Eye-tracking could warn drowsing drivers

An autonomous device can track the movements of a person’s eye using infrared light. Siobhan Wagner reports

Swedish engineers have developed a device claimed to be a first for embedded eye-tracking technology on a single chip.

Stockholm-based Tobii Technology claims that the device can be employed for a variety of applications, including detecting drivers who are becoming drowsy at the wheel. Other uses include medical diagnostics and gaming. 

The device is installed on the steering wheel or dashboard and uses an image sensor to detect multiple times per second if a driver’s eyes are alert.

The information is then sent to the car’s central processing unit (CPU) and is combined with other data, such as vehicle speed and steering-wheel movement, to determine if a driver should be alerted and woken up with an alarm.

The embedded eye tracker, which is roughly the size of a chocolate bar, is the latest and smallest version of Tobii Technology’s eye-tracking technology.

’All other eye trackers on the market, including our own previous systems, process all the signals on a PC platform,’ said John Elvesjö, executive vice-president and founder of the company. ’Now, we process on a single chip so we can embed everything on one board.’

He said that this means the device is more power efficient and more easily integrated. ’It’s autonomous, meaning you can connect it to any kind of instrumentation — Mac, PC, to a car, ATM machine, anything,’ said Elvesjö.

Tobii Technology, which was founded in 2001, has used the technology to make PCs more accessible for people with disabilities by allowing them to scroll and point to objects on the screen via eye movement.

According to Elvesjö, the main developer of the technology, the device tracks the movement of a person’s eye by shining a pattern of infrared light that is reflected off the cornea. An image sensor then detects these reflections.

He discovered the technology while conducting research at the Institute for Surface Chemistry in Stockholm about 10 years ago.

Elvesjö was working on an optical sensor chamber that his team developed to measure sedimentation for the paper industry. ’One late night, the optical sensor chamber actually started to pick up reflections from the cornea of my eye,’ he said. ’The cornea had a couple of similar ways of reacting to the sensor.’

A short time after that, Elvesjö developed a prototype tracking device, founded a company and sold the first version of the technology.

The company recently raised €16m (£13.8m) of expansion capital from new European investors Amadeus Capital Partners and Northzone Ventures, as well as from Investor Growth Capital, an existing backer of its technology.

The capital is expected to help Tobii Technology move its technology further into existing and new markets and applications.

A pre-series version of the latest incarnation of its eye-tracking technology has already been shipped to one initial customer over the past couple of months.

Elvesjö said that it is not fully available to other potential customers at the moment. It will be, he said, when the company has fully scaled up its production.

Siobhan Wagner