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Proceedings Paper

Optimal pneumatic settings for the Lithoclast Ultra in a cystolitholapaxy model
Author(s): Michael K. Louie; Gregory Lowe; Bodo E. Knudsen
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Paper Abstract

The Lithoclast Ultra(R) is a combined ultrasonic and pneumatic lithotrite shown to speed the fragmentation and clearance of renal calculi. We constructed an ex vivo cystolitholapaxy model to investigate the optimal pneumatic frequency for the Lithoclast Ultra(R). Bego and U-30 test stones were used. Ten trials of each stone type were performed at each setting. Each trial consisted of ultrasonic lithotripsy alone, and then in combination with pneumatic lithotripsy at frequencies of 2Hz, 4Hz, 8Hz, and 12 Hz. Ultrasonic lithotripsy alone was the control group. The ultrasound settings remained constant at 100% power and 90% duty. Time to 5mm fragments and time to stone clearance were recorded. Mean time to 5mm fragments for Bego stones using ultrasound alone, and with the pneumatic lithotrite at 2Hz, 4Hz, 8Hz, and 12Hz was 21min, 14min, 10min, 13min, and 14min respectively. Mean time to stone clearance for Bego stones was 29min, 25min, 23min, 22min, and 22min respectively. Mean time to 5mm fragments for U-30 stones was 101s, 89s, 68s, 64s, and 66s respectively. Mean time to stone clearance for U-30 stones was 162s, 148s, 133s, 137s, and 127s respectively. The combination of pneumatic and ultrasonic lithotrites decreases the time to stone fragmentation and clearance compared to ultrasound alone. The optimal pneumatic frequency appears to reach a plateau at 4Hz.

Paper Details

Date Published: 8 February 2008
PDF: 7 pages
Proc. SPIE 6842, Photonic Therapeutics and Diagnostics IV, 684214 (8 February 2008); doi: 10.1117/12.762911
Show Author Affiliations
Michael K. Louie, Univ. of California, Irvine Medical Ctr. (United States)
Gregory Lowe, The Ohio State Univ. Medical Ctr. (United States)
Bodo E. Knudsen, The Ohio State Univ. Medical Ctr. (United States)


Published in SPIE Proceedings Vol. 6842:
Photonic Therapeutics and Diagnostics IV
Kenton W. Gregory; Guillermo J. Tearney; Reza S. Malek; Nikiforos Kollias; Bernard Choi; Haishan Zeng; Brian Jet-Fei Wong; Justus F. R. Ilgner; Henry Hirschberg; Steen J. Madsen, Editor(s)

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