The aim of her research is to develop a sensor that is able to measure stress of a driver in the car. This research can be split up in two parts. The first is the development of the device, that should be able to measure stress in a robust way, without being sensitive to motion and adapted to the car environment. The sensor itself monitors the equilibrium between sympathetic and parasympathetic nervous system through HRV measurements. Secondly this sensor will be tested to see whether biofeedback can have an influence on driving performance and in general on a better lifestyle.