Automated External Defibrillators: The History and Invention of AEDs

The discovery that a person’s heart can be restarted with the use of an electrical charge is one of the greatest advances in modern medicine. This idea began around 1888 when Mac William suggested that ventricular fibrillation could be a cause of sudden death. In 1989, Batelli and Prevost discovered that large amounts of voltage delivered to the heart could stop ventricular fibrillation in animals. Other studies carried out in the 19th century by scientists furthered the effects of electricity on the heart.

An AED (automated external defibrillator) is a portable electronic device that can determine a person’s heart rhythm. It detects life-threatening problems within the heart and has the ability to treat them with defibrillation. If necessary, an AED can deliver electrical shocks to the heart to restore a normal heart rhythm. When someone goes into sudden cardiac arrest, their chances of survival drop by 7 to 10 percent with every minute that goes by without CPR or defibrillation.

The first successful defibrillation in a human was reported in 1947 by Dr. Claude Beck. During one of his surgeries, he noticed that his patient was experiencing ventricular fibrillation. He administered a 60 Hz alternating current and stabilized her heartbeat. This particular patient of yours lived; defibrillators were created.

An AED has a built-in computer that evaluates your heart rhythm, determines if you need defibrillation, and then delivers the necessary level of shock. The AED user is guided through this process with audible prompts, visual prompts, or both. Automated external defibrillators are generally sold in kits that contain a power unit, paddle electrodes, and accessories. Each part is individually manufactured and then assembled through an integrated process. Today, medical device manufacturers have created many defibrillators, external and internal, that are capable of adding years to the lives of many patients.

External defibrillators can be used in hospitals or emergency sites. The user begins by turning on the defibrillator and applying conductive gel to the patient’s chest or paddle electrodes. Then the power level is decided and the instrument is charged. The paddles are placed firmly on the chest with some pressure. Buttons on the electrodes are pressed at the same time, and then an electric shock is delivered to the patient. After this procedure, the heartbeat is monitored to determine if it is regular. The whole process is then repeated if necessary.

In 1954, William and Kouwenhoven Milnor performed the first closed-chest defibrillation on a dog. This process was studied by Paul Zoll in 1956 and achieved the first success in a human being. Qilliam Bennett Kouwenhoven, born in Brooklyn in 1886, was an electrical engineer and invented three defibrillators and also developed CPR techniques.

The AED (automated external defibrillator) was created in 1978. This particular device is made with sensors that are attached to the chest to decide if ventricular fibrillation is occurring. If detected, the device gives the appropriate instructions to deliver an electric shock. These automated devices have been able to reduce the training required to use defibrillators and have also saved the lives of thousands of people.