Effect of the body wall on lithotripter shock waves

Guangyan Li, James A. Mcateer, James Williams, Zachary C. Berwick

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Purpose: Determine the influence of passage through the body wall on the properties of lithotripter shock waves (SWs) and the characteristics of the acoustic field of an electromagnetic lithotripter. Methods: Full-thickness ex vivo segments of pig abdominal wall were secured against the acoustic window of a test tank coupled to the lithotripter. A fiber-optic probe hydrophone was used to measure SW pressures, determine shock rise time, and map the acoustic field in the focal plane. Results: Peak positive pressure on axis was attenuated roughly proportional to tissue thickness - approximately 6% per cm. Irregularities in the tissue path affected the symmetry of SW focusing, shifting the maximum peak positive pressure laterally by as much as ∼2 mm. Within the time resolution of the hydrophone (7-15 ns), shock rise time was unchanged, measuring ∼17-21 ns with and without tissue present. Mapping of the field showed no effect of the body wall on focal width, regardless of thickness of the body wall. Conclusions: Passage through the body wall has minimal effect on the characteristics of lithotripter SWs. Other than reducing pulse amplitude and having the potential to affect the symmetry of the focused wave, the body wall has little influence on the acoustic field. These findings help to validate laboratory assessment of lithotripter acoustic field and suggest that the properties of SWs in the body are much the same as have been measured in vitro.

Original languageEnglish
Pages (from-to)446-452
Number of pages7
JournalJournal of Endourology
Volume28
Issue number4
DOIs
StatePublished - Apr 1 2014

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Acoustics
Shock
Pressure
Myelinated Nerve Fibers
Electromagnetic Fields
Abdominal Wall
Swine

ASJC Scopus subject areas

  • Urology

Cite this

Effect of the body wall on lithotripter shock waves. / Li, Guangyan; Mcateer, James A.; Williams, James; Berwick, Zachary C.

In: Journal of Endourology, Vol. 28, No. 4, 01.04.2014, p. 446-452.

Research output: Contribution to journalArticle

Li, Guangyan ; Mcateer, James A. ; Williams, James ; Berwick, Zachary C. / Effect of the body wall on lithotripter shock waves. In: Journal of Endourology. 2014 ; Vol. 28, No. 4. pp. 446-452.
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