Multichannel Systems MPA32I Manual - Manual (Page 9)

FlexMEAs
3
2 Welcome to the MPA32I
The 32-Channel Miniature Preamplifier MPA32I is connected to the microelectrodes for providing
the initial tenfold amplification stage.
It has additional common ground and reference electrode inputs. The reference electrode
is ideally identical to the recording electrodes and placed into a comparable but inactive area or
tissue. Background or noise signals that are picked up by both the reference electrode and the
recording electrodes are removed.
The metal case provides electrical shielding. Electrode damage is prevented by the very
low bias current. The high input impedance ensures stable long-term recordings:
Ideally, the input impedance would be infinite. As low voltages are generally recorded, a high
current would flow if the input impedance were low. As a result, the amplifier would not be able
to deliver the current, and the voltage would break down. The miniature preamplifier has a high
input impedance to avoid this problem.
Adapters for all standard microelectrodes such as NeuroNexus probes (from
www.neuronexustech.com) for acute and chronic implantations ensure a close proximity to the
probe to minimize signal loss and cross talk. Adapters are not included in the standard scope of
delivery and have to be ordered separately. For custom adapters, please ask your local retailer or
contact Multi Channel Systems.