When we set a fluence on an IPL unit, it is based on ALL of the light energy coming from the handpiece. However, each filter will absorb some of that energy – it is supposed to! The filters are designed to ‘block’ certain wavelengths, so that only the desired wavelengths reach the skin surface. So,… Continue reading How much light energy actually emerges from IPL filters and reaches the skin surface?
A bit of fun…. If you treat 10 tattoo patients a day with a Q-switched laser (using a 10 nanosecond pulse width) and each treatment requires, say, 1000 pulses, then the total treatment time is 0.1 milliseconds. This is the actual time you have applied the laser energy! If you operate your laser clinic for… Continue reading How long have you actually treated patients/clients wth lasers?
New Paper – click here I just had a new paper published in the journal ‘Lasers in Medical Science’. It discusses the amount of back-scatter light emanating from the skin during laser treatments. It is much higher than we had previously thought. This comes from new Monte Carlo modeling which found that back-scattering is much… Continue reading New paper – my musings on back-scattered laser light from tattoo treatments
There is a curious anomaly around today. When we discuss our weight we invariably refer to the number of kilograms we ‘weigh’. But this is a measurement of mass, not weight! So, if someone claim a weight of 100 kg, they are really referring to their mass. This is where it gets interesting. To… Continue reading What is your weight on Mars? Or other planets???
All of the sun’s photons are generated through nuclear reactions within it. If a photon is generated at the centre of the sun it can take anywhere between 2 days and 200,000 years to escape the body of the sun. That’s because the path of the photon is purely probabilisitic. At the centre of the… Continue reading How long does it take a new photon to reach us from its creation in the sun?
So, just the other day, I was thinking about how much energy we need to destroy hair follicle and blood vessels. Typically we talk about 1 or 2 joules per pulse. Then I thought, what is 1 joule of energy? I had no idea what this actually meant in the ‘real’ world! So, I… Continue reading How much energy does it take to heat a cup of coffee or tea?