Scientists have developed a robotic device that could transform the treatment for strokes, which each year strike 795,000 Americans and kill 140,000. It’s a wormlike robot designed to wend its way through the maze of tiny blood vessels inside the human brain to break up the blood clots causing the stroke and restore the flow of blood.
The clot-busting device, which would open clogged blood vessels with beams of laser light or precisely delivered doses of clot-dissolving medication, is in an early stage of development. But experts hailed the potential of the device, which is described in a paper published Aug. 28 in the journal Science Robotics.
“It could markedly enhance access to clot-retrieval treatments, which at the moment are limited to comprehensive stroke centers,” said Ralph Sacco, chairman of neurology at the University of Miami’s Miller School of Medicine and past-president of the American Heart Association. “It would be a quantum leap … in access to clot retrieval therapy.”
Greater access to effective stroke treatment would mean more patients would be treated during the so-called golden hour, before oxygen-starved brain tissue dies and patients face an increased risk of death or permanent disability.
A new video from the MIT researchers who developed the magnetically steered device shows an early prototype quickly threading its way through a life-size silicone replica of the brain’s mazelike vasculature, which included simulated blood as well as simulated clots and aneurysms — weakened areas of blood vessels that might also be fixable with the new device.
Since the robot is guided by magnets rather than directly by the hands of a doctor with specialized expertise in stroke care — as is the case with conventional clot-retrieval catheters — doctors would be able to steer it from another room or even another hospital. Thus doctors could potentially limit their exposure to the X-rays needed to visualize the tiny blood vessels inside the brain. Patients in areas with limited local medical resources could also receive prompt treatment via telemedicine from specialists at a comprehensive stroke center far away in another city.
Xuanhe Zhao, an associate professor of mechanical engineering and civil and environmental engineering at MIT and a member of the team that developed the device, said it might even be possible to incorporate artificial intelligence into the magnetic-control system so that it could be operated by health care providers with even less specialized training.
“There are just not enough experienced doctors to perform the surgery,” Zhao said.
The device, which would be inserted into the patient’s body through a small incision in the groin or neck and then snaked up to the brain, is smaller than conventional clot-retrieval catheters and has a slippery, friction-reducing gel coating around the flexible alloy wire at its core. Those features could give the robot another potential advantage over existing catheters: the ability to venture inside even extremely narrow blood vessels.
“It can reach places that catheters can’t reach now,” said Bradley Nelson, a professor of robotics and intelligent systems at the Swiss technical university ETH Zurich. “We’re seeing devices that can go deeper into the body along more tortuous paths. This is a step along the way.”
Many steps lie between the current prototype and a commercial version of the robot. Zhao said tests of the device on animals might begin within a year or two but that it might take a decade or longer for the device to treat humans.