Scientists have been developing artificial hearts for quite some time now. However, many of the current designs are unfortunately clunky, which presents difficulties in successfully integrating them into human tissue. To approach this issue, a team of researchers from ETH Zürich decided to take a cue from the biological human heart.
One problem with artificial hearts is that metal and plastic mechanisms can be difficult to integrate with tissue, or damage the blood because of their unnatural movement style.
A small team at ETH, led by doctoral student Nicholas Cohrs, has created what they say is the first artificial heart that’s entirely soft, with its pumping mechanism achieved by causing the silicone ventricles to pump just like a real heart. Well, not exactly like a real heart — in-between the ventricles isn’t just a wall but a chamber that fills and deflates to create the pumping action. But it’s close.
A well-functioning artificial heart is a real necessity: about 26 million people worldwide suffer from heart failure while there is a shortage of donor hearts. Artificial blood pumps help to bridge the waiting time until a patient receives a donor heart or their own heart recovers.
The soft artificial heart was created from silicone using a 3D-printing, lost-wax casting technique; it weighs 390 grams and has a volume of 679 cm3. “It is a silicone monoblock with complex inner structure,” explains Cohrs, who led team. This artificial heart has a right and a left ventricle, just like a real human heart, though they are not separated by a septum but by an additional chamber. This chamber is in- and deflated by pressurized air and is required to pump fluid from the blood chambers, thus replacing the muscle contraction of the human heart.
This heart is a proof of concept, not built for actual implantation — so the materials they made it from don’t last more than a few thousands beats. That’s about half an hour, depending on your heart rate. But the plan, obviously, is to have materials and designs that work for much longer than that.