发明名称 |
Bubble measuring instrument and method |
摘要 |
Method 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.
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申请公布号 |
US6467331(B1) |
申请公布日期 |
2002.10.22 |
申请号 |
US20020113646 |
申请日期 |
2002.03.26 |
申请人 |
THE UNITED STATES OF AMERICA AS REPRESENTED BY THE ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION |
发明人 |
KLINE-SCHODER ROBERT;MAGARI PATRICK J. |
分类号 |
A61B8/08;G01N29/036;G01N29/34;G01N29/42;G01N29/46;G01S7/52;(IPC1-7):G01N7/00;G01N9/28;B01F3/04;C09K3/30 |
主分类号 |
A61B8/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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