التحلل الضوئي الانتقائي
As early as 1983, a scientific paper posted by way of two scholars, Anderson and Parrish, proposed "selective photothermal decomposition". This is a very necessary thought for the improvement and software of laser in dermatology. In that paper, the writer delves into the idea of selective photothermal decomposition.
Its precept is mostly divided into three aspects: the use of mild appropriate for (a) wavelength, (b) length of pulse and (c) injection amount, the use of as a selective photothermal decomposition, can precisely make the goal with the aid of the laser warmness damage.
Photothermolysis:
· Light electricity is transformed into warm work for the goal tissue, mild is absorbed with the aid of the target, and warmness electricity is produced;
· Heat acts on the goal tissue, inflicting bodily injury (transformation);
· The goal is in consequence cleared via immune device cells or metabolically absorbed.
Because specific pigment companies have specific absorptivity to exceptional wavelengths of light, the single wavelength of laser can gain the selective effect.
When a laser of a particular wavelength passes via the skin, it is absorbed by using the goal tissue (heme, melanin, collagen, or water); However, the absorption of particular wavelength spectra by using the surrounding tissues is less, so precise goal tissues (such as stains) can be selectively destroyed with much less influence on the surrounding tissues.
Given the splendid pulse duration, the warmth generated through these photothermal strategies is restrained to the target. This is all associated to the Thermal leisure time on the target.
The most vital factor is that the period of the laser/intense pulse mild pulse have to now not exceed the warmness dissipation time of the target, in any other case the warmness will radiate to the surrounding tissues, ensuing in tissue injury and feasible scab formation. The warmth dissipation time will be affected via the right quantity of the target, the smaller the target, the shorter the warmth dissipation time, so the laser pulse length is additionally shorter.
