Google has applied for a patent on a way to draw blood without using a needle. It could be used in a smartwatch to make life easier for people with diabetes.

The idea seems to be based around situations where only a small drop of blood needs to be extracted, meaning the traditional syringe needle can be overkill.

Google’s answer is a tiny cylinder which is configured as a negative pressure barrel filled with a gas and a microparticle. The gas would be triggered with a valve, forcing the microparticle into the skin at high speed causing a tiny puncture. That should result in a tiny amount of blood being ejected, which would be collected in the barrel.

Exactly what the microparticle would be made of is left open in the patent application. Google suggests it could be metallic, but could also be a biodegradable material such as salt or sugar that would cause no problems under the skin. It even ponders the idea that with the microparticle “fired” at such high speed, it could simply be a droplet of water.

According to Google, the technique could work as a standalone handheld device. However, it has also suggested the technology could be small enough to build into a wearable piece of tech such as a smartwatch.

The most likely use for the technology is for people with diabetes taking a blood sample to measure blood glucose levels. As well as being less disruptive to use, if the technology was built into a smartwatch, it would be easier to keep track of short and long term trends and variations.

One limitation would be that people with diabetes would still need to carry a (separate) needle for injecting insulin, so having the smartwatch wouldn’t mean a totally “clutter-free” diabetes management program.

As always with patent applications, there’s no guarantee Google will develop a commercial product or even that it is making efforts to do so.