If you stayed awake during biology in school, you might recognise the shapes at the left and top right of this image: they are models of the heart. The object at lower right, looking like a cross between a tape dispenser and a second-world-war gas mask, will be less familiar.
Developed by French firm Carmat, this is an artificial heart designed for people whose hearts are so weak that they can no longer pump enough blood to sustain life. It was implanted in its first human patient on 18 December 2013 at the Georges Pompidou European Hospital in Paris.
The device replaces the real heart and is meant to keep patients going while they wait for a donor: Carmat claims it can be used for up to five years. Lithium-ion batteries outside the body keep it pumping, while sensors monitor and automatically control blood flow to adapt to the patient's activity.
Biomaterials in the artificial heart help to prevent the body from rejecting it. It is about three times larger than the natural organ, so it fits only about 65 per cent of patients. It would fit 86 per cent of men, though, because they have larger chest cavities.
So far, the operation seems to have been a success: the patient is said to be awake and talking to his family, and in a statement issued to Reuters, the hospital said the device is working well.
"The artificial heart is functioning normally, automatically catering to the body's needs without any manual adjustment necessary," the surgeons said.