Flexible, high-density, laminated ECoG electrode array for high spatiotemporal resolution foci diagnostic localization of refractory epilepsy

Abstract

High spatiotemporal resolution brain electrical signals are critical for basic neuroscience research and high-precision focus diagnostic localization, as the spatial scale of some pathologic signals is at the submillimeter or micrometer level. This entails connecting hundreds or thousands of electrode wires on a limited surface. This study reported a class of flexible, ultrathin, high-density electrocorticogram (ECoG) electrode arrays. The challenge of a large number of wiring arrangements was overcome by a laminated structure design and processing technology improvement. The flexible, ultrathin, high-density ECoG electrode array was conformably attached to the cortex for reliable, high spatial resolution electrophysiologic recordings. The minimum spacing between electrodes was 15 μm, comparable to the diameter of a single neuron. Eight hundred electrodes were prepared with an electrode density of 4444 mm⁻². In focal epilepsy surgery, the flexible, high-density, laminated ECoG electrode array with 36 electrodes was applied to collect epileptic spike waves in rabbits, improving the positioning accuracy of epilepsy lesions from the centimeter to the submillimeter level. The flexible, high-density, laminated ECoG electrode array has potential clinical applications in intractable epilepsy and other neurologic diseases requiring high-precision electroencephalogram acquisition.