A French company will be moving forward with implanting a new artificial heart that incorporates biological tissue from a cow. Earlier this month Carmat won approval from four different cardiac centers in Saudi Arabia, Slovenia, Poland, and Belgium. While synthetic hearts aren't new, what sets the new Carmat "bioprosthetic" model apart is the way it uses existing biological tissue. Two chambers in the heart are divided by a membrane; hydraulic fluid is held in place on one side of the membrane. A pump within the heart pushes the fluid in and out of the chambers, which causes the blood to flow on the other side.

That membrane is created from tissue taken from the sac surrounding the heart of a cow. The idea is that using biological material will make the heart work better with the transplant recipient's own system, and perhaps lead to patients relying less on anti-coagulation medications. Cow heart tissue is also used in two valves in the Carmat device, while sensors built into the heart monitor pressure, allowing it to dynamically adjust the rate of blood flow in response to physical activity. While Carmat has yet to win approval for the device's use in its native France — regulators want the it tested on animals first — the company is expecting to win approval in additional countries in the near future. That said, it won't come cheap: the device is expected to cost around 150,000 euros (over $195,000).