A Smaller, Sleeker Heart Pump

Less intrusive and better-designed devices are in the works—and analysts predict profits for the companies that make them

by Reena Jana

The Levacor device has only one moving part, a spinning rotor. WorldHeart

Levacor relies on magnetic levitation to suspend the rotor, eliminating the need for bearings. WorldHeart

Artist's rendering of the Levacor implanted in patient. WorldHeart

The Levacor pushes blood from the heart into the circulatory system. WorldHeart

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Back in 1982, Barney Clark, a 61-year-old dentist, was implanted with the world's first artificial heart, the Jarvik-7, a cumbersome piece of equipment with complicated external mechanisms. The device, which extended Clark's life for 112 days, required the patient to be hooked up, via hose-like tubes emerging from his chest, to a machine the size of a laundry dryer. The machine supplied bursts of air that helped to pump the mechanical heart.

Today's medical-device designers foresee a more independent existence for patients suffering from heart failure. Just as the designers of popular consumer electronics such as Apple's (AAPL) iPod or Motorola's (MOT) RAZR phone have been able to slim their products to wafer-thinness, medical engineers and consultants are employing similar strategies and innovations to create slimline devices that are genuinely life-enhancing.

The current Holy Grail of heart-device design is an implanted, bio-compatible heart pump that helps an ailing organ (versus fully replacing an organic heart). It's so tiny, quiet, and devoid of complicated, power-churning apparatus as to be virtually undetectable.

A fresh vision of such a device can be found in the Levacor, under development by Oakland, (Calif.)-based WorldHeart (WHRT), named in June, 2006, as one of "50 Companies to Watch" by trade publication Medical Device & Diagnostic Industry (MDDI). WorldHeart's annual sales figures for 2005 reached $11.6 million. Currently, the Levacor is the simplest implantable and—here's the key to its distinctive technology—magnetically levitated rotary heart pump now in feasibility trials (in Europe).

WorldHeart's Initial Goals

Still very much in the development stage, and yet to enter U.S. clinical trials (meaning FDA approval is far off), Levacor was born nearly 15 years ago. Pratap Khanwilkar, vice-president for rotary systems and business development at WorldHeart, says that the initial team—of which he was a member—began by analyzing problems with existing heart-pump technology. (At the time, Khanwilkar's team was working under a different company name, Medquest. World Heart acquired Medquest in 2005.)

"Our goals were to deliver a pump in a package small enough to fit in a range of bodies—teens as well as adults of all sizes. One that wouldn't stop working in a year or two, and could have the potential for long-term use," recalls Khanwilkar, who holds a PhD in bioengineering.

In other words, they sought to create a pump that a patient could, if very young, grow old with—or, if elderly, grow older with—without having to replace it and undergo the stress of repeat surgery. The idea is called "destination therapy" in the medical world.

"The pump would have to be gentle to blood cells, so as not to rupture them, and at the same time vibrate as little as possible and require low power consumption," Khanwilkar adds.

Gradual Improvements

Khanwilkar and his colleagues turned to a technology that no other blood pumps or other heart devices incorporated in the early 1990s: magnetic levitation, which is more typically used for larger engineering projects, such as high-speed power turbines or trains. Khanwilkar and his team reasoned that magnetic levitation "could provide the greatest safety and had potential for high durability," he says, because the parts didn't have to come into contact with each other.

Instead, carefully balanced magnetic fields suspend the rotor so it can move without coming into contact with other parts, eliminating the need for bearings or shock absorbers. This translates into no friction, heat, or wear-and-tear on the pump, meaning the device could last longer.