Threshold of permanent cornea thermal damage due to incidental continuous wave CO2 laser irradiation

Cornea thermal damage due to incidental continuous wave CO2 laser irradiation is studied numerically based on bio-heat equation. The interaction of laser with tissue leads to a rapid temperature increased in target and the nearby tissue. As the temperature of the eye surface reaches 44?C, a sensation of pain will cause aversion response of the reflex blink and/or shifting away from the source of pain. The aim of the work is to predict numerically the threshold limit of incidental laser power that causes damage to the anterior part of the cornea, which can be healed within 2-5 days as long as damage is not exceeding the outer part of the eye (epithelium). A finite element analysis is used to predict temperature distribution through the cornea where the necroses region can be obtained using thermal dose equation. The thermal dose that required for damaging the cornea is predicted from previously published experimental data on rhesus monkeys and used later as a limit for shrinkage to human cornea. The result of this work is compared by international standard of safety and a good nearby result is obtained which verified the result of this work.

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Effect of scanned quasi-cw CO2 laser irradiation on tissue thermal damage

Laser-Tissue Interaction V; and Ultraviolet Radiation Hazards ◽

10.1117/12.182944 ◽

1994 ◽

Author(s):

Geoffrey Silver ◽

Norman S. Nishioka ◽

Jina Chung ◽

Yacov Domankevitz ◽

Dominic Bua ◽

...

Keyword(s):

Laser Irradiation ◽

Co2 Laser ◽

Thermal Damage ◽

Cw Co2 Laser

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Validity of reciprocity rule on mouse skin thermal damage due to CO2 laser irradiation

Optics and Spectroscopy ◽

10.1134/s0030400x13070138 ◽

2013 ◽

Vol 115 (1) ◽

pp. 147-154 ◽

Cited By ~ 3

Author(s):

P. Parvin ◽

H. R. Dehghanpour ◽

M. S. Moghadam ◽

V. Daneshafrooz

Keyword(s):

Laser Irradiation ◽

Co2 Laser ◽

Thermal Damage ◽

Mouse Skin

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Copper oxides obtained by CO2 laser irradiation of copper salts

Journal of Materials Research ◽

10.1557/jmr.1994.1257 ◽

1994 ◽

Vol 9 (5) ◽

pp. 1257-1263 ◽

Cited By ~ 2

Author(s):

C. Popescu ◽

D. Fatu ◽

Rodica Alexandrescu ◽

I. Voicu ◽

I. Morjan ◽

...

Keyword(s):

Copper Oxide ◽

Laser Irradiation ◽

Heating Rate ◽

Co2 Laser ◽

Continuous Wave ◽

Copper Oxides ◽

Thermal Heating ◽

X Ray Diffraction ◽

Copper Salts ◽

X Ray

Various copper salts have been irradiated with the help of a continuous wave CO2 laser. In other experiments the same salts have been decomposed under a controlled heating rate, in a thermal balance, and copper oxide crystallites have been detected as the final product of both types of experiment. The measurements of crystallites performed with the help of x-ray diffraction exhibited differences between the two types of oxides: those obtained by laser irradiation as compared with the oxides obtained by thermal heating. The magnitude of this difference seems to depend on the laser quanta absorptivity of the initial salts. The results are consistent with those obtained previously on nickel oxides.

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Thermal damage produced by high-lrradiance continuous wave CO2 laser cutting of tissue

Lasers in Surgery and Medicine ◽

10.1002/lsm.1900100115 ◽

1990 ◽

Vol 10 (1) ◽

pp. 74-84 ◽

Cited By ~ 45

Author(s):

Kevin T. Schomacker ◽

Joseph T. Walsh ◽

Thomas J. Flotte ◽

Thomas F. Deutsch

Keyword(s):

Co2 Laser ◽

Laser Cutting ◽

Thermal Damage ◽

Continuous Wave

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Thermal damage due to incidental continuous CO2 laser irradiation on human skin

Thermal Science ◽

10.2298/tsci1002451s ◽

2010 ◽

Vol 14 (2) ◽

pp. 451-458

Author(s):

Khalid Shibib

Keyword(s):

Human Skin ◽

Co2 Laser ◽

Thermal Damage ◽

Damage Zone ◽

Transient Temperature ◽

Thermal Dose ◽

Perfusion Rate ◽

Exposed Area ◽

Temperature Distributions ◽

Continuous Co2 Laser

The use of laser instruments in almost every aspect of technology may lead to sudden exposing of human skin to laser radiation, especially with an invisible laser, such as continuous CO2 laser, causing harmful thermal damage to the exposed area. This phenomena is studied in this work where the size of thermal damage is obtained using a well-known thermal dose equation which requires the transient temperature distributions obtained from finite element solution of the axi-symmetric heat equation. In this work a numerical simulation of these processes is applied indicating that the size of thermal damage zone inside human tissue seems to increase as power increases even if the exposing time is reduced, whereas the shape of thermally damage zone extends laterally much more than in-depth due to the effect of absorption coefficient and perfusion rate of skin tissue. Finally, this work may establish the concept of numerical investigation of an incidental laser hazard on human skin.

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Effect of CO2 laser irradiation on arc welding

International Congress on Applications of Lasers & Electro-Optics ◽

10.2351/1.5059064 ◽

1996 ◽

Cited By ~ 1

Author(s):

Nobuyuki Abe ◽

Yasuo Agano ◽

Masahiro Tsukamoto ◽

Takeshi Makino ◽

Masakazu Hayashi ◽

...

Keyword(s):

Laser Irradiation ◽

Co2 Laser ◽

Arc Welding

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Thin-Film Processing of Polypropylene and Polystyrene Sheets by a Continuous Wave CO2 Laser with the Cu Cooling Base

Polymers ◽

10.3390/polym13091448 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1448

Author(s):

Nobukazu Kameyama ◽

Hiroki Yoshida ◽

Hitoshi Fukagawa ◽

Kotaro Yamada ◽

Mitsutaka Fukuda

Keyword(s):

Thin Film ◽

Co2 Laser ◽

Continuous Wave ◽

Cw Laser ◽

Heat Effects ◽

Film Processing ◽

Carbon Dioxide Co2 ◽

A Minor ◽

Residual Heat ◽

Thin Film Processing

Carbon dioxide (CO2) laser is widely used in commercial and industrial fields to process various materials including polymers, most of which have high absorptivity in infrared spectrum. Thin-film processing by the continuous wave (CW) laser is difficult since polymers are deformed and damaged by the residual heat. We developed the new method to make polypropylene (PP) and polystyrene (PS) sheets thin. The sheets are pressed to a Cu base by extracting air between the sheets and the base during laser processing. It realizes to cut the sheets to around 50 µm thick with less heat effects on the backside which are inevitable for thermal processing using the CW laser. It is considered that the boundary between the sheets and the base is in thermal equilibrium and the base prevents the sheets from deforming to support the backside. The method is applicable to practical use since it does not need any complex controls and is easy to install to an existing equipment with a minor change of the stage.

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