A CPR chest compression machine includes a retention structure that is configured to retain a body of the patient, and a compression mechanism. The compression mechanism is coupled to the retention structure and configured to perform successive compressions to the patient's chest. Various types of chest compressions may be performed on a patient during a single resuscitation event. Some embodiments also include a driver configured to drive the compression mechanism. The compression mechanism may thus perform chest compressions that differ from each other in a number of aspects, for example the depth of the compressions or the height of the active decompressions between the compressions. Some embodiments also include an adjustment mechanism. The adjustment mechanism may shift the compression mechanism with respect to the patient so that the chest compressions are performed at different locations of the patient's chest.
