Choosing a Stimulator for Delivering 5-60 Hz, 1-2 mA AC to Animal Endocardium

Good morning,
I am conducing an experiment in which it is required to deliver, in order to produce a specific cardiac arrhythmia, 5à-60 Hz, 1-2 mA AC to the endocardium of the tested animal. Since it is a new model in our laboratory, we do not have any stimulator and I need to understand which kind of machine we need. I am totally incompetent (Intensive care physician) but I can only find small signal generators where i can decide the wave geometry, the frequency and the Vpp... so the question is: how can i replicate this apparently extremely easy task of delivering the specific amount of current i want?? which kind of device should I go for (no specific brand or model needed of course)?


Thank u in advance
have you all a good day!

I provide this information on the understanding that the work if necessary is ethically approved.Function generators are normally voltage output, and typically have a 50 Ohm output resistance, although some cheaper instruments may be higher. In theory you could put a resistor in series with output, which would provide a pseudo current source, but it is highly dependent on the load resistance, in other words the resistance of the endocardium. Assuming that the value is low, less than a few K Ohms,  then the series resistor should work provided the signal generator can supply the voltage. However, that assumes a   static with current  resistance model for the endocardium. You would have to monitor the voltage across the series resistance to verify its behavior and to monitor the current. There may be research papers you can look for through google scholar to check that out.Failing that, then you need a voltage to current converter on the output of the signal generator. These are quite simple to make if you only need a unipolar signal, more complex if bi-polar. These should have a very high output resistance, and are therefore insensitive to any variation of the low load impedance.If you are doing the work in a University environment, then they may have an electrical engineering school that could point you in the right direction.An arbitrary function generators allow specific user generated signals to be downloaded and played back, which may be of some use to you if you need  a waveform that isn't normally supplied by the instrument.Cheers,Richard

HiFollowing on from Richard's sound advice I must also advise that depending on your country, then you may be subject to very, very strict government controls regarding your intent. Failure to obtain the required licenses will result in detainment, and they are not given out lightly nor are they cheap.In EU the licenses can be in the tens of thousands and can only be conducted by government approved laboratories.Regards

Hello Mr. Annoni!50-60 Hz  1-2mA sounds reasonable for an arbitrary gen. Common test bench function generators can drive a max of 10mA output current so amplifiers shouldn't be a biggie/necessity, unless you're opting for a voltage that exceeds 10-20V+
Hope this helps in some way.Justin

It will be difficult to implement. The state is under great control. In addition, paperwork is a long process and not cheap.