Hypodermic needles often lead to medical complications when the jab penetrates too far in the skin. However, now MIT researchers have developed a novel needle that aims to reduce the risk.
Based on the drilling technique from the oil industry, scientists have developed a mechanical device that automatically stops once the needle tip enters a cavity or lower-density tissue.
It involves a hollow S-shaped needle containing a filament that acts as a guide wire. When a physician pushes the device against a tissue, she is actually applying force only to the filament, not the needle itself, courtesy a special clutch.
When the filament, which moves through the tip of the needle, encounters resistance from a firm tissue, it begins to buckle within the S-shaped tube.
The needle and wire proceed through the firm tissue. But once they reach the target cavity (for example, a blood vessel) there is no more resistance on the wire, and it quickly advances forward while the needle remains stationary.
Due to the combined buckling and interactions with the walls of the tube, the filament locks into place "and the needle and wire advance as a single unit," said Jeffrey Karp, an affiliate faculty member of the Harvard-MIT Division of Health Sciences and Technology (HST) and co-corresponding author of the paper.
The findings are published in the Proceedings of the National Academy of Sciences.