Ear Cllips

[Guest guest]

Kawnee,

I don't know if these are the type of ear clips that you had in mind. I converted to using tin electrodes after training with Marvin Sams who uses tin electrodes and used tin electrodes in the electrocap which he designed for full cap EEG acquisition. I have been purchasing from:

IMA Electronics,

Inc. P. O. Box 124

Gainesville, FL 32602-0124

Phone:

I have been able to purchase tin disc electrodes for 3.20 to 3.55 dollars each if I purchased in quantities of 10+. And for spring ear electrodes, I paid 6.30 to 6.85 dollars each for 10+ quantity. I don’t know what the per unit cost is if you don’t purchase in quantity. You have to place a minimum order of 25.00 dollars. I haven't purchased for more than four years, so the prices might be outdated.

Tin is reported to be a quality electrode, with great electrical qualities, without the worry of scratching the surface and having the quality of the electrical activity of the electrode degrade. I have been very happy with the electrodes and service that I have received from IMA.

You must be careful and not use different types of metal electrodes, because this can cause a dipole effect which can interfere with quality recordings.

I am still of the old school and use standard disc electrodes with 10-20 paste without cotton balls and I haven't felt the necessity to purchase the higher priced preamp electrodes or the shielded cables that some use. I believe that the high impedances of modern differential amplifiers and the great common mode rejection makes this high end equipment unnecessary. But I have been playing with the idea of using cotton or felt pockets of material over the electrodes and soaking them in saline and securing them in place with a strap type system, but I will have to check impedance levels to see if I want to pursue this.

Best Regards,

JD Elder