I wrote recently about Sedasys, a machine that automates anesthesia. It’s a first-of-its-kind device in the United States. Only four hospitals use it for now. It's restricted to colonoscopies in healthy patients.
But Sedasys, in development for 15 years, is no longer on the true cutting edge of what’s possible with automated anesthesia.
A machine with the clunky name of iControl-RP is. It's an experimental device that pushes the boundaries of how much responsibility is turned over to technology. It monitors brain wave activity. And it's even been tested on children.
One of the reasons that Sedasys was approved by U.S. health regulators is that it's a conservative leap forward. The device is innovative, but it doesn’t decide alone how much anesthesia to give to a patient.
It’s an open-loop system. The initial dose is pre-determined based on a patient's weight and age. And Sedasys only reduces or stops drug delivery if it detects problems. Only a doctor or nurse can up the dose. That gave regulators a level of comfort.
But the iControl-RP makes its own decisions. It is a closed-loop system.
This new device, being tested by University of British Columbia researchers, monitors a patient’s brain wave activity along with traditional health markers, such as blood oxygen levels, to determine how much anesthesia to deliver.
“We are convinced the machine can do better than human anesthesiologists,” said Mark Ansermino, one of the machine’s co-developers, who works as director of pediatric anesthesia research at the university’s medical school in Vancouver.
The iControl-RP has been used to induce deep sedation in adults and children undergoing general surgery. Researchers say the device has been used on 250 patients so far. These patients were totally knocked out. Some had liver resections and major spinal operations.
This goes far beyond anything that Sedasys does, which is approved in the U.S. only for light to moderate sedation in healthy adults undergoing colonoscopies.
Sedasys dips its toes into what’s possible. The iControl-RP dives right in.
The idea of fully automating anesthesia is not new. It was first proposed in the 1950s. But technology lagged behind theory. It wasn’t until the 1980s that the idea seemed plausible. And only in recent years have doctors tried closed-loops systems in real medical procedures. Doctors in Canada, France, India and China have all used different closed-loop systems in limited studies. One system with the catchy name McSleepy briefly caused a stir in 2008 when it was first used. It has since faded from the operating room.
But Ansermino and Guy Dumont, an electrical engineering professor at the medical school who helped develop the device, hope to see the wide adoption of iControl-RP.
One early role for the machine, they say, could be in war zones or remote areas where an anesthesiologist is unavailable.
Anesthesia is tricky. It’s often compared to flying a plane – keeping a patient hovering in just the right plane of consciousness. It’s called depth of hypnosis. Surgeons don’t want patients writhing on the table. And patients don’t want to be aware of the operation. Of course, no one wants patients to die, a distinct possibility if too much of an anesthesia drug is delivered.
The iControl-RP aims to thread that needle by using an EEG to scan a patient’s brain waves to make sure the sedation is adequate. And it looks at heart and breathing rates and blood oxygen levels to make sure the patient is not slipping too deeply into sleep. The machine’s algorithm makes all the medical decisions that a doctor usually does.
Ansermino said anesthesiologists are not very good at maintaining just the right amount of sedation. This is especially important in children, where studies show that deep sedation can have negative longterm cognitive impacts on infants and toddlers.
But iControl-RP has not been blessed by the U.S. Food and Drug Administration.
Right now, the machine is being tested on more adults in Vancouver.
The iControl-RP team says it has struggled to find a corporate backer for its project. Ansermino, the anesthesiologist in Vancouver, thinks he knows why.
“Most big companies view this as too risky,” he said.
But, he said, a device like this was inevitable.
“I think eventually this will happen,” Ansermino said, “whether we like it or not.”