Laser color is related to wavelength. In radiotherapy positioning, commonly used laser colors include red (wavelength 635 nm), green (wavelength 520 nm), and blue (450 nm). Because green laser lies in the yellow-green region, which is the most sensitive to the human eye, it is more easily perceived and recognized. Therefore, at the same power, the green laser beam appears brighter and clearer than the red laser, making it easier for the human eye to identify and observe. This results in better visibility for laser indication and alignment. In practical radiotherapy laser positioning systems, the power of green laser lights is usually kept within 0.5 milliwatts, achieving Class 1 laser safety level, thereby offering higher safety.
The potential hazards of laser exposure for Class 3B to Class 4 lasers mainly involve the risk of damage to human tissues and organs, as well as the risk of fire when directed at flammable materials. For Class 1 to Class 3R lasers, the primary potential risks are damage to the eyes and skin.
Therefore, taking appropriate safety measures is crucial to ensure the safe use of laser positioning systems. These safety measures include, but are not limited to, the design of the laser source, the use of protective equipment, the placement of safety warning labels, blocking and shielding of the laser beam, operational training, and the establishment of operational procedures. It is essential to ensure that all personnel using the laser system receive relevant safety training and guidance.
For radiotherapy laser positioning systems, since the selected laser sources are Class 1 or Class 2 lasers, the main potential risk is eye damage. Therefore, during the design and production of the product, it is necessary to place safety warning labels at prominent positions near the laser emission apertures. During training, users should be emphasized not to look at the laser beam for extended periods and to avoid direct laser spots entering the eyes.
