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Jiao L, Wang C, Zhang K, Wang J, Yang Z. Porcine skin damage threshold from mid-infrared optical parametric oscillator radiation at 3.743 µm. BIOMEDICAL OPTICS EXPRESS 2020; 11:7165-7174. [PMID: 33408987 PMCID: PMC7747919 DOI: 10.1364/boe.409387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/09/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
There is increasing use of mid-infrared optical parametric oscillator radiation operating in the wavelength range of 3-5 µm. To expand existing damage data for skin exposure to lasers in this wavelength region, the in-vivo damage threshold at the wavelength of 3.743 µm was determined in a Guizhou miniature pig model for an exposure duration of 1.0 s. The irradiance of the laser spot was nearly Gaussian-distributed and the 1/e2 beam diameter on the animal skin surface was fixed at 0.94 and 0.88 cm along horizontal and vertical directions. Damage lesion determinations were performed at 1- and 24-hour post-exposure. The probit analysis was employed to establish the ED50 values. The ED50 expressed in peak radiant exposure for the Gaussian spot was 4.04 J/cm2 at the 24-hour post-exposure. Sufficient margin existed between the damage threshold and MPE from the current laser safety standard. The obtained data may contribute to the knowledge base for refinement of laser safety standard in the wavelength range of 2.6-1000 µm.
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Affiliation(s)
- Luguang Jiao
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Chao Wang
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Kaizeng Zhang
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Jiarui Wang
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Zaifu Yang
- Beijing Institute of Radiation Medicine, Beijing 100850, China
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Tulsawani R, Sharma P, Sethy NK, Kumari P, Ganju L, Prakash S, Chouhan S. Acute exposure of 532 nm laser differentially regulates skin tissue transcription factors. PLoS One 2020; 15:e0230175. [PMID: 32191734 PMCID: PMC7082019 DOI: 10.1371/journal.pone.0230175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 02/24/2020] [Indexed: 12/16/2022] Open
Abstract
High energy laser, particularly 532 nm, is widely used in defense and medical applications and there is need to address its occupational safety. Thermal and non-thermal effects of 532 nm high energy laser on skin are cause of concern. This study indicates impact of 532 nm laser on rat skin and first of its kind of attempt to understand transcriptional activation of genes as an early response following laser exposure. Skin of experimental rats were exposed to 532 nm radiance at 0.1, 0.25 and 0.50 W/cm2 for 10 sec. Thermographic changes of skin exposed to 532 nm laser exhibited increased Tmax temperature in radiance dependent manner. After thermal imaging, skin of experimental rats was collected 1 h post laser exposure for studying differential gene expression. The skin exposed to lower power density (0.1 W/cm2) did not show significant changes in expression of gene pathways studied. At moderate radiance (0.25 W/cm2), predominantly canonical wnt/B-catenin pathway genes notch1, axin2, ccdn1, wnt5a and redox homeostasis genes; txn1, nqo1 and txnrd1 were expressed. At higher radiance (0.5 W/cm2), significant repression of genes related to wound healing process particularly notch/wnt pathway viz. hes5, wnt1, wn3b with higher expression of dab2 was recorded. The data obtained from these studies would help in drawing safety limits for skin exposure to 532 nm laser. Further, genes expressed at moderate and high level of radiance exposure to skin were distinct and differential and provide new avenue to configure pathway to counteract laser induced delay in tissue injury and hair follicular damage.
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Affiliation(s)
| | - Purva Sharma
- Defence Institute of Physiology and Allied Sciences, Delhi, India
| | | | - Pooja Kumari
- Defence Institute of Physiology and Allied Sciences, Delhi, India
| | - Lilly Ganju
- Defence Institute of Physiology and Allied Sciences, Delhi, India
| | - Satya Prakash
- Laser Science and Technology Centre, Metcalfe House, Delhi, India
| | - Satish Chouhan
- Defence Institute of Physiology and Allied Sciences, Delhi, India
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Jiao L, Wang J, Fan Y, Yang Z. Porcine skin damage thresholds and histological damage characteristics from 1319-nm laser radiation. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-9. [PMID: 31552723 PMCID: PMC6997579 DOI: 10.1117/1.jbo.24.9.095003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
There is an increasing use of near-infrared lasers in biomedical applications operating in the spectrum between 1300 and 1400 nm. To corroborate and expand the existing safety data for skin exposure to lasers in this wavelength region, the in-vivo ED50 damage thresholds were determined in Guizhou miniature pigs for 1319-nm laser radiation. Exposure durations of 0.4, 1.0, and 3.0 s and 1 / e2 beam diameters of 0.98 and 1.96 cm were employed. Damage lesion determinations were performed at 1- and 24 h post exposure. The Bliss probit analysis was employed to establish the ED50 damage thresholds. Histopathological studies of skin damage were performed at 48 h after irradiation to reveal the damage characteristics. The skin damage thresholds at 1 h post exposure, given in peak radiant exposure, were 35.5, 36.1, and 37.1 J / cm2 at exposure durations of 0.4, 1.0, and 3.0 s with the spot diameter of 0.98 cm, and 28.6 J / cm2 at exposure duration of 3.0 s with the spot diameter of 1.96 cm. At 24 h post exposure, the ED50s increased slightly. Histologically, the thermal damage characteristics at the near-threshold level included gathering of the nuclear chromatin and cell vacuolation in the epidermis and deposition of blood cells in the capillary vessels. However, at the apparently above-threshold level, the damage characteristics included obvious stretching of the nuclear chromatin in the epidermis, closing of the capillary lumen, structural change of collagen fibers, and coagulative necrosis of the hair follicle cells. The damage induced by this laser could go deep into the fatty tissue. The obtained results may contribute to the knowledge base for the damage mechanisms and expand the database for the refinement of laser safety standards in the wavelength range of 1300 to 1400 nm.
