Neucodia System Functions and Specifications
is a noninvasive, objective medical device that can be used in clinical practice, hospitals, and research laboratories for
quick and reliable assessment of visual function. It is a novel electroencephalographic (EEG) device that provides select
stimuli, synchronized data acquisition, amplification with adjustable filter settings, rich data processing tools in time
and frequency domains, and statistical analyses. It is also equipped with a mouse-driven graphical user interface and automatic
outlier removal algorithms, which facilitate easier, quicker, more accurate and reliable measurements of visual evoked potentials (VEPs) and pattern electroretinograms (PERGs).
Neucodia has 510k clearance from the FDA and is fully compliant with ISCEV standards.
optometrists, vision researchers, neurologists, and trained technicians.
Patients: Individuals at-risk for visual pathway dysfunction or with confirmed ophthalmic or
Clinical offices, hospitals and research laboratories.
Power supply: 110/220
V AC, 60/50 Hz, 5.5 Amp (110 V)
Neucodia includes a 17” CRT or high-speed LCD flat-screen display. The CRT monitor has a maximum
refresh rate (frame rate) of 150 Hz, which is capable of generating high frequency stimulus modulation. The stimulus generator
is configured with 8-bit or 16-bit grey levels for fine luminance modulation. A user-friendly graphical interface is provided
for display calibration. Linearization of luminance is achieved through generation of an individualized look-up-table (LUT)
for gamma correction. Neucodia is shipped with a stimulus generator calibrated by the manufacturer. The stimulus can be virtually
configured for any type of pattern, variety of temporal frequencies, spatial frequencies, luminance levels, contrasts,
and sweep functions.
Stimuli can be easily configured to different sizes, colors, temporal
frequencies, spatial frequencies and virtually any pattern. Sweep stimulus
display (a serial of stimuli displayed in timely sequence) is also available.
1 and 4 differential channels
0.5 – 100 Hz
Customized gain and bandwidth
mode rejection ratio (CMRR): > 120 dB
1 mV p-p (10 Hz)
+ 25 mV
+8 - +15 VDC
1.5 mm Male Safety jacks
is equipped with a 12-bit, 8-channel analog-to-digital converter. Data sampling is synchronized to the stimulus display’s
frame rate. Thus, samples are taken at the same time points in the stimulus frame interval. The data collection rate can be
set to 1–10 samples /per frame with a maximum sampling rate of 600 Hz per channel.
Users can select a variety of data processing tools for automatic
calculation and display of results immediately following the test. Analyses include the following techniques:
discrete Fourier transform, spectral analysis, digital filtering, peak detection, multi-variate statistics, frequency band
analysis with calculation of magnitude-squared coherence (MSC), outlier removal, T2circ
signal-to-noise calculation and visual acuity estimation.
Frequency components of interest (FCI) are displayed
in both sine-cosine plots or amplitude and phase plots.
In a sine-cosine plot, the means of the FCI (for each
step) in a sweep function and corresponding confidence circles (95% or 90%) calculated using T2circ are
In an amplitude or phase plot, the means derived from the
FCI for each step in a sweep function and corresponding confidence ranges (95% or 90%) are displayed vs. the sweep variable
(e.g., temporal frequency, spatial frequency, luminance contrast).
For a transient response (averaged VEP or PERG signal plotted vs. time), the program will
automatically detect the peaks within six time windows set by the user. Also, users can place two cursors to read the amplitude
and time values of marked points, and they can perform filtering of the response in the frequency domain. The entire waveform is quantified by calculation of magnitude-squared coherence for
each frequency component and for bands of frequency components.
the testing protocols and stimulus conditions are easily set through graphical menus. The configuration parameters are saved
in configuration files. Users can load the pre-configured parameters for the test to be performed.
real-time EEG signals on the user’s screen to monitor the status of electrode connections and the environmental EMF
noise. If excessive noise is present, it indicates that either the electrode is loose or that there is significant EMF noise in the testing room that might affect the test results.
Neucodia uses Microsoft Windows 7 as a software operating system. Data files are in text
format and easy to be exported to Excel or other spreadsheets. Display images can be saved in either bitmap or JPEG format.
Neucodia equips with an infrared camera, source, and display to monitor the observer’s fixation