Selective stimulation of the human femoral nerve with a flat interface nerve electrode

Abstract

In humans, we tested the hypothesis that a flat interface nerve electrode (FINE) placed around the femoral nerve trunk can selectively stimulate each muscle the nerve innervates. In a series of intraoperative trials during routine vascular surgeries, an eight-contact FINE was placed around the femoral nerve between the inguinal ligament and the first nerve branching point. The capability of the FINE to selectively recruit muscles innervated by the femoral nerve was assessed with electromyograms (EMGs) of the twitch responses to electrical stimulation. At least four of the six muscles innervated by the femoral nerve were independently and selectively recruited in all subjects. Of these, at least one muscle was a hip flexor and at least two were knee extensors. Results from the intraoperative experiments were used to estimate the potential for the electrode to restore knee extension and hip flexion through functional electrical stimulation. Normalized EMGs and biomechanical simulations were used to estimate joint moments and functional efficacy. Estimated knee extension moments exceed the threshold required for the sit-to-stand transition.

Human distal sciatic nerve fascicular anatomy: Implications for ankle control using nerve-cuff electrodes

“…Designing models of nerve-cuff electrodes to selectively stimulate distal musculature using fascicular anatomy [16] has been accomplished using similar data for the femoral nerve [22]. These studies have led to intraoperative verification of the designs and approval for human feasibility trials [24].…”

“…Modeling and simulation studies based on the detailed femoral fascicular anatomy [22] have been successfully employed to design and optimize implantable femoral nerve-cuff electrodes [16]. This model-driven approach to designing selective electrodes for the femoral nerve has been verified intraoperatively [23], and the resulting devices have been approved for human feasibility trials [24]. The first step in repeating this design and optimization procedure for the sciatic nerve is the specification of the fascicular structure of the branches that innervate ankle musculature.…”

Interfacing with the nervous system: a review of current bioelectric technologies

“…3) [63,66,105,151,161]. Additionally, intraoperative studies in the human femoral nerve showed that muscles innervated by the femoral nerve could be independently and selectively stimulated with a FINE device [133]. Surgical placement of FINE around the femoral trunk leads to selective activation of leg muscles, thereby aiding patients who suffer from lower trunk paralysis to stand from a sitting position [134].…”

An energy-efficient, dynamic voltage scaling neural stimulator for a proprioceptive prosthesis

“…Selective stimulation of efferent neurons (similar to the afferent Type Ia and Ib neurons we are targeting) in the human PNS has been demonstrated in [21], [22] to occur with charge packets of between 11±5 nC to 29±17 nC. Given these values our stimulator will be designed to deliver up to 50 nC in a 100 μs pulse (a common pulse duration).…”