Connecting the EEG components
  • 22 Sep 2021
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Connecting the EEG components

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Article Summary

Kernel Flow includes six internal active dry EEG electrodes integrated into the headset and are placed close to OZ, PZ, CZ, FZ, F3, and F4 on the 10-10 grid, as well as two external leads (for Reference and Bias).

Image: Brush-style EEG electrodes.

Internal EEG Electrodes

Image: External EEG leads and Red-dot electrodes.

External EEG Leads & electrodes

The EEG system is integrated into the Flow device and the electrical signals are digitized and synchronized with the optical data on the headset to be transmitted together to the Kernel Flow PC, and then to Kernel Cloud. 

Before you can record EEG data, you must install the six internal electrodes. Also, for each session, the two external leads must be connected to the participant in order to ensure accurate readings.

Image: Lightbulb Icon
Kernel provides six short-tip electrodes and six long-tip electrodes. Use the electrode type that you believe will create a comfortable fit while still making full contact with the participant's scalp.

Four electrodes go down the centerline of the headset, plus two more between the Frontal and Sensorimotor plates.

Image: Kernel Flow headset with EEG electrode holders called out.

To learn more about caring for the EEG electrodes, see Cleaning your Flow system.

To install the internal EEG electrodes:

  1. Invert the headset and rest it upside down in the inverted protective foam insert (from the shipping case), loosening and tightening the Tension Dial as necessary to keep the plates from moving excessively.
  2. Install the six EEG electrodes into the EEG electrode holders.
    Image: Kernel Flow headset inverted and resting on the protective foam insert.
    • Each electrode should fit snugly into place on an electrode holder in the underside of the headset.
    • They do not "snap" or "click" into place. 
    • It may be tricky to get the electrodes to stick in the holders. Firmly push them down until they adhere, taking care not to bend or squeeze the bristles excessively, (They are rubber, and so can handle some manipulation, but can be broken if handled too roughly).
    • Electrodes are interchangeable.
    • Electrodes can be left in the device between uses or swapped out as needed.
  3. Place the headset back onto the Headset Stand, loosening and re-tightening the Tension Dial as necessary.  

To connect the external EEG electrodes:

  1. While the headset is on the Headset Stand, before connecting the Power/Data Cable, connect the EEG leads (provided with your Kernel Flow system) to the 1/8” mini ports on the back of the headset.Image: Kernel Flow headset with the External EEG connectors called out.
    The wires are labeled Bias and Ref (for reference).
    Image: alert icon.
    To prevent equipment damage always insert the EEG leads into the Flow headset BEFORE the headset is powered on. 
  2. Attach disposable electrode pads to the ends of the two leads. Do not remove the sticky pad covers.
  3. Later, after the headset has been moved to the participant, you may remove the sticky pad covers and affix the external electrodes to the participant.
    Commonly these are placed on the mastoid bones behind each ear, but your workflow may vary.

Image Kernel Flow headset on a participant, researcher affixing electrode behind participant's ear.

Remove the external EEG leads

Once a session is complete, be sure to unsnap the external EEG leads from the Red Dot pads on the participant before attempting to remove the headset. Once the leads are removed, the Red Dot pads can be peeled off the skin or left on for subsequent studies on the same day.