Fetrode™ noise reduction technology


High impedance at the skin-electrode contact correlates directly with the amplitude of the noise artifacts that can plague bio-electric recordings. Historically, there have been only two ways to reduce such noise: 1) use the very best Ag/AgCl electrodes with a liquid-junction interface; and 2) abrade the skin to reduce the skin/electrode contact impedance. With the prevalence of HIV and hepatitis viruses, breaking the skin barrier is no longer advisable. Fetrodes™ minimize the requirement to abrade the skin.

The Fetrode is a unique, temperature-compensated amplifier with an extremely high input impedance and a very low output impedance. The circuitry is built with state-of-the-art surface mount technology into a miniature enclosure that can be snapped onto any high quality electrode. This innovation places signal buffering directly on the active electrode site. In so doing, the Fetrode virtually eliminates artifacts due to electrostatic potentials and cable noise, even with high electrode contact impedances.

In the comparison shown above, Ag/AgCl electrodes were applied to an adult male using the sternum/V6 electrode configuration, but without skin preparation of any kind. Gain was the same for both tests, approximately 1,500, and contact impedance between active electrodes was 120 KOhms. The UFI Model SRS2004/d performed the signal conditioning and data recording.

Three ways to take advantage of the Fetrode

Fetrode specifications

Published references to the UFI Fetrode

Product Families:
Bioamps/signal conditioners
Ambulatory data loggers
Hot Flash Recording
BAERCOM™ hearing tester
PC-based instruments
Multi-subject systems
Test instruments