Multichannel Systems Cardio2D Manual - Manual (Page 39)

Cardio 2D Software
35
When using the blanking feature, please enable the "Sync Out" check box. You have to define
the time of "Extension". The TTL pulse for the blanking signal starts synchronal to the stimulus
pulse, but it should last longer to avoid stimulus artefacts. This time interval is called extension
time. The extension time varies between 0 and 1000 μs, the default is 300 μs.
In some cases it may be necessary to see the stimulus artefacts. Please deselect the check box
"Sync Out" to switch off the Sync Out signal. Additional please select blanking feature in the
MEA_Select program, please see chapter “MEA_Select”.
Click the Start icon .
If your experimental schedule will always need the same pulse paradigm, please store the settings
in "File" menu "Save Defaults". This way the settings appear in a new file, and you do not have to
type in them again.
Stimulus Generator STG
It is recommended to use a stimulus generator STG of the 2000 or 4000 series from Multi Channel
Systems MCS GmbH.
Important: When working, for example, with four amplifiers with blanking circuit BC, you have
to connect a STG4004 or a STG2004. The TTL blanking signal and the stimulation pulse must be
synchronized, that is, you have to connect the stimulus pulse of channel 1 on MEA amplifier 1 to
the TTL blanking pulse of Sync Out 1 of the STG, channel 2 to Sync Out 2, channel 3 to Sync Out 3
and channel 4 to Sync Out 4 respectively.
When using an USB-ME256 device for data acquisition you can connect up to four MEA amplifiers.
You define the stimulation settings for each of the connected MEA amplifier independent from
each other, and you can start and stop the stimulation independent from each other.
Amplifier without Blanking Circuit BC
The stimulation electrode is manual selected directly on the amplifier via connector pins around
the MEA. You will see the answer of the stimulation during data recording because of the
stimulus artefacts, and the spreading of the field potential. It does not matter whether the
"Sync Out" check box in the stimulation dialog is selected or not, it will have no effect.
Amplifier with Blanking Circuit BC
The blanking feature is used to reduce stimulus artefacts in MEA recordings. A TTL pulse, the
blanking signal, that has to be timed exactly with the stimulus pulse triggers both, the stimulation
and the blanking. During the blanking signal, both stimulus inputs are connected to the software
selected stimulation electrode(s), while all recording electrodes are disconnected from the
amplifier. The last signal value on all electrode channels before the blanking pulse will be saved
and then kept until the channels are reconnected to the amplifier. This avoids that the amplifier
gets saturated on all channels during stimulation (which is the case with amplifiers without
blanking circuit).