CH 16 Lasers and Light: Chapter Review and Vocab Flashcards
What is composed of electrical and magnetic fields that vary over time and are oriented perpendicular to each other?
Electromagnetic radiation
What types of frequencies of electromagnetic radiation have clinical therapeutic applications?
- Shortwave
- Microwave
- IR
- Visible light
- UV radiation
What type of light has unique features of being monochromatic (one frequency), coherent, and directional?
Laser light
What type of light has a range of frequencies, noncoherent, and spreads?
LEDs and SLDs
What type of light may be used as physical agents in rehabilitation?
Low-intensity laser or noncoherent light
How do lasers and light affect cells?
via their interaction with intracellular chromophores leading to a range of cellular effects (increased ATP and RNA synsthesis)
What does the cellular effects (increased ATP and RNA synthesis) from laser and lights affect?
- Promote tissue healing
- Reduce pain
- Improve function in patients with a range of conditions (arthritis, neuropathy, and lymphedema)
Name the contraindications to the use of lasers
- Direct irradiation of the eyes
- Malignancy
- Within 4-6 months after radiation therapy
- Hemorrhaging regions
- Application to endocrine glands
Name the precautions of the use of lasers.
- Application to low back or abdomen during pregnancy
- Epiphyseal plates in children
- Impaired sensation or mentation
- Photophobia
- Abnormally high sensitivity to light
- Pretreatment with one or more photosensitizers
What should the clinician first consider when selecting a device?
Whether light therapy will be effective for the patient’s condition
What are the parameters the clinician should set after determining the type of diode (laser, LED, or SLD)?
Wavelength
Power
Energy density
What is considered to be a range of wavelengths within the electromagnetic spectrum (i.e. the band for UVA radiation is 320-400 nm)?
Band (frequency band)
What is considered parts of a molecule that gives it color by absorbing certain wavelengths and reflecting others?
Chromophores
What is considered a light therapy applicator with multiple diodes that may consist of any combination of laser diodes, light-emitting diodes, or supraluminous diodes?
Cluster probe
What allows for coverage of a larger treatment area, takes advantage of the properties of different types of diodes, and may reduce treatment time?
Use of multiple diodes
What is considered light in which all waves are in phase with each other?
Coherent (lasers produce coherent light)
What is considered the application of shortwave or microwave electromagnetic energy to produce heat within tissues, particularly deep tissues?
Diathermy
What is considered light with parallel waves?
Directional (collimated)
What is considered light that spreads?
Divergent (opposite of collimated)
What is considered radiation composed of electrical and magnetic fields that vary over time and are oriented perpendicular to each other?
Electromagnetic radiation
What type of radiation does not need a medium to propagate?
Electromagnetic radiation
What is considered the amount of electromagnetic energy delivered over the entire treatment time?
Energy
What is energy usually measured in?
joules (J)
What is equal to power multiplied by time?
Energy (1J=1W x 1s)
