Seatbelt Sensors to Fight Drowsy Driving

You can't kick back and enjoy a nap while cruising in a self-driving cars just yet. But a new generation of smarter cars may be able to watch out for signs of a nap attack by measuring your heartbeat and breathing patterns.

A European project called HARKEN has created a sensor system built into the safety belt and seat cover of cars that can detect fatigue or drowsiness even before the appearance of more obvious symptoms such as yawning or bad driving patterns. The system could potentially lead to a driver warning system capable of helping to chip away at the annual death toll from road accidents—33,561 fatalities in the United States and 28,100 fatalities in the European Union in 2012. Driving accidents may represent the third most common cause of death and disability worldwide by 2020.

"The variation in heart and respiratory rate are good indicators of the state of the driver as they are related to fatigue," said Jose Solaz, director of innovation in automobile markets and mass transportation at the Biomechanics Institute of Valencia in Spain, in a press release. "So when people go into a state of fatigue or drowsiness, modifications appear in their breathing and heart rate; HARKEN can monitor those variables and therefore warn the driver before the symptoms appear."

The HARKEN system consists of a seat cover sensor, a seat belt sensor and a signal-processing unit to crunch the sensor data in real-time. Such a system can also filter out background noise such as vehicle vibrations and other driver body movements, allowing it to focus on detecting the heart beat and breathing rate. Drivers have begun trying out the HARKEN system during closed-track tests.

Car manufacturers have already started deploying sensor systems to detect driver fatigue in higher-end cars. Some Lexus models use cameras to watch for drowsiness. Mercedes-Benz has vehicles that use steering sensors to detect erratic driving behavior. (Engineers at the University of Washington recently showed that subtle signals from the steering wheel can predict approaching drowsiness.) BMW has even considered the idea of incorporating information from blood-sugar monitors or possibly developing a smart car capable of stopping if it detects the driver having a heart attack. (HARKEN technology might possibly come in handy in the latter case.)

European researchers hope Project HARKEN's focus on a short time-to-market scope will soon lead to street testing under real traffic conditions. Any technology that allows for improved warnings for drowsy drivers may go a long way toward saving lives—driver fatigue accounts for about 8.3 percent of all vehicle crashes, according to the European Union's iMobility Forum. That rises to somewhere between 20 to 35 percent of all serious road accidents.