Detection of shockable and non-shockable rhythms in presence of CPR artifacts by time-frequency ECG analysis

Time-frequency domain features of chest compression (CC) artefacts, non-shockable (NShR) and shockable (ShR) rhythms were investigated. The aim was to provide reliable shock advisory analysis during CC by single channel electrocardiogram (ECG) processing. Three frequency bands were suggested to enhance specific components of the CC artefacts, NShR and ShR rhythms: (i) 2-3 Hz to emphasize the similarity of the basic wave of CC Artefacts; (ii) 4-7 Hz to highlight the irregularity of the fibrillation waves in ShR; (iii) 10-20 Hz to support the presence of QRS complexes in NShR. Based on our studies in the defined frequency bands, an automatic shock-advisory system (SAS) for detection of NShR and ShR in CC-contaminated ECGs was built. SAS assessed with ECGs from a testing dataset provided Se=94.2% for ShR, Sp=87% for NShR, Sp=83.7% for asystoles.