Abstract

To support refinement of the ANSI Maximum Permissible Exposure safety limits, a series of experiments were conducted in vivo on Dutch Belted rabbit corneas to determine corneal minimum visible lesion thresholds for 2.0μm continuous-wave laser irradiation. Single pulse radiant exposures were made at specified pulse durations of 0.1, 0.25, 0.5, 1.0, 2.0, and 4.0s for spot 1e2 diameters of 1.17mm and 4.02mm. Threshold lesions were defined as the presence of a superficial surface whitening one hour after irradiation. Temperature measurements indicated that threshold peak temperatures were dependent on spot size and exposure duration. The exposure duration dependence of threshold average radiant exposure was described by an empirical power law equation: threshold radiant exposure[Jcm2]=a×exposure duration[s]b.

© 2007 Optical Society of America

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References

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  1. E. J. Maher, "Transmission and absorption coefficients for ocular media of the rhesus monkey," Report SAM-TR-78-32 (U.S. Air Force School of Aerospace Medicine, Brooks Air Force Base, 1978).
  2. R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
    [CrossRef] [PubMed]
  3. R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
    [CrossRef] [PubMed]
  4. R. L. McCally and C. B. Bargeron, "Epithelial damage thresholds for multiple-pulse exposures to 80ns pulses of CO2 laser radiation," Health Phys. 80, 41-46 (2001).
    [CrossRef] [PubMed]
  5. C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
    [CrossRef] [PubMed]
  6. J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
    [CrossRef] [PubMed]
  7. R. L. McCally, R. A. Farrell, and C. B. Bargeron, "Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 microns," Lasers Surg. Med. 12, 598-603 (1992).
    [CrossRef]
  8. ANSI Z136.1-2007, American National Standard for Safe Use of Lasers, Laser Institute of America, Orlando, Florida (American National Standards Institute, 2007).
  9. B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
    [CrossRef]
  10. D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
    [CrossRef]
  11. A. E. Siegman, M. W. Sasnett, and T. F. Johnston, "Choice of clip levels for beam width measurements using knife-edge techniques," IEEE J. Quantum Electron. 27, 1098-1104 (1991).
    [CrossRef]
  12. D. J. Finney, Probit Analysis, 3rd ed. (Cambridge U. Press, 1971).
  13. R. L. McCally and C. B. Bargeron, "Corneal epithelial injury thresholds for multiple-pulse exposures to Tm:YAG laser radiation at 2.02 μm," Health Phys. 85, 420-427 (2003).
    [CrossRef] [PubMed]
  14. R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).
  15. G. M. Hale and M. R. Querry, "Optical constants of water in the 200nm to 200μm wavelength region," Appl. Opt. 12, 555-563 (1973).
    [CrossRef] [PubMed]
  16. D. M. Maurice, The Cornea and Sclera in the Eye, 3rd ed., H.Davson, ed. (Academic, 1984), pp. 289-368.
  17. S. L. Jacques, "Role of tissue optics and pulse duration on tissue effects during high-power laser irradiation," Appl. Opt. 32, 2447-2454 (1993).
    [CrossRef] [PubMed]
  18. L. A. Priebe and A. J. Welch, "Asymptotic rate process calculations of thermal injury to retina following laser irradiation," Mech. Eng. 100, 49-54 (1978).
  19. A. R. Moritz and F. C. Henriques Jr., "Studies of thermal injury: II. The relative importance of time and surface temperature in the causation of cutaneous burns," Am. J. Pathol. 23, 695-720 (1947).
    [PubMed]

2005 (2)

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).

2003 (1)

R. L. McCally and C. B. Bargeron, "Corneal epithelial injury thresholds for multiple-pulse exposures to Tm:YAG laser radiation at 2.02 μm," Health Phys. 85, 420-427 (2003).
[CrossRef] [PubMed]

2002 (1)

D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
[CrossRef]

2001 (1)

R. L. McCally and C. B. Bargeron, "Epithelial damage thresholds for multiple-pulse exposures to 80ns pulses of CO2 laser radiation," Health Phys. 80, 41-46 (2001).
[CrossRef] [PubMed]

1993 (1)

1992 (1)

R. L. McCally, R. A. Farrell, and C. B. Bargeron, "Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 microns," Lasers Surg. Med. 12, 598-603 (1992).
[CrossRef]

1991 (1)

A. E. Siegman, M. W. Sasnett, and T. F. Johnston, "Choice of clip levels for beam width measurements using knife-edge techniques," IEEE J. Quantum Electron. 27, 1098-1104 (1991).
[CrossRef]

1989 (1)

C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
[CrossRef] [PubMed]

1984 (1)

J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
[CrossRef] [PubMed]

1983 (1)

R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
[CrossRef] [PubMed]

1978 (1)

L. A. Priebe and A. J. Welch, "Asymptotic rate process calculations of thermal injury to retina following laser irradiation," Mech. Eng. 100, 49-54 (1978).

