Characterization of a 50-μm-core optical fiber for potential use in Thulium fiber laser lithotripsy

Richard L. Blackmon, Thomas C. Hutchens, Luke A. Hardy, Pierce B. Irby, Nathaniel M. Fried

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Our laboratory is currently studying the Thulium fiber laser (TFL) as a potential alternative laser lithotripter to the standard clinical Holmium:YAG laser. We have previously demonstrated efficient coupling of TFL energy into fibers as small as 100-μm-core-diameter without damage to the proximal end. Although smaller fibers have greater tendency to degrade at the distal tip during lithotripsy, fiber diameters (≤ 200 μm) have been shown to increase saline irrigation rates through the working channel of a flexible ureteroscope, maximize ureteroscope deflection, and reduce stone retropulsion during laser lithotripsy. In this study, a 50-μm-core-diameter, 85-μm-outer-diameter fiber is characterized for TFL ablation of human calcium oxalate monohydrate urinary stones, ex vivo. The stone ablation rate was measured to be 70 ± 22 μg/s for 35-mJ-pulse-energy, 500-μs-pulse-duration, and 50-Hz-pulse-rate. The ureteroscope working channel flow rate including the 50-μm fiber decreased by only 10% with no impairment of ureteroscope deflection. The fiber delivered up to 15.4 ± 5.9 W under extreme bending (5-mm-radius) conditions. Stone retropulsion and fiber burn-back averaged 201 ± 336 and 3000 ± 2600 μm, respectively, after 2 minutes. With further development, Thulium fiber laser lithotripsy using ultra-small, 50-μm-core fibers may introduce new integration and miniaturization possibilities and potentially provide an alternatiμe to conventional Holmium:YAG laser lithotripsy using larger fibers.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISBN (Print)9780819498397
StatePublished - 2014
EventPhotonic Therapeutics and Diagnostics X - San Francisco, CA, United States
Duration: Feb 1 2014Feb 2 2014


OtherPhotonic Therapeutics and Diagnostics X
Country/TerritoryUnited States
CitySan Francisco, CA


  • 50-μm-core fiber
  • Ablation
  • Burnback
  • Lithotripsy
  • Retropulsion
  • Thulium
  • Urinary stones

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Characterization of a 50-μm-core optical fiber for potential use in Thulium fiber laser lithotripsy'. Together they form a unique fingerprint.

Cite this