STG2004 and Powerlab

Hi,

I am using the STG2004 for electrical stimulaton (current mode). What I now would like to do is, control the STG2004 via AD Instruments Powerlab. From their homepage I learned that they seem to have some kind of support for the STG4004 series - so I hope that this would also be doable for the STG2004.

Basically: I would like to have an externl trigger impuls that comes from an MRI machine (e.g. TTL puls), after e.g. 100 Pulses I would like that the STG2004 produces its output signal (stimulus e.g. 1 mA, 6 Hz) for a time till my input trigger signal (from the MRI machine) arrives e.g. at 120. Then the STG2004 should stop the stimulation and may be at MRI trigger 200 till 220 do the same stimulation again.

I am now wondering if such a pattern could be done via the MC stimulus software, or if the STG2004 can be controlled via ADI Powerlab for such a stimulation pattern. AD offers also a kind of own stimulus generator control (e.g. stimulus frequency, amplituded etc.) but I guess the STG4004 support only is meant for a trigger signal. Does anyone successfully use an STG stimulus generator in concert with Powerlab? May be it can be operated in streaming mode and then fully controlled via the Powerlab stimulus generator modul (in Lab Chart)?

Any comments are welcome.

Thanks in advance

Hans

Dear Hans,
if your MRI can produce TTL pulses, would it not be easier jut to have a specific TTL to control the STG? You could use a TTL as gate for the STG, so as long as the TTL is on, the STG would produce the stimulus, and stop when the TTL is off. As for the Powerlab interface, the STG can be controlled via dot.NET DLLs. So if Powerlab can handle that, you can use it.

Regards Frank MCS

Hi Frank,

thank you very much for your answer. Well I considered triggering the STG2004 directly from the MRI, however the TTL signal is produced during the entire MR imaging time, i.e. every image obtained produces one TTL puls. However I would like to have the stimulation on only during certain images, e.g. image #100 to 120 are stimulated and the others are without stimulus.

I probably have to consider something like labview or give powerlab a try. However it would have been great if the MC stimulus software would have some kind of simple counter for the trigger signal implemented, e.g. count the TTL pulses and let the user specifiy from which to which TTL puls the STG should stimulate - I guess that would also help a lot of people that want to apply the STG for MRI stimulation studies.

Best,

Hans

Hi Hans,
if the pictures of the MRI are taken at a certain frequency, you can synchronize the STG timewise. Start the STG on the first trigger, in the advanced trigger options, choose "ignore", so every other trigger while the STG is active will be ignored. Start the stimulation pattern with a flat line, until 100 pictures are taken. Then program your pulse for the next 20 pictures. This will not be perfect, as there might be a little time shift, but better then nothing. Or maybe you can go the other way, and let the STG be the master. If the MRI can also accept TTL pulses, you could program the STG and use one of the SyncOuts to control the data acquisition of the MRI.

Regards Frank MCS