One of the major sources for complications in chronic neuromodulation are the wires connecting the different parts of the systems, or even penetrating the skin. They account for frequent device failures due to wire breaks and, especially when penetrating the skin, are a permanent risk of tissue irritations or infections.
To overcome these problems, a team of bioengineers around Mario Romero-Ortega at the University of Texas at Dallas recently developed a novel miniaturized neural stimulator – called electroparticle by the authors – that can be wirelessly powered and controlled from outside of the body by magnetic induction. The stimulator measures only about 2 mm in length and 1 mm in thickness. It was coupled to a CorTec Tunnel Cuff for delivering the stimulation to the sciatic nerve.
The authors showed that the electroparticle can deliver functionally effective neurostimulation after implantation in rats. When applying the wireless magnetically induced stimulation, they could induce consistent foot movements as a readout of nerve activation. The monophasic stimulation delivered through their tiny device proved to be as effective in inducing paw movements as classical biphasic stimulation with more conventional stimulation techniques.
Also, the implanted CorTec cuff remained functional over a period of at least 30 days, demonstrating its reliability and suitability for sub-chronic and chronic applications.
This study elegantly highlights how neuromodulation technologies can be further miniaturized and wirelessly controlled, paving the way towards less invasive and more patient-friendly neuromodulation for a variety of biomedical applications.
Hernandez-Reynoso AG, Nandam S, O’Brien JM, Kanneganti A, Cogan SF, Freeman DK, Romero-Ortega MI: Miniature electroparticle-cuff for wireless peripheral neuromodulation. J Neural Eng. 2019 Aug; 16(4):046002. doi: 10.1088/1741-2552/ab1c36.