medical micro-robots, USA News: While human shrinking remains confined to science fiction classics like the 1966 film Fantastic Voyage, the development of miniature medical robots is being seriously pursued by research groups around the world. A team in Beijing recently revealed a medical micro-robot designed for delivering drugs to precise locations in the gut. Other research groups are building devices aimed at destroying tumours, widening arteries, and dissolving blood clots, which are a common cause of strokes.
While more advanced devices small enough to navigate blood vessels are likely at least a decade away from routine patient use, NHS doctors are already deploying a basic kind of medical micro-robot: a swallowable capsule containing a tiny camera. These capsules are utilized to investigate gut issues such as bleeding or pain, offering an alternative to traditional endoscopy.
The Micro-Robots Already Helping to Spot Cancer
Traditional endoscopies involve pushing a camera on the end of a long, thin tube down the throat or up the rectum. First-generation camera capsules simply move along at the natural pace of the gut, exiting within a few days. However, advanced camera capsules can now be maneuvered inside the stomach using magnetic steering systems to investigate possible symptoms of stomach ulcers, growths, and cancer.
With a system known as NaviCam, patients fill their stomachs with a large drink of water and lie on a platform surrounded by magnetic controls. Doctors steer the tiny device using two joysticks while observing the camera feed on a screen to inspect the stomach’s interior.
Precision Drug Delivery
Magnets have proven effective for steering other medical micro-robots currently in earlier development stages. Researchers in Beijing developed a 6.5mm-diameter device called a “spiny milli-ball robot” for targeted drug delivery. Encased in a swallowable capsule that dissolves in the stomach, the spiny ball can be magnetically pulled into gut tissue once it reaches the target area, releasing its drug payload. In tests reported in the journal Cyborg and Bionic Systems, the device successfully delivered insulin to the lower intestine of pigs.
Professor Bradley Nelson, a roboticist at ETH Zürich, notes that approximately one-third of experimental drugs fail in clinical trials due to excessive toxicity. Releasing drugs precisely at the correct spot slashes the required dose, sometimes by a factor of several hundred, thereby solving toxicity hurdles.
Dissolving Blood clots and Treating Cancer
Nelson’s team has advanced micro-robots designed to travel through the bloodstream. Last year, they demonstrated that a 2-mm-wide micro-robot could be magnetically guided through a pig’s bloodstream while monitored via simultaneous X-ray imaging, using a PlayStation controller for steering. In a silicone model of the brain’s circulatory system, the robot delivered a drug that dissolved a blood clot. Potential applications also include treating tumors, localizing infections, and acting as a physical block for aneurysms.
Furthermore, Dr. Ali Kafash Hoshiar, a roboticist at the University of Essex, has developed drug-containing devices as small as one-tenth of a millimetre, along with magnetic specks acting in swarms. Steered to surround a cancer, these swarms can be heated via magnetic fields to destroy tumors, a method demonstrated in mice.
