A portable near-infrared spectroscopy (NIRS) -based brain-machine Interface (BMI) system featuring single-channel probe, BMI controller and Infrared-emission apparatus was developed. As a switching technology for external devices, the threshold logic was proposed, which detects the blood volume change in the operator's frontal lobe. Experiments showed that the operator was able to change the TV programs or get forward the toy robot within 16 s (the mean is 11.77 s and the standard deviation is 2.35 s) after the mental calculation. In addition, the menu selection program was proposed for motor disabilities and the preliminary test showed that he could successively select the sentence from several candidates. It was shown that this system would provide the external device's control capabilities for motor disabilities.

SUMMARYWe have developed a portable NIRS-based optical BCI system that features a non-invasive, facile probe attachment and does not require muscle movement to control the target devices. The system consists of a 2-channel probe, a signal-processing unit, and an infrared-emission device, which measures the blood volume change in the participant's prefrontal cortex in a real time. We use the threshold logic as a switching technology, which transmits a control signal to a target device when the electrical waveforms exceed the pre-defined threshold. Eight healthy volunteers participated in the experiments and they could change the television channel or control the movement of a toy robot with average switching times of 11.5 ± 5.3 s and the hit rate was 83.3%. These trials suggest that this system provides a novel communication aid for people with motor disabilities. key words: brain-computer interface (BCI), brain switch, near-infrared spectroscopy (NIRS)

SUMMARYImpact of the ubiquitous information technology on our society is so significant that directing technological development and preparing institutional apparatus are quite important and urgent. The present paper elaborates, with the efforts by both humanity and engineering disciplines, to find the sociotechnical issues of ubiquitous information society in 2010 by inspecting social implications of emerging technology as well as social expectations. In order to deliberate the issues, scenarios are developed that describe possible life in ubiquitous information society. The derived issues cover integrating information technology and the human body, producing smart sharable environment, protecting individual rights, fostering new service business, and forming community.

The authors propose a directional filter for eliminating noise from MRI images. Kido et al. developed a directional filter capable of detecting the minimal change direction in each image point, and of performing one‐dimensional (1D) nonlinear smoothing limited by that minimal change direction. This filter was effective in application to MRI images. In the current study, the authors improve this directional filter and develop an image filter for directional nonlinear smoothing that separates processing of edge and flat regions in an image. For the edge regions, this filter focuses on edge structure obscured by noise. It involves obtaining the group minimal change direction, taking into account the image structure in the vicinity of the current image element, and performing 1D nonlinear smoothing. This processing allows smoothing that produces neatly aligned edge directions for the adjoining image elements, even in sections where the image edge structure is obscured by noise. In addition, for the flat regions, the smoothing effect is enhanced by performing 1D nonlinear smoothing over a distance longer than that for the edge regions. Application to MRI images produces good images with neatly aligned edge directions, and enhanced smoothing effect in flat regions where excessive smoothing of the edge regions has been suppressed. ©1999 Scripta Technica, Syst Comp Jpn, 30(8): 72–78, 1999

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