In vitro erbium: YAG laser lithotripsy

Kin Foong Chan; Gracie Vargas; Patricia J. Parker; Joel M H Teichman; Randolph D. Glickman; H. Stan McGuff; A. J. Welch

In vitro erbium: YAG laser lithotripsy

Kin Foong Chan, Gracie Vargas, Patricia J. Parker, Joel M H Teichman, Randolph D. Glickman, H. Stan McGuff, A. J. Welch

Department of Ophthalmology

Research output: Chapter in Book/Report/Conference proceeding › Chapter

5 Scopus citations

Abstract

The potential application of an Erbium:YAG (Er:YAG) laser (Q _o = 50 mJ/pulse; τ _p = 275 μs; rep. rate = 2, 10 Hz) with a sapphire delivery fiber for intracorporeal laser lithotripsy was explored. Preliminary measurements on calculus mass-loss and fragmentation efficiency were conducted and results were compared with that of Ho:YAG laser lithotripsy. Laser induced bubble and lithotripsy dynamics were investigated to assess the mechanism(s) involved in the fragmentation process. Results showed that the fragmentation efficiency (mass-loss/H _o - g.μm ²/J) in Er:YAG laser lithotripsy was about 2.4 times that of Ho:YAG laser lithotripsy (used: Q _o = 500 mJ/pulse; τ _p = 250 μs; rep. rate = 10 Hz). Acoustic transients were found to have minimal effect during Er:YAG laser lithotripsy. Schlieren flash images suggested a predominantly photothermal mechanism due to direct laser energy absorption, which resulted in recrystallization and plume formation. These events indicated melting and chemical decomposition of the calculus composition. Another observation led to the possibility of a plasma-mediated photothermal mechanism. The 'Moses effect' facilitating pulsed mid-infrared laser delivery appeared more efficient for the Er:YAG laser than for the Ho:YAG laser. With the sapphire fiber, experimental results suggested the potential of an improved treatment modality by the Er:YAG laser for intracorporeal laser lithotripsy.

Original language	English (US)
Title of host publication	Proceedings of SPIE - The International Society for Optical Engineering
Publisher	Society of Photo-Optical Instrumentation Engineers
Pages	198-206
Number of pages	9
Volume	3914
State	Published - 2000
Event	Laser-Tissue Interaction XI: Photochemical, Photothermal, and Photomechanical - San Jose, CA, USA Duration: Jan 22 2000 → Jan 27 2000

Other

Other	Laser-Tissue Interaction XI: Photochemical, Photothermal, and Photomechanical
City	San Jose, CA, USA
Period	1/22/00 → 1/27/00

ASJC Scopus subject areas

Electrical and Electronic Engineering
Condensed Matter Physics

Cite this

Chan, KF, Vargas, G, Parker, PJ, Teichman, JMH, Glickman, RD, McGuff, HS & Welch, AJ 2000, In vitro erbium: YAG laser lithotripsy. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 3914, Society of Photo-Optical Instrumentation Engineers, pp. 198-206, Laser-Tissue Interaction XI: Photochemical, Photothermal, and Photomechanical, San Jose, CA, USA, 1/22/00.

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title = "In vitro erbium: YAG laser lithotripsy",

abstract = "The potential application of an Erbium:YAG (Er:YAG) laser (Q o = 50 mJ/pulse; τ p = 275 μs; rep. rate = 2, 10 Hz) with a sapphire delivery fiber for intracorporeal laser lithotripsy was explored. Preliminary measurements on calculus mass-loss and fragmentation efficiency were conducted and results were compared with that of Ho:YAG laser lithotripsy. Laser induced bubble and lithotripsy dynamics were investigated to assess the mechanism(s) involved in the fragmentation process. Results showed that the fragmentation efficiency (mass-loss/H o - g.μm 2/J) in Er:YAG laser lithotripsy was about 2.4 times that of Ho:YAG laser lithotripsy (used: Q o = 500 mJ/pulse; τ p = 250 μs; rep. rate = 10 Hz). Acoustic transients were found to have minimal effect during Er:YAG laser lithotripsy. Schlieren flash images suggested a predominantly photothermal mechanism due to direct laser energy absorption, which resulted in recrystallization and plume formation. These events indicated melting and chemical decomposition of the calculus composition. Another observation led to the possibility of a plasma-mediated photothermal mechanism. The 'Moses effect' facilitating pulsed mid-infrared laser delivery appeared more efficient for the Er:YAG laser than for the Ho:YAG laser. With the sapphire fiber, experimental results suggested the potential of an improved treatment modality by the Er:YAG laser for intracorporeal laser lithotripsy. ",

author = "Chan, {Kin Foong} and Gracie Vargas and Parker, {Patricia J.} and Teichman, {Joel M H} and Glickman, {Randolph D.} and McGuff, {H. Stan} and Welch, {A. J.}",

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T2 - Laser-Tissue Interaction XI: Photochemical, Photothermal, and Photomechanical

AU - Chan, Kin Foong

AU - Vargas, Gracie

AU - Parker, Patricia J.

AU - Teichman, Joel M H

AU - Glickman, Randolph D.

AU - McGuff, H. Stan

AU - Welch, A. J.

PY - 2000

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AB - The potential application of an Erbium:YAG (Er:YAG) laser (Q o = 50 mJ/pulse; τ p = 275 μs; rep. rate = 2, 10 Hz) with a sapphire delivery fiber for intracorporeal laser lithotripsy was explored. Preliminary measurements on calculus mass-loss and fragmentation efficiency were conducted and results were compared with that of Ho:YAG laser lithotripsy. Laser induced bubble and lithotripsy dynamics were investigated to assess the mechanism(s) involved in the fragmentation process. Results showed that the fragmentation efficiency (mass-loss/H o - g.μm 2/J) in Er:YAG laser lithotripsy was about 2.4 times that of Ho:YAG laser lithotripsy (used: Q o = 500 mJ/pulse; τ p = 250 μs; rep. rate = 10 Hz). Acoustic transients were found to have minimal effect during Er:YAG laser lithotripsy. Schlieren flash images suggested a predominantly photothermal mechanism due to direct laser energy absorption, which resulted in recrystallization and plume formation. These events indicated melting and chemical decomposition of the calculus composition. Another observation led to the possibility of a plasma-mediated photothermal mechanism. The 'Moses effect' facilitating pulsed mid-infrared laser delivery appeared more efficient for the Er:YAG laser than for the Ho:YAG laser. With the sapphire fiber, experimental results suggested the potential of an improved treatment modality by the Er:YAG laser for intracorporeal laser lithotripsy.

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ER -

In vitro erbium: YAG laser lithotripsy

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