Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Active Electrode: An electrosurgical instrument or accessory that concentrates the electric (therapeutic) current at the surgical site.
Active Electrode Monitoring: A system that continuously conducts stray current from the laparoscopic electrode shaft back to the generator and away from patient tissue. It also monitors the level of stray current and interrupts the power should a dangerous level of leakage occur.
Alternating Current: A flow of electrons that reverses direction at regular intervals.
Bipolar Electrosurgery: Electrosurgery in which current flows between two bipolar electrodes that are positioned around tissue to create a surgical effect (usually desiccation). Current passes from one electrode through the desired tissue to another electrode, thus completing the circuit without entering any other part of the patient’s body.
Bipolar Instrument: Electrosurgical instrument or accessory that incorporates both an active and return electrode pole.
Blend: A waveform that combines features of the cut and coag waveforms; current that cuts with varying degrees of hemostasis.
Capacitive Coupling: The condition that occurs when electrical current is transferred from one conductor (the active electrode) into adjacent conductive materials (tissue, trocars, etc.).
Cautery: The use of heat or caustic substances to destroy tissue or coagulate blood.
Circuit: The path along which electricity flows.
Coagulation: The clotting of blood or destruction of tissue with no cutting effect, electrosurgical fulguration and desiccation.
Contact Quality Monitoring: A system that actively monitors tissue impedance (resistance) at the interface between the patient’s body and the patient return electrode, and interrupts the power if the contact quality and/or quantity is compromised.
Current: The number of electrons moving past a given point per second, measured in amperes.
Current Density: The amount of current flow per unit of surface area; current concentration directly proportional to the amount of heat generated.
Current Division: Electrical current leaving the intended electrosurgical circuit and following an alternate path ground; typically the cause of alternate site burns when using a grounded generator.
Cut: A low-voltage, continuous waveform optimized for electrosurgical cutting.
Cutting: Use of the cut waveform to achieve an electrosurgical effect that results from high-current density in the tissue causing cellular fluid to burst into steam and disrupt the structure. Voltage is low and current flow is high.
Desiccation: The electrosurgical effect of tissue dehydration and protein denaturation caused by direct contact between the electrosurgical electrode and tissue. Lower current density/concentration than cutting.
Diathermy: The heating of body tissue generated by resistance to the flow of high-frequency electric current.
Direct Coupling: The condition that occurs when one electrical conductor (the active electrode) comes into direct contact with another secondary conductor (scopes, graspers). Electrical current will flow from the first conductor into the secondary one and energize it.
Direct Current: A flow of electrons in only one direction.
Electrosurgery: The passage of high-frequency electrical current through tissue to create a desired clinical effect.
ESU: ElectroSurgical Unit.
Frequency: The rate at which a cycle repeats itself. In electrosurgery, the number of cycles per second that current alternates.
Fulguration: Using electrical arcs (sparks) to coagulate tissue. The sparks jump from the electrode across an air gap to the tissue.
Generator: The machine that coverts low-frequency alternating current to high-frequency electrosurgical current.
Ground, Earth Ground: The universal conductor and common return point for electric circuits.
Grounded Output: The output on a electrosurgical generator referenced to ground.
Hertz: The unit of measurement for frequency, equal to one cycle per second.
Impedance: Resistance to the flow of alternating current, including simple direct current resistance and the resistance produced by capacitance or inductance.
Insulation Failure: The condition that occurs when the insulation barrier around an electrical conductor is breached. As a result, current will travel outside the intended circuit.
Isolated Output: The output of an electrosurgical generator that is not referenced to earth ground.
Leakage Current: Current that flows along an undesired path, usually to ground. In isolated electrosurgery, RF current that regains its ground reference.
Monopolar Electrosurgery: A surgical procedure in which only the active electrode is in the surgical wound; electrosurgery that directs current through the patient’s body and requires the use of a patient return electrode.
Monopolar Output: A grounded or isolated output on an electrosurgical generator that directs current through the patient to a patient return electrode.
Ohm: The unit of measurement of electrical resistance.
Pad: A patient return electrode.
Patient Return Electrode: A conductive plate or pad (dispersive electrode) that recovers the therapeutic current from the patient during electrosurgery, disperses it over a wide surface area and returns it to the electrosurgical generator.
Power: The amount of heat energy produced per second, measured in watts.
Radio Frequency: Frequencies above 100 kHz; the high-frequency current used in electrosurgery.
Resistance: The lack of conductivity or the opposition to the flow of electric current, measured in ohms.
RF: Radio frequency.
Tissue Response Technology: An electrosurgical generator technology that continuously measures the impedance/resistance of the tissue in contact with the electrode and automatically adjusts the output accordingly to achieve a consistent tissue effect.
Tissue Fusion Technology: An electrosurgical technology that combines a modified form of electrosurgery with a regulated optimal pressure delivery by instruments to fuse vessel walls and create a permanent seal.
Volt: The unit of measurement for voltage.
Voltage: The force that pushes electric current through resistance; electromotive force or potential difference expressed in volts.
Watt: The unit of measurement for power.
Waveform: A graphic depiction of electrical activity that can show how voltage varies over time.