The new method of non-invasive “pin-point” coagulation of skin cells with high content of melanin (PinpointCoagulationTechnology) allows solutions to problems such as:
- impossibility of treating dermal (lying deep) pigmented lesions;
- risk of mechanical damage to the skin;
- risk of overheating and resulting scarring of the skin;
- risk of post-operative hyperpigmentation.

The LINLINE method allows cells with high content of melanin to be coagulated selectively without mechanical or thermal damage of surrounding cells.
The method is based on the mechanisms of interaction of short nanosecond laser pulses with grains of melanin in combination with the process of heat exchange between melanin and surrounding tissues.
At the exposure of melanin to a short laser pulse with units or tens width of a certain wavelength and sufficient power, a non-linear change of optical properties of the melanin takes place – the coefficient of light absorption increases drastically.
Emission parametres are set up so that the energy should be completely transformed into heat without creating high-powered acoustic waves, which might otherwise cause mechanical damage to surrounding tissues.
We use sequences (packs) of pulses, each of which is of a certain power, sufficient to initiate a non-linear process.
Being exposed to one pulse, a particle of pigment receives a certain quantity of energy and becomes warm. The exposure finished, it begins to cool and pass heat into surrounding tissues. The outflow of heat from the melanin particle will vary in different directions. In places where there are no other grains of melanin nearby, heat will be redistributed in the soft tissues. And there, where the heat-wave meets a contradirectional one moving from another grain, the process of heat redistributing will slow down. That is why the next laser pulse and ensuing heat wave will result in the same temperature as before the laser exposure, everywhere except in the gaps between grains. As a result of this, we obtain a pin-point coagulation of the pigment stain without overheating of the surrounding tissues with normal pigmentation.
A further advantage of this new mode of generation as opposed to the use of high-powered single laser pulses is that it allows coagulation to be achieved at the whole depth of pigment occurrence in the skin.

Fig. 1. Area of hyperpigmentation.

Fig. 2. Exposure of the area of hyperpigmentation the laser emission.

Fig. 3. Coagulation of the melanin grains.

Fig. 4. Disappearance of coagulated substance.