Last Wednesday in Paris, a 75 year-old man received an artificial heart. That in itself might not be newsworthy, as such devices have been in use since the early 80s. In this case, however, the gadget in question was the first Carmat bioprosthetic artificial heart to ever be implanted in a human. According to its inventor, cardiac surgeon Alain Carpentier, it's the world's first self-regulating artificial heart.

When Carpentier uses the term "self-regulating," he refers to the Carmat's ability to speed up or slow down its flow rate based on the patient’s physiological needs – if they're performing a vigorous physical activity, for instance, the heart will respond by beating faster. This is made possible via "multiple miniature embedded sensors" and proprietary algorithms running on its integrated microprocessor.

Most other artificial hearts, by contrast, beat at a constant unchanging rate. This means that patients either have to avoid too much activity, or risk becoming breathless and exhausted quickly.

According to a Reuters report, although the Carmat is similar in size to a natural adult human heart, it's a little on the big side. It should therefore fit inside 86 percent of men, but only 20 percent of women – that said, the company has stated that a smaller model could be made. It's also almost three times heavier than a real heart, tipping the scales at approximately 900 grams (2 lb).

Power comes from an external lithium-ion battery pack worn by the patient, and a fuel cell is in the works. The heart itself is intended to operate continuously for at least five years (or 230 million beats) although in its first human trials, success will be gauged on whether or not it allows recipients to survive for at least another month. Needless to say, volunteers receiving the implant will already be in the final stages of heart failure.

The current lone recipient is reported to be recuperating in intensive care at Paris' Georges Pompidou European Hospital, where he is awake and carrying on conversations. "We are delighted with this first implant, although it is premature to draw conclusions given that a single implant has been performed and that we are in the early postoperative phase," says Carmat CEO Marcello Conviti.

Assuming the trials go well, the Carmat is expected to be available within the European Union by early 2015, priced between 140,000 and 180,000 euros (about US$190,000 to $250,000).

Prof. Carpentier developed the heart in collaboration with French aerospace firm EADS.

Sources: Carmat, Reuters