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iA4 Differential Bioamp

The iA4 is a four channel differential low-noise bioamp targeted for use in low channel count, low impedance neurophysiology recordings such as ABR, EEG, EMG, or EKG signals.

Connections to the subject (up to four pairs of channels and ground) are made with standard 1.5 mm touchproof safety connectors.

  • The iA4 includes impedance testing functionality for each of the four recording channels (+) and indifferent channels (-)

  • Manual impedance check buttons simplify testing and debugging of connected electrodes

  • Onboard LEDs provide live feedback of the recording (+) and indifferent (-) channel impedances

See the Hardware Manual for information on iA4 technical specifications.

iA4 Options

iA4 Interface

Select the number of Channels (differential pairs) to read from the iA4.

There are selectable Sample Rate options of ~750 Hz, ~1.5kHz, ~3 kHz, ~6 kHz, ~12 kHz, ~25 kHz, ~50 kHz or system rate (maximum ~50 kHz). The lowest practical rate improves noise performance.

Note

The iConZ only supports sampling rates up to 6 kHz.

A user-selectable Highpass filter has adjustable options that are: 0.3 Hz, 1 Hz, 2 Hz, 4 Hz, 8 Hz, 16 Hz, 32 Hz, 64 Hz.

The Target Impedance option allows the user to specify the impedance threshold for the runtime indicator for each channel.

Connect a Stream Data Storage gizmo to the iA4 output to visualize and store the signals.

iA4 output link connected to Stream Data Storage gizmo

Runtime Interface

iA4 Runtime Interface

There are Clip indicators on each channel to indicate if the signal is within ~1.5 dB of max input range.

Click the Impedance button to switch the iA4 into impedance checking mode.

iA4 Impedance Check Interface

Users can select a Probe Frequency of 100 Hz, 300 Hz, 500 Hz, or 1 kHz for the impedance check. Take care that you do not choose a frequency that is beyond the Nyquist frequency (~½ the sampling rate defined during designtime).

The (+) and (-) channel impedances are alternately measured every ~110 ms.