iAn BioAmp
iA4 Differential BioAmp
iA4 Overview
The iA4 is a four-channel differential bioamp targeted for use in low-channel-count, low-impedance neurophysiology recordings such as ABR, EEG, EMG, or EKG signals. The bioamp digitizes up to four channels at acquisition rates of approximately ~750 Hz, ~1.5 kHz, ~3 kHz, ~6 kHz, ~12 kHz, ~25 kHz, or ~50 kHz. The amplified digital signal is sent through the iCon or iConZ interface.
Connections to the subject (up to four differential pairs and ground) are made with standard 1.5 mm touchproof safety connectors.
- Manual impedance check buttons simplify testing and debugging of connected electrodes
- Onboard LEDs provide live feedback of the recording (+) and indifferent (-) channel impedances and activity
iA4 Features
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). Using the lowest practical rate for your application improves noise performance.
A user-selectable on-board highpass filter has adjustable options of 0.3 Hz, 1 Hz, 2 Hz, 4 Hz, 8 Hz, 16 Hz, 32 Hz, or 64 Hz.
For information on software control of the iA4 and all of its available features, see the Synapse Manual.
iA4 Clip Warnings and Activity Display
The status LEDs above each channel on the iA4 indicate channel activity and clip warning. LEDs for each channel are lit green to indicate an active channel and/or red to indicate a clip warning.
Clip Warning
Analog clipping occurs when the input signal is too large. When the input to a channel is within ~1.5 dB of the iA4's maximum voltage input range the LED for the corresponding channel is lit red to indicate that clipping may occur. This is ~±10.6 mV.
Activity
The activity LED is lit green whenever the channel is enabled.
iA4 Electrode Connectors
Plug the electrodes directly into the standard 1.5 mm touchproof connectors on the front of the iA4.
iA4 Impedance Checking
The Impedance checker on the iA4 provides a simple check of the channel impedance relative to ground. The impedance check can either be controlled in Synapse software, or by pressing the Imp button on the front panel. The impedance between channel and ground will be shown on the LED indicators.
When controlling impedance check from Synapse, the available frequencies are 100 Hz, 300 Hz, 500 Hz, or 1 kHz. A 100 Hz probe frequency is used when manually pressing the Imp button on the front panel of the iA4.
The impedance check alternates between the (+) and (-) channel inputs every ~110 ms and displays the (+) input impedance on the top row of LEDs on the front of the device (red K-Ohms LED row) and the (-) input impedance in the bottom row (green K-Ohms LEDs).
When testing through Synapse software, all active channels are tested simultanously and the highest (+) and (-) impedance of all channels is shown in the K-Ohms LED top and bottom rows respectively.
iA4 Technical Specifications
iA16 / iA32 BioAmp
iA16 / iA32 Overview
The iA16 / iA32 is a 16- or 32-channel bioamp with a single reference connection, targeted high-impedance neurophysiology recordings such as extracellular potentials. The bioamp digitizes up to 32 channels at acquisition rates of approximately ~750 Hz, ~1.5 kHz, ~3 kHz, ~6 kHz, ~12 kHz, ~25 kHz, or ~50 kHz. The amplified digital signal is sent through the iCon or iConZ interface.
Connections to the subject are made through mini DB26 connectors to standard headstages or splitter boxes.
- Onboard LEDs provide live feedback of the recording channel activity and impedances
iA16 / iA32 Features
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). Using the lowest practical rate for your application improves noise performance.
A user-selectable on-board highpass filter has adjustable options of 0.3 Hz, 1 Hz, 2 Hz, 4 Hz, 8 Hz, 16 Hz, 32 Hz, or 64 Hz. It can also be disabled for DC Coupled recording.
For information on software control of the iA16 / iA32 and all of its available features, see the Synapse Manual.
iA16 / iA32 Activity Display
The channel LEDs are dim green when enabled. At ~25 kHz sampling rate and above, the channel indicators flash greeen when there is spike activity.
iA16 / iA32 Electrode Connectors
Plug a headstage into the DB26 connector(s) on the front of the iA16 / iA32.
iA16 / iA32 Impedance Checking
The Impedance checker on the iA16 / iA32 provides a simple check of the channel impedance relative to ground. The impedance check can either be controlled in Synapse software, or by pressing the Imp button on the front panel. The impedance between channel and ground will be shown on the LED indicators.
When controlling impedance check from Synapse, the available frequencies are 100 Hz, 300 Hz, 500 Hz, or 1 kHz. A 100 Hz probe frequency is used when manually pressing the Imp button on the front panel of the iA4.
The impedance check alternates between the recording channels and reference channel every ~250 ms and displays the channel input impedances on the front panel LEDs.
iA16 / iA32 Technical Specifications
Analog Inputs
^Note: If recording at ~50 kHz on an iA32, only 16 channels are available.
Input Connectors
The iA32 has two 26-pin headstage connectors (analog) on the front of the unit. The connectors are labeled alphabetically from top to bottom. Each connector carries signal for one bank of channels with ground and reference. The corresponding channel numbers depend on the reference mode configuration.
For simplicity sake, the diagrams below assume channels for that connector begin with channel 1. For example, A1 - A16 represent the 16 channels coming from the connected headstage. The user must increment the channel numbers by 16 (or 8 if in Differential mode) according to the mode and position of the connector. So, for the connector labeled 'A', A1 is channel 1 while on the connector labeled 'B', A1 may be channel 17.
Pinout Diagrams
Shared Reference Mode
* Pin 5 on both DB26 connectors on the iA32 are shorted together internally.
Differential Reference Mode
Note
There are 8 (+) channels and 8 (-) channels per DB26 connector. Subsequent banks are indexed by an additional 8 channels.
Note
See Tech Note 0896 before attempting to make any custom connections.
iAn Sample Delay
Depends on iAn and RZ processor sample rates. All units in samples.