1973 (1)

1969 (1)

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

1947 (1)

A. R. Moritz and F. C. Henriques Jr., "Studies of thermal injury: II. The relative importance of time and surface temperature in the causation of cutaneous burns," Am. J. Pathol. 23, 695-720 (1947).
[PubMed]

Bargeron, C. B.

R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).

R. L. McCally and C. B. Bargeron, "Corneal epithelial injury thresholds for multiple-pulse exposures to Tm:YAG laser radiation at 2.02 μm," Health Phys. 85, 420-427 (2003).
[CrossRef] [PubMed]

R. L. McCally and C. B. Bargeron, "Epithelial damage thresholds for multiple-pulse exposures to 80ns pulses of CO2 laser radiation," Health Phys. 80, 41-46 (2001).
[CrossRef] [PubMed]

R. L. McCally, R. A. Farrell, and C. B. Bargeron, "Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 microns," Lasers Surg. Med. 12, 598-603 (1992).
[CrossRef]

C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
[CrossRef] [PubMed]

R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
[CrossRef] [PubMed]

Blankenstein, M. F.

J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
[CrossRef] [PubMed]

Bonney-Ray, J. A.

R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).

Chen, B.

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

Deters, O. J.

C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
[CrossRef] [PubMed]

Farrell, R. A.

R. L. McCally, R. A. Farrell, and C. B. Bargeron, "Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 microns," Lasers Surg. Med. 12, 598-603 (1992).
[CrossRef]

C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
[CrossRef] [PubMed]

R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
[CrossRef] [PubMed]

Finney, D. J.

D. J. Finney, Probit Analysis, 3rd ed. (Cambridge U. Press, 1971).

Gabel, V. P.

D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
[CrossRef]

Green, W. R.

R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).

R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
[CrossRef] [PubMed]

Hale, G. M.

Harrison, R. F.

J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
[CrossRef] [PubMed]

Henriques, F. C.

A. R. Moritz and F. C. Henriques Jr., "Studies of thermal injury: II. The relative importance of time and surface temperature in the causation of cutaneous burns," Am. J. Pathol. 23, 695-720 (1947).
[PubMed]

Jacques, S. L.

Johnston, T. F.

A. E. Siegman, M. W. Sasnett, and T. F. Johnston, "Choice of clip levels for beam width measurements using knife-edge techniques," IEEE J. Quantum Electron. 27, 1098-1104 (1991).
[CrossRef]

Maher, E. J.

E. J. Maher, "Transmission and absorption coefficients for ocular media of the rhesus monkey," Report SAM-TR-78-32 (U.S. Air Force School of Aerospace Medicine, Brooks Air Force Base, 1978).

Maurice, D. M.

D. M. Maurice, The Cornea and Sclera in the Eye, 3rd ed., H.Davson, ed. (Academic, 1984), pp. 289-368.

McCally, R. L.

R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).

R. L. McCally and C. B. Bargeron, "Corneal epithelial injury thresholds for multiple-pulse exposures to Tm:YAG laser radiation at 2.02 μm," Health Phys. 85, 420-427 (2003).
[CrossRef] [PubMed]

R. L. McCally and C. B. Bargeron, "Epithelial damage thresholds for multiple-pulse exposures to 80ns pulses of CO2 laser radiation," Health Phys. 80, 41-46 (2001).
[CrossRef] [PubMed]

R. L. McCally, R. A. Farrell, and C. B. Bargeron, "Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 microns," Lasers Surg. Med. 12, 598-603 (1992).
[CrossRef]

C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
[CrossRef] [PubMed]

R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
[CrossRef] [PubMed]

Mellerio, J.

D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
[CrossRef]

Moritz, A. R.

