Stimulation trough MEA1060-Inv-BC

Hi,

We used ST1004 to generate stimuli, which went through our MEA1060-Inv-BC to chips. One thing I concerned is: if the electrodes used for stimulating are bad or very high impedance, how large stimuli does the MEA1060-Inv-BC allow to go through the circuitry? (the ST1004 can generate constant current /-0.8 mA@ 100V). I just used 100uA/100us biphasic current, but kind of worried about as high as 100V would be generated to the chip.
Could you help me to figure out what it's gonna happen?

Thanks a lot!
Neu

Dear Neurozy

On page 30 of the current version of the MEA1060-INV-BC User Manual, you will find the information that the input voltage of the MEA1060-BC amplifier is limited to +/– 5 V.

http://www.mcs-download.com/download_data/manuals/MEA1060-Inv-BC_Manual.pdf

A new 30 µm TiN electrode has an impedance of about 30 kilohm. With a 100 µA pulse, you would still be in the range, i. e. 3 V.

But as you say, the electrode impedance can go up during use, resulting in a higher impedance and therefore higher voltage. Therefore, we recommend to use only voltage-driven stimulation. Customer's feedback and recent publication also showed that voltage-driven stimulation is more "controlled" and safer for the electrodes and the preparation.

However, the electronics are safe if the current is low, but you will see large artifacts if the maximum input voltage is exceeded.

Best regards, Christine (MCS)