Thanks for the link, Geoff!
The discussion mainly talks about 2 ESU using simultaneously in the situation of Cardiac case where the two site are quite a distance away.
I am wondering if any recommendation for site close by such as breast and groin area?
I remember seeing IEC 60601-2-2 says to limit the maximum power of 400W going in the patient in one of the older edition but could not seems to find one now.