Copyright June, 2007 by BC Group International, Inc.
Author: Michael R. Erwine
6
Revision 1 – June 13, 2007
generator’s microprocessor and actually adjusts the power level output of the generator in order to provide
relatively constant power delivery (and thus a consistent surgical effect) at the surgical site, regardless of tissue
impedance.
Electrosurgery generator improvements continue, with new introductions by leading manufacturers like Tyco
Healthcare / Valleylab, Conmed (Electrosurgery Division), Erbe, Bovie, etc. on a regular basis The need for
routine testing and performance verification of these generators has not deceased due to these introductions of
new technologies. In fact, there are more features and safeguards to test for proper operation on today’s average
electrosurgical generator than ever.
Some Common Electrosurgery Terminology
Active Electrode:
an electrosurgical instrument or accessory that concentrates the high frequency current at the
surgical site, thus enabling the heating effect at the site and producing the desired electrosurgical effect
Blend:
an electrosurgical generator output waveform that combines the features of cut and coag waveforms,
cutting with various degrees of hemostasis (coagulation)
Contact Quality Monitor (CQM):
a system that constantly monitors the impedance of the physical connection
between the patient’s body and the patient return electrode and interrupts power form the electrosurgical
generator is the quality of this connection is compromised electrically
Current Density:
the amount of electrical current flow per unit of surface area – as current density increases so
does the heating of the tissue in the immediate location
Current Division:
high frequency electrical current leaving the intended electrosurgical patient circuit and
following an alternate low impedance path of lesser resistance to earth ground, this introducing the possibility of
high frequency burns at the alternate earth ground contact point – typically a concern in ground-reference
generators and not isolated output generators.
Coagulation:
the clotting of blood or destruction of tissue with no cutting effect – electrosurgical fulguration and
desiccation.
Cut Mode:
electrosurgical mode that produces a low voltage continuous waveform optimized for tissue cutting
Desiccation:
the effect of tissue dehydration and protein denaturation caused by direct contact between the
electrosurgical “active electrode” and the tissue
Fulguration:
using electrical arcs (sparks) to coagulate tissue, whereby the sparks jump from the electrosurgical
“active electrode” across an air gap to the tissue
Ground-Referenced Output:
an electrosurgical generator with an output that is electrically referenced to earth
ground
Isolated Output:
an electrosurgical generator with an output that is not electrically referenced to earth ground
Leakage Current:
electrical current that flows along an undesired pathway, usually to earth ground – in an
electrosurgical generator, RF leakage current is high frequency current that regains its ground reference and
seeks earth ground.
Patient Return Electrode
: an electrically conductive plate or pad (also known as the dispersive electrode) that
recovers the high frequency current introduced into the patient’s body by the “active electrode” during
electrosurgery. This electrode minimizes the current density of this return current flow in order to minimize the
possibility of high frequency burns at this electrode site.
Radio Frequency (RF):
frequencies above 100 kHz that transmit radio signals – the high frequency current
utilized in electrosurgery
Tissue Response Technology:
the Tyco Healthcare / Valleylab electrosurgical generator technology that
continuously measures the impedance/resistance of the tissue in contact with the patient return electrode and
automatically adjusts the output of the generator accordingly to achieve a consistent tissue effect.
