According to an aspect, there is provided a cardiopulmonary resuscitation, CPR, device (1) for enhancing the delivery of CPR to a patient. The device (1) comprises: a patient side (3) for engagement with the chest of the patient; and a user side (2) for engagement with the hands of a user delivering CPR to the patient; and an actuator configured to at least partially alter the external form of one or more of the patient side (3) and the user side (2) so as to regulate a shape profile of the one or more of the patient side (3) and the user side (2). According to other aspects, there is provided a control method for a cardiopulmonary resuscitation, CPR, device and a computer program which, when executed on a computing device, carries out a control method for a cardiopulmonary resuscitation, CPR, device.