抄録
For conventional functional near-infrared spectroscopy (f-NIRS) system, the reconstruction of signals is based on simple back-projection, and it cannot distinguish the depth of the activated area. However, skin blood perfusion, which significantly varies and is affected by autonomic nerve activities, often masks the signals from a deeper target region. To improve the quality of the reconstructed images, we proposed a depth-selective space filter that suppresses the signals from the surface layer with Moore-Penrose pseudo-inversion. In this study, we performed brain-activity tests applied to forehead by using a prototype CW (continuous wave) -NIRS system which was designed for the depth-selective filter method with multi-distance channels. To validate the performance of the depth-selective filters, simultaneous measurement of Laser-Doppler flowmetry were also performed. We demonstrate the experimental results, and discuss problems in f-NIRS measurement.
