Myoelectric and Common-Mode Interference Rejection in a Quasi-Tripole Amplifier Configuration

In this paper we present a simple technique for removing myoelectric interference in neural recording tripoles. Cuff imbalance is simply unavoidable with the conventional quasi-tripole (QT) configuration and this technique is based on a modified version of the QT, which is capable of compensating for cuff imbalance that is causing electromyogram interference to be present at the output of an amplifier. By carrying out in-vitro experiments we show that, with a tripole that was intentionally made imbalanced, the interference can be reduced about 10-fold.