Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data

J Neurosci Methods. 2009 May 30;180(1):185-92. doi: 10.1016/j.jneumeth.2009.03.022. Epub 2009 Apr 1.

Abstract

The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Biological Clocks / physiology
  • Brain / physiology
  • Brain / surgery
  • Computer Security*
  • Data Collection / methods*
  • Data Compression / methods
  • Electrodes, Implanted
  • Electroencephalography / methods*
  • Electrophysiology / methods*
  • Epilepsy / physiopathology
  • Epilepsy / surgery
  • Humans
  • Information Storage and Retrieval*
  • Information Systems
  • Monitoring, Intraoperative / methods*
  • Neurons / physiology
  • Signal Processing, Computer-Assisted
  • Software