An alternative to derive the instantaneous frequency of the chest compressions to suppress the CPR Artifact

The activity due to chest compressions during cardiopulmonary resuscitation (CPR) corrupts the ECG, and adversely affects the diagnosis of Automated External Defibrillators (AED). Filtering methods based on reference signals have been proposed to suppress the CPR artifact, however the acquisition of additional reference signals involves hardware modifications in current AEDs. In this study the transthoracic impedance (TTI) was used as a reference signal. Current AEDs acquire TTI via de defibrillation pads. The improvement in sensitivity and specificity was similar to that obtained using the compression depth estimated via additional accelerometers. The results suggest that TTI can be used as a reference signal to suppress the CPR artifact, which would only involve software modifications in current AEDs.