A wireless millimetric magnetoelectric implant for the endovascular stimulation of peripheral nerves

Abstract

Implantable bioelectronic devices for the simulation of peripheral nerves could be used to treat disorders that are resistant to traditional pharmacological therapies. However, for many nerve targets, this requires invasive surgeries and the implantation of bulky devices (about a few centimetres in at least one dimension). Here we report the design and in vivo proof-of-concept testing of an endovascular wireless and battery-free millimetric implant for the stimulation of specific peripheral nerves that are difficult to reach via traditional surgeries. The device can be delivered through a percutaneous catheter and leverages magnetoelectric materials to receive data and power through tissue via a digitally programmable 1 mm × 0.8 mm system-on-a-chip. Implantation of the device directly on top of the sciatic nerve in rats and near a femoral artery in pigs (with a stimulation lead introduced into a blood vessel through a catheter) allowed for wireless stimulation of the animals’ sciatic and femoral nerves. Minimally invasive magnetoelectric implants may allow for the stimulation of nerves without the need for open surgery or the implantation of battery-powered pulse generators.

Photoactive Nanomaterials for Wireless Neural Biomimetics, Stimulation, and Regeneration

“…Chen et al designed a double-layer device by magnetostrictive layer of metallic glass and piezoelectric layer of lead zirconium titanate (PZT). When a magnetic field is applied, the deformation of the magnetostrictive material causes the displacement of the piezoelectric layer surface, and the piezoelectric layer then generates an electric field . The team applied an external magnetic field to the sciatic nerve of rats, and the wirelessly powered device can arise the repeatable compound muscle action potentials and the observed leg movements of rats.…”

Physical Cue‐Based Strategies on Peripheral Nerve Regeneration

“…In particular, such miniaturized device can through blood vessels introduce into the targeted site to realize minimally invasive neuromodulation. [ 165 ] Wireless and battery‐free power supply technology delineated a novel strategy to exert exogenous ES for PNR in a less‐invasive and bio‐friendly manner. Nevertheless, magnetic field and radio‐frequency penetrate skin and muscle will suffer major energy attenuation attributed to their low tissue‐penetrating capability thus leading to inefficient electrical power transmission.…”

“…g) Schematic illustrations of minimally invasive magnetoelectric neurostimulator. Reproduced with permission [165]. Copyright 2022, Springer Nature.…”

Low-cost and prototype-friendly method for biocompatible encapsulation of implantable electronics with epoxy overmolding, hermetic feedthroughs and P3HT coating

“…sharp) edges can substantially reduce foreign body rejection by the soft tissue 2 , 14 . Some sources mention hand coating of the epoxy on the surface of the electronic package without any control over the final shape of the device and control over the design of feedthroughs 15 . A use of a PTFE mold for epoxy potting was reported for neurostimulation implants but the shape of the molded device was limited to a ring with sharp edges 16 .…”