The system uses a pressure barrel to extract the blood. The air in the barrel is evacuated, and a trigger shoots a "microparticle" (IFLScience has asked Google for clarification on what this is) at supersonic speed towards the barrel's opening, which is positioned on the wearer’s skin. The microparticle, which is smaller than a human hair, creates a minuscule cut in the skin, and the negative-pressure barrel sucks in the little droplet of blood escaping from the cut.
There are very few details on the type of analysis performed on the blood and, according to the patent, the smartwatch won’t be doing the analysis itself.
“In a typical scenario, a person's blood is drawn and either sent to a lab or input into a handheld testing device, such as a glucose meter, where one or more tests are performed to measure various analyte levels and parameters in the blood,” the patent states.
The main application for this technology is the management of conditions that require regular and frequent blood testing, like diabetes. Google says that "such an application might be used to draw a small amount of blood, for example, for a glucose test". People suffering from diabetes have to prick their fingers several times a day to test the amount of glucose they have in their blood.
According to the World Health Organization, 9 percent of adults worldwide live with diabetes, and an estimated 1.5 million people died from it in 2012. This year Google has developed a smart contact lens that, among other features, can monitor the sugar levels in the blood of the wearer.
Filing a patent doesn’t mean that Google is actually pursuing the blood-sampling smartwatch, though. “We hold patents on a variety of ideas – some of those ideas later mature into real products or services, some don’t,” a spokesperson for the company told The Verge. “Prospective product announcements should not necessarily be inferred from our patents.”