Outsourcing The Surgeon

It's been less than a decade since the FDA approved the first robotic surgical system, and robot-assisted surgeries are already common. Of course, the machines aren't doing the thinking: That's up to the surgeons, who control the robots remotely. For now, that means surgeons and robots still work side-by-side, or at least room-by-room, in the operating theater. But it might not be long before they're separated by hundreds or even thousands of miles, linked by high-speed data cables. Patient and surgeon could be in different countries, or even different continents. That's called telesurgery, and it's the next frontier.

"Surgery is one field that robotics people should be proud of," said Yoky Matsuoka, a Washington University roboticist who designs prosthetic hands. "In terms of applying to people, it's moving as fast as anything in the field." Indeed, since the FDA's approval of Intuitive Surgical's da Vinci system in 2001, robot-assisted surgery has become the de facto standard for procedures in hard-to-reach places. Robot-assisted surgeons performed roughly two-thirds of all prostectomies in the U.S. last year, and the systems are becoming steadily more popular among heart surgeons. In Europe, robot-assisted surgery is even more common. There, as in the United States, remote controls span a few hundred feet—but it may not be long before that stretches to a few thousand miles.

Three years ago, asked if she'd have telesurgery on her heart, Matsuoka declined. She had "seen too many half-working prototypes to be anything but cautious." The issue is different now, Matsuoka says: transferring data between a robot hand and the surgeon's takes time. The farther apart surgeon and robot are, the more lag there is. This might not matter for a video chat or networked game of Halo 3, but it's an issue for surgeons. "Even a delay of several hundred milliseconds could be problematic," says Stephen Bartlett, chief of surgery at the University of Maryland Medical Center. "In the split second between your move and the patient on the other end, things could have changed."

The processors converting the data at each end of a fiber-optic cable account for relatively little lag, says Reiza Rayman, president of Titan Medical; it’s the speed of light that is the problem. It may not be fast enough for some long-distance telesurgery applications. The company's Amadeus Robotic Surgical System was designed specifically for long-distance telesurgery, and is about to be tested for speed over a 4,000-mile loop from Vancouver to Toronto. Rayman expects transmission to take about 270 milliseconds, of which just 20 milliseconds will be used to convert signal into information. Continent-spanning telesurgery might never be feasible for procedures on critical, moving structures, like the surface of a beating heart—but these could still be done from less-ambitious distances. Meanwhile, long-distance surgery on relatively motionless body parts, like prostates, should be unaffected by lag.

As for sheer bandwidth, existing technologies are already sufficient. According to Rayza, a high-definition, three-dimensional image composed from two combined camera feeds can be fit within commercially available 30 Mbps pipes. As bandwidth continues to grow—100 Mbps cables are already available in many parts of the world—plenty of transmission room will be left over for the other remaining telesurgery challenge: feedback. Surgeons using robots currently have no tactile sense of their actions, relying solely on a screen display. A robot which can transmit what it's feeling as it cuts, says Matsuoka, "is still 10 or 15 years away."