In vivo pressure measurements of lithotripsy shock waves in pigs

Robin O. Cleveland, David A. Lifshitz, Bret A. Connors, Andrew Evan, Lynn R. Willis, Lawrence A. Crum

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

Stone comminution and tissue damage in lithotripsy are sensitive to the acoustic field within the kidney, yet knowledge of shock waves in vivo is limited. We have made measurements of lithotripsy shock waves inside pigs with small hydrophones constructed of a 25-μm PVDF membrane stretched over a 21-mm diameter ring. A thin layer of silicone rubber was used to isolate the membrane electrically from pig fluid. A hydrophone was positioned around the pig kidney following a flank incision. Hydrophones were placed on either the anterior (shock wave entrance) or the posterior (shock wave exit) surface of the left kidney. Fluoroscopic imaging was used to orient the hydrophone perpendicular to the shock wave. For each pig, the voltage settings (12-24 kV) and the position of the shock wave focus within the kidney were varied. Waveforms measured within the pig had a shape very similar to those measured in water, but the peak pressure was about 70% of that in water. The focal region in vivo was 82 mm x 20 mm, larger than that measured in vitro (57 mm x 12 mm). It appeared that a combination of nonlinear effects and inhomogeneities in the tissue broadened the focus of the lithotripter. The shock rise time was on the order of 100 ns, substantially more than the rise time measured in water, and was attributed to higher absorption in tissue.

Original languageEnglish
Pages (from-to)293-306
Number of pages14
JournalUltrasound in Medicine and Biology
Volume24
Issue number2
DOIs
StatePublished - Feb 1998

Fingerprint

swine
Lithotripsy
pressure measurement
shock waves
Swine
hydrophones
kidneys
Pressure
Kidney
Water
Silicone Elastomers
Membranes
water
membranes
silicone rubber
comminution
Acoustics
Shock
entrances
waveforms

Keywords

  • Dornier HM3
  • ESWL
  • In vivo acoustic pressure measurement
  • Lithotripsy
  • PVDF hydrophone
  • Shock waves

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Cleveland, R. O., Lifshitz, D. A., Connors, B. A., Evan, A., Willis, L. R., & Crum, L. A. (1998). In vivo pressure measurements of lithotripsy shock waves in pigs. Ultrasound in Medicine and Biology, 24(2), 293-306. https://doi.org/10.1016/S0301-5629(97)00270-6

In vivo pressure measurements of lithotripsy shock waves in pigs. / Cleveland, Robin O.; Lifshitz, David A.; Connors, Bret A.; Evan, Andrew; Willis, Lynn R.; Crum, Lawrence A.

In: Ultrasound in Medicine and Biology, Vol. 24, No. 2, 02.1998, p. 293-306.

Research output: Contribution to journalArticle

Cleveland, RO, Lifshitz, DA, Connors, BA, Evan, A, Willis, LR & Crum, LA 1998, 'In vivo pressure measurements of lithotripsy shock waves in pigs', Ultrasound in Medicine and Biology, vol. 24, no. 2, pp. 293-306. https://doi.org/10.1016/S0301-5629(97)00270-6
Cleveland, Robin O. ; Lifshitz, David A. ; Connors, Bret A. ; Evan, Andrew ; Willis, Lynn R. ; Crum, Lawrence A. / In vivo pressure measurements of lithotripsy shock waves in pigs. In: Ultrasound in Medicine and Biology. 1998 ; Vol. 24, No. 2. pp. 293-306.
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