Fig. 4

The experimental results of the wireless text-communications using EBCM. a The experimentally measured EEG signals in the text communication scheme. The EEG segments corresponding to five letters “HELLO” are presented for demonstration. b–d The measured EM signals of the letters ‘HELO’, ‘BCIS’, and ‘META’. The normalized amplitude-modulated signals present the ASCII codes of these letters, where high and low amplitudes mean ‘1’ and ‘0’