title: Conversion of an HM3 lithotripter into a research device.
abstract: OBJECTIVE
  To describe the conversion of a Dornier HM3 lithotripter into a research device and evaluate its performance.
  
  
  METHODS
  A used HM3 lithotripter was donated to our university by the St. Thomas' Hospital in London. It was disassembled, shipped to our laboratory, partially assembled, and modified as a research lithotripter. Pressure measurements at several positions and kidney stone model fragmentation tests were performed to evaluate the modified system. Results were compared with information published by other authors and data obtained in our laboratory using another electrohydraulic research lithotripter.
  
  
  RESULTS
  Pressure records showed typical lithotripter waveforms with a rapid rise to about 50 MPa, followed by decay to a negative peak of approximately 9 MPa. Maximum compressional peaks were obtained at F2 and 25 mm below F2. Kidney stone model fragmentation was typical for electrohydraulic shockwave lithotripters.
  
  
  CONCLUSIONS
  Comparison of pressure measurements with data obtained by other authors on the same lithotripter several years ago indicate that the pressure waveform has not changed significantly. A much smaller water tank, a small X-Y-Z positioner, and no X-ray imaging system facilitate the use of this shockwave generator for in vitro experiments with small samples such as vials containing cell suspensions, having the advantage of a reliable, well-known, and well-characterized commercial shockwave generator.
authors.affiliation: Centro de Física Aplicada y Tecnología Avanzada, UNAM, Juriquilla, Qro, México. loske@fata.unam.mx
authors.forename: Achim M
authors.initials: AM
authors.lastname: Loske
authors.forename: Arturo
authors.initials: A
authors.lastname: Méndez
authors.forename: Francisco
authors.initials: F
authors.lastname: Fernández
authors.forename: Helmuth
authors.initials: H
authors.lastname: Busch
authors.forename: Mario
authors.initials: M
authors.lastname: Granizo
authors.forename: Fernando E
authors.initials: FE
authors.lastname: Prieto
mesh_terms: D035843:Biomedical Research / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D008096:Lithotripsy / Q000295:instrumentation*; D008962:Models, Theoretical