How to extract feature and classify that signals

Dear I am looking for help about how to extract feature and classify signals.

Suppose we have eeg signal of hand flexion and eeg signal of hand extension, we want to classify it by using the matlab.

1-suppose we give any random signal and then matlab show that given signal is of flexion. 2-then that signal give to robotic arm and it will flex

How we can do it in simple way?

thank you