Automated external defibrillator (aed) with dual ecg analysis algorithms

An automated external defibrillator (AED) for use during cardiopulmonary resuscitation (CPR) comprising:

• a user interface having at least one of an aural instruction output and a visual display;
• an input of an ECG signal;
• a shock delivery circuit;
• a memory for storing instructions related to
• a first ECG analysis algorithm that is operable to determine one of a “shock advised” (SA) and an “undecided” determination from the ECG signal in the presence of a CPR-related signal noise artifact from the input,
• a second ECG analysis algorithm that is operable to determine one of a SA and a “No Shock Advised” (NSA) determination from the ECG signal in the absence of CPR-related signal noise artifact from the input, and
• a CPR rescue protocol that includes at least two periods for providing CPR compressions;
• and
• a controller disposed in controlling communication with the user interface, the input, the memory and the shock delivery circuit to arm the shock delivery circuit responsive to any SA determination from either of the first or second algorithms,
• wherein the controller is further operable to always automatically switch from the first to the second ECG analysis algorithm at an end of one of the periods during which the first ECG analysis algorithm determines any other than a SA determination.