InfoSight LabeLase 4000, Руководство по эксплуатации и техническому обслуживанию

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1.4 BIOLOGICAL EFFECTS OF LASER IRRADIATION
1.4.1 Eye Injury
Because of the high degree of beam collimation, a laser serves as an almost ideal point source of intense light. A laser
beam of sufficient power can theoretically produce retinal intensities at magnitudes that are greater than conventional light
sources, and even larger than those produced when directly viewing the sun. Eye exposure to a direct beam can cause
permanent eye damage including blindness. Protective eyewear should always be worn when potential exposure to direct
laser beams exist.
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Due to the lens-like focusing effect of the human eye, it is 100,000 times more vulnerable to injury than the
skin.
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Laser safety eyewear should always be available for the wavelengths of lasers in use.
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Eye protective equipment, however, should be considered the last line of defense against laser beam exposure
– engineering and administrative controls should be used first.
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Remove all jewelry when working with an open beam to prevent reflection of the beam in unsafe directions.
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When possible, use all protective housings, interlocks and shields.
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Laser Safety Eyewear should always be worn during laser repair, alignment, or installation, or at any time when
any laser safety control is not in place.
1.4.2 Thermal Injury
The most common cause of laser-induced tissue damage is thermal in nature, where the tissue proteins are denatured
due to the temperature rise following absorption of laser energy.
The thermal damage process (resulting in burns) is generally associated with lasers operating at exposure times greater
than 10 microseconds and in the wavelength region from the near ultraviolet to the far infrared. Tissue damage may also
be caused by thermally induced acoustic waves following exposures to sub-microsecond laser exposures.
1.4.3 Skin Injury
To the skin, UVA (315-400 nm) can cause hyperpigmentation and erythema (aka: sunburn). Exposure in the UVB (280-
315 nm) range is most injurious to skin. In addition to thermal injury caused by ultraviolet energy, there is also possibility
of radiation carcinogenesis from UVB. The shorter wavelengths are absorbed in the outer dead layers of the epidermis
(stratum corneum) and the longer wavelengths have an initial pigment-darkening effect followed by erythema if there is
exposure to excessive levels.
The hazards associated with skin exposure are of less importance than eye hazards; however, with the expanding use of
higher-power laser systems, particularly ultraviolet lasers, the unprotected skin of personnel may be exposed to extremely
hazardous levels of the beam power if used in an unenclosed system design.
Skin burns caused by lasers can happen quite fast and with great intensity. Protective clothing should be worn when
potential exposure to direct laser beams exist.
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UVC: 200-280 nm exposure may cause erythema (sunburn), skin cancer, and burns.
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UVB: 280-315 nm exposure may cause accelerated skin aging, increased skin pigmentation and burns.
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UVA: 315-400 nm exposure may cause pigment darkening and skin burns.
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Visible: 400-700 nm exposure may cause photosensitive reactions and skin burns.
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Infrared 700-100,000 nm exposure may cause skin burns.