Thermal Relaxation Time – what is wrong with it?

  The theory which has underpinned many skin-laser treatments since 1981 is called ‘Selective Photothermolysis’. It is based on matching the laser wavelength to the absorbing chromophore. It also matches the pulse duration of the laser to the thermal relaxation times of those targets. However, there is a problem with this approach. The thermal relaxation… Continue reading Thermal Relaxation Time – what is wrong with it?

“No Pain, No Gain” – hair removal using light energy!

OK! PDF version This is really quite simple! Human thermal/pain receptors (nociceptors) are triggered at around 45 C. Below that temperature you feel heat – above it, and you feel pain. NASA has proved this beyond doubt! So, to achieve permanent, or even ‘semi-permanent’ hair removal you need to apply sufficient heat energy, for a… Continue reading “No Pain, No Gain” – hair removal using light energy!

“Thermal Energy Levels” – my description of how RF operates in the skin

Article People kept asking me how radio frequency (RF) worked in the treatment of skin conditions. It’s pretty simple, really. It’s just electrical heating – nothing new! But, there appears to be a lot of, shall we call it, ‘mis-information’ out there, so I wrote this piece.   I’ve also included some info on ‘Heat… Continue reading “Thermal Energy Levels” – my description of how RF operates in the skin

Q-switched laser removal of tattoos: a clinical and spectroscopic investigation of the mechanism, 1996

via Q-switched laser removal of tattoos: a clinical and spectroscopic investigation of the mechanism | DeepDyve A lot of patients kept asking me why green ink was so difficult to remove with the ruby laser. At the time we didn’t know. So I gathered a bunch of tattoo inks from Terry’s Tattoos in Glasgow and… Continue reading Q-switched laser removal of tattoos: a clinical and spectroscopic investigation of the mechanism, 1996

Variable pulsewidth vascular system for dermatology | (1994) | Gustafsson | Publications | SPIE

via Variable pulsewidth vascular system for dermatology | (1994) | Gustafsson | Publications | Spie   ┬áThis report describes the world’s first IPL system, developed by Morgan Gustafsson in the early 1990s. Back then we didn’t call it IPL – that name came later. Morgan approached me at an ASLMS conference after I gave a… Continue reading Variable pulsewidth vascular system for dermatology | (1994) | Gustafsson | Publications | SPIE