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Bubble Measuring Instrument and MethodMethod and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer. respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble. In a preferred embodiment, software control maintains the beat signal at a preselected frequency while varying the pump transducer frequency to excite bubbles of different diameters to resonate depending on the range of bubble diameters selected for investigation.
Document ID
20020078061
Acquisition Source
Johnson Space Center
Document Type
Other - Patent
Authors
Kline-Schoder, Robert
(NASA Johnson Space Center Houston, TX United States)
Magari, Patrick J.
(NASA Johnson Space Center Houston, TX United States)
Date Acquired
September 7, 2013
Publication Date
June 25, 2002
Subject Category
Instrumentation And Photography
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-Patent-6,408,679|NASA-Case-MSC-22980-1
Patent Application
US-Patent-Appl-SN-498440
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