A device has been approved that quickly numbs the skin for painless injections, paving the way for such things as pain-free blood tests, glucose sensing and insulin delivery for diabetics.

SonoPrep uses ultrasonic waves to make skin temporarily more permeable. The sound waves open small cavities in the skin, creating reversible microchannels through which fluids can be extracted and delivered.

A painless 15-second treatment by the device, followed by the application of a topical anesthetic such as lidocaine, will anesthetize skin in five minutes. By itself, lidocaine can take up to an hour to work.

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