An experimental high energy therapeutic ultrasound equipment: Design and characterisation

  • T. Kirkhorn
  • L. -O. Almquist
  • H. W. Persson
  • N. -G. Holmer
Technical Note

Abstract

High energy ultrasound equipment for well controlled experimental work on extracorporeal shockwave lithotripsy (ESWL) and hyperthermia has been built. The design of two sets of equipment with operating frequencies of 0.5 and 1.6 MHz, respectively, is described and characterised in terms of measured generated pressure fields. The treatment heads consist of six or seven focused ultrasound transducers. The transducers have a diameter of 50 mm each and are mounted in a hemispherical Plexiglass fixture with a geometrical focus 100 mm from the transducer surfaces. Measurements were performed in a water bath in several planes perpendicular to the central axis of the ultrasound beam, using a miniature hydrophone which was positioned with a computer controlled stepping motor system. Resulting diagram plots show well defined pressure foci, located at the geometrical foci of the transducer units.

Keywords

High energy focused ultrasound Acoustic pressure measurements ESWL Hyperthermia 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Almquist, L.-O., Holmer, N.-G., andHolmer, M. (1994): High energetic ultrasound. Part II Measurement of pressure focus. Report 3/1994 Dept. of Biomedical Engineering, Lund University, ISSN 1104-5841, ISRN LUMEDW/MEMT-94/7005-SE (in Swedish)Google Scholar
  2. Bamber, J. C. (1986): ‘Attenuation and absorption’,in Hill, C. R. (Ed.), ‘Physical principles of medical ultrasound’, (Ellis Horwood, England), pp. 118–199Google Scholar
  3. Berggren, M., andSvensson, T. (1993): ‘Power-generator for therapeutic ultrasound’. Report 10/1993 Department of Biomedical Engineering, Lund University, ISSN 1104-5841, ISRN LUMEDW/MENT-93/5007-SE (in Swedish)Google Scholar
  4. Coleman, A. J., andSaunders, J. E. (1989): ‘A survey of the acoustic output of commercial extracorporeal shock wave lithotripters’,Ultrasound Med. Biol.,15, pp. 213–227CrossRefGoogle Scholar
  5. Eisenberger, F., Miller, K., andRassweiler, J. (1991): ‘Stone therapy in urology’. (Georg Thieme Verlag, Stuttgart)Google Scholar
  6. ter Haar, G. R., andRobertson, D. (1993): ‘Tissue destruction with focused ultrasoundin vivo’,Eur. Urol.,23, (suppl 1), pp. 8–11Google Scholar
  7. Hynynen, K. (1987): ‘Demonstration of enhanced temperature elevation due to nonlinear propagation of focussed ultrasound in dog’s thigh in vivo’,Ultrasound Med. Biol.,13, pp. 85–91CrossRefGoogle Scholar
  8. Hynynen, K., Shimm, D., Anhalt, D., Stea, B., Sykes, H., Cassady, J. R., andRoemer, R. B. (1990): ‘Temperature distributions during clinical scanned, focused ultrasound hyperthermia treatments’,Int. J. Hyperthermia,6, pp. 891–908CrossRefGoogle Scholar
  9. Kossoff, G. (1979): ‘Analysis of focusing action of spherically curved transducers’,Ultrasound Med. Biol.,56, pp. 359–365CrossRefGoogle Scholar
  10. Persson, H. W. (1984): ‘A miniature hydrophone for ultrasonic field measurements’. Report 2/84 Department of Electrical Measurements, Lund Institute of Technology, Lund University, LUTEDEX/(TEEM-1023)1-10/(1984)Google Scholar
  11. Persson, H. W., Dymling, S. O., andHolmer, N.-G. (1991): ‘A measurement system for continuous wave ultrasound fields’,Ultrasound Med. Biol.,5, pp. 501–504CrossRefGoogle Scholar
  12. Vallancien, G., Chartier-Kastler, E., Chopin, B., Veillon, B., Brisset, J. M., andAndré-Bougaran, J. (1991): ‘Focussed extracorporeal pyrotherapy: Experimental results’,Eur. Urol.,20, pp. 211–219Google Scholar
  13. Vallancien, G., Harouni, M., Veillon, B., Mombet, A., Prapotnich, D., Brisset, J. M., andBougaran, J. (1992): ‘Focused extracorporeal pyrotherapy: Feasibility study in man’,J. Endourol.,6, (2), pp. 173–181CrossRefGoogle Scholar

Copyright information

© IFMBE 1997

Authors and Affiliations

  • T. Kirkhorn
    • 1
  • L. -O. Almquist
    • 1
  • H. W. Persson
    • 2
  • N. -G. Holmer
    • 1
  1. 1.Dept. of Biomedical EngineeringLund University, University Hospital MT-KLundSweden
  2. 2.Dept. of Electrical MeasurementsLund Institute of TechnologyLundSweden

Personalised recommendations