Features of this Cap
1. Large electrode surface area for better signal acquisition.
2. The cap size is adjustable, so there I no need to have different caps for different sized clients.
3. The cap is very light and comfortable on the head and will not typically induce drowsiness in subjects.
4. Ear clips are attached there is no need to correct ear clip connections during impedance checks.
5. The cap has an open design allowing for accessories such as TDCS and photo biomodulation devices to be used simultaneously with the cap.
6. The open design also allows the clinician to access each electrode site in the event of an error, such as dispensing too much gel, and correct the issue without disturbing the other electrodes.
7. The Robust amplifier connector is easy to grip for removal and is resistant to breakage.
8. Wires on this cap are resistant to breakage at the connection to the electrodes. In order to break the wires, the clinician would need to exert so much force that the wire itself breaks, but the connection between the wire and electrode should remain intact.
9. The cap is easy to clean and dry. There is no cloth component to wash or dry (other than the chin strap) so water can be removed with canned air between clients allowing the cap to be used again very quickly.
10. Wiring is more flexible and comfortable when compared with ribbon wire.
Required Materials:
Included
1. Cap
2. Ear Clips
3. Grey Amplifier Connector
Not Included
1. Nuprep™ or equivalent skin preparation gel designed for EEG.
2. Electro-Gel (insert proper trademark indicator) or equivalent electrolyte gel product designed for EEG electrodes.
3. 16ga x 1” blunted needle
4. 10ml Syringe **
5. Washcloth
6. Measuring Tape
7. 6” cotton tipped applicators
8. EEG acquisition software and amplifier (connection spec)
9. Impedance checking device or software
10. Denture brush or toothbrush
Preparing a Subject for a QEEG Recording
Before The Session
It is important for clients to take the following precautions before participating in a qEEG recording.
1. Clients should not be wearing makeup, especially on their foreheads.
2. Clients should not be wearing earrings.
3. Their hair should be:
a. Recently washed.
b. Completely dry.
c. Free from sweat (no hats).
d. Free from all products such as hairspray, gel, conditioner, etc.
e. Toupee’s, wigs and hair extensions should be removed.
f. Free from hairclips, pins, barrettes, etc.
Determining Electrode Locations
- The cap is pre-adjusted to match the International 10/20 locations for a medium to medium large head size. The cap may be adjusted to fine tune the electrode locations, as the correct location for each electrode may vary between clients depending on the size and shape of their skulls. It is important, therefore, to learn how to measure each client’s 10/20 locations and ensure the center of each electrode is resting directly above the corresponding location. A great tutorial on 10/20 measurement can be found at https://www.trans-cranial.com/docs/10_20_pos_man_v1_0_pdf.pdf.
Preparing the Forehead and Ear Lobes:
1. After adjusting the cap electrodes, it is time to exfoliate their forehead and ear lobes with a little Nuprep™. Squeeze a pea sized drop of gel onto two fingers and massage the client’s scalp at location Fp1 to remove dead skin cells. Rub the Nuprep™ on the skin using a circular motion about 1 inch in diameter.
2. Repeat step 2 for location Fp2.
3. Use a pea sized drop of gel to exfoliate the back of each ear lobe (the part of the earlobe which is not visible and is closest to the head). Be sure to avoid locations with holes from ear piercings.
4. Remove the Nuprep™ from the client’s forehead and earlobes using a soft cloth or towel.
FITTING THE CAP:
Fitting the Cap
1. After adjusting the cap electrodes, it is time to exfoliate their forehead and ear lobes with a little Nuprep™. Squeeze a pea sized drop of gel onto two fingers and massage the client’s scalp at location Fp1 to remove dead skin cells. Rub the Nuprep™ on the skin using a circular motion about 1 inch in diameter.
2. Repeat step 2 for location Fp2.
3. Use a pea sized drop of gel to exfoliate the back of each ear lobe (the part of the earlobe which is not visible and is closest to the head). Be sure to avoid locations with holes from ear piercings.
4. Remove the Nuprep™ from the client’s forehead and earlobes using a soft cloth or towel.
FITTING THE CAP:
Attaching the Ear Clips
1. Once the cap is adjusted and the electrodes are in the proper position, open one of the attached ear clips to expose a metal electrode. Each ear clip contains only 1 electrode which appears as a metal disk, inside the clip, opposite the spring. Using a syringe, with a blunted needle full of gel, cover the entire surface of the electrode with Electro-Gel™, ensuring the drop of gel is 1-2mm thick.
