Remote electrical stimulation by means of implanted rectifiers

Abstract

Miniaturization of active implantable medical devices is currently compromised by the available means for electrically/npowering them. Most common energy supply techniques for implants – batteries and inductive couplers – comprise bulky/nparts which, in most cases, are significantly larger than the circuitry they feed. Here, for overcoming such miniaturization/nbottleneck in the case of implants for electrical stimulation, it is proposed to make those implants act as rectifiers of high/nfrequency bursts supplied by remote electrodes. In this way, low frequency currents will be generated locally around the/nimplant and these low frequency currents will perform stimulation of excitable tissues whereas the high frequency currents/nwill cause only innocuous heating. The present study numerically demonstrates that low frequency currents capable of/nstimulation can be produced by a miniature device behaving as a diode when high frequency currents, neither capable of/nthermal damage nor of stimulation, flow through the tissue where the device is implanted. Moreover, experimental/nevidence is provided by an in vivo proof of concept model consisting of an anesthetized earthworm in which a commercial/ndiode was implanted. With currently available microelectronic techniques, very thin stimulation capsules (diameter/n,500 mm) deliverable by injection are easily conceivable.