Imagine a future where surgeons no longer have to enter war zones to treat soldiers injured on the battlefield. Instead, they would just rig themselves up to a surgical robot like the Da Vinci and operate on wounded fighters remotely. This is the promise of telesurgery—when a doctor performs surgery on a patient without being in the same physical location.
But to make it work, surgeons have to be sure that issues of latency are under control, so there's not too much of a time lag between an action and a response.
"If you're a human surgeon and latency is happening while you're doing surgery, how much of that can you tolerate before your surgery breaks down and it's not safe [to operate] any more?" said Roger Smith, a chief technology officer at the Florida Hospital Nicholson Center.
Smith has been heading up time lag simulation tests with the aid of a $4.2 million grant from the US Department of Defense since 2011.
Latency is frequently experienced by video gamers who move their controller in real-time only to have their avatar move a fraction of a second slower. These delays don't matter so much in the gaming world, but in surgery dealing incorrectly with a split-second delay could cost a patient's life. Smith gave the example of a surgeon going in to grab a blood vessel based on the image on a screen. If they're not used to the time lag, they could think they've gone the right distance, but in reality have gone to far, puncturing an artery or an organ.
"It's important to get latency under control," he said. "You need to be careful about your movements, and not just trust the instincts that you've built up in your mind and hand over a lifetime, because they'll be a little bit wrong now."
Smith has tasked surgeons to carry out simulation tests, and found that experienced surgeons could operate safely with delays of up to 200 milliseconds, and adapt to delays between 200 and 500 milliseconds. Anything above that, he says, is a no-go zone.
Telesurgery is not new. The concept of telemedicine developed as early as the 1970s, and the notion of giving telepresence to surgeons in the 1980s. But slow communications networks and limited bandwidths have been a major obstacle.
"The hurdle was the communications network."
"The US military started to imagine that robots could be involved in surgery 20 years ago, and that perhaps a surgeon in one country could operate on a soldier in another country somewhere near the battlefield where there are modern communications and technology," Smith said.
He explained that back in the 2000s when the military first started developing their early surgical robot prototypes, the surgeon was seated at a 20-foot distance from the patient and surgical robot. But progress was stunted by internet speeds.
"When they started to put this on what was the emerging internet back then the network bandwidth to go any distance at all was terrible, so in general it wasn't doable," said Smith. "The hurdle was the communications network."
With the advent of improved, high-speed networks, telesurgery is finally becoming a reality. In 2001, Jacques Marescaux performed a gall bladder surgery from New York on a patient in France. Canadian surgeon Mehran Anvari has performed multiple remote surgeries on patients in Canada.
"The only way to do some real application in society is if the military finishes developing it."
Now, Smith said that licensing and liability were still hurdles that had to be discussed and dealt with. As doctors are licensed by state in the US, he asked if it would be possible for one surgeon in Florida to operate on a patient in Texas. If the internet connection passed through multiple states, would that mean that doctors had to be licensed in all those states too?
"The only way to do some real application in society is if the military finishes developing it, uses it themselves, and it proves its values in the military environment," he said.
Telesurgery might not have entered the mass civilian market yet, but it's future applications are pretty tantalizing. It could potentially connect doctors living in urban areas to communities in need in rural areas, as long as they have the required network connections.
"If we get more science fiction-y, you could provide these surgical services for people going up into space," said Smith.