Questions WHY NOT APPEARING WHEN VIEWED????

Q1) How many Joules per second would a 1W laser produce
A1) 1J/s

Q2) How many total Joules would this 1W laser output in 5 minutes?
A2) 60 x 5 = 300 so 300 Joules

Q3) How do we calculate irradiance?
A3) Power output (w) ÷ spot size or beam area (cm2)

Q4) Have a go at calculating this dose. We are aiming for a therapeutic dose of 6J/cm2 – the area we want to treat is 200cm2

How many total joules would we need to deliver to reach the therapeutic dose that is right for that size area?

A4) 6 x 200 = 1200 total joules

Q5) If we treated an area of 100cm2 with a total of 1500J what is the energy density (J/cm2)?
A5) 1500 ÷ 100 = 15J/cm2

Q6) Is the irradiance higher, nearer to the source of power (eg: PBM delivery head) or further away? Explain your answer.

A6) The irradiance is higher, nearer to the source as this is where the spot size would be smaller (same power output but more concentrated). This is important because, if the spot size is calculated in contact with the skin and then you need to move the head further away from the skin, for reasons such as its too painful or there is a risk of contamination, you must be aware that this will change the spot size and therefore the irradiance and ultimately the total dose being delivered.

Q7) What is the accepted therapeutic dose range for superficial penetration with PBM?
A7) 4 – 5 J/cm2

Q8) What is the accepted therapeutic dose range for deeper conditions?
A8) 8/20 J/cm2

Q9) According to Zein, Selting and Hamblin’s 2018 review, what are the two most important measures when determining the success of an in vivo study?
A9) Fluence and Irradiance

Q10) What patient specific variables need to be considered when calculating dose?
A10) Size, body condition, hair and skin colour and skin length.