Miniature electroparticle-cuff for wireless peripheral neuromodulation

Abstract

Objective. Recent developments in peripheral nerve electrodes allow the efficient and selective neuromodulation of somatic and autonomic nerves, which has proven beneficial in specific bioelectronic medical applications. However, current most clinical devices are wired and powered by implantable batteries which suffer from several limitations. We recently developed a sub-millimeter inductively powered neural stimulator (electroparticle; EP), and in this study, we report the integration of the EP onto commercial cuff electrodes (EP-C) allowing the wireless activation of peripheral nerves. Approach. The current output of this device was defined at different magnetic field strenghts, and with respect to external antenna distance and activation angles. In acute in vivo testing, stimulation of the rat sciatic nerve (ScN) with the EP-C was able to evoke motor responses quantified by 3D tracking of the hind limb movement. Motor recruitment curves were obtained in response to variations in magnetic field strength (0–92.91 A m−1), stimulation frequencies (2–7 Hz), and pulse widths (50–200 µs). Main results. The results show constant output voltage throughout 50 400 stimulating cycles on a benchtop setting, and successful ScN motor activation with a 4 cm distance between external antenna and receiver. We achieved optimal motor recruitment indicated by maximizing range of hindlimb movement (6.01 ± 2.92 mm) with a magnetic field of 40.02 ± 2.85 A m−1 and 150 µs pulse width. Stimulating pulse width or frequency did not significantly influence motor recruitment. Significance. We confirmed that continuous stimulation for 14 min using monophasic pulses did not deleteriously affect the evoked motor responses when compared to wired charge-balanced biphasic electrical stimulation. We observed, however, a 36%–44% decrease in the evoked limb movement in both groups over time due to muscle fatigue. This study shows that the EP-C device can be used effectively for peripheral nerve neuromodulation.

Targeted neuromodulation of pelvic floor nerves in aging and multiparous rabbits improves continence

“…Since electrical stimulation has been shown to activate the injured pudendal nerve in rats 24 , we evaluated the use of electrical stimulation of pelvic floor nerves, which branch from the pudendal nerve, to restore their urethral sphincter function. To that end, we used a miniature wireless cuff electrode for nerve stimulation, as reported previously 25 , 26 , and evaluated whether electrical stimulation of the pelvic nerves in mid-age multiparous rabbits, could evoke pelvic muscle contraction and partially reverse the reduced voiding efficiency and weak urethral pressure in this animal model.…”

A chronic photocapacitor implant for noninvasive neurostimulation with deep red light

“…The most common approaches involve radio frequency (RF) power transmission or electromagnetic induction 13 . Although these technologies are being developed for clinical use 11,[14][15][16] , RF imposes size and shape constraints for transmitting and receiving components. The volume of the receiver (implanted inside the body) ranges from 30-600 mm 3 , 17 including antenna for RF transmission, electrodes for nerve stimulation, and device packaging for protection of rigid Si-based electronics from body fluids.…”

Redox Polymers for Tissue Engineering

“…The development of wireless, implantable stimulation systems is also critical to in vivo deployment. There have been marked advances in this area in recent year including very small RF transmission systems (175,176) and indirect methods that use ultrasound to deliver (piezo) electrical effects (177)(178)(179)(180). Neither have been coupled to OCPs to date.…”