Chapter 8: Laser, Light Energy, and Radiofrequency Therapy

Ablation

The removal of surface material from the body. This device vaporizes, cuts, or removes all or part of the epidermis and or dermis.

Ablative

The ability to cut, vaporize, or remove using a laser.

Absorption

The uptake of one substance into another. In laser/light therapy, the attraction of energy particles, liquid, or gas to a particular chromophore or target in the skin.

Attenuation

The act of removing light energy from a beam before it exits a second medium; A method of blocking laser energy.

Bipolar Radiofrequency Energy

A current that flows on a path of least resistance between positive and negative electrodes that are placed at opposite ends of the treatment forceps or device head. No dispersive electrode is needed.

Chromophore

The colored cells or target in the epidermis or dermis that absorbs the laser beam's thermal energy, causing the desired injury or destruction of the material.

Coherent Light

Parallel rays of light that travel spatially and temporally in phase with each other.

Cryogen

A liquified gas that is cooled to -238 degrees F

Dispersing Electrode

A "grounding pad" placed on the individual's thigh or an area of large tissue mass that receives the radiofrequency energy.

Fluence

Irradiance multiplied by the exposure time, measured in joules per square centimeter (J/cm2)

Infrared

Electromagnetic radiation found in the invisible spectrum of light.

Intense Pulsed Light

A polychromatic, noncoherent, dispersive band of light commonly used wavelengths from 500 to 1,200 nm; A common photoepilation hair reduction method.

Irradiance

See power density.

Joules

Units of energy or work. In thermodynamics, joules are defined as a unit of heat energy used to measure the energy change in an object as it warms or cools from temperature T, to temperature T2.

Laser-Generated Air Contaminants

Plume or smoke that is generated from an ablative laser device.

Laser Safety Officer

The person responsible for the laser safety program at the facility. This person is authorized to monitor operation, enforce controls, and oversee hazards associated with laser usage.

Light-Emitting Diode

A device made up of panels of tiny diodes that are pulsed in an exclusive array sequence to trigger a photobiochemical response.

Lipolysis

The splitting up or destruction of fat cells.

Maser

Microwave amplification by stimulated emission of radiation.

Maximum Permissible Exposure

The level of laser to which a person may be exposed without hazardous ocular or tissue effects.

MIcrothermal Zone

A column of tissue that is heated by a fractional laser device.

Modulate

To stimulate or change cellular function.

Monochromatic

Describes light consisting of one wavelength that is typically found emitted from a laser system.

Monopolar Radiofrequency Energy

Radiofrequency electrical current that uses a dispersive electrode to return the energy back to the generator device.

Nevus of Ota

A deep dermal pigmented lesion usually found on the face in populations of darker-skinned asians.

Nominal Hazard Zone

The zone in which direct, reflected, or scattered radiation, during normal operation, exceeds the maximum permissible exposure.

Optical Density

The amount of attenuation or reduction of radiant laser energy as it passes through the filter material in the laser eyewear.

Optical Resonator

A cavity containing a laser rod or tube made up of two reflective mirrors at each end. The mirrors reflect light back and forth to build up amplification of the laser light under external stimulus.

Oxyhemoglobin

Hemoglobin in red blood cells that has been oxygenated; A protein in red blood cells.

Photomodulation

LED technology that uses energy-producing packets of light to enhance fibroblast collagen synthesis.

Photons

In quantum theory, the elemental unit of light; A particle of energy that has motion and travels in waves.

Power Density

The rate of energy that is being delivered to tissue by a laser light source. Measured in watts per square centimeter.

Pulse Duration (Pulse Width)

The duration of an individual pulse of laser light; Usually measured in milliseconds.

Scatter

A general physical process involving moving particles that are dispersed through a medium in a nonuniform manner.

Selective Photothermolysis

Treatment using an appropriate wavelength, exposure time, and pulse duration with sufficient energy fluence to absorb light into a specific area; It allows damage to targeted tissue without involving the surrounding area.

Spot Size

The diameter of the optical or laser light beam.

Thermal Relaxation Time

The time it takes for the target tissue to dissipate one-half of the heat attained by a laser pulse.