It is hard to tell that, just six weeks ago, she made medical history. Abigail Hall is bouncing up and down on her new trampoline, her family gathered round in amazement at the three-year-old who brushed with death so many times.

As the toddler showed off the newfound strength in her legs, Abigail is blissfully unaware that she is a world first when it comes to the treatment of the complex heart defect with which she was born. She is the only child suffering from her condition who has been fitted with a mechanical heart - and survived.

The Berlin heart, which is controlled by a laptop computer, crucially bought little Abigail, and her parents Gillian and Stephen, the extra time they needed as the "rollercoaster" wait for a suitable transplant heart went on.

Normally, those who have Hypoplastic Left Heart Syndrome, can't take the artificial organ. But somehow, the last hope for survival connected with the little girl, who thanks to the device just made it through to the day her replacement heart arrived.

Her mother Gillian, 35, a primary school teacher, said: "When I was told Abigail was a world first, I just burst into tears. To say thanks to the doctors just seems so inadequate. It just doesn't seem enough."

The family returned home to Lenzie from the Freeman Hospital in Newcastle on Thursday and are now enjoying getting into a more normal family routine having spent long spells of the past three years at Abigail's hospital bedside.

Things like splashing in puddles and climbing stairs may be little activities to many children, but, for Abigail, they are massive steps forward. In her short life, she has suffered two mini-heart attacks and she had her first open-heart surgery at just six-days old.

Her father, Stephen, 40, an architect, said: "She has always been our special wee girl, but we don't want to put her on a pedestal. We just want her to enjoy the childhood she should have had all along. Nothing more, nothing less."

There have been many changes for Abigail since her transplant, but one thing that stands out for her parents is the colour of her little fingernails and lips. Now they are a rosy pink, but in the past they were blue. Her poor heart function made it difficult for the blood to be fully pumped to her face, hands and feet.

"We have looked back at photographs and sometimes her lips are the colour of blackberries. That was when she really went downhill, when we were first waiting for a transplant," said Mr Hall.

The couple were waiting for a phone call for six weeks which would give the go ahead for the transplant.

"And boy did we cram a lot into those six weeks. We went to the beach at St Andrews, went to as many playparks as we could and took as many trips as we could.

"We didn't know when we were going to get the call and didn't know what that call would bring, or what it would lead to. We just wanted to enjoy each other as much as we could," added Mr Hall.

When they heard that a possible heart had been found, the toddler was quickly on an NHS plane - the "yellow plane" as Abigail calls it - to Newcastle. Cruelly, the organ was a poor match and couldn't be used.

It was shortly after that Abigail's condition severely deteriorated and that a Berlin heart was first considered. After an initial improvement in her condition, it emerged that the artificial organ might not sustain Abigail for as long as expected.

Then a phone call came informing them that another suitable heart had been delivered from the continent - just in time for Abigail's third birthday.

"We can't express enough our gratitude to the family who allowed their own child's heart to be used. It was a tragic time for them and a dark time for us. But thanks to their selflessness, we got hope - and they gave Abigail life."

Berlin heart

Named after the German city in which it was invented, it is designed to pump blood around the heart in the proper manner.

Devised in 1997, the first Berlin Heart was implanted in 2002.

The device works by helping the right ventricle of the heart pump blood to the lungs and the left ventricle to pump blood to the body.

The pump comes in a range of sizes, which means that even newborn babies can benefit from a Berlin Heart.

The bulk of the artificial heart device sits outside the body with only the tubes "plumbed into" the damaged chambers.