"The electric field generated by heartbeat is much stronger than that generated by a brain," said Masaaki Sato, director of the Brain Information Communication Research Laboratory Group of ATR.

To remove such artifacts generated by heartbeat, eye movements and so forth, about 10 current sources are allocated in eye balls, heart and other body parts than brain in the process of estimating current sources by using the inverse filter.

In the learning process, data on the electric fields generated by eye movements, etc are measured by sensors, and they are input as "teaching signals." But, when the new BMI technology is being used, it is possible to remove such artifacts without using those sensors.

To use the latest BMI technology, the user has to actually move his/her finger. But the researchers aim to develop a BMI technology that can be used just by imagining a movement. For the future, they will consider combining an EEG and an NIRS.