Chapter 8: Laser, Light Energy & Frequency Therapy

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.

What term refers to the vaporization, cutting, or removal of a portion of epidermis and/or dermis?

Ablation

What do photons do?

travel at the speed of light in the form of a wave

What term refers to light energy that is "in phase"?

Coherent light

What aspect of a laser determines the type of chromophore with which the light will react?

Color

What is NOT one of the common chromophores in the body?

Lymph

What is NOT one of the four tissue effects of lasers?

Collection

What type of surface poses the greatest potential safety hazard when using lasers?

Flat and smooth

What is the most commonly-reported hazard for those working with laser devices?

Eye injuries

What are lasers usually named in reference to?

Their medium

What term refers to the energy of a pulsed laser beam?

Fluence

Thermal relaxation time is the amount of time necessary for a chromophore to lose ________ percent of the heat produce by the laser.

More then 50

What unit is measurement is used to measure energy fluence in pulsed lasers?

joule

What term refers to the rate of energy being delivered to tissue by a laser light source?

Power density

what body determines who can use a specific type of radiation-emitting electronic device?

State regulatory agency

What term is used to refer to the entire laser apparatus used in a health care facility?

Health care laser system (HCLS)

What statement about the door to the laser room is correct?

It should be close but unlocked whenever the laser is in use

What effect can the lens in the eye have on a laser's energy

Magnify its intensity by as much as 100,000 times

Most laser eyewear has an optical density level of ________ for visible and infrared wavelengths of light.

4 to 8

What statement about operating laser equipment is correct?

You should document all problems with the devices in you service records

What should clients do during laser treatments to help prevent a fire?

Refrain from placing anything between the laser device an area of treatment

What is NOT one of the administrative practices mandated by American National Standards Institute (ANSI)?

Conducting monthly competency skills checks of the laser-trained staff

What happens to cells when they undergo a photothermal tissue reaction?

They are destroyed

What is NOT one of the purposes for which CO2 and Er:YAG laser were traditionally used?

hair removal

What is the average surface coverage per treatment when using a Fraxel laser to treat photo-aging or acne scarring?

20 percent

What is one the main factors to consider when determining whether photomechanical laser therapy is appropriate for a client?

Client's tendency for wound healing

What are Q-switched laser commonly used for?

Treating pigmented lesions

What is a diode laser with a wavelength of 800 nm used for?

Hair removal

What type of laser is commonly used to treat vascular and pigmented lesions?

Pulsed dye

What are Alexandrite Q-switched lasers commonly used for?

Tattoo removal

What is a quality of intense pulse light (IPL)?

Polychromatic

When should double and triple pulses be used when using IPL?

When treating pigmented lesions

What is NOT a method of skin cooling used with IPL?

Submerging the treatment area in water durning treatment

What term refers to a current that flows on a path of least resistance between positive and negative electrodes placed at opposite ends?

Bipolar radiofrequency

What type of LED is using for treating hyperpigmentation?

Green, 525 nm+ 10nm

What is NOT a benefit of LE rejuvenation?

Stimulation of hair follicles