Electricity in the Surgical Environment

Vocabulary terms based on the STT11 lecture regarding basic principles of electricity, circuits, and electrosurgery (ESU) in the operating room environment.

Electricity

A form of energy that is the product of stationary or moving electrons and protons, described as the flow of one electron to another.

Matter

Anything that has mass and occupies space, existing in states such as solid or liquid.

Atoms

The building blocks of all matter, composed of protons, neutrons, and electrons.

Nucleus

The center of an atom.

Protons

Particles within an atom that possess a positive charge.

Neutrons

Particles within an atom that possess a neutral charge.

Electrons

Particles within an atom that possess a negative charge.

Electron flow

The process of electrons transferring from one atom to another.

Electron Theory

The principles that govern the behavior of electrons, serving as the basis for the design of all electrical equipment.

Shells (or Orbit)

The paths around the nucleus in which electrons revolve.

Free electrons

Outer electrons not attached to an atom that create an electric current when they move.

Conductors

Materials through which electrons flow easily, such as silver, zinc, copper, or saltwater.

Copper

The most commonly used conductor in electrical systems.

Insulators

Materials that inhibit the flow of electrons and are poor conductors, such as rubber, plastic, or wood.

Magnetic field

The region around a magnet where magnetic forces are active.

Electromagnetism

A phenomenon that occurs when an electric current flowing through a wire generates a magnetic field.

Electrical Circuit

The path electricity travels from its energy source to a device and then back to the energy source.

Load

A component in a circuit that transforms electrical energy into a useful function and acts as the limit for what the circuit can handle without overheating.

Switch

A device used to open or close a circuit to control the flow of electricity.

Ampere (Amps)

The unit used to measure electrical current.

Voltage (Volt)

The unit that measures electrical pressure applied to force electrons through a circuit; OR circuits are supplied with $220\,Volts$.

Wattage (Watts)

The measurement of electrical power, calculated by combining volts and amps.

Power

The rate at which work is done, measured in watts.

Ground (Third Prong)

The prong on a plug that captures excess or leakage current to reduce the risk of electrical shock to the surgical team and patient.

Direct Current (DC)

Electrical current that flows in only one direction, from a negative pole to a positive pole, such as in batteries.

Alternating Current (AC)

Electrical current that flows in two directions and reverses its course periodically.

Frequency

The number of AC cycles per second; the most common power used in the United States is $60$ cycle AC.

Isolated Power Systems (Red Light)

An indicator on the OR wall panel signaling that the last piece of equipment plugged in may have a short or overloaded the system and should be unplugged.

Electrosurgery

The clinical use of high-frequency electrical current.

Generator

The ESU component that provides the source of electrical current to the active electrode.

Patient Return Electrode

Also known as a dispersive electrode or grounding pad, it must be properly placed to avoid electrical burns to the patient.

Active Electrode

Also called an electrosurgical pencil or Bovie pencil, it delivers the current to the surgical site.

Monopolar Electrosurgery

The most commonly used mode for coagulation and cutting in large surgical areas, requiring a generator, active electrode, and grounding pad.

Bipolar Electrosurgery

A mode used for coagulation ONLY in delicate procedures to prevent damage to tissue and nerves, activated via a foot pedal.

Surgical Plume

A vaporized tissue smoke created during electrosurgical procedures.