This thesis describes the research carried out by the author on the exploitation of acoustic emissionsdetected during extracorporeal shockwave lithotripsy (a non-invasive procedure for the treatment ofurinary stones) to develop a new diagnostic system. The work formed part of a research project onlithotripsy undertaken by the University of Southampton in collaboration with Guy's and St Thomas'NHS Foundation Trust (London) and a UK based company, Precision Acoustics Ltd (Dorchester). Ittakes to a clinical conclusion the proposition made by Leighton and Coleman in 1992 that it might bepossible to build a sensor which would automatically exploit these passive acoustic emissions tomonitor the efficacy of a lithotripsy treatment. The work, predominantly experimental, involved bothin vitro and in vivo investigations. In particular, a first prototype diagnostic system (i.e. sensor plusanalysis software) was developed and tested in vitro during trials which included the use of a novelcavitation sensor (on loan from the National Physical Laboratory, Teddington) and stone phantomsdesigned by the author. This initial system was, then, refined and tested during clinical trials thatinvolved 130 patients. A preliminary trial on 51 patients aimed at refining the system and gatheringknowledge on the features of emissions recorded in vivo to produce an on-line monitoring system.This trial was followed by other two trials that compared the output of the on-line acoustic systemagainst the ‘gold standard’ X-Ray assessment of treatments outcomes. The former of these two trialsinvolved 30 patients, and empirically defined the values of the key parameters (identified during thein vitro tests) that would be used as the basis of the diagnosis. In particular, a classification rule oftreatments as being successful or unsuccessful was identified, and shown to agree significantly(kappa=0.95) with the ‘gold standard’ follow-up assessment. The latter trial tested the final systemon 49 patients and confirmed an accurate treatment classification (kappa=0.94) in terms of thesuccessful/unsuccessful criterion.
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