Basic Parameter for Beauty Equipment | Choicy Beauty- a beauty training academic

Among the optoelectronic beauty treatment technologies, we have many core knowledge points that must be mastered. These key knowledge points are very important for beauty therapists, and they must also grasp the core points, otherwise you cannot really make safe and effective treatment results.

In this article, we will focus on the four key concepts of laser energy, power, power density, and energy density. Only by mastering these knowledge points can we be able to achieve true laser "end-point response" and achieve therapeutic goals.

Strength of energy affects the treatment effect

We must provide enough energy to the target tissue to destroy them, if not, will not achieve the effect of cosmetic treatment

Laser hair removal: hair removal treatment should be given a sufficient depth of laser energy (808nm diode laser), so that after the hair pigment wrapped around the hair papilla is heated, the hair follicle is partially damaged, and the hair is "eradicated"; if the energy is not enough, it will stimulate hair growth so that it does not have the effect of hair removal.

CO2 fractional laser skin rejuvenation: The fractional laser uses many small thermal damage points to activate the skin's damage-repair mechanism, achieving the effect of skin reconstruction and collagen hyperplasia; if the energy is too low, the effect will be much weaker

Age pigment removal: Q-switched 532nm laser is used to achieve the effect through acousto-optical mechanical blasting; we need to do immediate hoarfrost reaction after laser irradiation, and scab fall off after 4-6 days; if the energy is not enough, only reddish, but can not be scabbed and exfoliated. This age pigment cannot be removed.

Photothermal conversion and absorption

All of the above examples are lasers that achieve therapeutic effects by applying energy to the target tissue of the skin. Well, if there is not enough energy, it is useless.

The "light-heat" transformation is the common form of laser treatment. A laser beam shots on the skin, we generally feel hot. When the power of the laser is increased, we feel thermal pain. After that, vaporization, burning and even carbonization may occur. It is the natural process of laser energy conversion to thermal energy, and our laser treatment is to precisely control these processes, so that the laser energy emitted by beauty equipment becomes a reasonable means for our beauty treatment.

Energy

The process of controlling the amount of energy applied by the laser to the skin is a core technology that we must master.

Energy, in laser treatment, is often referred to as "joule." What we often talk about is the amount of joules or how many millijoules in one single light (1 J = 1000 mJ), which is how much energy is applied to skin irradiation this time. We usually see the markings on the Q-switched laser, the maximum energy of "1200mJ" or "1600mJ" for a single light emission.

Power

What is the relationship between energy and power? What is the relationship between Joule and Watt?

The unit of power is "Watt", which is related to time. It expresses the efficiency of providing energy.

Energy = power * time (Joules = watts * seconds)

In many devices, such as CO2 lasers, is marked how many watts for the power. We usually use 30W (watts) and 60W (watts). Which one do you think is better?

The laser applied to the skin, the higher the energy, the more heat it converts into; the higher the power, the shorter time the energy can be provided and the faster the skin tissue warms up.

Energy density (Fluency)

The energy density is related to the irradiated area.

A beam of laser light hits the skin. We set the energy at 10 Joules. Focusing on a small diameter area (for example, a round spot with a diameter of 4 mm) produces a very high temperature rise. If we radiate 10 Joules of heat in a large circle of 1m in diameter, you do not feel warm at all.

The concept of [energy density" is related to the area. When the same energy is applied, the smaller the irradiation area, the greater the energy density and the faster the skin tissue warms up.

Power density

The power density is related to the exposure time.

"Power density", based on the area irradiated, also adds a concept of time. We still use the above example to illustrate that the same total energy of 10 Joules shoots on a spot of 4 mm in diameter. It takes 1 second to increase the temperature to 1°. If the irradiation time is shortened to 10 ms, it may heat up to 10°. This is the effect of increasing power density.

The concept of [power density" is related to time: when the same energy is applied to the same area, the shorter the shooting time, the greater the power density and the higher the temperature rise.

We know that when the skin is heated by a laser, it will heat up, but it will also dissipate heat. If 10 seconds of energy is applied to the skin for 1 second, it may heat up without apparent warming; if 10 ms (1 s = 1000 ms) is applied With 10 Joules of energy, it is possible to produce a temperature increase of 5-10°on the skin. Similarly, if we want to treat vascular diseases with the aim of coagulating the blood flowing in the blood vessels, and the blood coagulation requires a temperature of around 70-80°, then we may swiftly give them dozens or even hundreds of joules of energy within tens of milliseconds. If time is too long, the blood will flow and the skin will dissipate the heat, and the desired result of the treatment will not be achieved.

Therefore, during the treatment, energy should be sufficient, energy density should be sufficient, and power density should be sufficient. They are indispensable.

The relationship between spot diameter and energy density

We must achieve the corresponding therapeutic effect, expand the diameter of the spot, that is, increase the total irradiation area. If we want to maintain the same energy density, its total energy will increase.

If we want to increase energy density, in addition to increasing energy, there is a more important way, that is to reduce the area of laser shooting treatment. The smaller the treated spot area, the greater the energy density and the more obvious the skin is heated and damaged.