2. Keeping the ear clip open, clip it on the back of the earlobe of the ear which is on the same side of the cap the ear clip is connected to. This should be the same area you scrubbed with Nuprep™ that avoids earring holes. Also, make sure no hair is touching the electrode on the ear clip after it is clamped. Repeat these steps with the second ear clip on the opposite ear.
Attaching the Electrodes
1. Gently insert the Electro-Gel filled syringe into the hole in the middle of the electrode, using the blunted needle, until it contacts the client’s scalp. Pull back just enough that the scalp is not preventing gel from flowing out of the needle tip, but where the tip remains between the electrode and the scalp.
2. Using your thumb to depress the plunger, deposit a small amount of gel on the scalp so it fills the gap between the electrode and the scalp. You can test to see if you have the right amount of gel by gently pressing the electrode down on the scalp. If the gel leaks out from under the electrode, you dispensed too much. If you dispensed too little, you will not see any gel rising in the hole where you previously inserted the blunted needle. You can always flip the electrode up clean off the electrode and scalp and reapply the gel if you get into trouble.
3. The right amount of gel will not leak out from under the electrode but can be seen entering the hole in the middle, when the electrode is pressed. This process takes practice but will eventually become second nature.
4. Repeat the steps above for all 19 electrodes.
Acquiring Good Impedance Values
- Once the cap is properly attached to the client and gel has been applied to all electrodes, including the ear clips, it is time to ensure a good connection between the scalp and electrode. To do this, you will need to attach the grey connector to impedance checking software or a separate impedance checking device.
- The software or device will display the impedance for each electrode in kilohms, including the ear clips. The goal is to get an impedance value of 5 or less kilohms(K), 10K or less is acceptable. Impedance for the ear clips also needs to be as low as possible. Aim for under 5K at the ears, but under 20K if you are having difficulty.
- Follow these steps to lower the impedance values of an electrode. One method is to take the wooden end of a cotton tipped applicator and insert it into the hole in the middle of the electrode until it contacts the scalp. Taking care to not break the client’s skin, twist the applicator between your fingers in alternating directions to abrade the scalp. For the client’s comfort, abrade for 1-2 seconds, then lift the applicator off the scalp for 1 second, return the applicator to the scalp and abrade, then lift again. As you abrade the scalp and ensure the gel is filling the gap between the electrode and the scalp, the impedance values will fall. Repeat the process until the desired impedance value is reached, then move on to the next electrode. Do this for all 19 electrodes.
- The ear clips impedance value can depend on how well the ear lobes are abraded with the Nuprep™. If the ear clips’ impedance value is too high, first check to make sure there is no hair between the electrode and the ear. Even a couple strands of hair can raise the impedance value. If removing hair does not lower the impedance enough, remove the ear clips, wipe the gel from the earlobe with a cloth, and rescrub the ear lobe with Nuprep™. Then wipe off the Nuprep™, reapply gel and attach the clip to the ear like it was before. You can also check to see if the ear clip electrode is resting on an earring hole. Moving the ear clip to an area without holes should lower the impedance value as well.
- When the impedance values are adequate, attach the grey connector to a NeuroField or BrainMaster amplifier and follow the manufacturer’s instructions. IMPORTANT: WHEN PLUGGING IN OR UNPLUGGING THE CAP, GRIP THE GREY CONNECTOR ONLY, DO NOT EVER PUSH OR PULL ON THE WIRES.
Cleaning the Cap
- Turn the cap inside out and scrub each electrode with a small brush or toothbrush, under warm running water, making sure to remove all gel from the surface of each electrode and ear clip.
- Next, take a blunted needle and clear the hole in the middle of the electrode by repeatedly inserting and retracting the needle under warm running water. To ensure all gel is out of the hole, canned air can be sprayed in each hole, although that may not be necessary if you clean the hole well enough with the needle.
- Excess water can be removed with canned air between clients allowing the cap to be used again very quickly.
- Hang the cap to dry.
IMPORTANT: PLEASE KEEP THE GREY CONNECTOR DRY DURING THE CLEANING PROCESS. It is best to place it off to the side away from the water source. Also, when hanging the cap, make sure the connector is not directly under the cap where water could drip on it. It is best to hang the connector higher than the cap or off to the side.
