Course goal: This course introduces basic EEG (electroencephalographic) instrumentation.  This is a beginning course intended to help the technologist/scientist to understand basic instrumentation concepts as they apply to EEG and also other neurodiagnostic procedures using a differential amplifier and filters.  These concepts include digitization, differential amplification, common mode rejection, standard polarity convention, impedance, cancellation, summation, field distributions, use of montages in localization, analysis time,  eye polarity, and the basics of a frequency response curve.

Course objectives include:

  • Defining differential amplification and symbols used to depict the differential amplifier
  • Identify the means of using a system reference in a digital EEG allowing remontaging after the recording
  • Recognize frequency bands used in EEG
  • Describe analog to digital conversion, the Nyquist Theorem and the sampling rate importance
  • Compare and contrast CMR (common mode rejection) to the concept of in-phase cancellation, also called equipotential, how it impacts the intended EEG signals and also artifacts
  • Describe the standard polarity convention in EEG and use it to determine deflections and voltages
  • Recognize the importance of impedance and the difference between impedance and resistance
  • Identify other factors that impact a quality EEG recording, and effectiveness of CMR, such as electrode security and lead wire placement
  • Define Ohm's law and calculate for all voltage, current and resistance
  • Recognize scientific notation and the metric system prefixes and identify how these are used in neurophysiology
  • Calculate frequency, sensitivity, voltage and deflection using a legend
  • Visualize a number line to help make calculations
  • Calculate voltage and deflection problems
  • Describe summation, cancellation, equipotential and apply them to waveform analysis
  • Read graphic representations of field distributions across the scalp
  • Use referential, bipolar, common average reference and Laplacian source derivation montages appropriately
  • Recognize and take action to rectify contaminated references
  • Visualize montages and their usefulness in recording specific types of waveforms
  • Recognize samples of horizontal dipoles
  • Recognize the direction of eye movements, and define the polarity of the eye
  • Use a frequency response curve to answer questions about the impact of filters on waveform amplitude, morphology and frequency
  • Identify the impact of analysis time on the display of waveforms, and calculate frequency at varying analysis times
  • Compare and contrast calibration in analog and digital instruments and recognize the appropriate calibration of an digital instrument