Influence of optical absorption on urinary calculus threshold fluence and ablation efficiency during infrared laser ablation

Kin Foong Chan, Daniel X. Hammer, Bernard Choi, Gracie Vargas, Brian Sorg, T. Joshua Pfefer, Joel M.H. Teichman, H. Stan McGuff, Hans Pratisto, E. Duco Jansen, A. J. Welch

Research output: Contribution to journalConference article

1 Scopus citations

Abstract

The objectives of this study were to determine if the optical absorption properties of urinary calculi affect the threshold fluence for ablation or fragmentation and the ablation efficiency due to laser irradiation. The Vanderbilt free electron laser (FEL) was tuned to selected wavelengths based on the absorption spectrum of various types of urinary calculi. The threshold fluences for ablation of the calculi were measured at different wavelengths. A preliminary study of the ablation efficiency (ablation depth per unit incidence fluence) was performed. The results were found to be in agreement with a thermal ablation model for which the threshold fluences were proportional to 1/μa. The ablation efficiencies were higher in regions of the infrared spectra in which absorption was higher. For a fixed laser irradiation, the lower threshold fluences within regions of high optical absorption allowed more energy to enhance calculus ablation. This study provided insight into determining the optimum wavelengths for ablation and laser lithotripsy.

Original languageEnglish (US)
Pages (from-to)60-68
Number of pages9
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume3925
StatePublished - Jan 1 2000
Externally publishedYes
EventBiomedical Applications of Free-Electron Lasers - San Jose, CA, USA
Duration: Jan 22 2000Jan 22 2000

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Chan, K. F., Hammer, D. X., Choi, B., Vargas, G., Sorg, B., Pfefer, T. J., Teichman, J. M. H., McGuff, H. S., Pratisto, H., Jansen, E. D., & Welch, A. J. (2000). Influence of optical absorption on urinary calculus threshold fluence and ablation efficiency during infrared laser ablation. Proceedings of SPIE - The International Society for Optical Engineering, 3925, 60-68.