A snake, a magnetically controlled robot capable of maneuvering through some of the narrowest arteries of the body, can one day help prevent deaths related to strokes and aneurysms.
With magnetic entrails and a rising friction-reducing hydrogel, a thread-like robot can seamlessly slide through "complex and restricted" environments such as vascular structures in the body and brain, engineers at the Massachusetts Institute of Technology (MIT) describe Robotics. When associated with currently used endovascular technologies, it may allow physicians to quickly treat difficult-to-access blockages and lesions in the brain that occur with aneurysms and strokes.
'Stroke is the number five cause of death and a major cause of disability in the United States. If acute stroke can be treated within the first 90 minutes or more, patients' survival rates can increase significantly, "said Associate Professor Xuanhe Zhao at MIT. If we could design a device to block the blood vessels within this "golden hour", we could potentially avoid permanent brain damage. This is our hope. ”
Current treatments are minimally invasive and at the same time difficult. To clear blood clots in the brain, surgeons pass through a thin wire through a major artery in the body, often through the legs or groin, while a radiation beam that emits radiation takes pictures and x-rays that help direct the wire to the brain. The catheter then either supplies clot-reducing drugs or a device extracts the clot. But this process is taxing and requires specially trained doctors who withstand radiation exposure over time.
"One of the challenges in surgery is being able to move through complex blood vessels in the brain that is very small in diameter, where commercial catheters cannot reach," says Kyujin Cho, a professor of mechanical engineering at Seoul National University. "This study has shown the potential to overcome this challenge and to enable surgical procedures in the brain without open surgery."
That's where the robotic thread comes from, building on years of research around detention. hydrogels and 3D printed materials that use creep and jump magnets. The hydrogel layer keeps the thread smooth and reduces friction by more than 10 times, while the magnets in the second layer allow the surgeon outside of the room to work and maneuver the threads throughout the human body, reducing radiation exposure from fluoroscopes. Its core is made of nickel-titanium alloy or nitinol, which is bent but can still return to its natural shape, allowing flexible winding through tight vessels. Together, the thread is below several hundred micrometers in diameter.
"Given their compact, self-actuated and intuitive manipulation, our ferromagnetic soft continuous robots can open the way to minimally invasive robotic surgery for previously inaccessible lesions, thus coping. challenges and unmet health needs, ”the authors wrote.
Researchers tested the technology on a full-size silicone replica of the brain's blood vessels filled with realistic clots and aneurysms and blood-like fluid. Although promising, the experiments were conducted under the eyes of an operator, not under conditions as difficult as when entering a human body. In addition, the magnetic control is made by adjusting the position of a permanent magnet and not in ways that could mimic those used in the operating room.
Nevertheless, the authors argue that their work may undergo more effective and simplified treatment in the near future.