Comparison of three ENG tripolar cuff recording configurations

Cuff electrodes are a safe and reliable technique for long-term recording of the electroneurogram (ENG) from peripheral nerves. However, the usefulness of the recorded ENG depends on the amount of electromyogram (EMG) and stimulus artifact present. Interference cancellation may be offered by tripolar cuff recording configurations, such as the quasi-tripole (QT) and the true-tripole (TT), but in practice their performance is severely degraded by cuff imbalance. The adaptive-tripole (AT) has been developed to compensate for possible cuff imbalance and hence minimize the interference pick-up on the recorded ENG. In this paper, the signal-to-interference ratios of the three tripolar cuff recording configurations are compared in-vivo in the presence of cuff imbalance. The results of the experiments, which were conducted using stimulation-induced signals, indicate that even though two different imbalances were present, the AT outperforms the other two configurations in the majority of cases.