My history-5 treatments w/ minimal success using apogee alex.
I went and discussed the benefits of gentlelase vs apogee with my laser nurse. I tried to push the importance of spot size, depth of penetration of laser and the light/conical/scatter idea.
She answered with the pulsewidth being most important and 3ms on gentlelase vs variable pulse on apogee arguement.
My questions: Does pulse matter? Will the 3ms fixed gentlelase setting just fracture a coarse hair follicle? Why have a set 3ms rather than using a variable pulsewidth? Does higher numbered pulsewidths thin the hair out first?
I need some ammo to debate why the gentlelase is better other than spot size. What do I say to the 3ms fixed pulse on the gentlelase will not kill coarse hair arguement.
The issue of pulsewidth has to do with a related issue concerning thermal relaxation time. This is a fairly complex issue related to how fast the target loses energy compared to how fast the energy is put into the target. But think about a crock pot. You can’t use a crock pot effectively if you don’t put the lid on because you lose heat out the top faster than you are putting it in.
But here is the bottom line. The pulse width of laser has an impact in multiple ways. At very short pulse widths (say around 500 or so nanoseconds or shorter), the laser actually doesn’t input heat but acts more as a shock wave, which can be used to break up tattoo pigments. But these shock waves have no real effect on hair follicles or skin, which is the concept behind laser tattoo removal.
Once you move into the “longpulse” lasers (1 millisecond or more) the shock wave effect goes away and we are dealing with heat absorption. There are two essential targets (skin and hair). We want to affect hair and not affect skin. It turns out that the thermal relaxation time of skin is somewhere around 1 millisecond and hair ranges from 5 to 100 ms depending on how coarse it is. Furthermore it turns out that putting energy in faster than the TRT will allow the structure to absorb hair but that putting it slower will allow the structure to lose heat (like the crock pot).
Short pulsewidths are more risky for skin, but do a better job of targeting all hair sizes.
Longer pulsewidths are less risky for skin but do not target finer hair as well.
The goal is to try to protect the skin and get the hair. So each company makes a decision on how they will deal with the tradeoff. Cynosure came up with a variable pulsewidth to allow the operator to chose longer pulsewidths when the hair is coarser, but that pulsewidth must be reduced as the hair gets finer. With subsequent risk of burning. The downside is that the laser is more complex and breaks down more.
Candela went with a simpler approach which is a fixed pulse width but then developed the cyrogen cooling to offset the increase risk to the skin. But the short pulsewidth still works on coarse hair. This decision made their lasers a little less expensive and more reliable.
Grumpy,
I remember you were holding out on going for another treatment. How has your wait gone, has all the hair grown back?
Have you gone for an alex treatment yet?
I have waited now 3months to see how my 2 treatments on the back has gone with the alex, results aren’t looking good however… The first of my alex treatments was at setting 10 and my second at 16. So I think I will go for another 2 quick treatments now at 18 (2months apart).
was 10 and 16 joules? is this the GentleLASE alex or another? What is the spot size you’re using at each? 10 joules is pretty useless. 14-16 joules on 18mm spot size on GentleLASE should be minimum used and higher joules if you’re using a lower spot size. Can you find out more detail and provide the name of the machine?