Faculty Advisor

Clancy, Edward A.


EMG signals are often disguised beneath DC offsets and electrical noise. To isolate the signal, it must be amplified when it is acquired. The amplification stage can be embedded in an electrode-amplifier so that it has an AC-coupled, differential gain with high CMRR and input impedance. This project compares three possible electrode-amplifier circuit designs that use an instrumentation amplifier to provide a high input impedance and CMRR. The first design is a classic, DC-coupled instrumentation amplifier circuit with a gain of 20. The second design features an AC-suppression circuit within the classic design. The third design prepends an AC-coupling circuit to the classic design; it was analyzed and implemented with a gain of 100, a CMRR greater than 90 dB, and a low input-referred noise.


Worcester Polytechnic Institute

Date Accepted

May 2009


Electrical and Computer Engineering

Project Type

Major Qualifying Project



Advisor Department

Electrical and Computer Engineering