Natural Versus Artificial Sensors Applied in Peroneal Nerve Stimulation

Abstract

We have attempted to quantify the performance of natural versus artificial sensors when used in a closed-loop functional electrical stimulation system. Peroneal nerve stimulation was applied during gait to a multiple sclerosis subject with a drop foot. Stimulation was applied only during the swing phase to provide artificially induced dorsiflexion of the foot. Detection of the onset of the stance phase was accomplished using a standard heel contact switch mounted inside the subject's shoe (the artificial sensor) and using processed nerve signals derived from an implanted nerve-cuff electrode (the natural sensor). A detection percentage of at least 85% was achieved using the afferent nerve signal information only. When muscle activity (also recorded in the cuff) and additional information about the gait cycle were incorporated, functional detection ratios approaching 100% were achieved.

Real-time control of hind limb functional electrical stimulation using feedback from dorsal root ganglia recordings

“…Recent efforts have used a wide variety of external sensors to monitor limb state including position sensors [5], goniometers [6], force sensors [7–11], accelerometers [7–9, 11, 12], gyroscopes [7, 8, 11] and other sensors [11]. Challenges with the reliability, positioning and mounting of external sensors have limited the development of continuous feedback control of FES systems [13, 14]. Furthermore, potential users desire assistive devices that have minimal visibility or are implanted, to limit drawing additional attention towards their condition [15–17].…”

Multiple-electrode nerve cuffs for low-velocity and velocity-selective neural recording

“…NEURAL AFFERENT signals generated by natural sensors within the body can be used to obtain information such as skin contact, force and position HAUGLAND et aL, , 1999UPSHAW and SINKJAER, 1997;STRANGE and HOFFER, 1999), and so they can be used in closed-loop neuroprostheses.…”

Clinical Application of Peroneal Nerve Stimulator System Using Percutaneous Intramuscular Electrodes for Correction of Foot Drop in Hemiplegic Patients

“…This system produces dorsiflexion and eversion of the foot during the swing phase of gait. Since its introduction, FES for correction of foot drop has been studied by American and European researchers (3–12). They have found two advantages of FES over an AFO: FES provides active gait correction, and the action of FES can be tailored to fit individual requirements.…”