Modification of the design of the invasive lithotripter sheath for effective urinary calculi disintegration

Human urinary calculi is still a major problem facing urologists and scientists. Besides the standard surgical removal it has been shown that these stones can be removed by non-surgical disintegration using invasive or non-invasive techniques. This paper describes an in-vitro experiment performed to study the effect of a modification introduced to the design of the sheath being used with the electrohydraulic lithotripter (EHL). The details of the design will not be discussed here, however, various parameters, namely, spark duration, the standoff distance between the electrode tip and the urinary test concretions, and the repetition rate of the electrical discharge, were examined in this experiment. It was shown that the modification not only can eliminate the EHL sources of deficiency but it can make the technique more versatile and effective, particularly for removing ureteric calculi