Re: Electrosurgical Testing - Is there a specific standard for Electrosurgical Testin
There are some of particular standards that specify testing for immunity against electrosurgical units (ESUs).
An example is IEC 60601-2-27:2005 (ECG, monitoring), Clause 36.202.101. That standard specifies a 300W cut and 100W coag mode (both with 400kHz +/- 10% fundamentals).
A critical point is that they specify that an arc is drawn between the active electrode and a metal block which simulates real world (ESU are typically used in this way, with an arc).
It is the high frequency content of the arc (well above 400kHz) that is likely to cause the most disturbance. It is a bit unpredictable, which is why the standard requires to repeat the test 5 times cut mode + 5 times in the coag mode.
The ESU should be tested with a special high power non-inductive test load (e.g. 200-500 ohms, 300W thick film resistors), since just shorting the electrodes will probably trigger the ESUs short circuit protection so that nothing is coming out.
And finally you need to simulate electrical connection between the ESU and your infusion device (assuming we are talking here about ESU operation on the same patient that is being infused), and the return path. Note that this is not expected to be a radiated issue, but rather conducted problem through the fluid circuit. IEC 60601-2-27 includes a circuit for this appropriate for ECGs, and this could be adapted for an infusion circuit. I would go for saline fluid with the minimum length of tubing, with the patient simulated by an electrode in the fluid at the end of the tubing. This electrode would connect to one pole of the ESU test load. IEC 60601-2-27 then specifies a 47nF capacitor (should be a HV type) which should also connected between the other pole and earth. I cannot see any reason why you would not use the same value.
Having written all the above, it also seems clear that this might be difficult to set up without some hands on experience with ESUs. On the other hand, better to do it properly, especially if you are going to claim ESU immunity as part of your intended purpose or advertising material.