LONDON — At this week's Design, Automation and Test in Europe (DATE) conference and exhibition, research institute IMEC is set to present a prototype multi-electrode stimulation and recording probe for deep-brain stimulation.

Brain implants for electrical stimulation of specific brain areas are used as a therapy of last resort for brain disorders such as Parkinson's disease, tremor, or obsessive-compulsive disorder. The present state-of-the-art uses millimeter-sized probes, which stimulate a large area of the brain in an unfocused way and with side effects.

IMEC’s design and modeling strategy allows brain implants with ten micrometer-size electrodes and various electrode topologies. The design strategy uses finite-element modeling of the electrical field distribution around the brain probe using Comsol Multiphysics 3.4 and 3.5 from Comsol AB (Stockholm, Sweden). The Comsol software also allows simulation of the mechanical properties of the probe during surgical insertion and the effects of temperature. The results indicate that adapting the penetration depth and field asymmetry allows the electrical field around the probe to be “steered” for more precise stimulation. The IMEC probe also has a mixed-signal compensation scheme enabling multi-electrode probes capable of stimulation as well as recording for closed-loop systems.

“To have a more precise stimulation and recording, we need electrodes that are as small as individual brain cells — neurons. Such small electrodes can be made with semiconductor process technology, appropriate design tools, and advanced electronic signal processing. At DATE, we want to bring this message to the design community, showing the huge opportunities that the healthcare sector offers,” said Wolfgang Eberle, project manager at IMEC's bioelectronics research group.

Related links and articles:

www.comsol.com

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