Photodestruction of tattoos dye
Different methods are used for destruction of tattoo dye – chemical, mechanical, thermal and laser. The main problem of all non-laser methods is the creation of a rough scar. Using laser methods has allowed us to greatly improve the solving of the problem of removing tattoos. However, using a laser doesn’t guarantee a good aesthetic result.
There are many different lasers and they have a completely different effect on biological tissues. So, in case of using carbon dioxide or erbium lasers (non-selective methods) the tattoo pigment is removed together with the skin containing it, which makes this method very similar to non-laser methods. The result of such removal is also very far from ideal – a scar appears in place of the tattoo.
Selective methods of tattoo removal using long-pulse lasers, not depending on used radiation wavelength (neodymium, alexandrite, diode, ruby, metal vapor, argon etc.) also in most cases leads to scarring. The reason for this lies in fact that the thermal relaxation time of the dye particles is significantly smaller than the duration of pulses used in those devices. Thereby the powerful outflow of heat from pigmented areas into surrounding normal tissues is inevitable. That causes their overheating up to coagulation and, therefore, scarring.
The only method which allows destruction of tattoo dye without traumatising surrounding tissues is the method of selective photodestruction of tattoo dye using Q-sw pulses. In this case the process is non-thermal and destruction of particles takes place because of the creation of a powerful acoustic wave inside the pigment which mechanically destroys the dye.
Unfortunately, in practice it appears that using classical Q-sw pulses permits the achievement of a good aesthetic effect only for surface tattoos. Along with increasing the depth of the tattoo dye this increases the risk of skin scarring after the procedure. This occurs because of the fact that during the absorption of Q-sw pulses the coefficient of absorption or irradiated substance increases up to 100%. As a result, all energy of the laser pulse is absorbed into the upper levels of the tattoo. That is, the radiation isn’t able to penetrate deep into skin to destroy the dye located deeper. To destroy it, it is needed to increase the energy of laser pulses which leads to increase of power of acoustic waves and thereafter, the depth of their penetration. These waves, formed on the skin’s surface, destroy deeply located pigment. Unfortunately, these waves have a destructive influence not only on the tattoo dye particles but also on all biological tissues located in their way.
The new original method of selective photodestruction of tattoo dye developed by our company accounts for mechanisms of optical, thermal and nonlinear selectivity.
The core of the method is the fact that the Q-sw pulse is divided into train of Q-sw pulses of lower energy. As a result, every pulse of the train causes fragmentation of dye only in its thin layer, clearing a way for the next pulse. Thus, with one train there is a layer-by-layer fragmentation without creating powerful acoustic waves that are able to traumatise surrounding tissues.