Robotic worm that can snake through blood vessels could revolutionise surgery

30 Aug 2019

The robotic thread (in black) that can be steered magnetically through narrow spaces. Image: MIT

MIT engineers have developed a thin, magnetically controlled soft robotics device coated in a slippery skin to pass through tight pathways.

A tiny worm-like robot capable of gliding through narrow, winding pathways, such as those found in the brain, has been developed by scientists at Massachusetts Institute of Technology (MIT).

The robotic thread can be steered remotely using magnetic fields, supported by a self-lubricating skin to help it smoothly manoeuvre with minimal friction through its delicate surroundings.

MIT engineers tested the ultra-thin guidewire on an obstacle course of small rings, as well as a life-size silicone replica of the brain’s blood vessels.

They hope that it could one day be used to speed up treatment of conditions such as an aneurysm or a stroke, and make existing procedures simpler for surgeons by doing away with the necessity to physically push a wire around.

‘If we could design a device to reverse blood vessel blockage within this ‘golden hour’, we could potentially avoid permanent brain damage’

“If acute stroke can be treated within the first 90 minutes or so, patients’ survival rates could increase significantly,” said Xuanhe Zhao, associate professor of mechanical engineering and of civil and environmental engineering at MIT.

“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.”

Next steps

The soft robotic design – which is described in the Science Robotics journal – is made from a flexible nickel-titanium alloy, giving it the advantages of being bendy and springy as it makes its way around tight vessels.

Tests of the robotic thread coated in hydrogel showed that it was able to move much faster than one without hydrogel, and reduced the risk of injury to vessel linings.

“Existing platforms could apply magnetic field and do the fluoroscopy procedure at the same time to the patient, and the doctor could be in the other room, or even in a different city, controlling the magnetic field with a joystick,” lead author Yoonho Kim envisaged.

“Our hope is to leverage existing technologies to test our robotic thread in vivo in the next step.”

More in soft robotics

In another study published to Science Robotics this week, MIT scientists working with researchers from the Science Foundation Ireland research centre AMBER and NUI Galway announced a significant breakthrough in the field of soft robotics.

Their bio-inspired soft robotic device, known as a dynamic soft reservoir (DSR), manipulates the environment at the point where body and device meet, using mechanical oscillation to modulate how cells respond around an implant. The device has been shown to significantly reduce the build-up of fibrous capsules around implants, which can render them useless.

Dr Ellen Roche, a senior co-author of the study, said: “This has vast potential for a range of clinical applications and will hopefully lead to many future collaborative studies between our teams.”

– PA Media, with additional reporting from Elaine Burke