electrophysical agents EPAs - lasers and ultrasound

Question 1

what does LASER stand for?

Answer 1

-light
-amplification by
-stimulated
-Emission of
-Radiation

Question 2

what is laser therapy used for in physiotherapy?

Answer 2

low intensity light therapy used to reduce tissue inflammation, reduce pain etc

Question 3

what are 3 characteristics of laser therapy that set it apart from other therapy’s?

Answer 3

-monochromatic - single wave length
-coherant - all electromagnetic wave are in phase together
-collimated - light waves travel in parallel

Question 4

what lasers produce laser radiation in the red or infrared part of the wavelength spectrum?

Answer 4

solid state lasers

Question 5

why are lasers so useful clinically?

Answer 5

-produce a single wavelength - which targets specific types of tissue
-many different wavelengths available - many diff applications

Question 6

what 2 factors determine the type of laser tissue interaction that occurs?

Answer 6

-colour / wavelength of the laser radiation eg red, blue etc
-the laser parameters eg power, area, exposure etc

Question 7

why does laser radiation in the UV to IR region of the e-m spectrum penetrate far into the tissue?

Answer 7

• the wavelengths have high tissue penetration capabilities

Question 8

what 3 things does the type of interaction that occurs within the tissue depend on?

Answer 8

-amount of energy delivered to the tissue
-time period over which the energy is delivered
-the area over which the energy is delivered

Question 9

what are 3 types of interactions that can occur in the tissue?

Answer 9

-photochemical
-thermal interactions
-photomechanical

Question 10

describe photochemical interactions

Answer 10

results from exposure to low irradiances
eg bio stimulation

Question 11

describe thermal interactions

Answer 11

• as the energy deposited increases, it is converted to heat and the tissue temp increases

Question 12

describe photomechanical interactions

Answer 12

-exposure to very high irradiances
eg mechanical shockwaves

Question 13

what do most laser applications in physiotherapy use?

Answer 13

-low level laser therapy
-low intensity laser therapy

Question 14

what laser in the most popular choice for wound healing?

Answer 14

-helium neon

Question 15

what does ultrasound consist of?

Answer 15

consists of longitudinal pressure waves with a freq greater than 20,000 Hz

Question 16

how can ultrasound be useful for physiotherapy?

Answer 16

wound repair

Question 17

what happens when ultrasound enters the body?

Answer 17

-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

Question 18

what are the effects of thermal effects vs non thermal effects of ultrasound?

Answer 18

-thermal effects - reduced stiffness, pain relief and increased blood flow
-non thermal effects - soft tissue repair, bone repair etc