Abstract
Wireless transmission of cortical signals is an essential step to improve the safety of epilepsy procedures requiring seizure focus localization and to provide chronic recording of brain activity for Brain Computer Interface (BCI) applications. Our group developed a fully implantable and externally rechargeable device, able to provide wireless electrocorticographic (ECoG) recording and cortical stimulation (CS). The first prototype of a wireless multi-channel very low power ECoG system was custom-designed to be implanted on non-human primates. The device, named ECOGIW-16E, is housed in a compact hermetically sealed Polyether ether ketone (PEEK) enclosure, allowing seamless battery recharge. ECOGIW-16E is recharged in a wireless fashion using a special cage designed to facilitate the recharge process in monkeys and developed in accordance with guidelines for accommodation of animals by Council of Europe (ETS123). The inductively recharging cage is made up of nylon and provides a thoroughly novel experimental setting on freely moving animals. The combination of wireless cable-free ECoG and external seamless battery recharge solves the problems and shortcomings caused by the presence of cables leaving the skull, providing a safer and easier way to monitor patients and to perform ECoG recording on primates. Data transmission exploits the newly available Medical Implant Communication Service band (MICS): 402–405 MHz. ECOGIW-16E was implanted over the left sensorimotor cortex of a macaca fascicularis to assess the feasibility of wireless ECoG monitoring and brain mapping through CS. With this device, we were able to record the everyday life ECoG signal from a monkey and to deliver focal brain stimulation with movement elicitation.
Highlights
In patients with refractory epilepsy or brain tumors, direct cortical electrical stimulation (DCS) and ECoG are the gold standard intraoperative technique to identify the tissue to be removed, with regard to neighboring potentially eloquent cortex [1, 2]
Interindividual variability of cortical organization and changes of the location of function due to neural plasticity can be assessed by preoperative functional Magnetic Resonance Imaging, but intraoperative DCS is needed to maximize the extent of the resection and to prevent neurological injury [4]
ECoG has the additional opportunity to record the remote effect of electrocortical stimulation without distortion within a limited distance of a few millimeters, and can provide further details about the potential functional reorganization caused by the individuals brain pathology [3, 5]
Summary
In patients with refractory epilepsy or brain tumors, direct cortical electrical stimulation (DCS) and ECoG are the gold standard intraoperative technique to identify the tissue to be removed, with regard to neighboring potentially eloquent cortex [1, 2]. Given the high spatial (of ≈1–2 mm) and temporal resolution (within the timescale of neural activity), ECoG recording is required to identify an ictal focus and to guide the resection ECoG is the most effective tool for brain–computer interface (BCI) applications. ECoG recordings from sensorimotor cortex are a promising tool to guide a prosthetic limb or an exoskeleton, providing functional restoration to patients with a variety of neurological injuries such as post-traumatic tetraplegia or paraplegia. The high signal-to-noise ratio of this technique enables the examination of high-frequency bands, unavailable for scalp EEG recordings, allowing to use the spectral analysis as a tool www.frontiersin.org
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
