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Category: Instrumentation

Description: Welcome to the Open EEG Phantom project! OVERVIEW: The goal of this project is to provide freely available information for anyone interested in fabricating their own “phantom” for EEG and similar electrophysiology recording. Below are design files for 3-D printing (or whatever medium you prefer) mold and construction parts and related instructions for making your own EEG phantom. BACKGROUND: Why would we need an EEG phantom? For the same reason as any other biomedical imaging phantom – to provide a “ground truth” signal for use in validation, testing, and calibration of new data acquisition (DAQ) components. While MRI, PET, CT, and most other imaging modalities have well-established phantom methods, nothing has been adopted by the EEG development community. Classically, developers have used human subjects their test medium. Unfortunately this is not a good solution because of the lack of control of the underlying signal, or known for certain where the generating sources are, etc. The goal of this work is to provide a means to address this gap, freely available to the community. USES: The are a number of uses for such a device – basically, any case where you need a realistic, known-quantity signal. Examples: - Quantifying timing synchrony between devices in a complex DAQ setup (e.g. getting a timelocked signal into an EEG system along with other DAQ components) - Providing a training fixture for new technicians and lab members, for setting up and confirming the proper placement of electrodes without needing a human volunteer - Test fixture for calculating a true signal to noise ratio (SNR) of new electrodes or other DAQ components through input-output comparison with a realistic medium - Consistent, reliable medium for comparing signal quality of different electrodes or other DAQ components - Assessment tool for anticipated artifacts for a given environment or type of motion (e.g. placed in electrically noisy area, used with motion platform to recreate motion noise, etc) - Reliable model for re-creation of motion artifacts or other undesirable features, for testing efficacy of new de-noising or signal-extraction techniques MATERIALS: A full list of materials are included in each Components page, for each phantom type. Our intention is for this model to be easily fabricated without need for special tools or materials. Note – the proper materials used for the phantom “skin” in order to be a true replication of the human scalp is a very complex matter. At this moment, there is no ideal material that is easily fabricated. (However we are working diligently on new things!). At the moment, we suggest using ballistics gelatin, as it is the least expensive and easiest to work with that is “good enough” for many applications. As better materials are discovered this page will be updated…. * Initial work and design have been provided by W. David Hairston and Alfred Yu, at the Combat Capabilities Development Command Army Research Laboratory. As work created by U.S. Government employees, the files are considered to be in the public domain for copyright purposes in the United States of America. We're eager to see our products in use! Please send a picture of your phantom to alfred.b.yu.civ@mail.mil and william.d.hairston4.civ@mail.mil if it's been useful to you. This project also has a citeable Digital Object Identifier (DOI). Additionally, we welcome any feedback, comments, or anyone to join in the project of making phantoms for EEG applications. More information will be coming to this site soon.