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Affiliation(s)
- Luguang Jiao
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Jiarui Wang
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Yan Fan
- Beijing Institute of Radiation Medicine, Beijing, China
| | - Zaifu Yang
- Beijing Institute of Radiation Medicine, Beijing, China
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DeLisi MP, Schmidt MS, Hoffman AF, Peterson AM, Noojin GD, Shingledecker AD, Boretsky AR, Stolarski DJ, Kumru SS, Thomas RJ. Thermal damage thresholds for multiple-pulse porcine skin laser exposures at 1070 nm. JOURNAL OF BIOMEDICAL OPTICS 2019; 25:1-11. [PMID: 31489806 PMCID: PMC7011167 DOI: 10.1117/1.jbo.25.3.035001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
As solid-state laser technology continues to mature, high-energy lasers operating in the near-infrared (NIR) band have seen increased utilization in manufacturing, medical, and military applications. Formulations of maximum permissible exposure limits establish guidelines for the safe use of these systems for a given set of laser parameters, based on past experimental and analytical studies of exposure thresholds causing injury to the skin and eyes. The purpose of our study is to characterize the skin response to multiple-pulsed laser exposures at the NIR wavelength of 1070 nm, at a constant beam diameter of 1 cm, using anesthetized Yucatan mini-pig subjects. Our study explores three constant total laser-on times of 0.01, 0.1, and 10 s as single- and multiple-pulse sequences. Exposures consisting of 10, 30, and 100 pulses have identical individual pulse durations but different duty cycles in order to include variable degrees of thermal additivity. A plurality of three observers quantifies skin damage with the minimally visible lesion metric, judged at the 1- and 24-h intervals postexposure. Calculation of the median effective dose (ED50) provides injury thresholds for all exposure conditions, based on varying laser power across subjects. The results of this study will provide a quantitative basis for the incorporation of multiple-pulsed laser exposure into standards and augment data contained in the existing ED50 database.
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Affiliation(s)
| | - Morgan S. Schmidt
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
| | - Aaron F. Hoffman
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
| | | | | | | | | | | | - Semih S. Kumru
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
| | - Robert J. Thomas
- 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, Texas, United States
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Hibst R, Saal D, Russ D, Kunzi-Rapp K, Kienle A, Stock K. Thermal effects of white light illumination during microsurgery: clinical pilot study on the application safety of surgical microscopes. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:048003. [PMID: 20799846 DOI: 10.1117/1.3475953] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Modern operating microscopes offer high power illumination to ensure optimal visualization, but can also cause thermal damage. The aim of our study is to quantify the thermal effects in vivo and discuss conditions for safe use. In a pilot study on volunteers, we measured the temperature at the skin surface during microscope illumination, including the influence of anaesthesia and the effects of staining, draping, or moistening of the skin. Irradiation within the limit given by safety regulations (200 mW/cm(2)) results in skin surface temperature of 43 degrees C. Higher intensities (forearm 335 mW/cm(2), back 250 mW/cm(2)) are tolerated, resulting in reversible hyperaemia. At a very high illumination intensity (750 mW/cm(2)), pain occurs within 30 s at temperatures of 46 degrees C+/-1 degrees C (hand and forearm), and 43 degrees C+/-2 degrees C (back), respectively. Anaesthesia has no distinct effect on the temperature, whereas staining and drapes result in much higher temperatures (>100 degrees C). Moistening at practicable flow rates can reduce temperature efficiently when combined with a light absorbing and water absorbent drape. In conclusion, surgeons must be aware that surgical microscope illumination without protective means can cause skin temperatures to rise much above pain threshold, which in our study serves as a (conservative) benchmark for potential damage.
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Affiliation(s)
- Raimund Hibst
- Universitat Ulm, Institut fur Lasertechnologien in der Medizin und Messtechnik an der Universitat Ulm, Ulm, Germany.
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Schaaf D, Johnson T. Relationships of skin depths and temperatures when varying pulse repetition frequencies from 2.0-microm laser light incident on pig skin. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:045007. [PMID: 20799802 DOI: 10.1117/1.3477324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Human perception of 2.0-microm infrared laser irradiation has become significant in such disparate fields as law enforcement, neuroscience, and pain research. Several recent studies have found damage thresholds for single-pulse and continuous wave irradiations at this wavelength. However, the only publication using multiple-pulse irradiations was investigating the cornea rather than skin. Literature has claimed that the 2.0-microm light characteristic thermal diffusion time was as long as 300-ms. Irradiating the skin with 2.0-microm lasers to produce sensation should follow published recommendations to use pulses on the order of 10 to 100 ms, which approach the theoretical thermal diffusion time. Therefore, investigation of the heating of skin for a variety of laser pulse combinations was undertaken. Temperatures of ex vivo pig skin were measured at the surface and at three depths from pulse sequences of six different duty factors. Differences were found in temperature rise per unit exposure that did not follow a linear relation to duty factor. The differences can be explained by significant heat conduction during the pulses. Therefore, the common heat modeling assumption of thermal confinement during a pulse may need to be experimentally verified if the pulse approaches the theoretical thermal confinement time.
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Affiliation(s)
- David Schaaf
- Colorado State University, Department of Environmental and Radiological Health Sciences, Fort Collins, Colorado 80523, USA
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Laser literature watch. Photomed Laser Surg 2006; 24:661-76. [PMID: 17069502 DOI: 10.1089/pho.2006.24.661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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