An American who had been given only 30 days to live before he became the world's first recipient of a self-contained artificial heart has finally been named.

Surgeons from the University of Louisville implanted the titanium and plastic pump last month, but refused to identify their patient, saying only that he was a man in his fifties.

But Robert Tools, 59, of Franklin in Kentucky, has now chosen to talk about the operation, which has guaranteed him a place in the history books. Looking frail and speaking with an croaky voice, the result of an earlier tracheotomy, he said: "I had a choice to stay home and die or come here and take a chance. I decided to come here and take a chance.

"I realise that death is inevitable, but I also realise that if there's an opportunity to extend it, you take it."

Mr Tools, a former teacher, had the pump implanted in his chest on 2 July. A diabetic with a history of heart problems, he was deemed too ill to receive a heart transplant.

Before the surgery, he was so weak he could take only a few steps at a time and doctors predicted he would live no more than 30 days.

His public appearance comes nearly two weeks after Mr Tools was put on a ventilator to assist his breathing. He had also developed an infection and was running a fever, but the mechanical heart continued to pump without problems. The most noticeable difference, according to Mr Tools, is the sound it makes. He said: "It feels a little heavier than my old heart. The biggest thing is getting used to not having a heartbeat – I have a whirring sound.

"And that makes me realise that I'm alive because I can hear it without a stethoscope."

He said that after the surgery he felt "happy to wake up and see people – to know that I got that far".

David Lederman, the chairman and chief executive officer of Abiomed, the company based in Massachusetts that created the device, said Mr Tools' clinical progress was encouraging. "It is too early to claim success, but we are today more confident than ever that we will succeed," he said in a statement.

Earlier, Abiomed had said it would consider the trial a success if the device doubled the patient's life expectancy, which in Mr Tools' case would be 60 days. Federal regulators have approved the procedure for an additional four patients.

Bulky mechanical hearts produced in the 1980s used to be attached by wires and tubes to machinery outside the body, while the new device, known as an Abicor, fits inside the body.

The implant is designed to do the work of the lower chambers of the heart and is powered by a battery pack outside the body. There is also an internal battery, about the size of a matchbox, which can work on its own for about 30 minutes – long enough, for example, for the patient to have a bath.