Fall 2010 IAB
September 15 to 17

Plenary 12: Peter Ledochowitsch

A High-Density Large-Area Micro-Electrocorticography (µECOG) Array

Electrocorticography (ECoG) strives to bridge the gap between traditional
electroencephalography (EEG) and microneedle array
recordings. While requiring a craniectomy, ECoG does not damage cortical
tissue and is thus less invasive than microneedles.
ECoG can achieve significantly higher spatiotemporal resolution than EEG
because ECoG-electrodes are placed much closer to the
signal sources in the brain. Commercially available ECoG arrays feature a
small number of channels (<64) and a large electrode
pitch (> 4 mm). Such coarse arrays likely undersample the signals
available on the cortex surface. There is currently no agreement
on the optimal inter-electrode pitch in the community and surprisingly
little research has been published on the topic of optimal
inter-electrode spacing for ECoG. I am designing, fabricating, packaging
and testing a flexible, large-scale (>256 electrodes)
high-density (pitch < 0.5 mm) μECoG array. Scaling-down an ECoG array and
increasing the number of recording sites poses
many engineering challenges in terms of SNR, interconnects complexity and
device lifetime. Addressing these challenges lies at
the heart of my project. Data collected from the array in vivo will allow
conclusions about optimal electrode spacing and size. All
devices will be optimized for decreased impedance resulting in better SNR.