Systems and methods related to the field of cardiac resuscitation, and in particular to devices for assisting rescuers in performing cardio-pulmonary resuscitation (CPR) are described herein. The system includes an applicator device configured to provide ACD CPR treatment to a patient's chest according to a plurality of phases at least one sensor configured to be coupled to the patient's chest and to measure at least one parameter related to the ACD CPR treatment and information for determining whether at least one transition point of the ACD CPR treatment has been reached; and one or more processors configured to provide a feedback signal based on a parameter for administering ACD CPR treatment to the patient's chest according to a desired treatment protocol.