Abstract
In the biomagnetic measurement performed in laboratory, the biomagnetic signal is extremely weak compared with environmental magnetic noise. We propose the noise reduction method of estimating the subspace spanned by the sensor outputs. It is estimated from the lead-field vectors for the uniformly distributed lattice points in the head. It has been shown by simulation that projection of the measurement to the signal subspace reduces the noise effectively. By applying this method to vector AEF data (averaging: 10, 20, 50), the effect of noise reduction with 30 % was obtained to each data. And, it has been shown this method is more effectively vector MEG than not vector MEG.
