Capacitive Coupling During Endoscopy
Metal Cannula System
A capacitor is not a part labeled “capacitor” in an electrical device. It occurs whenever a nonconductor separates two conductors.
During MIS procedures, an “inadvertent capacitor” may be created by the surgical instruments. The conductive active electrode is surrounded by nonconductive insulation. This, in turn, is surrounded by a conductive metal cannula.
A capacitor creates an electrostatic field between the two conductors and, as a result, a current in one conductor can, through the electrostatic field, induce a current in the second conductor.
In the case of the “inadvertent capacitor” in an MIS procedure, a capacitor may be created by the surgical instruments’ composition and placement.