Non Thermal (laser)

Question 1

What does LASER stand for

Answer 1

Light amplification by stimulated emission of radiation

Question 2

Characteristics of LASER

Answer 2

Monochromacity (most NB) = uniformity of wavelength
Coherence = identical wave forms and length of which amplify the effect
Collimation= avoid divergence ( thus more focused light produced)

Question 3

What is LILT

Answer 3

Delivers energy to tissue to disturb local electron orbit causes= generate heat/chemical change.
Main target =cell membrane

Question 4

Physiological processes of LASER

Answer 4

Arndt schultz law

Photobioactivation

• 1st absorption in cel membrane
• 2nd intracellular effects

Question 5

Physiological effects

Answer 5

Alters: cell proliferation / cell motility /action potentials
Stimulates: immune responses /macrophages
Activates: phagocytes/ fibroblasts

Question 6

What is the analgesic mechanism

Answer 6

Stimulates release of endogenous opioids
Decrease bradykinin which may sensitise c-fibers
Block nerve conduction

Question 7

Therapeutic benefits of LILT

Answer 7

Promote wound healing

Improve time to resolution for superficial wounds

Question 8

Precautions of LILT

Answer 8

Use lowest intensity

Eye goggles worn by pt and therapist

Question 9

When to not use LILT

Answer 9

over Uterus in pregnancy 
Malignant-tissue
Bleeding/haemorrhage 
Deep vein thrombosis 
epilepsy
Infected wounds

Question 10

Energy density for types of wounds

Answer 10

Superficial wound healing = 2 J/cm2 over open wounds

Peripheral unexposed wounds= J/cm2

Question 11

Different dosage parameters of LASER

Answer 11

Output power = watts
Irradiation area= cm2
Time= seconds
Duty cycle= pulse frequency

Question 12

Calculations for dosage parameters

Answer 12

Energy density (J/cm2) = total amount of energy (J) / irradiation (cm2)

Total energy (J)= average power (watts) x time (seconds)

Average power (watts) = peak power (watts) x frequency (Hz) x pulse duration (sec)