Editing Analog EEG Amp
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[[Image:Analog EEG Amp.jpg|thumb|right|300px|The analog EEG amp.]] | [[Image:Analog EEG Amp.jpg|thumb|right|300px|The analog EEG amp.]] | ||
This analog EEG amplifier was donated to Noisebridge a couple of years ago. It is a medical-grade amp, probably used for clinical monitoring purposes. Since we've currently only tested the output by looking at noise through the fairly rudimentary electrodes shown, we don't have a good idea, at present, of the signal quality, but it should be in reasonably good shape. Electrodes die quickly in EEG and amps usually live substantially longer, but it's definitely possible that some of the channels will have artifacts or noise issues. Probably it will still amplify EEG signal sufficiently well to serve as an actuator for other projects. | This analog EEG amplifier was donated to Noisebridge a couple of years ago. It is a medical-grade amp, probably used for clinical monitoring purposes. Since we've currently only tested the output by looking at noise through the fairly rudimentary electrodes shown, we don't have a good idea, at present, of the signal quality, but it should be in reasonably good shape. Electrodes die quickly in EEG and amps usually live substantially longer, but it's definitely possible that some of the channels will have artifacts or noise issues. Probably it will still amplify EEG signal sufficiently well to serve as an actuator for other projects. | ||
==Goals and Milestones== | ==Goals and Milestones== | ||
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===10 May 2012, Kelly & Nima=== | ===10 May 2012, Kelly & Nima=== | ||
We hooked up the amp to an oscilloscope and just tried plugging in a couple electrodes and grounding and ungrounding them. We were able to get a nice line noise signal and verify that the signal multipliers do ''something''. I was not impressed by the analog filters, though we forgot to test the 35 low pass when we had that nice sine wave going, and when we tested it the signal was much noisier. It is normal to get enormous noise and signal drift when you just have an electrode that you're waving around. The strongest signal at that point is line noise. I tried putting the electrode next to my eye ungelled but either it needs the gel or the oscilloscope is just bad at rendering low-frequency voltage shifts because we didn't see any obvious evidence of the [http://en.wikipedia.org/wiki/Electroencephalography#Biological_artifacts blink dipole]. | We hooked up the amp to an oscilloscope and just tried plugging in a couple electrodes and grounding and ungrounding them. We were able to get a nice line noise signal and verify that the signal multipliers do ''something''. I was not impressed by the analog filters, though we forgot to test the 35 low pass when we had that nice sine wave going, and when we tested it the signal was much noisier. It is normal to get enormous noise and signal drift when you just have an electrode that you're waving around. The strongest signal at that point is line noise. I tried putting the electrode next to my eye ungelled but either it needs the gel or the oscilloscope is just bad at rendering low-frequency voltage shifts because we didn't see any obvious evidence of the [http://en.wikipedia.org/wiki/Electroencephalography#Biological_artifacts blink dipole]. | ||