A wearable cardiopulmonary resuscitation assist device or system including: a wearable article to be worn by a cardiopulmonary resuscitation performer or a patient, for assisting administration of cardiopulmonary resuscitation by the performer; at least one sensor for measuring at least one parameter to assist in cardiopulmonary resuscitation; at least one feedback component for conveying feedback information based on the parameter to the performer for assisting the performer in performing cardiopulmonary resuscitation; and a processing unit, the processing unit being configured to receive the at least one parameter from the at least one sensor and to send information based on the parameter to the at least one feedback component. Also a method for training or improving cardiopulmonary resuscitation procedures using the device.