not intentional and the responder was acting within the limits of their training and in good faith. in the united states, good samaritan laws provide some protection for the use of aeds by trained and untrained responders. aeds create little liability if used correctly; nremt-b and many state emergency medical technician (emt) training and many cpr classes incorporate or offer aed education as a part of their program. canada in addition to good samaritan laws, ontario, canada also has the "chase mceachern act (heart defibrillator civil liability), 2007 (bill 171 – subsection n)", passed in june, 2007, which protects individuals from liability for damages that may occur from their use of an aed to save someone's life at the immediate scene of an emergency unless damages are caused by gross negligence. australia legislation in australia varies by state, with separate liability issues relating to providing and using aed equipment. each state and territory has enacted "good samaritan" laws that offer legal protection to a person who gives assistance in a medical emergency - the standard of care expected corresponds to their training (or lack of training). in new south wales, the work health and safety regulation (2011) requires an employer to use a risk assessment to ensure that there is adequate provision for first aid; when there is a sufficient risk it warrants providing a defibrillator. reliability in 2012, aed's (automated external defibrillators) were under scrutiny by the u.s. food and drug administration (fda) which considered reclassifying aeds as class iii premarket approval devices. technical malfunctions likely contributed to more than 750 deaths in the 5-year period between 2004 and 2009, in most cases by component failures or design errors. during the same period, up to 70 types of aeds were recalled, including recalls from every aed manufacturer in the world. in january and february 2015, the fda issued this news release: "the fda issued a final order that will require aed manufacturers to submit premarket approval applications (pmas), which undergo a more rigorous review than what was required to market these devices in the past. the agency's strengthened review will focus on the critical requirements needed to ensure the safety and reliability of aeds and their necessary accessories, including batteries, pad electrodes, adapters and hardware keys for pediatric use." in the united kingdom there is concern that poor maintenance may make public defibrillators unreliable. the henley standard reported on 21 july 2017 that more than half the defibrillators in henley-on-thames and the surrounding area were at risk of failing, either because of low battery power or because adhesive pads had deteriorated. history the first use of an external defibrillator on a human was in 1947 by claude beck. the portable version of the external defibrillator was invented in the mid-1960s by frank pantridge in belfast, northern ireland, a pioneer in emergency medical treatment. pantridge's defibrillator required a trained operator to perform the shock procedure and charted a course for many new innovations in external defibrillation. in the late 1970s the heart-aid was developed as the first truly automated external defibrillator that was designed for the public. the principles of abc assessment and a human voice relaying instructions helped bystanders respond to a sudden cardiac event while waiting for the first responders to get to scene. many of the early innovations in the heart-aid model are still part of the current generation of aeds, although some innovations, like the airway electrode have fallen from use. case studies in a study published in 2017, researchers in poland selected the main entrances of buildings which had aeds, although the researchers themselves did not know the exact locations of the devices. in drills of pretend heart attack, the average time to bring the aed to the patient was 96 seconds, with a time that ranged from 52 to 144 seconds. this met the three minute goal. in some cases, the use of the aed required the continuous presence of building personnel. future improvements include more obvious signage and public-access aeds which do not require a staff member of the building to either retrieve or use the device.