Instantaneous beamwidth measurements of an electrohydraulic lithotripter

Ketterling, Jeffrey A.; Filoux, Erwan; Alibakhshi, Mohammad Amin

doi:10.1109/ultsym.2010.5935813

Cited by 2 publications

(2 citation statements)

References 6 publications

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“…Because of the observed variation in direct-wave pressure and previous measurements that demonstrated the relative sensitivity of all the elements from a single hydrophone array typically were within 10% of the mean sensitivity, 24 we made the decision to calculate a single, uniform sensitivity value for all of the elements rather than to obtain an elementby-element sensitivity or to determine a new sensitivity for every direct wave. However, for two of the arrays, the relative sensitivity displayed an unusually large variation on a select few central elements.…”

Section: Ehl Testing and Calibrationmentioning

confidence: 99%

Single-shot measurements of the acoustic field of an electrohydraulic lithotripter using a hydrophone array

Alibakhshi

Kracht

Cleveland

et al. 2013

The Journal of the Acoustical Society of America

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Piezopolymer-based hydrophone arrays consisting of 20 elements were fabricated and tested for use in measuring the acoustic field from a shock-wave lithotripter. The arrays were fabricated from piezopolymer films and were mounted in a housing to allow submersion into water. The motivation was to use the array to determine how the shot-to-shot variability of the spark discharge in an electrohydraulic lithotripter affects the resulting focused acoustic field. It was found that the dominant effect of shot-to-shot variability was to laterally shift the location of the focus by up to 5 mm from the nominal acoustic axis of the lithotripter. The effect was more pronounced when the spark discharge was initiated with higher voltages. The lateral beamwidth of individual, instantaneous shock waves were observed to range from 1.5 mm to 24 mm. Due to the spatial variation of the acoustic field, the average of instantaneous beamwidths were observed to be 1 to 2 mm narrower than beamwidths determined from traditional single-point measurements that average the pressure measured at each location before computing beamwidth.

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Section: Ehl Testing and Calibrationmentioning

confidence: 99%

Single-shot measurements of the acoustic field of an electrohydraulic lithotripter using a hydrophone array

Alibakhshi

Kracht

Cleveland

et al. 2013

The Journal of the Acoustical Society of America

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“…The hydrophone arrays were fabricated using a technique similar to that described in [2], [5], [6]. The hydrophones were constructed by bonding a 9 µm polyvinylidene fluoride (PVDF) film to a copper-clad-polyimide (CCP) film with a non-conductive epoxy (Fig.…”

Section: A Hydrophone Arraysmentioning

confidence: 99%

Multiple-frequency calibration of two-dimensional hydrophone arrays for instantaneous beam width measurements of shock-wave lithotripters

Groß

Filoux

Ketterling

2011

2011 IEEE International Ultrasonics Symposium

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Characterizations of electrohydraulic lithotripters (EHLs) are usually limited to single-point measurements because hydrophone arrays are not readily available, or are prohibitively expensive. Furthermore, beamwidth measurements of peak pressure values made with single-point hydrophones are inaccurate. This inaccuracy comes from the high variability of the acoustic field and the fact that several shocks must be averaged to create a single beamwidth profile when using single-element hydrophones. Previous work demonstrated that characterizing the beam of an EHL with a single-point measurement technique led to an overestimate error of 25% compared to an instantaneous beamwidth measurement using a linear hydrophone array. In this paper, the improvement of our disposable, repeatable, hydrophone array is presented. The geometry was changed to that of a two-dimensional hydrophone array, which allows for the measurement of the instantaneous acoustic field of an EHL and its variation in 2-D. Modifications were made to the hydrophone fabrication methods which improved sensitivity and performance. Finally, a multiple-frequency calibration technique was implemented, allowing absolute pressures to be obtained for each hydrophone element.

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Instantaneous beamwidth measurements of an electrohydraulic lithotripter

Cited by 2 publications

References 6 publications

Single-shot measurements of the acoustic field of an electrohydraulic lithotripter using a hydrophone array

Single-shot measurements of the acoustic field of an electrohydraulic lithotripter using a hydrophone array

Multiple-frequency calibration of two-dimensional hydrophone arrays for instantaneous beam width measurements of shock-wave lithotripters

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