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US 8,539,812 B2Granted
Air bubble detector
AssigneeZevek, Inc.
InventorsMark Stringham, Roger Millis, John Foley, David Blaine
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Abstract
Air bubbles may be characterized by an air bubble detector by choosing an optimum set of frequencies and then comparing a return signal from a sensor receiving those frequencies against an internal reference. The number of pulses that exceed the internal reference represents a width and may be counted. The width, as counted, may be correlated to bubble characteristics including volume.
Claims4
A method of detecting bubbles comprising:
- sending a first ultrasonic signal through a fluid path by an ultrasonic transmitter, the signal corresponding to a first range of ultrasonic frequencies;
- reporting a detected signal by an ultrasonic receiver;
- selecting an internal receiver signal reference;
- determining the amount of time the detected signal exceeds the internal reference;
- and
- calculating bubble size based on the amount of time the detected signal exceeds the internal reference;
- determining a resonant frequency based upon the detected signal from the first range of ultrasonic frequencies;
- storing the resonant frequency;
- sending a second ultrasonic signal through the fluid path by the ultrasonic transmitter, the signal corresponding to a second range of ultrasonic frequencies surrounding the resonant frequency;
- resending the first ultrasonic signal after a degradation in the detected signal is detected from sending the second ultrasonic signal;
- and
- redetermining the resonant frequency based upon the detected signal from the resending of the first range of ultrasonic frequencies.
9 more elements
Dependencies are inferred from the claim text.