EEG Electrodes








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User Instruction :

Electrodes Dimensions:
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Gereonics EEG electrodes transmit stable and clean signals for precise EEG measurements. The plastic encased silver/silver chloride electrode is designed as a direct replacement for a 10mm gold cup electrode and has a very low DC offset potential, minimal motion artifact and good low frequency response.

Gereonics EEG electrode bodies are manufactured using FDA quality high impact plastic, which is chemically resistant to collodion. The body is 12mm in diameter and has a 2mm hole in the top for gel addition. A very flexible, small and durable gray leadwire is available in 2, 3, 4, 5, 6, 8, & 10 foot lead lengths to suit your requirements. The electrodes are terminated in a 1.5mm (.060in) female blue safety connectors meeting the DIN standard.

The specially compounded sensing element of silver/silver chloride is the key to precision low drift design. As a result, offset voltage and polarization-two key performance parameters, are unsurpassed. The electrodes never need to be chloridized. Since only the plastic body touches the skin, motion artifacts are significantly reduced compared to metal cup electrodes.

Gereonics EEG silver/silver chloride electrodes can be used many dozens of times and maintain their quality performance characteristics. Performance is significantly superior to gold and silver cup electrodes.

Instructions for Use (EEG Electrodes)...

The skin should be clean where the electrodes will be attached. The cavity and surface of the electrode should also be clean and dry before filling the cavity with the electrolyte gel or paste. Squeeze sufficient electrolyte gel or paste to completely fill the cavity. Check carefully to be sure that no air bubbles are introduced into the cavity. Press the electrode down firmly to attach and seal the electrode.

Gereonics electrodes have been tested by multiple applications of commercial gels and pastes widely used in EEG labs. Those suitable are ECG2 by Grass/AstroMed, Ten20 and Nu-Prep by Weaver and Elefix by Nihon Kohden.

The plastic body of the Gereonics EEG electrode is chemically resistant to collodion. Electrode exposure to acetone used for cleaning collodion should be limited to less than 20 minutes.

The open cavity design allows the electrolyte gel, cream or paste to be easily applied and rapidly cleaned using deionized or distilled water.

The electrode can also be attached to the skin, for example, the body, limbs, and face, using double sided adhesive washers.

Cleaning Electrodes & Other Cleaning Tips...

Immediately after removing the electrode, wash out the gel or cream using distilled or deionized water. A plastic wash bottle with spray tip is very suitable. Never use tap water. A cotton swab can be used to remove the main bulk of the gel or cream. Soak the electrode in a mild saline solution or distilled or deionized water until the next application. Your lab or hospital may have normal saline solution available in prepared bottles. Do not let the old gel or cream dry or harden the cavity.

If electrodes are used only occasionally, a brown coating may form over the sensing element. This can be removed by wiping with a mild ammonium hydroxide solution r by lightly abrading with a very thin strip of 200 mesh emery cloth. Electrodes will turn black if continuously exposed to bright light. The finely divided silver in the electrode pellet oxidizes to silver oxide (black) much like a photographic negative. The electrode will perform normally even when the appearance is almost jet black. Cleaning by abrasion to remove the oxide layer is appropriate, however. Store electrodes not in use in a dark drawer or a closed opaque box.
Electrodes can be permanently damaged or poisoned when only small amounts of bromide, sulfide and some other metal ions are present. Do not expose the electrodes to tap water, EEG pastes containing abrasive clays, miscellaneous soap solutions or abrasive cleaners.

Gereonics silver/silver chloride electrodes may be sterilized using the low temperature peroxide sterilization method. This utilizes the STERRAD 100 Sterilizer from Advanced Sterilization Products, a Johnson and Johnson Company.

Gereonics silver/silver chloride (Ag/AgCl) electrodes are made from very finely powdered high purity silver and silver chloride. They are mixed in a specific ratio and compacted into the electrode body at very high pressures. The resulting pellet is relatively thick (0.7 to 1.0mm) and never needs to be rechloridized, because it is a homogenous mixture. This is unlike electrodeposited Ag/AgCl which is very thin and needs renewal after multiple uses. The only American standard for electrodes is ANSI EC-2 for "Pregelled EEG Disposable Electrodes." The electrical performance requirements, test procedures and test circuity are set forth in this standard. Specific electrical tests are AC Impedance, DC Offset Voltage, Combined Offset Instability and Internal Noise, defibrillation Overload Recovery and Bias Current Tolerance. Gereonics electrodes test very significantly better than the specifications for each of these tests. All Gereonics electrodes are 100% tested for Continuity and DC Offset Voltage.