Heart failure affects more than 10 million people in the US and Europe each year, and the outlook for patients is often bleak. Medication can only keep the condition under control for so long, and most patients require a full heart transplant. If your slow-failing heart isn’t scary enough, the number of donor hearts that become available each year is small compared to the number of people waiting for them. For some patients, their size or blood type means that the chances of finding a donor heart are virtually zero.
Attempts to design artificial hearts have been made since the 1950s, with little success. Many tests of artificial hearts over the years have looked at how many days — and it was often days — a poor animal could survive with one installed instead of its natural heart.
The complex system of artificial pumps and valves — which must beat more than 100,000 times a day and tens of millions of times a year — is wearing out, meaning mechanical hearts can fail even faster than the diseased hearts they replace.
The few artificial hearts approved for human use are currently only used as a last resort, to buy a patient time for a real transplant. Patients have to wear cumbersome power boxes at all times and wiring runs in and out of their chests, leading to infections.
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But a completely new design, known as BiVACOR, could revolutionize the use of artificial hearts and the way heart failure is treated. Rather than trying to mimic the way a real heart pumps, the device uses a single spinning disk to pump blood to the lungs and body. With the high-tech rotary pump floating between magnets, there is virtually no mechanical wear. The lack of other moving parts allows the rest of the heart to be made from ultra-rugged titanium.
In addition to state-of-the-art floating disc technology, the BiVACOR heart can tailor its output to the patient’s physiological needs (so it pumps faster during exercise) and can be made small enough to fit a child. It is also hoped that the device could one day be combined with wireless charging technology, meaning the battery could also be implanted in the patient, rather than worn externally.
BiVACOR is the brainchild of Dr. Daniel Timms, who started developing artificial hearts when his father Gary, a plumber, suffered a heart attack in 2001. When the problem of heart transplant shortages became clear to him, Timms – then a student – started working on a prototype using 3D printing and sanitary equipment.
“We didn’t have the money to do something like animal studies, it was just way too expensive. So my father and I built a circulatory system that mimicked the human body,” said Timms, now chief executive of BiVACOR Inc. and an expert in heart transplant technology.
“We just went to Bunnings, our big hardware store here in Australia, and built a circulation loop to test if it was giving proper flow and pressure to the different parts of the artificial body we had created. From there, we refined the devices.”
In 2001, spinning disc technology was still in its infancy, but it was used in implants that help blood flow in damaged areas of the heart. Timms’ idea was to use that technology to design a whole heart from scratch.
“Actually, everyone had given up making a complete artificial heart,” he says. “Instead, they made these little devices that could only be placed on the left side, for example, and they just started using spinning disk technology. My take was, why not apply that to a total replacement heart?”
The first artificial heart implant was performed in 1969 at the Texas Heart Institute in Houston. When the patient survived 64 hours without the heart he was born with, it was considered a success; hopes were high that artificial heart transplants would become commonplace in the coming decades. But it just didn’t happen. More than half a century later, heart doctors are seeing more heart failure patients every year, but they’re still waiting for a device that can reliably do the job of the organ that’s constantly beating away in our chests.
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BiVACOR has once again raised hopes that artificial hearts can put an end to the fraught and often futile search for donor hearts. Not only has the new design garnered millions of dollars in funding, but it has also gained the support of the Texas Heart Institute, a global leader in advanced heart health care.
The great promise of the design is that it doesn’t look like a real human heart at all, says Timms. “It’s a bit like a flight that’s heavier than air. Mother Nature gave birds fluttering wings with bones and tendons and muscles. When we tried to do that in the early days of flying, it really didn’t work that well. It wasn’t until we stopped trying to imitate birds and developed propellers and engines that we got off the ground.”
BiVACOR has partnered with NASA since 2019, leveraging their expertise in building ultra-reliable hardware for situations where failure means certain death. The device was tested on a cow, which reportedly not only survived but was also able to run on a treadmill, as well as other animals. And last year, after decades of development, doctors temporarily fitted BiVACOR devices into human patients undergoing heart transplants as a first step toward human trials. Custom devices, tailored to the patient’s anatomical dimensions, were fitted to see if they would work before real donor hearts were implanted.
The company is now working on the first real human trials. The plan is to implant the devices for three months in patients who cannot find a suitable heart donor and monitor their performance. In the long term, it is hoped that BiVACOR hearts can replace the overall function of patients’ hearts and provide hope for the millions of people awaiting or unfit for heart transplants. If successful, it will end one of the great challenges of biomedical engineering.
“I didn’t have a tendency for it to turn into what it is now, not at all,” Timms says. “It was just a crazy idea that I thought someone else had already had it, or that the field could move and then someone would take over from there.”