Open the device: Use the adjustment buttons (marked C above) to open the front and back adjustment zones, and gently open the top adjustment bars so that the EEG device is fully extended.
Place the headset on the participant: Move any hair away from the forehead and position the flat sensors in the front band directly on the skin. The central mark (labeled E above) should be centered and aligned with the bridge of the nose. Slide the back of the headset back until is aligns with the inion (most prominent part of the back of the head).
Tighten headset: Verify that the central mark E is still aligned with the participant's nose, then gently tighten all four straps so that they are touching but not uncomfortable. Be sure that the adjustment is symmetrical on both sides of the head and that the headset is not overly tight.
Position the REF ear clip: Place the clip on the left earlobe, with the sensor on the front of the year facing backwards.
Attach the amplifier: Plug the Diadem cable into the amplifier box. There should be an audible double-click when the connector is in place.
Step 2: Power Up and Connect the Diadem
Power up: Hold the power button until the LED on the amplifier blinks. This will turn steady when a connection is established with the Bitbrain Device Viewer acquisition software. If the device is already paired with the computer or tablet, skip to step 3.
Note: Do not run the Diadem system while charging. If the low-battery indicator is lit, charge the battery before running a study.
Pairing with MS Windows: The amplifier must be paired with the Bluetooth receiver on the Windows computer or tablet that will run the acquisition software. This requires Bluetooth version 2.1 or higher.
When doing this for the first time, press the Windows Key and type "Settings". Choose "Devices" from the list and select "Add Bluetooth or other device". The name of the Diadem amplifier in the list of available devices will correspond to the serial number listed on the product label of the amplifier itself.
Note that the device will not appear in the list if it is already paired with the computer or if it is already paired to another device in the vicinity. If the amplifier is listed as "paired" but does not connect, click on it, choose "remove device" and repeat the pairing procedure.
Connect to Bitbrain Acquisition Software: Run the Bitbrain Device Viewer software. Click "Connect" to establish a connection. Choose "Bluetooth" then select the device from the drop-down menu. The device name will correspond to the serial number listed on the product label of the Diadem amplifier.
If the amplifier does not connect, go back to step 3 to verify that it is properly paired in Windows. Click on "Start" to view data from the EEG system.
Step 3: Check Signal Quality and Start Acquisition
Verify signal quality: Wait approximately 10 seconds for the signal to stabilize. Individual electrodes are color-coded by impedance level. Channels listed as "green" are giving good signal quality and are ready for data acquisition. Red or yellow channels should be corrected where possible.
Note: if all channels are red, verify that reference and ground channels are making proper contact.
Fix problem sensors: Gently move the mobile sensors back and forth so that the sensor pads work through the hair and make contact with the scalp. Wait for 10 seconds for the signal to stabilize and then recheck the acquisition software. If the sensors fail to make contact with the scalp, it may be necessary to tighten the adjustment straps (see step 1, part 3 above).
For help with sensor position and channel numbers, see Diadem EEG Layout.
Start recording: Data can be recorded to an on-board memory card, and/or streamed and recorded to the computer or tablet running the Bitbrain Device Viewer software.
To record data to the microSD card, check "SD card record". Be sure to use an appropriate memory card.
To record data to the computer hard drive, click "Hard drive record". Remember that hard drive recording can be interrupted if the participant leaves Bluetooth transmission range.
Select "Enable LSL Server" to use LSL-compatible features in the software developer kit.
To stop recording, click "Stop"
Step 4: Removing the Headset
Turn off the Amplifier: Press and hold the power button until the LED light turns off.
Remove the REF clip: Remove the reference clip from the participant's ear.
Remove the headband: Press the side adjustment buttons (marked C above) and open up the front and back straps. Remove the headband by first lifting the front away from the face.
Store the Diadem headset: Between uses, place the Diadem headset on the provided stand, resting on the occipital strap (back).
until the LED on the amplifier blinks. This will turn steady when a connection is established with the Bitbrain Device Viewer acquisition software. If the device is already paired with the computer or tablet, skip to step 3.