An anonymous reader writes: Google has published a patent for a needle-free blood draw technology which could be incorporated into a wrist wearable or hand-held device. The patent filing explained that the system releases a pulse of gas into a barrel or 'hollow cylinder', containing a 'micro-particle' which can break through the skin and draw a small sample of blood. According to Google, once the drop of blood forms it is drawn up into the negative pressure barrel. This technique is a quicker and less invasive alternative to using needles, or other blood measures which administer pin pricks to the finger to release the blood. The patent, which is still pending, suggests that the mechanism could also provide a replacement for glucose testers used by diabetics.