Hi,
I'm constructing a sleep measurement system in which I need to amplify EEG, EOG and EMG signals before sampling them. I have very limited time so I need to buy some premade amplifier but have discovered that even simple amplifiers are extremely expensive. It is possible to get an amplifier premade from the open-EEG project (2 channels, $US125) but since my company needs it for medical research it would be good with some sort of certification. Does anyone know of biopotential amplifiers in a reasonable price range,