Controlled reshaping of nerve geometry

The purpose of this study is the development of a nerve electrode that reshapes nerve geometry slowly and controllably. The flat interface nerve electrode (FINE) can reshape the nerve into an elongated oval and provide selective stimulation. However, the FINE´S ability to reshape nerve geometry quickly may cause acute nerve insult. The slowly closing flat interface nerve electrode (SC-FINE) is designed to increase the opening height to accommodate the nerve and initial swelling. Moreover, the SC-FINE controls the reshaping period to alleviate nerve compression injury. The SC-FINE is manufactured by combining the reshaping properties of the FINE and the controllable degradation of poly (DL lactic-co-glycolic) acid (PLGA). Bonding 50/50 or 65/35 PLGA to a stretched FINE increased the opening heights on average from .1 mm to 1.66 ± 0.45 mm and 2.05 ± 0.55 mm respectively. The addition of PLGA films controls the time course of closure over a period of 16 ± 1 days and 14 to 16 hours for the 50/50 and 65/35 SC-FINEs respectively in vitro. An in vivo chronic experiment using 50/50 SC-FINEs implanted in 28 rats with an average opening height of 1.87 ± 0.34 mm show that the reshaping periods in vivo are in vitro are similar.