous
vertical line length above 5 correctly identified 1126 of the 1340 events (sensitivity
84%) with a total number of 1881 positive detections.
Conclusions: We conclude that recurrence plot analysis is a promising tool for detection and delineation
of CSA epochs from EDR signals with high time resolution. Moreover, the approach is
likewise applicable to directly measured respiratory signals.
Keywords
Central sleep apnea - ECG-derived respiration - multivariate recurrence plot analysis