Laser Safety Standards and Measurements of Hazard Parameters for Medical Lasers

Abstract

Laser sources are nowadays largely adopted in medicine and hence they are widespread in medical environment, where patients are present and the users are not always highly specialized in managing laser sources. This has greatly boosted the attention towards safety issues related to exposure to laser beams and to strictly assess the values of well defined laser radiation standard parameters characterizing the level of hazard of laser sources. In this framework, we measured two of the most important parameters, Maximum Permissible Exposure (MPE) and Nominal Ocular Hazard Distance (NOHD), for some of the laser sources mostly employed in medicine. Additionally, we compared our results with data elaborated from standards in order to single out safe and comfortable working conditions. The results here reported have shown that information provided by manufacturers is often not enough to define the hazard level of the laser source and measurements of the main safety parameters are mandatory.

Laser shock peening (LSP): Electrochemical and hydrodynamic investigation of corrosion protection pre-treatment for a copper surface in 3.5 % NaCl medium

“…It is worthy to mention that the proposed LSP process is cost-effective especially at industrial scale since the same laser source can be used for a large number of products. It is easily applicable by simply shinning the laser light on the metal surface and environmentally friendly since the biological hazard can only occur at exposure such as a direct incident of laser on eye or skin and this can be managed through the laid down protocols [32].…”

Computational modelling of scleral photocrosslinking: from rat to minipig to human

“…Although increasing these three treatment parameters (per cent inspired O 2 , laser intensity, injected MB concentration) can improve crosslinking, there are safety limitations that must be balanced. Increasing laser intensity has the risk of adverse side effects, since exposure to visible light can cause damage by focusing radiation to the retina and from heat generation [ 47 ]. The maximum permissible dose of 660 nm light to human eyes for 30 min is 211 mW cm −2 [ 10 ], indicating that localized light damage is possible at the higher fluences examined in this study and associated side effects would need to be assessed.…”

1540 nm LIBS Investigation of Healthy and Pathological Human Nails

“…To excite the plasma, the radiation of a frequency-doubled Nd: YAG laser (λ = 532 nm) was used, which is the main drawback, because does not exclude damage to the eyes of the doctor and patient during LIBS excitation at this wavelength. The radiation of a Yb, Er: Glass laser (λ = 1540 nm), in contrast to the radiation of frequencydoubled Nd: YAG laser (λ = 532 nm), belongs to the eye-safe spectral range, since the radiation of this laser is absorbed by hydrated tissues of the anterior segment of the eye and does not reach the more sensitive retina [18][19][20]. In this regard, 1540 nm LIBS analysis can be an effective, remote and safe method for diagnosing a wide range of diseases, including the diagnosis of onychomycosis.…”