A man who had been without a heart for 555 days was being kept alive by the grey backpack he carried everywhere he went.
We all know we carry our laptops and notebooks in our backpacks, but what about carrying a replacement heart? Well, that sounds interesting.
Stan Larkin has been living without an organ for over a year while waiting for a human heart transplant.
The Michigan man went completely unnoticed by passersby because he appeared to be a typical young, healthy adult.

Stan Larkin lived 555 days without a heart. (CNN)
But the grey backpack Stan carries everywhere he goes may have seemed harmless at first glance, but it’s actually keeping him alive.
But Stan hasn’t let this slow him down and he still enjoys taking his three young children to the park and even playing basketball with them while wearing a backpack.
Inside the bag was the power source for the artificial heart that was beating inside his chest.
Stan’s real heart was removed from his body in November 2014 and then replaced with a machine that would allow him to stay out of hospital while waiting for a transplant.
His heart transplant finally arrived in May 2016, and the surgery took place at the University of Michigan Frankel Heart and Vascular Center.
“Most people would be scared to go that long. [an artificial heart]”But I want to tell people that they have to get over their fear, it helps them,” he told CNN shortly after the surgery.
“It helps me stay healthy before the transplant so I can go home sooner after.”

He had to wait a while to receive a heart transplant. (Getty Stock Photo)
Cardiovascular surgeon Dr. Billy Cohn said unfortunately, people waiting for transplants will have to wait years to get the treatment they need.
“Many of these patients have very weak hearts and their kidneys, livers and other vital organs will fail while they wait,” he said.
“Without some assistance, many of these patients will die.”
Stan needed a transplant because of a genetic heart condition called familial cardiomyopathy.
The Michigan man was unaware his heart was suffering until he suddenly collapsed during a basketball game in 2007.
According to the Department of Cardiology, familial cardiomyopathy is “a heart disease characterized by an enlarged diameter of the heart and a weakened pumping function.”
Dr Jonathan Haft, the surgeon who performed Stan’s surgery, said the type of cardiomyopathy Stan has can cause irregular heart rhythms and heart failure on both sides of the heart.