Magnetically operated robot can move through arteries to treat stroke patients

A team of roboticists at Multi-Scale Robotics Lab, ETH Zurich, working with several hospitals in Switzerland, has developed a magnetically operated robot that could potentially be used to treat people after a stroke. Their paper is published in the journal Science Robotics.

In ischemic strokes, an obstruction (typically a blood clot or plaque) becomes lodged in tiny vessels in the brain. The result is a blockage, which prevents blood from flowing to the brain, killing brain cells. Such strokes can cause brain damage and sometimes death. Treating them is extremely time-sensitive—the longer it takes to remove the blockage, the more brain damage occurs.

Current treatments involve drugs that can break up the mass causing the blockage or use of a guide wire inserted into a femoral artery and pushed until its tip reaches the blockage. Both therapies take time, which means brain cells die waiting for blood to reach them. In this new effort, the research team developed a new approach that allows for a much more rapid response.

The team involved developed a screw-shaped robot small enough to fit inside tiny blood vessels. Application of an external magnet causes the robot to rotate, propelling itself forward. The team added a soft tip at the front of the robot to prevent damage to blood vessels.

The robot, the team believes, could be used to move through blood vessels rapidly until reaching a blockage—it could also be inserted much closer to the brain. Upon reaching the blockage, the robot could be used to drill through the material causing the backup, allowing blood to once again pass through.

Thus far, the team has tested their robot on silicon models, a human placenta in their lab, and in a living pig. The robot has performed well enough to continue testing, with the goal of treating human patients sometime in the near future.