Dr. William E. “Billy” Cohn
Image: Charles Ford
Dr. William E. “Billy” Cohn

Less than 12 hours after “a bear of a case” in the OR, Dr. William E. “Billy” Cohn is relaxing behind his desk at the Texas Heart Institute and asking if I believe in magic. Grinning, he tells me to pick a number between one and 10,000.  

“Don’t think of an easy one,” he counsels me. 

I think of the number 7246 and Cohn scratches something on a notepad. “You ready?” I nod, and he tears a sheet from the pad. John Lomax, the number you picked is 7246, it says.

I’m impressed, but still, it’s no match for the practical magic performed by this master heart surgeon, medical inventor, and all-around real-life wizard.

Cohn’s office is cluttered with magnets made from rare-earth elements. It’s an obsession dating back to the 53-year-old’s early days in Memorial, when his mom would leave newspaper clippings about the feats of Texas Medical Center doctors next to his cereal. The same electromagnetism at play in Cohn’s rare-earth magnets also lies at, well, the heart of what Cohn calls his “grail-quest,” which is to say the first practical mechanical replacement for the failing human heart.

“This is the most exciting point of my career because this is something I’ve been dreaming of for years, and now it looks like we’ve got a shot on goal,” he says with the energy of an ingenious adolescent. 

The BiVACOR is that something, a device the size of an orange that’s the brainchild of Australian biomedical engineer Daniel Timms and his team. It’s a continuous-flow device, meaning it doesn’t mimic the pumping action of a human heart but rather distributes blood via a rotor propelled by electromagnetism. Recipients of the BiVACOR—only calves, sheep, and pigs so far (human trials are still in the works)—have neither a pulse nor a heartbeat, and yet are very much alive.

The quest for a durable artificial heart has stumped some of the greatest medical minds of this century and the last. Previous models have rarely lasted more than a couple of years. They either had too many moving parts or too many nooks and crannies where blood could gum up the works. 

Timms’s device has only one moving part: a rotor suspended in an electromagnetic field. What’s more, that rotor recalibrates itself millimeter by millimeter in response to the body’s movement. (Our hearts behave differently if we are standing or sitting, walking or running, coughing or sneezing. The BiVACOR knows this and shifts accordingly.)

The 40-year-old Aussie had devoted the bulk of his professional life to the device, but with no breakthroughs to his credit, Timms was having a hard time getting funding or attention. He finally persuaded Australian doctors to implant the BiVACOR in two animals—both of which died on the operating table.

It was one of Cohn’s colleagues who alerted him to a talk Timms had given in Singapore, and Cohn enticed Timms to come to Houston. The Aussie brought the BiVACOR with him in a backpack. “I immediately thought it was the coolest thing I’d ever seen,” Cohn says. “Elegant” is his favorite way to describe it.

“It’s got functionality that no one else has been able to do, using algorithms that no one else has ever conceived of—brilliant, brilliant stuff. When he showed it to me, I was thinking ‘Is this really happening to me? Who are you? Are you a time traveler?’ Dude, I would love to implant this.”

Cohn made arrangements for Timms and his team to relocate to Houston late last year, a move aided by a large furniture donation from Jim “Mattress Mack” McIngvale. A few months later, Cohn implanted the BiVACOR in a cow, which was up and munching hay faster than the runtime of Flatliners. Human trials are years away, however.

Downstairs from his office, Cohn has a workshop wherein he tinkers with prototypes of a multitude of his own devices. He builds them on the cheap, with expired high-tech medical components and parts bought from fabric stores and Home Depot. Asked which he loves more—the surgery or the tinkering—Cohn beams.

“Everything! It’s really cool! You get to implant something you helped put together yourself, and you get to see the animal get up and you say, ‘That’s right, man, I made an artificial heart!’”