User:Enginerd1/Sandbox

A Driven Right Leg Circuit or “DRL” circuit is an electric circuit that is often added to biological signal amplifiers to reduce Common-mode interference. Biological signal amplifiers such as EKG (Electrocardiogram) or EEG (Electroencephalogram) circuits measure very small electrical signals emitted by the body, often as small as several micro-volts (millionths of a volt). Unfortunately, the wires used to transmit these small biological signals to measuring equipment act as antennas that pick up electrical interference, especially 60Hz noise from electrical outlets. This interference creates voltages in the transmission wires that are often larger than the biological signals themselves. This makes the biological signals very hard to measure. Right Leg Driver circuitry is used to eliminate interference noise by actively cancelling the interferance.

Design of a DRL Circuit

TODO

Sources of Noise

Electromagnetic interference

Other Methods of Noise Cancellation

TODO Shielding Faraday cage
Twisting Wires
High Gain Instrumentation Amplifier
Filtering

Further Reading

IEEE Citation format (ISBN added)
[1] J.G. Webster, "Medical Instrumentation", 3rd ed, New York: John Wiley & Sons, 1998, ISBN 0-471-15368-0.

Enginerd1 21:45, 27 August 2006 (UTC)