A. R. Moritz and F. C. Henriques Jr., "Studies of thermal injury: II. The relative importance of time and surface temperature in the causation of cutaneous burns," Am. J. Pathol. 23, 695-720 (1947).
[PubMed]

O'Dell, D. C.

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

Peabody, R. R.

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

Peppers, N. A.

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

Priebe, L. A.

L. A. Priebe and A. J. Welch, "Asymptotic rate process calculations of thermal injury to retina following laser irradiation," Mech. Eng. 100, 49-54 (1978).

Querry, M. R.

Rockwell, B. A.

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

Rose, H. W.

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

Sasnett, M. W.

A. E. Siegman, M. W. Sasnett, and T. F. Johnston, "Choice of clip levels for beam width measurements using knife-edge techniques," IEEE J. Quantum Electron. 27, 1098-1104 (1991).
[CrossRef]

Schulmeister, K.

D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
[CrossRef]

Siegman, A. E.

A. E. Siegman, M. W. Sasnett, and T. F. Johnston, "Choice of clip levels for beam width measurements using knife-edge techniques," IEEE J. Quantum Electron. 27, 1098-1104 (1991).
[CrossRef]

Sliney, D. H.

D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
[CrossRef]

Thomas, S. J.

J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
[CrossRef] [PubMed]

Thomsen, S. L.

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

Vassiliadis, A.

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

Welch, A. J.

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

L. A. Priebe and A. J. Welch, "Asymptotic rate process calculations of thermal injury to retina following laser irradiation," Mech. Eng. 100, 49-54 (1978).

Zuclich, J. A.

J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
[CrossRef] [PubMed]

Zweng, C.

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

Am. J. Pathol. (1)

A. R. Moritz and F. C. Henriques Jr., "Studies of thermal injury: II. The relative importance of time and surface temperature in the causation of cutaneous burns," Am. J. Pathol. 23, 695-720 (1947).
[PubMed]

Appl. Opt. (2)

Arch. Ophthalmol. (1)

R. R. Peabody, C. Zweng, H. W. Rose, N. A. Peppers, and A. Vassiliadis, "Threshold damage from CO2 lasers," Arch. Ophthalmol. 82, 105-107 (1969).
[CrossRef] [PubMed]

Exp. Eye Res. (1)

R. L. McCally, C. B. Bargeron, W. R. Green, and R. A. Farrell, "Stromal damage in rabbit corneas exposed to CO2 laser radiation," Exp. Eye Res. 37, 543-550 (1983).
[CrossRef] [PubMed]

Health Phys. (5)

R. L. McCally and C. B. Bargeron, "Epithelial damage thresholds for multiple-pulse exposures to 80ns pulses of CO2 laser radiation," Health Phys. 80, 41-46 (2001).
[CrossRef] [PubMed]

C. B. Bargeron, O. J. Deters, R. A. Farrell, and R. L. McCally, "Epithelial damage in rabbit corneas exposed to CO2 laser radiation," Health Phys. 56, 85-95 (1989).
[CrossRef] [PubMed]

J. A. Zuclich, M. F. Blankenstein, S. J. Thomas, and R. F. Harrison, "Corneal damage induced by pulsed CO2 laser radiation," Health Phys. 47, 829-835 (1984).
[CrossRef] [PubMed]

D. H. Sliney, J. Mellerio, V. P. Gabel, and K. Schulmeister, "What is the meaning of threshold in laser injury experiments? Implications for human exposure limits," Health Phys. 82, 335-347 (2002).
[CrossRef]

R. L. McCally and C. B. Bargeron, "Corneal epithelial injury thresholds for multiple-pulse exposures to Tm:YAG laser radiation at 2.02 μm," Health Phys. 85, 420-427 (2003).
[CrossRef] [PubMed]

IEEE J. Quantum Electron. (1)

A. E. Siegman, M. W. Sasnett, and T. F. Johnston, "Choice of clip levels for beam width measurements using knife-edge techniques," IEEE J. Quantum Electron. 27, 1098-1104 (1991).
[CrossRef]

Johns Hopkins APL Tech. Dig. (1)

R. L. McCally, C. B. Bargeron, J. A. Bonney-Ray, and W. R. Green, "Laser eye safety research at APL," Johns Hopkins APL Tech. Dig. 26, 46-55 (2005).

