In most cases, when an institution (school, municipality, organization) purchases an AED, a medical authority is involved as a quality control mechanism and for insurance purposes. The licensed physician or medical authority will ensure that all designated responders are properly trained and that the AED is properly maintained (Some companies will handle this now as well). An AED operator must know how to recognize the signs of a SCA (sudden cardiac arrest), when to activate the AED, and how CPR is performed. It’s also important for responders to have some formal training on the use of the specific AED model. Training also teaches the operator how to avoid potentially hazardous situations.