Billh
Billh
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James, Good idea. I think that somebody should definitely do this. Trouble is, just getting an official copy of the required documents costs real money. It's a nice racket I guess for the IEC, as far from open source as it gets . If you are…
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An easy way is to look for a threshold of very high differential voltage numbers (very high numbers) in the frontal electrode leads and delete the EEG data near those peaks. For more sophisticated methods, see for example: https://eeglab.org/tutori…
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William: I agree about Raspberry being superior to Arduino as an interface device here. In fact, most commercial portable cloud-based-EEG devices use a device running tablet Android or equivalent, so the processor tends to be much closer to a Raspb…
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Ahmedh, There are resources on the internet for sending data from Arduino to the cloud. Perhaps you should look into these and see if they are workable for you, then determine how you would create a data path from the Ganglion to the Arduino to t…
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cananthk, I am confused about what you want to measure. Isn't your male voice "F0" an auditory frequency? If so, are you assuming that you will be synchronizing the EEG frequency with your auditory frequency in some way? I do not think such sy…
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There is also this cheaper Arduino version of an airflow (not a stretch meter) spirometer, which could be connected to an external signal pin on the OpenBCI board as it was to the A0 pin on that Arduino device: https://maker.pro/arduino/tutorial/di…
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Beta or gamma band power as measured in frontal regions of the scalp can be considered a lossy function that discards all of cognition except whether one is awake. To get the information you want to extract properly, you might need to measure gam…
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They used suction cups with gold electrodes inside for dolphins, but human hair would keep suction cups from working. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151498/
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The eyeball, as a rotating semispherical 3D object, is relatively symmetrical in 2 of 3 of certain 3D axes. Therefore it can be portrayed as an electrically polarized dipole with the pupil of the eye at one end relative to the back of the eye (the r…
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Here is a good video on the subject:
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It is a terminology issue. OpenBCI EEG or EMG terms are [electrode, reference, ground] and Myoware terms for its bipolar are [mid, end, reference]. In addition both types of electronic equipment may also be grounded in some other, electrical resp…
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Vinny, Imagine a basement of a large ten-story office building filled with a thousand typists, all typing different reports at once. You put a decibel sound meter on the outside of the roof of the building. You want to use the readings of the d…
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By your description, your enclosure is acting as an antenna and picking up artifacts from the environment. You might try temporarily connecting the enclosure to one of your grounds or bias pins -- this may either make things much worse or might elim…
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Way back when, I knew someone who did experiments using a type of snake venom on rat sciatic nerve. He used an oscilloscope, but that was way before laptops existed.
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I agree with the above. You want a sample interval of about 1 microsecond for good axon spike recordings from rat sciatic nerve. I would ask the lab instructor or company that is providing your rats about whom to ask for such gear (maybe rent for …
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To measure velocities, you may need a precise trigger time. You might need different kit, as in the message above, for better accuracy.
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The colors do not have to be in a specific pattern, but when a bunch of wires are taped or bundled together it can be hard to follow a wire from one end to another without confusing it with a nearby wire in the bundle. So, color coding helps you ma…
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So, Marvin, if you are thinking of creating a new 19-lead EEG OpenBCI database, 19 leads cannot be done with current equipment, due to lack of proper time-lock synchrony between 2 boards not connected via daisy board, and I additionally was told whe…
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Can't you restrict, adjust or average what is taken from the database to allow a comparison to work with a different number of channels? If not, the database would seem inflexible for a commercial product.
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MRI magnets can induce currents in nearby wires as the high strength magnetic field changes. So I would tell you not to use equipment like OpenBCI without carefully verifying the equipment after special modifications, such as shielding, are comple…
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If both are microvolts and you are using the same electrodes and references, you may also want to look at the number of frequency bins for the two FFT and make sure that sampling rate and bin numbers match up as the same.
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Do you know the units of the input data for OpenBCI and for Matlab then??
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It's just that you can't compare voltages well if the units do not match, and you lack Matlab units. So I dunno.
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Do you know what the units are on the Y axis on the right hand side Matlab plot?
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Why would anyone have access to the original of EDF file without proper authorization? That is a privacy issue. As it stands, being able to alter the identifying data on a digital EEG is nice because it allows the sharing of anonymized files for …
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Marcus, FFT of a signal that has a noisy signal at X hertz is going to show peaks at 2X, 3X, and 4X hertz because there is, possibly, a slight pattern to the noise which may make the troughs between the peaks larger, or the front third of every thi…
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the more salt in the water the better it conducts, but otherwise it does not matter. Silver solutions are better than sodium, but all work.
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You could try small gauze squares wet with a supersaturated solution of table salt, especially if the leads are clipped on (since the gauze will not be sticky as the paste is). Put the damp gauze where the paste would be. There are few things les…
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If the data was not just voltage readings but was a time measure (as in the time() computer function) interleaving somehow with a microvolts type EEG voltage reading, it might look like this.
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The graph appears to be a line graph composed of 2 components. One, the bottom of the vertical lines, is a somewhat sinusoidal graph, and might be data. The other is a linearly increasing function which might be time points. Why your plot could be…