Abstract: Amplification of an evoked potential signal is carried out utilizing a high pass filter implemented as an integrator in a feedback loop which drives the DC offset voltage to zero. As a result, the feed-forward amplifier circuit has almost zero volts at its output since the only voltage remaining is the offset voltage of the operational amplifier, which is selected so as to maintain this parameter as low as possible. Because the voltage impressed across the feed-forward amplifier section is close to zero, the gain of this section can be set to zero during the time that the electrical stimulus pulse is present without introducing any additional artifacts and subsequent amplifier stages are not driven into saturation.

Abstract: Amplification of an evoked potential signal is carried out utilizing a high pass filter implemented as an integrator in a feedback loop which drives the DC offset voltage to zero. As a result, the feed-forward amplifier circuit has almost zero volts at its output since the only voltage remaining is the offset voltage of the operational amplifier, which is selected so as to maintain this parameter as low as possible. Because the voltage impressed across the feed-forward amplifier section is close to zero, the gain of this section can be set to zero during the time that the electrical stimulus pulse is present without introducing any additional artifacts and subsequent amplifier stages are not driven into saturation.