Among the reasons of accidents on roads there is drivers' drowsiness. So, it is very important to develop a system that detects an approach of drowsiness and awakes a driver in a case of alarm. The method of detection of drowsiness based on analysis of ECG parameters is convenient and informative enough. A problem of monitoring a driver's state by controlling his heart rate is actual because this parameter is simple to register. But a threshold of drowsiness can vary for different people. So, it is necessary to control some additional parameters.

Research of how parameters of heart rate variability (LF/HF and index of stress of Bayevsky) change in time depending on a state person (during wakefulness, drowsiness and stress) has been carried out. The results showed that there are certain intervals of values characterizing each kind of state. To sum up, it's suggested to use the analysis of three ECG parameters (HR, LF/HF and index of stress of Bayevsky) in drivers' drowsiness detecting systems. Using a GPRS data transmission system allows to realize processing and storage of ECG information on a powerful server.