Conform to brain surface

Provide high spatial resolution

Active electronics allows for

multiplexing

[1] Dae-Hyeong Kim, Jonathan Viventi, et al. Dissolvable films of silk fibroin for ultrathin conformal bio-inspired electronics. Nature Materials, April 2010

A real-time system was developed that provides users with experimentally relevant analyses of multiplexed EEG data during experimentation. Acquired data is demultiplexed, filtered, analyzed, and shown in a visual display. The system interfaces with the new generation of flexible active electrodes developed by Kim and Viventi et al [1] and enables researchers to observe and analyze results of experiments in real-time.

Reports single electrode data Averaged filtered response after stimulus presentation Fundamental first-stage processing

Reports data for all electrodes Feature of running average computed for each electrode Localization of activity

Reports data for all electrodes and all positions Draws a color map for each location on the gridUses RMS value of evoked response as feature

Electrode Array

Data Acquisition Software

Multiplexed Data

Demultiplexed Data

DemultiplexingEvoked Response

Averaging

(C)

SavedTo Disk

Raw Data

Data Acquisition Hardware

Demultiplexed Data2D Sparse Noise(MATLAB)

Offline Processing

(CPU + GPU)

GPU Dedicated Computer via

network stream

ReconstructedDemultiplexed Data

Multiplexing: Using active electronics to use a single wire to carry multiple signals from multiple sources.

•Maximize quality of experimental results•Provide real-time feedback to experimentalists•Allow for real-time quality checks of results•Make system scalable as electrode arrays grow

2d-Sparse Noise: An experimental paradigm in which flashes of light are randomly presented in a 2-d grid. At each given time, one grid location is randomly flashed for a duration of 200ms.

Signal 1

Signal 2

Signal 3

Signal 4

Signal 1

Signal 2

Signal 3

Signal 4

Multiplexing

Demultiplexing

Multiplexed Signal

Evoked Response Average: Averaging the signal from a region of brain for repeated presentation of a stimulus in order to determine the characteristic response of that region to the stimulus.

The real time processing system was built and tested in experiments. The experimentalists were able to use the feedback from the system to alter the experimental setup to yield better results. The GPU was used for some basic frequency domain analysis. Future work will involve adding more sophisticated analyses and online use of the GPU.

• 110 MB/s sustained throughput

• Raw sampling rate of 100 kHz per channelData Acquisition

Hardware PXI-1033

• Controls multiplexing, row selection signalsIn-House Data

Acquisition Hardware

• 512 Cuda cores

• 1544 MHz Processor Clock

GPU

(GeForce GTX 580)

Running Average Color Map

2D Sparse Noise

Flexible Electrodes

Simulated Evoked

Response Average

Blue Individual Trials

Red Average