|
|
 |
|
|
|
Sensorium EPA-6
The EPA-6 EEG/ERP is an analog differential input 64 channel electro-physiology amplifier designed to measure EEG/ERP, field potentials, and single units. The at a glance electrode resistance measurement system vastly reduces subject preparation time. Typically with this system, the prep time for 128 channels is less that 25 minutes. With this new technology more time will be spent recording and less in the prep room.
High electrode resistance no longer compromises measurement accuracy with the 1 Gohm input resistance.
Features:
- high pass corner frequencies are guaranteed to +/- 2%, and the low
pass filter to +/- 0.2 dB
- choice of 8th order low pass filters, linear phase, Bessel,
or Butterworth
- a new high pass filter design which enables the DC high input
impedance buffers to operate is higher than traditional gains
- five high pass and five low pass filter settings
- a flexible decade and unit gain arrangement
- very low powered integrated circuits - greater very low
frequency stability
- optical isolation with gain accuracy of 0.01% over the bandwidth
- a 64 channel enclosure - expandable in increments of 16 channels
- enclosures operate in parallel without worry of ground
electrode polarization
For those interested in mapping, calculating current densities, and localizing sources, the EPA-6 high and low pass filters have been refined to minimize phase and amplitude distortion. The high pass corner frequencies are guaranteed to + to - 2%, and the low pass filter to +/- 0.2 dB. For those primarily interested in ERP measurement the 8th order linear phase Bessel filter is optimal. By changing a jumper on the board, the amplitude conserved 8th order Butterworth filter would be the choice for studies of energy distributions resulting from EEG measurements.
 |
Features
|
 |
 |
|
Feature
|
Benefit
|
|
Ensemble electrode resistance measurement
|
Short electrode preparation time
|
|
Amplifier parameters digitally controlled
including gain, and filters
|
Computer control offers added flexiblity
|
|
System Gain to 100,000
|
Good for cortex and brain stem studies
|
|
Bandwidth 0.01 to 3K hertz
|
Record from electrodes and transducers
|
|
Independent gain and filter settings for each channel
|
Easily adapted to new experimental paradigms
|
|
Multi-mode input box
|
Access to + and - inputs, and grounding of unused channels
|
|
Sine wave calibration source
|
No external function generator necessary
|
|
64 channel analog multiplexer (option)
|
Use a low cost high speed ADC board
|
|
Systems operate in parallel
|
Expansions in increments of 16 channels
|
|
Surface mount construction
|
Enhanced performance and reliability
|
|
Powered by the mains
|
No batteries to recharge
|
|
AC power supply separated from DC electronics
|
No AC radiator close to recording site
|
|
 |
 |
 |
 |
|
Circuit Design
|
|
|
|
Feature
|
Benefit
|
|
High Input impedance
|
Less error from electrode impedances drift and mismatch
|
|
High CMRR
|
High immunity to environmental noise
|
|
Bi or mono polar
|
Record with or without reference
|
|
8th order low pass filter
|
Effective filtering of high frequencies, excellent anti-alias filter
|
|
Elliptic line filter option
|
Very narrow attenuation band
|
|
Servo high pass filter
|
Wider range of offset potentials, wider dynamic range
|
|
High pass corner frequency accurate to +/- 1.8%
|
Excellent channel to channel phase characteristics
|
|
Very low noise
|
Very high signal to noise ratio recordings
|
|
Digital opto-coupling of control lines
|
Eliminates ground loops and isolates the recording subject
|
|
|
|
|
|
|
Design Safety
|
|
|
|
Feature
|
Benefit
|
|
Optical isolation
|
Protects from off ground currents and loops
|
|
Input protection
|
Protects from high voltage assaults and ESD
|
|
Magnetic isolation
|
Protects from line source ground fault
|
|
|
|
|
|
|
Specifications
|
|
|
|
Input impedance:
|
1G-ohm, differential
|
|
Common mode:
|
>110 dB, 1st stage100X
|
|
Rejection ratio:
|
>100 dB, 1st stage 10X
|
|
High pass filter:
|
12 dB/octave
|
|
Low pass filter:
|
8th order Bessel, Butterworth, Elliptic
|
|
Attenuation:
|
40 db (optional)
|
|
Gain accuracy:
|
<0.6% of selected value
|
|
Noise:
|
<0.2 µV p-p 0.1-10 Hz
<1.5 µV p-p 0.01-55 Hz
<3.5µV p-p 1 Hz - 3 KHz
(referred to input)
|
|
Bandwidth:
|
DC - 3 KHz
|
|
Isolation:
|
3750 Vrms, 60Hz, continuous
|
|
Output Voltage:
|
+ to - 5 Volts
|
|
|
|
|
|
|
Dimensions
|
|
|
|
Amplifier
|
Power unit
|
| Width |
11.5" |
9" |
| Height |
4.75" |
5" |
| Depth |
12" |
12" |
| Weight |
3 lb |
9 lb |
|
|
|
|
|
|
|
|
|
|
|
|
