In a new study published Wednesday in the Science Robotics journal, MIT engineers announced they have developed a magnetically steerable, thread-like robot that can actively glide through narrow, winding pathways, such as the labrynthine vasculature of the brain.
The engineers hope this robotic thread may enable doctors in the future, to remotely guide the robot through a patient's brain vessels to quickly treat blockages and lesions, such as those that occur in aneurysms and stroke.
The study lead author Xuanhe Zhaosaid said in a report published on the institute's website: "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. Our goal is to design a device to reverse blood vessel blockage within this golden hour."
To clear blood clots in the brain, doctors often perform an endovascular procedure, a minimally invasive surgery in which a surgeon inserts a thin wire through a patient's main artery, usually in the leg or groin. The surgeon then manually rotates the wire up into the damaged brain vessel guided by a fluoroscope that simultaneously images the blood vessels using X-rays. A catheter can then be threaded up along the wire to deliver drugs or clot-retrieval devices to the affected region.
The design of this robotic thread helps treat these problems and reduces doctors' exposure to any associated radiation. Its core is made from nickel-titanium alloy, or "nitinol," a material that is both bendy and springy, so it would return to its original shape, giving it more flexibility in winding through tight, tortuous vessels.
The researchers used a large magnet, much like the strings of a marionette, and tested it in a life-size silicone replica of the brain's major blood vessels in conditions like clots and aneurysms.
