Automated External Defibrillators, or AED's, are becoming more and more common in businesses, schools and other locations. And they're proving they can save lives wherever they're placed. The computerized devices provide step by step directions on procedures to save someone in cardiac arrest. And recently, they proved their value at Sheppard Air Force Base. In tonight's Sheppard Profile Erin Shryock found two people on base who are still on the job thanks to the devices and the people who knew what to do.

"So what you do is you turn it on. Begin by removing all clothing from the patient's chest, cut clothing if needed, explains Lori Stewart, AED Trainer."

Stewart is demonstrating how easy it is to use an AED.

Senior Master Sergeant Ronnie Woodard says this machine saved his life last week. "

"It makes the difference between life and death, he says."

Woodard was running on a gym elliptical when he went into cardiac arrest. Tech Sergeant Lindsay Wyburn, Sergeant Ryan Hayword and others jumped to action and administered CPR- but Woodard was still unresponsive.

"Probably about 30-45 seconds later the Navy gentleman that had the AED, opened it up, I took the pads from him we placed the pads on the gentleman's chest and the machine analyzed him and did say a shock was advised so we shocked him and I started CPR again, TSgt. Lindsay Wyburn."

This time it worked and Woodard's heart began beating again. He now has a defibrillator in his chest- and realizes he's lucky to be alive.

Varina Rolen and Lori Stewart teach CPR classes at Sheppard but never thought they would be the ones to put them to use.

"No never, never wanted to, hope I never have to use it again. But, they work. It's an amazing piece of equipment, says Stewart."

A couple months ago Stewart and Rolen found a co-worker face down at her desk and came to her rescue with an AED.

"Oh, it's self explanatory. You push the button it tells your exactly what to do. It shows your where to put the pads, it tells you what button to push and when to push it. If you hit the information button it tells you how to do CPR if you don't know how to do that, says Stewart."

"It's very, very important and it proved to us that these things work and they're simple to use and absolutely I would urge all businesses to put them in place, says Rolen."

Every minute of delay before putting an AED to use reduces the chance of survival by ten percent. That's a statistic Woodard is glad was not tested to the limit in his case.

"That day they were there for me and it was their quick action that actually kept me around, he says."

"Wyburn agrees, obviously if we were not there and the AED was not there this gentleman probably would not be here today, we're glad it turned out the way it did."