Editing Programmable Chip EEG
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Welcome to the PCEEG Wiki, where everyone can add to this EEG brain-computer interface! | Welcome to the PCEEG Wiki, where everyone can add to this EEG brain-computer interface! | ||
− | == | + | == What it is and what it can be used for == |
− | + | [http://pceeg.sourceforge.net The Programmable Chip EEG] is a Modular Multi-channel electroencephalograph that could be used for a brain-computer interface, biofeedback.... | |
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− | + | [http://pceeg.sourceforge.net The Programmable Chip EEG] is programmable because it uses [http://opencircuits.com/Programmable_Potentiometers Digitally Programmable Potentiometers]. They are used to set the Gain, frequency range, and can calibrate multiple analog boards for different EEG tests. | |
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− | The | + | == Discription of How it Works == |
− | + | The differential analog signal is amplified by the instramentation amplifier. Then the signal is amplified and conditioned by high pass and low pass filters. | |
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− | The | + | The common mode signal is inverted summed and sent back to the body to decrese common mode signal thsi is done by the driver right leg circuit. |
− | + | Band reject filters may be added soon in the future. | |
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− | + | Then the analog signals are simultaniously digitized and the digital values can be clocked to the digital board. | |
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− | == | + | == News == |
+ | The design is switching to EAGLE CAD, because the auto-router is excellent for open-source productivity. It will allow the design to evolve faster and with less work with a wider selection of PCB [[production houses to choose from]]. | ||
− | + | Here is a picture of the PCEEG being done in [http://www.cadsoft.de/freeware.htm EagleCAD]. | |
+ | [[Image:Eagle_sample.GIF]] | ||
− | + | The ideas and monkey to robot arm interface by [http://www.answers.com/topic/miguel-nicolelis Miguel Nicolelis]is very inspiring. He used implanted electrodes to monitor and allow monkeys to control a robot arm as if it was their own. Could the PCEEG do the same with its electrodes on the scalp. Only the future will show. | |
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== Parts used in the PCEEG: == | == Parts used in the PCEEG: == | ||
− | * [http://opencircuits.com/LT1168 LT1168 | + | * [http://opencircuits.com/LT1168 LT1168 Programmable-Gain Precision Instrumentation Amplifier] is used to amplify the weak electric signals coming from the brain through electrodes attached to the scalp, etc. |
− | * and | + | * Several [http://opencircuits.com/LT1114 LT1114 Low Power Precision OP-Amps] are used for amplification and filtering of the signal |
− | + | * The [http://opencircuits.com/Digitally_Programmable_Potentiometers Digitally Programmable Potentiometers AD5204] 4-Channel Digitally Controlled Potentiometer is used to make calibration of this device easier. (Historically, a weak point of homebrew designs has been their sensitivity to component value; tolerance and drift have made them require constant tweaking for good results.) | |
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To reduce noise in the readout of the analog part of this circuit, a common-mode feedback is passed back into the body by the driver right leg circuit. Band reject filter may also be used (to reject, for example, 60Hz noise from nearby A/C power wiring). | To reduce noise in the readout of the analog part of this circuit, a common-mode feedback is passed back into the body by the driver right leg circuit. Band reject filter may also be used (to reject, for example, 60Hz noise from nearby A/C power wiring). | ||
− | The analog | + | The resulting analog signals will be passed into a digital circuit, based on the Cypress [[PSoC microcontrollers]], which will digitize the signals, further process them, and provide an interface to a computer. |
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== Open Source Circuit Design == | == Open Source Circuit Design == | ||
− | + | [http://opencircuits.com/Programmable_Chip_EEG Open Source Circuit Design ] | |
− | + | [http://www.thinkcycle.org/ Think Cycle] | |
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== Open source (public) results! == | == Open source (public) results! == | ||
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Please contribute and make the PCEEG a great tool for researching brain computer interfaces. | Please contribute and make the PCEEG a great tool for researching brain computer interfaces. | ||
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