US5601086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beat frequency ultrasonic microsphere contrast agent detection system
Assignee: National Aeronautics and Space Administration
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Filing: 1995-05-12
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Granted: 1997-02-11
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Expires: 2015-05-12
Abstract
Abstract A system for and method of detecting and measuring concentrations of an ultrasonically-reflective microsphere contrast agent involving detecting non-linear sum and difference beat frequencies produced by the microspheres when two impinging signals with non-identical frequencies are combined by mixing. These beat frequencies can be used for a variety of applications such as detecting the presence of and measuring the flow rates of biological fluids and industrial liquids, including determining the concentration level of microspheres in the myocardium.
Inventors
- 👤 Robert A. Pretlow, III
- 👤 William T. Yost
- 👤 John H. Cantrell, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:09
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/48; A61B8/481; G; G01; G01S; G01S7/00; G01S7/52; G01S7/52017; G01S7/52023; G01S7/52036; G01S7/52038; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/895; G01S15/8952
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
99 words
An apparatus for detecting the presence of ultrasonically relative microsphere contrast agents in a fluid, comprising: means for directing ultrasonic energy into a region of the fluid at a first discrete frequency, the first frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; means for simultaneously directing ultrasonic energy into the region of fluid at a second discrete frequency that is also an approximate resonant frequency of the microspheres, wherein the microspheres in the fluid interact to emit sum and difference frequencies; and means for detecting the sum and difference frequencies.
Claim 2
Independent Claim
99 words
An apparatus for detecting the presence of ultrasonically relative microsphere contrast agents in a fluid, comprising: means for directing ultrasonic energy into a region of the fluid at a first discrete frequency, the first frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; means for simultaneously directing ultrasonic energy into the region of fluid at a second discrete frequency that is also an approximate resonant frequency of the microspheres, wherein the microspheres in the fluid interact to emit sum and difference frequencies; and means for detecting the sum and difference frequencies.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1 wherein the directing means for the ultrasonic energy at the first frequency is a transducer.
Claim 4
Dependent Claim
20 words
The apparatus of claim 2 wherein the directing means for the ultrasonic energy at the second frequency is a transducer.
Claim 5
Dependent Claim
13 words
The apparatus of claim 3 wherein the detecting means is a receive transducer.
Claim 6
Independent Claim
110 words
An apparatus for measuring the presence of ultrasonically reflective microsphere contrast agents in a living body fluid, comprising: means for injecting microbubble contrast agents into a living body; means for directing ultrasonic energy into a region of the body fluid at a first discrete frequency, the first frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; means for simultaneously directing ultrasonic energy into the region of body fluid at a second discrete frequency that is also an approximate resonant frequency of the microspheres, wherein the microspheres interact to emit sum and difference frequencies; and means for detecting the sum and difference frequencies.
Claim 7
Independent Claim
110 words
An apparatus for measuring the presence of ultrasonically reflective microsphere contrast agents in a living body fluid, comprising: means for injecting microbubble contrast agents into a living body; means for directing ultrasonic energy into a region of the body fluid at a first discrete frequency, the first frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; means for simultaneously directing ultrasonic energy into the region of body fluid at a second discrete frequency that is also an approximate resonant frequency of the microspheres, wherein the microspheres interact to emit sum and difference frequencies; and means for detecting the sum and difference frequencies.
Claim 8
Dependent Claim
20 words
The apparatus of claim 5 wherein the directing means for the ultrasonic energy at the first frequency is a transducer.
Claim 9
Dependent Claim
20 words
The apparatus of claim 6 wherein the directing means for the ultrasonic energy at the second frequency is a transducer.
Claim 10
Dependent Claim
13 words
The apparatus of claim 7 wherein the detecting means is a receive transducer.
Claim 11
Independent Claim
94 words
An method for detecting the presence of ultrasonically reflective microsphere contrast agents in a fluid, comprising: directing ultrasonic energy into a region of the fluid at a first frequency, the first discrete frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; simultaneously directing ultrasonic energy in to the region of fluid at a second discrete frequency that is also an approximate resonant frequency of the microspheres, wherein the microspheres in the fluid interact to emit sum and difference frequencies; and detecting the sum and difference frequencies.
Claim 12
Independent Claim
94 words
An method for detecting the presence of ultrasonically reflective microsphere contrast agents in a fluid, comprising: directing ultrasonic energy into a region of the fluid at a first frequency, the first discrete frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; simultaneously directing ultrasonic energy in to the region of fluid at a second discrete frequency that is also an approximate resonant frequency of the microspheres, wherein the microspheres in the fluid interact to emit sum and difference frequencies; and detecting the sum and difference frequencies.
Claim 13
Independent Claim
118 words
A method for detecting the presence of ultrasonically reflective microsphere contrast agents in a body fluid, comprising the steps of: injecting microbubble contrast agents into a living body; directing ultrasonic energy into a region of the body fluid at a first discrete frequency, the first frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; simultaneously directing ultrasonic energy into the body fluid region at a second discrete frequency that is also an approximate resonant frequency of the microspheres, such that the microspheres interact to emit sum and difference frequencies; and detecting the mixed frequencies generated by interaction of the resonant microspheres with ultrasonic energy at the first and second frequencies.
Claim 14
Independent Claim
118 words
A method for detecting the presence of ultrasonically reflective microsphere contrast agents in a body fluid, comprising the steps of: injecting microbubble contrast agents into a living body; directing ultrasonic energy into a region of the body fluid at a first discrete frequency, the first frequency being approximately at a resonant frequency of the microspheres in the range of 1 MHz-30 MHz; simultaneously directing ultrasonic energy into the body fluid region at a second discrete frequency that is also an approximate resonant frequency of the microspheres, such that the microspheres interact to emit sum and difference frequencies; and detecting the mixed frequencies generated by interaction of the resonant microspheres with ultrasonic energy at the first and second frequencies.
Claim 15
Dependent Claim
38 words
A method for detecting the presence of ultrasonically reflective microsphere contrast agents in a body fluid as in claim 10 wherein said means for injecting microbubble contrast agents further comprise a means for injecting albumin-coated microbubble contrast agents.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-11 | 2000-08-12 | 2001-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-11 | 2004-08-12 | 2005-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-11 | 2008-08-12 | 2009-02-11 | $7700.00 | Window Closed / Lapsed |