Tohru Yagi

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BACKGROUND A new method of stimulating the retina electrically, called suprachoroidal transretinal stimulation (STS), was shown to be effective in eliciting electrically evoked cortical potentials (EEPs) in Royal College of Surgeons (RCS) rats. Before extending this technique to patients, it is important to determine its safety and feasibility in eliciting(More)
The frontal cortex is the part of the brain that relates to higher brain functions, such as logical thinking and emotion. As part of the development of a brain-computer interface, we tested whether the frontal cortex reacts differently in people as they performed three different cognitive tasks. The reaction of the cortex was tested using near-infrared(More)
An eartip made of conductive rubber that also realizes bio-potential electrodes is proposed for a daily-use earphone-based eye gesture input interface. Several prototypes, each with three electrodes to capture Electrooculogram (EOG), are implemented on earphones and examined. Experiments with one subject over a 10 day period reveal that all prototypes(More)
A drift calibration technique for DC-coupled EOG (electrooculogram) systems is proposed. It assumes a non-linear relationship between EOG and eye angle and estimates the absolute eye angle by the EOG differences during saccade. Drift is calibrated every saccade without user's explicit action, so it is especially suitable for long-term gaze input interfaces.(More)
PURPOSE Several approaches for placing an electrode device for visual prosthesis have been previously proposed. In this study, we investigated if transretinal stimulation from the suprachoroidal space can elicit an electrical evoked potential (EEP) in albino rabbits. METHODS A flat electrode array (polyimide plate, platinum electrode) was developed and(More)
This research demonstrates the orientation-modulated attention effect on visual evoked potential. We combined this finding with our previous findings about the motion-modulated attention effect and used the result to develop novel visual stimuli for a personal identification number (PIN) application based on a brain-computer interface (BCI) framework. An(More)