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In vitro analysis of stone fragmentation ability of the FREDDY laser.
J Endourol. 2003 Apr; 17(3):177-9.JE

Abstract

BACKGROUND AND PURPOSE

The Frequency-Doubled Double-Pulse Nd:Yag) (FREDDY) laser (World of Medicine, Berlin Germany) is a short-pulsed, double-frequency solid-state laser with wavelengths of 532 and 1064 nm. This low-power, low-cost laser was developed for intracorporeal lithotripsy. We designed an experimental set-up to test its fragmentation efficiency at different energy and frequency settings.

MATERIALS AND METHODS

Forty previously weighed plaster-of-Paris stone phantoms were divided into four groups in order to test fragmentation at 5 and 10 Hz for 2 and 4 minutes. A hands-off underwater laboratory set-up including a holder to keep the stone phantom in contact with the quartz laser fiber was utilized. The 280-microm laser fiber was cleaved and stripped between runs to ensure optimal energy delivery. After fragmentation was completed, all of the stone fragments remaining within the holder were allowed to desiccate for 48 hours and reweighed. Fragmentation was measured as the percentage weight loss.

RESULTS

Stone phantoms fragmented at 5 Hz for 2 minutes sustained a mean 24% loss of weight, whereas the 4-minute treatment at 5 Hz reduced stone weight by 54%. Treatment at 10 Hz for 2 minutes demonstrated results similar to those of stones treated for 4 minutes at 5 Hz, reducing stone weight by 51%. Fragmentation at 10 Hz for 4 minutes revealed a 64% loss of mass, less than expected for these power settings. Fiber deterioration observed at the higher energy settings may be the cause of the reduced stone-fragmentation efficiency.

CONCLUSIONS

Fragmentation with the FREDDY laser in the 5 Hz, 4 minutes and 10 Hz, 2 minutes protocols is comparable, suggesting that stone fragmentation correlates well with the total energy delivered to the stone. The slight drop in fragmentation efficiency at 10 Hz, 4 minutes is most likely explained by fiber damage occurring consistently at these higher energy settings. The safety profile and low investment and running costs of this laser are advantages that suggest the laser warrants further clinical trials.

Authors+Show Affiliations

Comprehensive Kidney Stone Center, Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

12803991

Citation

Delvecchio, Fernando C., et al. "In Vitro Analysis of Stone Fragmentation Ability of the FREDDY Laser." Journal of Endourology, vol. 17, no. 3, 2003, pp. 177-9.
Delvecchio FC, Auge BK, Brizuela RM, et al. In vitro analysis of stone fragmentation ability of the FREDDY laser. J Endourol. 2003;17(3):177-9.
Delvecchio, F. C., Auge, B. K., Brizuela, R. M., Weizer, A. Z., Zhong, P., & Preminger, G. M. (2003). In vitro analysis of stone fragmentation ability of the FREDDY laser. Journal of Endourology, 17(3), 177-9.
Delvecchio FC, et al. In Vitro Analysis of Stone Fragmentation Ability of the FREDDY Laser. J Endourol. 2003;17(3):177-9. PubMed PMID: 12803991.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - In vitro analysis of stone fragmentation ability of the FREDDY laser. AU - Delvecchio,Fernando C, AU - Auge,Brian K, AU - Brizuela,Ricardo M, AU - Weizer,Alon Z, AU - Zhong,Pei, AU - Preminger,Glenn M, PY - 2003/6/14/pubmed PY - 2003/8/9/medline PY - 2003/6/14/entrez SP - 177 EP - 9 JF - Journal of endourology JO - J Endourol VL - 17 IS - 3 N2 - BACKGROUND AND PURPOSE: The Frequency-Doubled Double-Pulse Nd:Yag) (FREDDY) laser (World of Medicine, Berlin Germany) is a short-pulsed, double-frequency solid-state laser with wavelengths of 532 and 1064 nm. This low-power, low-cost laser was developed for intracorporeal lithotripsy. We designed an experimental set-up to test its fragmentation efficiency at different energy and frequency settings. MATERIALS AND METHODS: Forty previously weighed plaster-of-Paris stone phantoms were divided into four groups in order to test fragmentation at 5 and 10 Hz for 2 and 4 minutes. A hands-off underwater laboratory set-up including a holder to keep the stone phantom in contact with the quartz laser fiber was utilized. The 280-microm laser fiber was cleaved and stripped between runs to ensure optimal energy delivery. After fragmentation was completed, all of the stone fragments remaining within the holder were allowed to desiccate for 48 hours and reweighed. Fragmentation was measured as the percentage weight loss. RESULTS: Stone phantoms fragmented at 5 Hz for 2 minutes sustained a mean 24% loss of weight, whereas the 4-minute treatment at 5 Hz reduced stone weight by 54%. Treatment at 10 Hz for 2 minutes demonstrated results similar to those of stones treated for 4 minutes at 5 Hz, reducing stone weight by 51%. Fragmentation at 10 Hz for 4 minutes revealed a 64% loss of mass, less than expected for these power settings. Fiber deterioration observed at the higher energy settings may be the cause of the reduced stone-fragmentation efficiency. CONCLUSIONS: Fragmentation with the FREDDY laser in the 5 Hz, 4 minutes and 10 Hz, 2 minutes protocols is comparable, suggesting that stone fragmentation correlates well with the total energy delivered to the stone. The slight drop in fragmentation efficiency at 10 Hz, 4 minutes is most likely explained by fiber damage occurring consistently at these higher energy settings. The safety profile and low investment and running costs of this laser are advantages that suggest the laser warrants further clinical trials. SN - 0892-7790 UR - https://www.unboundmedicine.com/medline/citation/12803991/In_vitro_analysis_of_stone_fragmentation_ability_of_the_FREDDY_laser_ L2 - https://www.liebertpub.com/doi/10.1089/089277903321618752?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -