Page 90 - Blog Posts v1

This differs from the conventional ‘stamping’ technique which fires just one shot each area of the skin, with a greater fluence.
And this is very interesting...
There is clearly a significant difference between these two techniques. The SHR technique builds up a substantial amount of heat energy in the full treatment area, while the stamping technique delivers just one, large pulse of energy – sufficient to generate enough heat to cook the germ cells in the follicles.
The SHR technique cannot do that – the fluence is too low. So, how does it work? Well, the researchers suggest that the surrounding dermis is slowly heating up due to the high number of passes. As a result, the follicles, which do get much hotter than the dermis, cannot cool so quickly. They postulate that this means that the follicles stay hotter for longer, resulting in cooking of the germ cells.
I thought I’d test this idea in my computer model – which I had created to study the effects of heat generation in the skin and hair follicles.
To my surprise, they were correct!!! Even raising the background dermal temperature by a couple of degrees makes a significant difference to the outcome.
SHR – if the repetition rate does not match the scanning speed, the shots will be very inconsistent leading to patchy results.
And then I realised why – the cooking (denaturation) process is exponentially dependent on the local temperature. This means that even a small increase in temperature will induce much more denaturation.
So, if the surrounding dermis is just a few degrees warmer than normal (37oC) then the follicles will cook much more easily. However, the thermal pain nerves kick in at 45oC – meaning that the dermis should be kept below that temperature. This leaves only a small 8oC ‘window’ to work in, to prevent great pain.
This is why the cooling is so important – without proper cooling, the skin will become too hot and the treatment very uncomfortable.
Mike’s Blog Posts 90