Selectivity of recording of neural signals with micromachined intraneural multi electrodes

The number uf afferent fibers in a peripheral nerve fascicle and the electrical volume conduction in neuraI tissue determine the interelectrode spacing, needed for selective recording with mufticontact devices. These factors taking into account, and also assuming uniform distribution of fibers throughout the fascicle cross section, it is calculated that for selective sensing in peroneal nerve fascicles, the electrode spacing must be about 80 pm. This is for the nelve, embedded in its natural saline environment. The selectivity, thus reached, however reduces dmstically to zero when an insulating cuff is positioued around the nerve at the position of the intraneural multielectrode device.