Strokes are among the top five causes of death but if an acute stroke can be treated within ninety minutes of it happening, the survival rates increase significantly.
Aiming to make that possible and make surgeons lives easier, researchers at Massachusetts Institute of Technology have developed a thread-like robot that can slip through narrow passageways such as the labyrinthine vasculature of the brain.
Current procedure taxing on surgeons
The robot could someday be used to treat blockages and legions in the brain that typically occur when someone is experiencing an aneurysm or stroke.
As it stands to clear any blood clots in the brain, doctors have to perform a minimally invasive surgery called an endovascular procedure in which the surgeon inserts a thin wire into the main artery of the patient. Using a fluroscope the doctor has to rotate the wire in the blood vessel. A catheter is then threaded up along the wire to deliver drugs.
The procedure can be taxing on the surgeons, the researchers said because they are repeatedly exposed to radiation from the fluoroscopy. It also requires specific training. Because of the demands, the researchers said there aren't enough surgeons to perform the procedure, particularly in the suburbs and rural parts of the country.
Xuanhe Zhao, associate professor of mechanical engineering and civil and environmental engineering at MIT and a team of researchers including lead author Yoonho Kim, a graduate student in MIT’s Department of Mechanical Engineering, laid out their work in the journal Science Robotics.
Researchers combined hydrogels and magnetic actuation to make the thin robot
In order to create this thread-like robot, the researchers combined their work in hydrogels and magnetic actuation to create the guidewire, which is thin enough to slip through a life-size silicon replica of the blood vessels in the brain. The core of the thread is made out of nickel-titanium alloy, which is bendable and springy. It can return to its original shape, giving it the ability to fit through tight vessels.
To demonstrate the accuracy of the robotic thread, researchers used a large magnet to steer the robot through a course of small rings. They also tested it in the silicon replica of the brain's blood vessels that included clots and aneurysms that were taken from CT scans of real patient's brain.
“Stroke is the number five cause of death and a leading cause of disability in the United States. If acute stroke can be treated within the first 90 minutes or so, patients’ survival rates could increase significantly,” says Xuanhe Zhao, associate professor of mechanical engineering and of civil and environmental engineering at MIT said in a press release. “If we could design a device to reverse blood vessel blockage within this ‘golden hour,’ we could potentially avoid permanent brain damage. That’s our hope.”