Lasers Surg. Med. (2)

B. Chen, D. C. O'Dell, S. L. Thomsen, B. A. Rockwell, and A. J. Welch, "Porcine skin ED50 damage thresholds for 2,000nm laser irradiation," Lasers Surg. Med. 37, 373-381 (2005).
[CrossRef]

R. L. McCally, R. A. Farrell, and C. B. Bargeron, "Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 microns," Lasers Surg. Med. 12, 598-603 (1992).
[CrossRef]

Mech. Eng. (1)

L. A. Priebe and A. J. Welch, "Asymptotic rate process calculations of thermal injury to retina following laser irradiation," Mech. Eng. 100, 49-54 (1978).

Other (4)

D. M. Maurice, The Cornea and Sclera in the Eye, 3rd ed., H.Davson, ed. (Academic, 1984), pp. 289-368.

ANSI Z136.1-2007, American National Standard for Safe Use of Lasers, Laser Institute of America, Orlando, Florida (American National Standards Institute, 2007).

E. J. Maher, "Transmission and absorption coefficients for ocular media of the rhesus monkey," Report SAM-TR-78-32 (U.S. Air Force School of Aerospace Medicine, Brooks Air Force Base, 1978).

D. J. Finney, Probit Analysis, 3rd ed. (Cambridge U. Press, 1971).

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Figures (5)

Fig. 1
Fig. 1

Experimental configuration for corneal damage study.

Fig. 2
Fig. 2

Slit lamp images of thermal damage at 1 h post exposure. (a) Spot diameter 4.02 mm , exposure duration 0.5 s , power 789.7 mw (approximately equals threshold power); Grade 1 was assigned as the severity of this lesion; this superficial surface whitening was defined as threshold lesion. (b) Spot diameter 1.17 mm , exposure duration 0.25 s , power 181 mw (approximately 1.2 times threshold power); Grade 2 was assigned. (c) Spot diameter 1.17 mm , exposure duration 0.25 s , power 231.2 mw (approximately 1.5 times threshold power); Grade 3 was assigned.

Fig. 3
Fig. 3

Example of the linear fit of peak temperature rise versus power. Laser condition: 1.17 mm spot diameter, 0.5 s exposure duration; circles represent damage observed on cornea after laser irradiation.

Fig. 4
Fig. 4

Comparison of transient peak temperature responses by threshold power irradiation at 1.17 mm and 4.02 mm spot diameters: Solid curve: 2.0 s exposure duration, 93.2 mW power (threshold power 87.6 mW ). Dashed curve: 2.0 s exposure duration, 412.4 mW power (threshold power 402.4 mW ).

Fig. 5
Fig. 5

Comparison of threshold average radiant exposures along with the power-law fitting curves for 1.17 mm and 4.02 mm spot sizes.

Tables (6)

Tables Icon

Table 1 Maximum Permissible Exposure (MPE) for Corneal Exposure to a Laser Beam

Tables Icon

Table 2 ED50 Threshold Power [mw] and Standard Deviation Associated with Their Fiducial Limits and Probit Curve Slopes

Tables Icon

Table 3 Slopes of the Linear Fits of Peak Temperature Rise with Respect to Power a

Tables Icon

Table 4 Peak Temperature at the Spot Center for Threshold Irradiation ( 0 C )

Tables Icon

Table 5 Results of Power-Law a Fitting of Threshold Radiant Exposure

Tables Icon

Table 6 Experimental Threshold Average Radiant Exposures a and ANSI MPE Values with Their Safety Factors

Equations (12)

Equations on this page are rendered with MathJax. Learn more.

P tot = ε T R P ( T obj ) + ( 1 ε ) T R P refl .
N tot = ε N ( T obj ) + ( 1 ε ) N refl ,
{ N tape = 0.95 N ( T tape ) + ( 1 0.95 ) N refl N cor = ε N ( T cor ) + ( 1 ε ) N refl ,
ε = 0.95 N cor N refl N tape N refl .
σ = ( ED 84 ED 16 ) 2 ,
Slope = δ p δ d ,
H = J π r 2 ,
μ a = μ water w ,
H = a t b ,
H max = 0.56 t 0.25 ,
k = a 0.56 t ( b 0.25 ) ,
Ω ( x , y , z , t ) = 0 t A e [ E R T ( x , y , z , t ) ] d t ,

Metrics