A semi-automatic AED is a portable device that is used to treat sudden cardiac arrest (SCA) by delivering an electric shock to the heart in order to re-establish a normal rhythm. The device is designed to be easy to use, with clear audio and visual prompts to guide the user through the rescue process. The purpose of a semi-automatic AED is to provide a quick and effective way to save the life of someone experiencing SCA, by allowing trained lay responders or professionals to intervene immediately in an emergency situation.