NewScITech

Drink drivers could find themselves subjected to roadside blood tests in future. InLight Solutions, a US company that specialises in testing blood sugar levels in diabetics without needles, has developed a similar test for measuring blood alcohol. The company’s device generates a beam of infrared (IR) radiation and channels this through optical fibres into a cradle designed to attach to a forearm.

When a suspect’s arm is placed in the cradle, the infrared light penetrates to a depth of 5 millimetres and the reflected light is picked up by a bunch of IR sensors. The beam is constantly moved over the skin to avoid burning it.

The reflected beam is combined with the original one to create an interference pattern. This will change depending on the amount infrared absorbed, which will depend on levels of alcohol in the blood. To calibrate the device, the inventors took 1500 measurements from 133 subjects (to simulate a range of sobriety) and compared the results with both blood samples and breath tests.

The device should produce a stable infrared signal for at least two years, the company says. But, to avoid legal challenges, the patent recommends police surgeons periodically check the device for accuracy by putting a piece of gel soaked in pure alcohol into its cradle.

By NewScientistTech