DD,
Valleylab do actually suggest in their manuals that two electrosurgery units (Force FX) have to be used for dual operation - CH1 and CH2 outputs on a single FX unit definitely should not be used on a patient together. The force FX has floating outputs so I guess that, generally speaking, the issues that we have been discussing are not a problem with floating devices. However you would have to refer to manufacturers recommendations.
