The effect of nonlinearity in the extrafascicular field in tripolar electrode cuffs on interference pick-up was investigated. It was concluded that the interference is sensitive to electrode separation, especially in short cuffs. This suggests that significant improvements can be obtained by placing the end electrodes a few mm from the cuff ends.
Rahal, M., Taylor, J., & Donaldosn, N. (2000). The effect of nerve cuff geometry on interference reduction: a study by computer modeling. IEEE Transactions on biomedical engineering, 47(1), 136-138. https://doi.org/10.1109/10.817629