i am working on a project based on biofeedback where we are analysing EEG signals and giving a feedback to the brain through flickering of lights to reduce stress. i have samples of EEG waveforms of few people. now i have to develop this system in labview. i have to amplify these EEG signals and then i am filtering the alpha frequency range. after filteringi have to follow the algorithm given below:
i) A .25 second interval of data is analyzed
(ii) Maximum and Minimum values are determined
(iii) .7(Max-Min) + Min is determined and set as a threshold value
(iv) The signal data is then compared to this value
(v) If the data is > than the threshold the y-value = 1.
(vi) If the data is < than the threshold the y-value = 0.
(vii) This outputs a square wave of which the frequency can easily be determined.
i dont know how to go about with this. pls if any one can give me advice or guide me on the right track
i tried your given code with the EEG waveforms i had. it works fine but the square wave generated at the output has frequency of about .6hz whereas i want the frequency to be between 9hz to 12hz. how do i go about with it. what changes should i make and also am attaching my code. please guide me.