Engineers at Massachusetts Institute of Technology (MIT) have developed a magnetically steerable robotic thread which could be paired with existing endovascular technologies to treat blockages and lesions in the brain.
To clear blood clots in the brain, doctors often perform an endovascular procedure, whereby a thin wire is inserted into a patient’s body through a main artery in the leg or groin. The wire is then manually rotated up into the damaged brain vessel, guided by a fluoroscope, and delivers drugs or clot-retrieval devices to the affected region via a catheter.
The procedure is physically taxing and requires specially trained surgeons who must endure repeated radiation exposure from the fluoroscope. The robotic thread developed by the MIT team could help to bypass some of these obstacles.
The research team coated the wire’s core in a rubbery paste embedded with magnetic particles. These particles can be activated by a large magnet and guided around the body. The magnetically steerable device does away with the need for surgeons to physically push a wire through a patient’s blood vessels, meaning doctors wouldn’t need to be in close proximity to the patient or the radiation-generating fluoroscope.
The hydrogel-coated thread has been magnetically guided through a life-size silicone replica of the brain’s blood vessels. The core of the robotic thread is made from a nickel-titanium alloy which is bendy and springy, giving it the flexibility to wind through taught blood vessels, while the hydrogel gives it the necessary slippery coating to guide through tight spaces.
Blockages in the brain are common in stroke patients. Stroke is the fifth leading cause of death and a leading cause of disability in the US, but if treated within the first 90 minutes, survival rates increase significantly. The researchers hope their work can help aid the development of magnetically-assisted endovascular surgeries to help treat these patients.
MIT associate professor of mechanical engineering Xuanhe Zhao said: “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.”