Home Defibrillator Fast Facts

What is an AED?

An Automated External Defibrillator, or AED, is a portable device designed for use at home or in a workplace by a layperson to revive a patient who has had sudden cardiac arrest (search).

The user attaches adhesive pads to the patient's bare torso, and the AED instructs him via voice prompts on whether to administer electric shocks to restart the patient's heart.

How it works:

The person controlling the battery-operated, textbook-sized device pushes the green power button and follows the voice prompts.

The defibrillator first instructs the user to pull back the plastic shield in the center of the gadget and take out the two chest pads, which are wired to the machine.

It then tells the user to remove all clothing from the patient's upper body — there are scissors included with the AED kit in case garments need to be cut off — then take off the pads' adhesive backing and place one on the upper right corner of the chest below the shoulder, the other on the lower left side under the armpit.

Diagrams are included to ensure the pads are put in the right places.

As the AED determines whether the patient has suffered cardiac arrest and needs a shock to get the heart started again, it gives orders not to touch the patient and says it's "analyzing."

If a shock is required, it tells the user to push the orange button to deliver the shock, with more warnings to stay away from the patient.

It will continue advising the person to administer shocks until the heart restarts or until it’s deemed futile to do so because the patient has flatlined.

It also walks the user through cardiopulmonary resuscitation (search) — which involves alternating chest pumping with assisted breathing — and gives reminders about calling 911.

What kind of shock it delivers to the heart:

A powerful electric shock of about 2,000 volts, lasting 10 to 20 milliseconds.

How it differs from the big contraption used in the ER:

The technology of the at-home or at-work defibrillators is similar to that of those used by medical professionals in emergency rooms and ambulances. The only difference is the ease of use provided by the computerized home/work models, which have more intelligence built into them and do most of the work for the person at the controls.

Those handled by professionals allow doctors and paramedics to do more of their own assessments and readings of the patient's condition. The at-home or at-work defibrillators are also much smaller and more portable than the ones in hospitals, which are the size of a small suitcase.