US4452081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measurement of velocity and tissue temperature by ultrasound
Assignee: Varian Medical Systems Inc
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Filing: 1982-09-30
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Granted: 1984-06-05
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Expires: 2002-09-30
Abstract
Abstract Temperature inside a tissue volume is noninvasively determined on the basis of its known relationship with the velocity of ultrasound inside the volume. The velocity of ultrasound between two field points inside the volume of interest is calculated from measurements of differences in transit times of sound beams scattered in substantially opposite directions at these field points.
Inventors
- 👤 Edward J. Seppi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:04
CPC Classifications
G; G01; G01H; G01H5/00; G01K; G01K11/00; G01K11/22; G01K11/24; G01N; G01N29/00; G01N29/04; G01N29/07; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02881
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
90 words
A method of determining the velocity of sound between two field positions F and F' inside a medium which occupies a region including the space between said field positions, said method comprising the steps of transmitting a first incident sound beam and a second incident sound beam directed respectively towards said two field positions, preselecting two receiver positions R and R' on opposite sides with respect to both said incident beams, and detecting for each of said instant beams two scattered sound beams traveling respectively along lines FR and F'R'.
Claim 2
Independent Claim
90 words
A method of determining the velocity of sound between two field positions F and F' inside a medium which occupies a region including the space between said field positions, said method comprising the steps of transmitting a first incident sound beam and a second incident sound beam directed respectively towards said two field positions, preselecting two receiver positions R and R' on opposite sides with respect to both said incident beams, and detecting for each of said instant beams two scattered sound beams traveling respectively along lines FR and F'R'.
Claim 3
Dependent Claim
44 words
The method of claim 1 further comprising the step of comparing for each of said incident beams the transit times of sound between the time of transmission and the times at which said scattered beams are detected at said positions R and R', respectively.
Claim 4
Dependent Claim
39 words
The method of claim 1 wherein said first and second incident beams are transmitted respectively from positions T and T', lines TF and T'F' being substantially parallel to each other, TFR and T'F'R' are equal to a predetermined angle.
Claim 5
Dependent Claim
25 words
The method of claim 3 wherein said two positions R and R' lie on the plane defined by said positions T, T', F and F'.
Claim 6
Dependent Claim
16 words
The method of claim 3 wherein said predetermined angle is between 60 degrees and 120 degrees.
Claim 7
Dependent Claim
12 words
The method of claim 3 wherein said predetermined angle is 90 degrees.
Claim 8
Dependent Claim
15 words
The method of claim 2 wherein said comparing step involves use of phase matching techniques.
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein said medium is a tissue structure.
Claim 10
Dependent Claim
13 words
The method of claim 1 wherein said detecting step involves use of transducers.
Claim 11
Dependent Claim
52 words
The method of claim 3 or 4 further comprising the step of evaluating the time interval (t T'R +t TR' -t TR -t T'R' ) where symbol t AB , A and B being dummy indices, denotes the time which it takes for sound to travel from point A to point B.
Claim 12
Dependent Claim
14 words
The method of claim 1 wherein said first and second beams are transmitted successively.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |