| Zugriffsnummer | 27079 |
| Dokumenttyp | Konferenzartikel in Zeitschrift |
| Sprache | Englisch |
| Titel | Measurement of time-averaged power in HITU fields - effects of duty cycle and target distance |
| Autor(in); Institution |
Jenderka, Klaus-Vitold; 1.6, Schall, PTB-Braunschweig; University of Applied Sciences Merseburg, Faculty of Engineering and Natural Sciences, GERMANY
Wilkens, Volker; 1.6, Schall, PTB-Braunschweig
|
| Quelle/Jahr | Conference on Advanced Metrology for Cancer Therapy 2011. Metrologia: 49 (2012), 5, S275 - S278 |
| ISSN | 0026-1394 (PRINT) ; 1681-7575 (ONLINE) |
| DOI | |
| URL | |
| Verlag | Bristol: IOP |
| Konferenzangaben | Conference on Advanced Metrology for Cancer Therapy, Braunschweig, 29, November - 01, December, 2011, Germany |
| Klassifikationscode | PACS: 43.35.+d ; PACS: 43.38.+n ; PACS: 43.58.+p ; PACS: 43.80.Vj ; PACS: 43.80.Sh ; PACS: 43.35.Yb ; PACS: 43.80.Qf |
| Freie Schlagworte | High Intensity Ultrasound ; Exposimetry ; Ultrasound Power Measurement |
| Zusammenfassung | The measurement of acoustical output parameters of high-intensity therapeutic ultrasound (HITU) and the characterization of HITU-fields are strongly required for therapy planning, safety, and system characterization. To avoid damages of sensors and targets due to high intensities and peak pressures, the applied time averaged power can be reduced by performing these measurements in burst mode. For providing reliable data of the HITU fields, thorough investigations of the differences between operation in continuous wave (cw) and burst mode and of the measurement procedures themselves are needed. In this study the influences of duty cycle and target distance on time-averaged power measurements are analyzed. Different turn-on and turn-off behaviour of the transducers depending on the applied driving voltage and the type of the power amplifier lead to variations of the effective duty cycle. Consequently, effective duty factors established at low power levels are not always retained unchanged for measurements in burst mode at high power levels.utes (PTB/Germany, NPL/UK, INRIM/Italy) and several sonication modes have been investigated (continuous wave mode, burst mode, scanning mode). The results obtained from the different types of measurement will be compared and some general aspects of the methods are discussed, not only with regard to their uncertainties during in vivo application but also with regard to their suitability for the in vitro-characterization of transducers for treatment planning. |
