One man in France has gone from a diagnosis of a terminal heart condition to being able to ride a bicycle within the span of eight months as the result of participating in a medical trial.

"I told myself 'you're screwed, you need to do something,'" the transplant recipient said.

He then became the second person in France to receive an artificial heart. The 69-year-old man, who wishes to remain anonymous, was diagnosed with a terminal heart condition. His options were already limited so despite the first patient dying after 75 days of getting an artificial heart, he had no hesitations about undergoing the procedure.

Fortunately for him, the surgery was a success, and he's survived eight months with an artificial heart. He was discharged from a hospital in Nantes, in western France, in January and since then has been able to get back to his usual activities.

"I have completely recovered. I can walk, I can get up and I can bend down ... without any difficulty. In fact, I have never felt so good," he said.

The artificial heart was developed by French firm Carmat. The transplant is part of its trial for the device, which is designed to function as a permanent implant, extending the life of a patient while they await a human heart donor. If the artificial heart works, it may even be possible to do away with waiting for an actual heart to be transplanted. It is about three times larger than a human heart, and fits into about 65 percent of patients. It will fit men more than women for that reason, 86 percent, according to information [pdf] in the newsletter Biomedical Materials.

To be as close to a real heart as possible, the artificial device utilizes soft biomaterials, lessening risks of the immune system rejecting the transplant and blood clots cropping up after the procedure. Its key feature is its physiological auto-regulation, where it uses sensors to detect the patient's needs and then maintains proper aortic pressure using a series of algorithms. To keep the artificial heart running, a series of lithium batteries are installed in it. These batteries require recharging.

The second recipient of the artificial heart understands very well the importance of recharging his transplant, getting a system down pat to keep him on track. Other patients may devise their own recharging plan but he uses a spreadsheet where he marks down hours and changes.

Daniel Duveau was the surgeon in charge of transplanting the artificial heart. After observing the man during rehabilitation, he was surprised at how far the patient has come, doing physical activities beyond what was prescribed to him. He even rides a bicycle, although Duveau said he told doctors "don't worry, I avoid big hills'."

According to Carmat, patients diagnosed with advanced bi-ventricular heart failure no longer respond to a number of treatments. The only solution is a heart transplant, but unfortunately fewer than 4,000 hearts from donors are available every year throughout the world. There's just not enough to go around for everyone when more than 100,000 patients are in need of heart transplants.

In the coming months, two artificial heart transplants are being scheduled, according to Duveau.

Carmat's first phase of feasibility trials will test the artificial hearts on four patients whose condition is categorized as terminal. In the second phase of testing, the company says around 20 patients are expected to receive an artificial heart.