ROCHESTER, Minn. (WCCO) — It’s easy to forget to re-charge our cell phones, or iPads, but what if your life relied on a battery?

For one patient at the Mayo Clinic, his lifeline is a plastic, rechargeable heart.

Alvin Carter carries around this backpack at all times.

Inside it is a portable device that keeps the artificial heart in his chest beating — Carter is the first man in the state to receive an artificial and portable heart.

While the sound could come across as almost annoying after a while, to Carter, it’s the difference between life and death.

“If I don’t hear that, I probably be gone,” Carter said. “I could never walk with other people, I had to just take my time and walk slow.”

Carter was diagnosed with a disease called amyloidosis two months ago, a condition that damages the heart through protein build-up.

“It just sort of fractured as we cut across it,” said Mayo Clinic Cardiovascular Surgeon Dr. Lyle Joyce. “It was just crunchy.”

As a result, neither ventricle could pump blood. Joyce performed the operation, first taking out Carter’s real heart. For a man without a heart, Carter shows a lot of heart.

“I’m the human tin man,” Carter said.

Inside his chest, connected to two air hoses, is what’s called “the Freedom Driver.” It’s a device recently approved for trial by the FDA. So now, two artificial pumping chambers are placed in the same cavity where Carter’s heart once sat.

“Compressed air is pumped in and out of one side, which then allows the blood to come in and out on the other side,” Joyce said.

In the past, patients have been tethered to what doctors call “the big machine,” or a large generator.

“That weighs about 416 pounds and you’re literally stuck to the hospital with that device,” Joyce said.

At times, patients would have to sit for more than two years in the hospital while waiting for a donor heart. Now, thanks to a set of batteries, there’s hope of going home. The pump even has air conditioning and car adapters.

Joyce said it’s a concept that even after 30 years of witnessing medical advances first hand, still mystifies him.

“You know it is a miracle, there’s no doubt about it, that a person can live, without a heart,” Joyce said.

Said Carter, “the tin man is happy.”

Carter is still on the list for a heart transplant in his hometown of Detroit and doctors say the “Freedom Driver” will be helpful for holding over patients who are on long waiting lists for a heart transplant.

The Mayo Clinic said you could see the Freedom Driver approved for general use within a year.