A low-cost, scalable, current-sensing digital headstage for high channel count μECoG.
Journal Article (Journal Article)
Objective
High channel count electrode arrays allow for the monitoring of large-scale neural activity at high spatial resolution. Implantable arrays featuring many recording sites require compact, high bandwidth front-end electronics. In the present study, we investigated the use of a small, light weight, and low cost digital current-sensing integrated circuit for acquiring cortical surface signals from a 61-channel micro-electrocorticographic (μECoG) array.Approach
We recorded both acute and chronic μECoG signal from rat auditory cortex using our novel digital current-sensing headstage. For direct comparison, separate recordings were made in the same anesthetized preparations using an analog voltage headstage. A model of electrode impedance explained the transformation between current- and voltage-sensed signals, and was used to reconstruct cortical potential. We evaluated the digital headstage using several metrics of the baseline and response signals.Main results
The digital current headstage recorded neural signal with similar spatiotemporal statistics and auditory frequency tuning compared to the voltage signal. The signal-to-noise ratio of auditory evoked responses (AERs) was significantly stronger in the current signal. Stimulus decoding based on true and reconstructed voltage signals were not significantly different. Recordings from an implanted system showed AERs that were detectable and decodable for 52 d. The reconstruction filter mitigated the thermal current noise of the electrode impedance and enhanced overall SNR.Significance
We developed and validated a novel approach to headstage acquisition that used current-input circuits to independently digitize 61 channels of μECoG measurements of the cortical field. These low-cost circuits, intended to measure photo-currents in digital imaging, not only provided a signal representing the local cortical field with virtually the same sensitivity and specificity as a traditional voltage headstage but also resulted in a small, light headstage that can easily be scaled to record from hundreds of channels.Full Text
Duke Authors
Cited Authors
- Trumpis, M; Insanally, M; Zou, J; Elsharif, A; Ghomashchi, A; Sertac Artan, N; Froemke, RC; Viventi, J
Published Date
- April 2017
Published In
Volume / Issue
- 14 / 2
Start / End Page
- 026009 -
PubMed ID
- 28102827
Pubmed Central ID
- PMC5385258
Electronic International Standard Serial Number (EISSN)
- 1741-2552
International Standard Serial Number (ISSN)
- 1741-2560
Digital Object Identifier (DOI)
- 10.1088/1741-2552/aa5a82
Language
- eng