Robotic ‘thread’ to treat blood clots in the brain

MIT engineers have developed a robotic “thread” that is magnetically directed and can move in extremely narrow and labyrinthine areas, such as the brain vascular system.

As the MIT News reports, in the future this “thread” could be combined with existing intravascular technologies, with doctors guiding it through the patient’s brain vessels to quickly deal with cases of heart attacks, wounds and other problems, such as observed in aneurysms, strokes, etc.

“Stroke is the No. 5 cause of death and a major cause of disability in the US. If acute stroke can be treated within about 90 minutes, the patient’s chances of survival can be significantly increased.”,

says Swanhe Zhao, an assistant professor of mechanical engineering and civil / environmental engineering at MIT.

“If we could design a device to reverse infarctions in blood vessels in this ‘golden hour’, we could potentially avoid permanent brain damage. We hope for that.”,

he added.

Zhao and his team, including Yoon Kim, a graduate of MIT’s Department of Mechanical Engineering and lead author of the research, describe their work in “Science Robotics”.

To neutralize blood clots in the brain, doctors often perform an intravascular procedure; a minimally invasive procedure, where the surgeon inserts a thin cord into a patient’s artery, mainly the foot or groin. The cord is then directed to the target via X-ray images. This procedure is particularly tedious for physicians who need specialized training.

In their scientific article, the researchers combined their knowledge and experience in the field of hydrogel and magnetism to make this robotic ‎‎ ‎‎ ‎‎”thread”‎‎, which may be ‎‎directed magnetically and has a hydrotzel coating‎‎. The core of the yarn ‎‎is made of nickel-titanium alloy (Nitinol)‎‎, which is flexible but can also be restored to its original shape.

What the researchers were doing was to cover the core with an “ink” containing magnetic particles; and in the end they applied a hydrogel to make the surface smoother (reducing friction) and biocompatible. The robotic “thread” is precisely directed by a magnet, and its performance, as found in tests performed on dummies, was particularly high.

According to Kim, there are opportunities to further improve and enhance it with new features (eg drug delivery or laser clot cleavage).

Also, the advantage is that doctors do not need to be close to the patient during surgery, which results in less exposure to radiation.