1. HOW OR LIGHT WORKS
1. HOW OR LIGHT WORKS
A few words about light
Two words about light
The sun is a natural source of light.
There are also other sources of light such as a candle or incandescent lamps. Light is also called white light or the visible spectrum.
Light moves in a wave-like manner.
If we observe a light source from the front, we notice that it propagates in concentric circles, like waves on the surface of water.
If we cut these concentric circles, we observe waves with maxima and minima.
The distance between two maxima is called the wavelength. This wavelength is expressed in a submultiple of the meter called the nanometer.
There are thus waves of different maximums.
The operation by pulsed light Or Light
A pulsed light device or flash lamp is a system that delivers a beam of high-energy natural light.
This beam is emitted in very short pulses. The characteristics of the emitted beam are crucial to ensure the device’s effectiveness as well as the patient’s safety.
The applicator is applied to the patient’s skin and transmits the device’s light energy to the skin.
The difference between pulsed light and laser
Pulsed light is often confused with laser.
The basic technology is similar, but the characteristics of the light beam differ completely.
Indeed, in both cases, the source of the light energy is a lamp known as a flash lamp. This lamp contains a particular gas, usually xenon.
In Laser technology, the original light beam passes thru a very sensitive solid or liquid element, allowing for the precise selection of a single wavelength and the amplification of the initial beam energy.
Finally, the laser beam is focused, meaning it is reduced to a surface area, which is not the case with pulsed light that can treat larger areas in the same amount of time.
In dermatology, there are 4 main lasers commonly used: Ruby, Alexandrite, Diode, and Yag.
These four lasers combined represent only four wavelengths, whereas a pulsed light alone covers a spectrum approximately 150 times wider.
The skin
The skin
The skin is the most extreme organ of the body. By its color, texture, and hairiness, it allows individuals to be differentiated from one another. This information is genetically coded.
The expression of this information is called the phototype. In order to codify it, we classify individuals into 6 categories. This classification is called the Fitzpatrick classification.
The phototype of an individual does not change over time.
On the other hand, its pigmentation can vary over time depending on the time of year or the geographical area.
This is the case with tanning, which darkens the skin to protect it against the harmful effects of the sun’s UV rays. This pigmentation is temporary.
The skin is made up of 3 different layers. The outermost layer is called
1. The outermost layer is called EPIDERMIS.
Its thickness varies depending on the area of the body.
The main active cells are keratinocytes producing keratin and melanocytes producing melanin, a protective pigment.
2. The second layer is called the DERMIS.
It contains different glands: the sweat glands, producing sweat, and the sebaceous glands, producing sebum, the fatty layer of the skin.
In the dermis lies the hair implanted in an invagination of the epidermis.
3. The last layer is THE HYPODERMIS
This layer mainly consists of adipocytes or fat-storing cells.
These cells distributed throughout the body are, however, more concentrated in certain areas, depending on the sex and the individual.
The skin performs multiple functions.
It has a role in mechanical protection, chemical protection, and protection against UV rays from the sun.
Similarly, the skin has a major role in metabolism by synthesizing vitamin D, which is essential for the body.
The skin also ensures the thermoregulation of the body, thru the production of sweat and then thru the vasodilation of blood capillaries.
Finally, the skin performs a function of interaction with the environment, thanks to the multiple sensory receptors located in the different layers.
The hair
The hair visible on the surface of the skin originates in the dermis, while remaining a structure of the epidermis.
It is mainly composed of keratin and melanin, giving it its color.
The hair follicle is composed of four layers.
We distinguish between two types of hair.
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- The down, fine hair whose hair follicle is superficial. It contains little melanin.
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