EMG amplifier circuit
An EMG amplifier circuit that filters and amplifies eye twitching EMG signals.
I have designed an electrical circuit which amplifies and filters eye twitching EMG signals. This circuit helps us visualize EMG signals in the order of 200 uV using a gain of ~1000.
The initial stage consists of a instrumentation amplifier which provides high impedence at the input. The instrumentation amplifier has a set gain of 10 and outputs the difference between the input signal and the reference signal. This output signal is then passed to an active high-pass filter with a gain of 10 and has a corner frequency of 0.16 Hz. This helps prevent any DC noise.
The next stage of the circuit is an active low-pass filter with a gain of 10 and a corner frequency of 480 Hz. This filter prevents high frequency noise in the output and also provides low output impedence.
The Vcc power is split and is used to provide a reference to the body using unity gain buffers.