Smartwatches already collect data about your heart rate, how much exercise you do and your stress levels, but in the future they could take this a considerable step further. Google has filed a patent for a 'needle-free blood draw' system that could be built into a wearable attached to someone's wrist, or a hand-held device.

The filing describes a machine that sends a pulse of gas into a barrel containing a 'micro-particle' capable of puncturing the skin and drawing a small drop of blood. Instead of using the traditional needle to draw blood the proposed system is gas-based, and will suck the blood into a very small barrel. The patent, which is still pending, suggests the device may be used for testing blood sugar levels and be able to take blood automatically or manually.