ECoG Series Thin-Film Grids
An ECoG grid is a 12 µm polyimide array that records from the cortical surface, placed epidurally on intact dura or subdurally on the pia; the film follows the curvature and movement of the cortex, which is what keeps the sites in contact.
Epidural placement leaves the dura intact, with lower risk and better chronic behavior, but the dura attenuates and blurs the signal reaching the sites; subdural placement gives higher amplitude and finer resolution at the cost of opening it. Catalog designs have 4 to 256 platinum sites with diameters from 25 µm to 1 mm, and the diameter is the selection axis: a small site records a local patch at high impedance, a large one averages a wide patch at low impedance. A grid is often paired with a penetrating probe for a surface map and a laminar profile in one animal; the grid goes on first. The signal and the placements are under electrocorticography, the four grid families and their packaging under thin-film grid, and the surgical steps in the ECoG surgical guide.
Records and stimulates. Research use only.
Typical values
| Catalog designs | 33 |
|---|---|
| Sites | 4 to 256 |
| Site diameter | 25 µm to 1 mm |
| Substrate | 12 µm polyimide; platinum sites |
| Placement | epidural or subdural |