Innovative thinkers

Vol. 232 No.8

The Cameron artificial heart team
Re-engineering oilfield technology to save lives

Ron Webb, Heart Project Manager (Cameron); Mark Patterson (Cameron); Dr. Bud Frazier (Texas Heart Institute); Omar Kabir (Cameron); and Dr. Denton Cooley, seated (Texas Heart Institute).

While the heart is considered one of the most complex organs in the human body, its function is based on simple principles of physics. At least that’s the way one team of volunteer oilfield engineers sees it. Working with surgeons at the Texas Heart Institute, Cameron engineers are adapting a unique oilfield pump to accommodate the world’s first pulseless artificial heart.

The concept of an artificial heart started far from the oil field. In 1949, two doctors from the Yale School of Medicine compiled parts from bargain stores to build the first artificial heart pump. Then, in 1969, Houston-based heart surgeons Denton Cooley and Domingo Liotta implanted a mechanical heart into a patient who suffered from congenital heart failure. The implant was replaced with a donor heart within several days.

Several decades and attempts later, artificial hearts have been largely successful as a stopgap measure until a donor heart can be implanted, but a machine that can permanently replace the human heart remains elusive. Enter Texas Heart Institute surgeons O. H. Frazier and William Cohn. Unlike previous designs that have mimicked the human heart’s rhythmic circulation, Frazier and Cohn’s concept provides continuous blood flow using a whirling rotor—heart function with no heartbeat. Two of these continuous-circulation pumps can conceivably replace the entire human heart. While their mechanical heart had kept a human patient alive for a month and had done well in trial tests using livestock, the surgeons knew they needed help to replicate the levels of sensitivity and responsiveness necessary to sustain a human body in the long term. They believe they’ve found the answer in an unlikely place: a team of engineers at oilfield service company Cameron.

This year, the Cameron artificial heart team, composed of Ron Webb, Mark Patterson, Omar Kabir, John Etcheverry and Daniel Baxter, along with heart surgery pioneer Cooley, was assembled to improve the design of Frazier and Cohn’s artificial heart. “They have taken this as far as they can as physicians, and now they need the engineering help,” Webb said.

After scrubbing in with Cohn and Frazier to watch how the heart is implanted into livestock, the team went to work applying diffusion technology to the design. The redesigned pump receives blood through an inlet guide vein, which directs the liquid into a small impeller—the pump’s only moving part. “By adjusting the [inlet guide vein], we make it to perform like a tiny or large pump. This gives it a variation of geometry,” said Kabir, the team’s compressor design expert. The rotating motion of the impeller forces the blood outward, reducing its velocity and increasing pressure. “We are changing the energy of blood from kinetic to potential energy, from flow to pressure,” Kabir said.

The team is designing and testing the heart pump virtually using computational fluid dynamics, which allows them to simulate even the effect of mechanical wear on blood cells (hemolysis). “Blood cells can be destroyed by mechanical processes … We can see where are the highest shear stresses, where the hemolysis is the highest,” Etcheverry said.

Also in development is a control system that will allow the heart to make real-time adjustments in flow and pressure. “In a rig system, if the oil flow becomes higher, we can open valves to manage that pressure,” Kabir said. “If [the heart] needs more flow or pressure, the controls can make the necessary changes.”

Cameron has committed to supporting the artificial heart team, all of whom work on a volunteer basis on the project, for the next several years. “Anything in the medical industry I would have been thrilled to get involved with, but the heart is about as complex and important of an organ as we have,” Webb said. 

Ron Webb, Heart Project Manager (Cameron); Mark Patterson (Cameron); Dr. Bud Frazier (Texas Heart Institute); Omar Kabir (Cameron); and Dr. Denton Cooley, seated (Texas Heart Institute).

An x-ray shows the dual turbinelike blood pumps in the artificial heart.

The team watching Texas Heart Institute surgeons implant an artificial heart into a cow in 2011.

Schematic of the heart compressor.

nell.lukosavich@worldoil.com