Drivers that drive while drowsy, or fall asleep while driving, are a significant cause of traffic accidents. To prevent this drowsy driving, various methods and apparatuses have recently been studied.
For example, after an image is analyzed by observing and sensing physical changes of the driver, that is, a motion of an eyelid, a gaze direction of an eye, a nod, and the like using a camera to sense when the driver is drowsy, if the sensed image has a predetermined value or more, it is determined that the driver is in a state of drowsy driving, and warns the drowsy driving of the drowsiness, thereby preventing the drowsy driving.
Another method is determining whether or not the driver is in the state of drowsy driving by sensing and analyzing various biometric signals of the driver to determine a drowsy or sleeping state of the driver.
That is, there is a method for measuring and analyzing an electro-encephalography (EEG), electro-oculography (EGG), an electro-cardiography (ECG), and the like of the driver.
A physical state and a mental state of the driver described above may be detected by fine current signals flowing in both hands of the driver using an ECG sensor and a galvanic skin resistance (GSR) sensor, and may be more directly detected by fine current signals which may be detected from a skin around a head of the driver when a brain of the driver is active using an EEG sensor and an EGG sensor.
In particular, when the EEG sensor and the EGG are used, a drowsy driving situation of the driver or a state in which an attention of the driver is distracted may be sensed by a change in the electro-encephalography and the electro-oculography of the driver.
However, even in the case in which biometric signals of the driver are collected using a variety of sensors, when noise is mixed in the collected biometric signals, there is a problem that it is difficult to accurately determine the state of the driver. Therefore, in order to accurately diagnose a drowsy state and an emotion state of the driver and provide feedback on these states to the driver, it is required to collect the biometric signals of the driver from which surrounding environment factors (e.g., noise, etc.) are removed.