The ‘standard’ definition of penetration depth in skin only considers the incident wavelength and optical properties of the skin. While this may be useful from a physics perspective, it is not particularly useful when considering clinical treatments. A more useful definition must include wavelength, anisotropy, spot diameter and incident fluence. All of these have an… Continue reading Laser-IPL Penetration Depth – a more useful definition
The following is an experiment I carried out to test a theory. A number of experiences had made me think that the time between laser sessions is more important than first thought. My clinical group first developed scar-free laser tattoo removal back in the 1980s in Canniesburn Hospital, Glasgow, Scotland. Back then, we were using… Continue reading Tattoo removed in just 4 sessions using a QS Nd:YAG at 1064nm
How do you know what fluence or energy is coming out of your IPL unit? Some devices will have an on-board meter, but many don’t. In that case, you really should get it properly calibrated. You can only do this with an appropriate meter which should be able to measure both the fluence and the… Continue reading Calibrating an IPL device
Most laser systems have a lens to focus the laser energy down to a sale spot diameter (see figure 1 below). However, in many systems, the focal point (where the spot diameter is the smallest) is outside the handpiece assembly. This has a potentially hazardous effect if not properly understood! The problem with this design… Continue reading Laser spot size – how it changes with distance from the target…
Recently I tried the new ‘carbon facial’ treatment using the 1064nm wavelength of the Q-switched Nd:YAG laser. My wife was keen to try it! I painted a little black carbon ink solution (which I made myself) onto my wife’s face. After about 20 minutes, or so, to allow it to dry, I applied the laser… Continue reading Carbon Facial treatment with a QS Nd:YAG laser
Many laser operators are not sure what is meant by energy density or fluence. They should know this as it is fundamental to generating good clinical outcomes. Here’s a video I made explaining how to calculate ED/fluence… You can download a pdf copy of the above here. Hope this clears this topic… Continue reading What is ‘energy density’ or ‘fluence’?
What happens when India ink absorbs laser energy? I irradiated some dry India ink trapped between two glass slides here (the ink was allowed to dry overnight). I used 5 J/cm^2 with a 1064 nm wavelength. As you can see, the laser energy ‘vapourises’ the ink and leaves voids behind. But, very little ink leaves… Continue reading Experiments with India ink and a Q-switched Nd:YAG laser
Research from around the world clearly shows that the coronavirus sits on saliva droplets in the air for hours. This is not widely understood. Even The WHO have only recently begun to ‘get’ this!! I put together a video to explain the physics behind this – its not rocket science!!! Watch here – You can… Continue reading The virus is in the air…
I found a great video showing ‘The Scale of the Universe’… Ciao, Mike.
I wrote an article for Aesthetics recently regarding the plume generated by laser/IPL hair removal and other treatments. All ablative treatments will generate a plume. In addition, many other laser/IPL treatment will also generate plume. What is a ‘plume’? Plume consists of smoke particles and tiny, invisible particles of tissue, hair, bacteria, viruses and potentially… Continue reading Laser/IPL Hair Removal – plume and precautions!!!