Bubble detector and method of use thereof
AssigneeTherOx, Inc.
InventorsDaw J. Derek, Jeffrey L. Creech, William R. Patterson
Life of this patent
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Abstract
A bubble detector utilizes an ultrasonic transducer to sample bubbles as they pass the transducer. The envelope of the return signal is analyzed to determine the volume of each sampled bubble. If the total volume of bubbles sampled within a certain period of time exceeds a desired maximum volume, the bubble detector may initiate a system shut down. A bubble detector can be evaluated or calibrated by introducing bubbles into a conduit, detecting the bubbles introduced into the conduit using visual inspection or a bubble detector of known resolution and comparing the results with the examination of a bubble detector under evaluation.
Claims31
A bubble detector comprising:
- an ultrasonic transducer pair comprising a transmitting transducer and a receiving transducer, the ultrasonic transducer pair being positionable to sense bubbles in a fluid flow, wherein a pressure of the fluid is higher than a patient's blood pressure;
- a transducer driver operatively coupled to the transmitting transducer to cause the transmitting transducer to deliver a pulsed ultrasonic signal across the fluid flow to the receiving transducer;
- a signal conditioner operatively coupled to the receiving transducer to receive the pulsed ultrasonic signal from the receiving transducer, the signal conditioner conditioning the pulsed ultrasonic signal to produce a conditioned signal;
- and
- a signal processor operatively coupled to the signal conditioner to receive the conditioned signal, the signal processor determining a first volume of each bubble based on the conditioned signal and converting the first volume to a second volume based on the fluid pressure and an atmospheric pressure, wherein the first volume is a measured volume of the bubble in the fluid and the second volume is a predicted volume of the bubble when it enters the patient.
A method of detecting bubbles in a fluid flow, wherein a pressure of the fluid is higher than a patient's blood pressure, comprising the acts of:
- (a) transmitting a pulsed ultrasonic signal across the fluid flow;
- (b) receiving the pulsed ultrasonic signal transmitted across the fluid flow;
- (c) conditioning the received pulsed ultrasonic signal to produce a conditioned signal;
- (d) processing the conditioned signal to determine a presence of bubbles in the fluid flow and a first volume of each bubble;
- and
- (e) converting the first volume of the bubble into a second volume based on the fluid pressure and an atmospheric pressure, wherein the first volume is a measured volume of the bubble in the fluid and the second volume is a predicted volume of the bubble when it enters the patient.
Dependencies are inferred from the claim text.