By Li Han
Staff Writer of the Tsinghua News Center
Maybe you have heard of the RoboCup, but have you heard of controlling a robot playing football by means only of brain waves? The students and professors at the Institute of Neural Engineering in the School of Medicine recently demonstrated their brain-computer interface system, which has the capability of controlling external activities by means of channeling the natural waves of the brain.
The brain computer interface (BCI) provides the brain with a new communication and control channel for conveying messages and commands to the outside world. By linking the brain activity to a computer, the interface enables a person to communicate with others or control devices directly, without even using nerves and muscles.
“Human mental activity elicits a certain kind of rhythm and spatial pattern in the brain waves recorded on the surface of the head. With help of a high-performance bio-amplifier and a specific computer algorithm, this feature of brain waves can be extracted and classified automatically to display the class of the ongoing mental states in real time. The label of the mental states given by computer can be mapped into a predefined control command and then delivered to external devices through wireless network,” said Dr. Hong Bo from the Institute of Neural Engineering in the School of Medicine.
In the laboratory, a student using only his imagination is showing how he can control a robotic dog to kick a football. The BCI system taps into the brain activity in the motor cortex. When one imagines the movement of his left hand, the robotic dog moves to the left. When one imagines the movement of his right hand, the robotic dog moves to the right. When one imagines the movement of his feet, the robotic dog just moves forward. In order to do this, one needs only to be trained for a short training period and to wear an electrode cap.
The BCI system can also be used in active rehabilitation training. The training device is controlled completely by the patient’s own intention as extracted from their brain waves.
During the development of the BCI system, the Tsinghua researchers applied advanced signal processing methods to extract temporal, frequency, and spatial information of brain activity. Then, they successfully applied these methods to the designed and development of the BCI systems. In 1999, they developed the BCI system using the brain activity recorded from the scalp over the visual cortex. It presents the user with a matrix of flickered squares. The user simply selects a specific square by looking directly at it. The BCI system is the highest speed brain-computer- interface in the world.
