Bubble measuring instrument and method
First Claim
1. A video bubble sizing test system for performing dynamic bubble measurements, comprising:
- a video camera with software and associated memory for capturing a set of video images of a group of bubbles as said group of bubbles moves along a fluid flowpath over a time interval, which video camera includes software and memory means for measuring bubble sizes in comparison to a known reference size or scale, a sight tube extending along said fluid flowpath and containing said group of moving bubbles, and a strobe for producing a plurality of separate video frames that show said bubbles resolved and separated over said time interval so as to facilitate said video bubble sizing.
0 Assignments
0 Petitions
Accused Products
Abstract
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.
83 Citations
14 Claims
-
1. A video bubble sizing test system for performing dynamic bubble measurements, comprising:
-
a video camera with software and associated memory for capturing a set of video images of a group of bubbles as said group of bubbles moves along a fluid flowpath over a time interval, which video camera includes software and memory means for measuring bubble sizes in comparison to a known reference size or scale, a sight tube extending along said fluid flowpath and containing said group of moving bubbles, and a strobe for producing a plurality of separate video frames that show said bubbles resolved and separated over said time interval so as to facilitate said video bubble sizing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
a video monitor for viewing said separate video frames with bubbles therein.
-
-
3. The video bubble sizing test system of claim 1, further comprising:
said software being operable for providing statistically independent frames such that the same bubble is not measured twice in said separate video frames.
-
4. The video bubble sizing test system of claim 1, further comprising:
a bubble generator operable for selectively generating bubbles having varying diameters.
-
5. The video bubble sizing test system of claim 4, wherein said bubble generator is operable for generating bubbles at least over the range of 40 micrometers to 200 micrometers.
-
6. The video bubble sizing test system of claim 1, further comprising:
a tissue phantom through which said bubbles flow.
-
7. The video bubble sizing test system of claim 6, further comprising:
said ultransonic bubble monitor being positioned adjacent said tissue phantom for monitoring bubbles in said tissue phantom.
-
8. The video bubble sizing test system of claim 1, further comprising:
a peristaltic pump for pumping fluid so as to mimic blood flow.
-
9. A bubble diameter measuring apparatus for performing dynamic bubble measurements, comprising:
-
a controller device which is electrically connected to a bubble measuring detector, where said controller device is configured and operated to generate a set of control software that varies in response to an output from said bubble measuring detector, and a software-controlled computer with an associated memory that is operable for producing a virtual instrument on a computer monitor; and
a selection indicator on said virtual instrument for selecting a range of bubble diameters to be examined by said bubble measuring detector and software-controlled computer. - View Dependent Claims (10, 11, 12, 13)
a screen for said virtual instrument for displaying a frequency domain signal related to a particular size bubble.
-
-
11. The bubble measuring apparatus of claim 9, further comprising:
one or more selection indicators for selecting an amplitude and frequency range of said time domain signal to thereby determine whether a bubble is detected or not.
-
12. The bubble measuring apparatus of claim 10, further comprising:
a second screen for said virtual instrument with the capability of forming a virtual image for displaying a Doppler signal.
-
13. The bubble measuring apparatus of claim 9, further comprising:
a selection indicator on said virtual instrument for selecting a frequency increment related to said range of bubble diameters to be examined.
-
14. A bubble measuring apparatus, comprising:
-
a software controlled computer operable for producing a virtual instrument on a computer monitor;
a selection indicator on said virtual instrument for selecting a range of bubble diameters to be examined;
a screen for said virtual instrument for displaying a frequency domain signal related to a particular bubble size; and
software for generating summary charts that display the number of bubbles detected over a selected range of bubble diameters.
-
Specification