Improvement of Input Time for Communication Aid on ALS Patients

Abstract

We are studying with the aim of practical application of spelling type brain-computer interface (BCI) as intention transmission means of amyotrophic lateral sclerosis (ALS). There is a problem that the character input time per character is long in the character input BCI. In our previous study they needed more than 60 (sec/char). Therefore, such as a decrease in concentration ability and fatigue of eye movements, they are burdensome. Thus, the present, we propose a character estimation method to shorten spelling time by using the feature of discriminant score. This proposed method can extract intention from electroencephalogram with minimum stimulation. We investigated the purpose of improving character input speed while maintaining character input accuracy of character input type BCI by proposed method. As a result, the effectiveness of the proposed method is higher than that of the conventional method (averaging method). In addition, character input speed in ALS patients was shortened from 81.6 (sec/char) to 21.1 (sec/char).