System and method for electrocardiogram analysis and optimization of cardiopulmonary resuscitation and therapy delivery

A method performed by a defibrillator, the method comprising:

• outputting an instruction to perform chest compressions on a patient during a time period extending from a first time to a second time;
• identifying physiological parameter data corresponding to a physiological parameter of the patient detected after the first time and before the second time;
• generating filtered physiological parameter data by removing, from the physiological parameter data, an artifact associated with the chest compressions using a comb filter, wherein a Q of the comb filter is greater than 4;
• determining, based on the filtered physiological parameter data, that a heart rhythm of the patient is shockable;
• and
• in response to determining that the heart rhythm is shockable, charging an energy storage module before the second time.