A robotic arm that can accurately inject drugs directly into tiny veins at the back of the eyeballs could help treat a disease that causes degenerative blindness.
Retinal vein occlusion occurs when blood clots block veins in the retina. It affects more than 16 million people worldwide and can eventually lead to blindness. An experiment treatment called retinal vein cannulation (RVC) involves injecting drugs to dissolve these blockages, but it is a tricky procedure because the veins are just 60 to 120 micrometres in diameter.
鈥淵ou have to insert a needle into a blood vessel that鈥檚 the size of human hair, and the needle itself is even smaller than that,鈥� says at Johns Hopkins University in Maryland. 鈥淎nd your hand tremor exceeds the diameter of the needle itself in amplitude.鈥�
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Previous work on using robotic arms for RVC has focused on aiding the accuracy of a human surgeon, but and his colleagues have developed the Steady Hand Eye Robot (SHER) to perform the procedure autonomously. They claim that the device can carry out injections faster and more accurately than humans.
The robot is controlled by an artificial intelligence that was trained on video of human surgeons and learned to spot visual cues that occur when a needle touches a vein, presses against it and eventually pierces it. When directed to a point by a human operator, SHER inserts a needle just 15 micrometres wide into the eye through a small incision in the sclera, the white outer layer, and into a vein towards the back of the eye.
In 24 experiments performed on eyes removed from pigs, SHER was able to navigate to target veins with an accuracy of 22 micrometres in under 35 seconds and consistently puncture the target vein without causing damage 鈥� exceeding the ability of trained human surgeons.
Woong Kim says operating on live animals or humans is more complex, as the robot would need to accurately track micromovements from breathing, but he is confident that SHER is up to the task.
arXiv
