Patent US5016641A successfully refreshed from Google Patents.
US5016641A
Expired / Lapsed
US
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Spectral interpolation of ultrasound Doppler signal
Assignee: Advanced Technology Laboratories Inc
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Filing: 1989-11-13
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Granted: 1991-05-21
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Expires: 2009-11-13
Abstract
Abstract A method and apparatus for producing the Doppler audio output in a medical ultrasound system. The system includes a transmitter for transmitting ultrasound into a body, a receiver for receiving and processing echoes to produce a Doppler signal, and a Doppler signal processor for converting the Doppler signals into an audio signal that in turn is converted into audible sound. The system alternates between first time intervals during which the Doppler samples are produced, and second time intervals when imaging is performed. The improvement of the invention involves producing at least one actual spectrum of the Doppler signal, based upon Doppler samples produced during one of the first time intervals. A synthetic spectrum is then produced for an adjacent second time interval, based upon the actual spectrum. The synthetic spectrum is then converted into a corresponding time domain data set, and the audio signal for the second time interval is then produced based upon the time domain data set. At least some of the points of the synthetic spectrum preferably include a randomly selected phase factor, to reduce echo artifacts and other modulation effects.
Inventors
- 👤 Gary Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:37
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/8979; A; A61; A61B; A61B8/00; A61B8/48; A61B8/488; G01S15/02; G01S15/50; G01S15/58; G01S15/582
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
175 words
In a Doppler medical ultrasound method that includes transmitting ultrasound energy into a body, receiving echoes of the ultrasound energy and processing the echoes to produce a Doppler signal that includes information representing the velocity within the body, converting the Doppler signal into an audio signal, and converting the audio signal into audible sound, the transmitting and receiving steps alternating between first time intervals during which the Doppler signal is produced and second time intervals, an improved method for synthesizing the audio signal during the second time intervals, the method comprising: producing at least one actual spectrum of the Doppler signal based upon the Doppler signal produced during one of the first time intervals; producing a synthetic spectrum of the Doppler signal for a second time interval adjacent to said one first time interval, based at least in part upon said actutal spectrum; converting the synthetic spectrum into a corresponding time domain data set; and producing the audio signal for the second time interval based at least in part upon said time domain data set.
Claim 2
Dependent Claim
175 words
In a Doppler medical ultrasound method that includes transmitting ultrasound energy into a body, receiving echoes of the ultrasound energy and processing the echoes to produce a Doppler signal that includes information representing the velocity within the body, converting the Doppler signal into an audio signal, and converting the audio signal into audible sound, the transmitting and receiving steps alternating between first time intervals during which the Doppler signal is produced and second time intervals, an improved method for synthesizing the audio signal during the second time intervals, the method comprising: producing at least one actual spectrum of the Doppler signal based upon the Doppler signal produced during one of the first time intervals; producing a synthetic spectrum of the Doppler signal for a second time interval adjacent to said one first time interval, based at least in part upon said actutal spectrum; converting the synthetic spectrum into a corresponding time domain data set; and producing the audio signal for the second time interval based at least in part upon said time domain data set.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein the Doppler signal comprises a time series of Doppler samples.
Claim 4
Dependent Claim
37 words
The method of claim 2, wherein each spectrum comprises a plurality of points, each point having a magnitude and a phase, and wherein at least some points of the synthetic spectrum include a randomly selected phase factor.
Claim 5
Dependent Claim
31 words
The method of claim 3, wherein the phase factor is selected from a range extending from approximately -R to +R, where R is in the range of π/10 to π/2 radians.
Claim 6
Dependent Claim
16 words
The method of claim 1, wherein the second time interval immediately follows the first time interval.
Claim 7
Dependent Claim
50 words
The method of claim 1, wherein first and second actual spectra of the Doppler signal are produced based upon the Doppler signal produced during first time intervals preceding and following, respectively, the second time interval, and wherein the synthetic spectrum is produced based upon the first and second actual spectra.
Claim 8
Dependent Claim
38 words
The method of claim 1, wherein a plurality of synthetic spectra and corresponding time domain data sets are produced during each second time interval, and wherein the audio signal is produced by combining the time domain data sets.
Claim 9
Dependent Claim
50 words
The method of claim 7, wherein each spectrum comprises a plurality of points, each point having a magnitude and a phase, and wherein at least some of the points of each synthetic spectrum include a randomly selected phase factor, such that the time domain data sets differ from one another.
