Advertisement

Pressure Measurements in a Wolf Piezolith 2200 Lithotripter

  • C. J. Chuong
  • P. Zhong
  • G. M. Preminger

Abstract

We have developed a PC-based system and a measurement protocol to study characteristics of acoustic shock waves generated by a extracorporeal shock wave lithotripter. * The system has the following capabilities: data acquisition, data transfer, mass storage, wave form analysis, and graphics display. Using this system, we measured the peak pressure distribution within a cylindrical region of 120 × 70 mm (diameter × height) surrounding the geometric focal point of a Richard Wolf Piezolith 2200 lithotripter. At a given point, we aligned the transducer along the local radial line from the focal point so that its sensing element would capture the incident wave front. Due to the axisymmetric nature of the wave-generator geometry and of the pressure loadings generated, measurement from one meridian plane was deemed sufficient. On a meridian plane, a total of 105 measurements were made with 15 taken from each of the seven radial lines at θ = 0, 15, 30, 45, 60, 75, 90 degrees, respectively. We repeated measurements at meridian planes at every 90 degrees to make a total of four measurements for one location. Results were mapped and displayed with a three-dimensional surface plot to show the spatial distribution of peak pressure within the region of measurement. We also made a two-dimensional contour plot to show the shape and size of the focal zone within the region. The peak pressure at the geometrical focal point was measured to be 8.6 Kpsi (600 bar). An ellipsoidal shaped focal zone with peak pressure of 6 Kpsi or higher was found to have major and minor axes of 9.8 and 2.6 mm, respectively. We may have underestimated peak pressures due to the transducers used. Experiments with new probes are currently underway.

Keywords

Shock Wave Peak Pressure Shock Wave Lithotripsy Extracorporeal Shock Wave Lithotripsy Meridian Plane 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Chaussy C: Extracorporeal Shock Wave Lithotripsy, Second Edition. Basel, Switzerland: Karger.Google Scholar
  2. 2.
    Sauerbruch T, Delius M, Paumgartner G, et al: Fragmentation of gallstones by extracorporeal shock waves. NEJM 314: 818, 1986.PubMedCrossRefGoogle Scholar
  3. 3.
    Hunter PT, Finlayson B, Hirko RJ, et al: Measurement of shock wave pressures used for lithotripsy. J Urol 136: 733, 1986.PubMedGoogle Scholar
  4. 4.
    Coleman AJ and Saunders JE: The lithotripter: a non-invasive method for the disintegration of renal stone by extracorporeally generated shock waves. IPSM Report 47.Google Scholar
  5. 5.
    Coleman AJ, Saunders JE, Preston RC, et al: Pressure wave forms generated by a Dornier extracorporeal shock wave lithotripter. Ultrasound Med Biol 13: 651, 1987.PubMedCrossRefGoogle Scholar
  6. 6.
    Richard Wolf Inc: User Instructional Manual for the Piezolith 2200, Richard Wolf Inc., West Germany.Google Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • C. J. Chuong
    • 1
  • P. Zhong
    • 1
  • G. M. Preminger
    • 2
  1. 1.Biomedical Engineering ProgramUniversity of TexasArlingtonUSA
  2. 2.Urology Division, Surgery DepartmentUniversity of Texas Southwestern Medical CenterDallasUSA

Personalised recommendations