electrophysical agents EPAs - lasers and ultrasound Flashcards
what does LASER stand for?
-light
-amplification by
-stimulated
-Emission of
-Radiation
what is laser therapy used for in physiotherapy?
low intensity light therapy used to reduce tissue inflammation, reduce pain etc
what are 3 characteristics of laser therapy that set it apart from other therapy’s?
-monochromatic - single wave length
-coherant - all electromagnetic wave are in phase together
-collimated - light waves travel in parallel
what lasers produce laser radiation in the red or infrared part of the wavelength spectrum?
solid state lasers
why are lasers so useful clinically?
-produce a single wavelength - which targets specific types of tissue
-many different wavelengths available - many diff applications
what 2 factors determine the type of laser tissue interaction that occurs?
-colour / wavelength of the laser radiation eg red, blue etc
-the laser parameters eg power, area, exposure etc
why does laser radiation in the UV to IR region of the e-m spectrum penetrate far into the tissue?
- the wavelengths have high tissue penetration capabilities
what 3 things does the type of interaction that occurs within the tissue depend on?
-amount of energy delivered to the tissue
-time period over which the energy is delivered
-the area over which the energy is delivered
what are 3 types of interactions that can occur in the tissue?
-photochemical
-thermal interactions
-photomechanical
describe photochemical interactions
results from exposure to low irradiances
eg bio stimulation
describe thermal interactions
- as the energy deposited increases, it is converted to heat and the tissue temp increases
describe photomechanical interactions
-exposure to very high irradiances
eg mechanical shockwaves
what do most laser applications in physiotherapy use?
-low level laser therapy
-low intensity laser therapy
what laser in the most popular choice for wound healing?
-helium neon
what does ultrasound consist of?
consists of longitudinal pressure waves with a freq greater than 20,000 Hz
how can ultrasound be useful for physiotherapy?
wound repair
what happens when ultrasound enters the body?
-its effect on the tissue can be thermal ( for high intensity ultrasound) or non thermal (lower intensities)
-amount of absorption of the ultrasound depends on the nature of the tissue, its degree of vascularisation and the freq of the ultrasound
what are the effects of thermal effects vs non thermal effects of ultrasound?
-thermal effects - reduced stiffness, pain relief and increased blood flow
-non thermal effects - soft tissue repair, bone repair etc