Claim 10
Dependent Claim
39 words
The method of claim 8, wherein the time domain data sets overlap one another, and wherein for each time during the second time interval, the audio signal is produced by averaging two or more overlapping time domain data sets.
Claim 11
Dependent Claim
47 words
The method of claim 9, wherein the first time domain data set produced during the second interval overlaps the Doppler signal produced during the preceding first time interval, and wherein the last time domain data set overlaps the Doppler signal produced during the subsequent first time interval.
Claim 12
Dependent Claim
201 words
In a Doppler medical ultrasound system that includes means for transmitting ultrasound energy into a body, means for receiving echoes of the ultrasound energy and processing the echoes to produce a Doppler signal that includes information representing the velocity of a target volume within the body, means for converting the Doppler signal into an audio signal, and means for converting the audio signal into audible sound that corresponds to the Doppler signal, the transmitting and receiving means alternating between first time intervals during which the Doppler signal is produced and second time intervals, improved means for synthesizing the audio signal during the second time intervals, said improved means comprising: means for producing at least one actual spectrum of the Doppler signal based upon the Doppler signal produced during one of the first time intervals; means for producing a synthetic spectrum of the Doppler signal for a second time interval adjacent to said one first time interval, based at least in part upon said actual spectrum; means for converting the synthetic spectrum into a corresponding time domain data set; and means for producing the audio signal for the second time interval based at least in part upon said time domain data set.
Claim 13
Dependent Claim
201 words
In a Doppler medical ultrasound system that includes means for transmitting ultrasound energy into a body, means for receiving echoes of the ultrasound energy and processing the echoes to produce a Doppler signal that includes information representing the velocity of a target volume within the body, means for converting the Doppler signal into an audio signal, and means for converting the audio signal into audible sound that corresponds to the Doppler signal, the transmitting and receiving means alternating between first time intervals during which the Doppler signal is produced and second time intervals, improved means for synthesizing the audio signal during the second time intervals, said improved means comprising: means for producing at least one actual spectrum of the Doppler signal based upon the Doppler signal produced during one of the first time intervals; means for producing a synthetic spectrum of the Doppler signal for a second time interval adjacent to said one first time interval, based at least in part upon said actual spectrum; means for converting the synthetic spectrum into a corresponding time domain data set; and means for producing the audio signal for the second time interval based at least in part upon said time domain data set.
Claim 14
Dependent Claim
16 words
The improvement of claim 11, wherein the Doppler signal comprises a time series of Doppler samples.
Claim 15
Dependent Claim
37 words
The improvement of claim 12, wherein each spectrum comprises a plurality of points, each point having a magnitude and a phase, and wherein at least some points of the synthetic spectrum include a randomly selected phase factor.
Claim 16
Dependent Claim
31 words
The improvement of claim 13, wherein the phase factor is selected from a range extending from approximately -R to +R, where R is in the range of π/10 to π/2 radians.
Claim 17
Dependent Claim
16 words
The improvement of claim 11, wherein the second time interval immediately follows the first time interval.
Claim 18
Dependent Claim
50 words
The improvement of claim 11, wherein first and second actual spectra of the Doppler signal are produced based upon the Doppler signal produced during first time intervals preceding and following, respectively, the second time interval, and wherein the synthetic spectrum is produced based upon the first and second actual spectra.
Claim 19
Dependent Claim
38 words
The improvement of claim 11, wherein a plurality of synthetic spectra and corresponding time domain data sets are produced during each second time interval, and wherein the audio signal is produced by combining the time domain data sets.
Claim 20
Dependent Claim
50 words
The improvement of claim 17, wherein each spectrum comprises a plurality of points, each point having a magnitude and a phase, and wherein at least some of the pionts of each synthetic spectrum include a randomly selected phase factor, such that the time domain data sets differ from one another.
Claim 21
Dependent Claim
39 words
The improvement of claim 18, wherein the time domain data sets overlap one another, and wherein for each time during the second time interval, the audio signal is produced by averaging two or more overlapping time domain data sets.
Claim 22
Dependent Claim
47 words
The improvement of claim 19, wherein the first time domain data set produced during the second interval overlaps the Doppler signal produced during the preceding first time interval, and wherein the last time domain data set overlaps the Doppler signal produced during the subsequent first time interval.
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