Temporal stability of nerve cuff electrode recruitment properties
The recruitment properties of multiple contact nerve cuff electrodes chronically implanted on the cat sciatic nerve were measured, and the week to week variability was documented. The variability in recruitment properties was greatest between 1 week and 8 weeks post-implant. After 8 weeks the session to session changes were significantly smaller than in the early post-implant period. No trends were observed in the recruitment patterns that would suggest any damage to the nerve occurring during the implant period. These results suggest that the implant is safe and that tissue encapsulation acts to stabilize the cuff electrode and prevent relative movement between the cuff and the nerve trunk. This study, combined with previous studies, demonstrates that multiple contact spiral nerve cuff electrodes can be used in long-term implants to activate discrete regions of peripheral nerve trunks.