EP0321717A2
Expired / Lapsed
EP
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Ultrasonic speckle velocity measurement method and apparatus
Assignee: Hitachi Ltd
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Filing: 1988-11-23
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Granted: —
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Expires: 2008-11-23
Abstract
Abstract An ultrasonic speckle velocity measurement method and apparatus that uses the transmission and reception of ultrasonic waves to detect the velocity of moving members comprised of random scattering bodies. The ultrasonic wave transmitted toward a moving measurement object containing a large number of microscopic scattering bodies, and echo signals reflected by the measurement object are received. If, for example, the scattering bodies are blood corpuscles, the blood flow can be regarded as a random aggregation of these corpuscles, in which case the echo signal received will be the product of the random interference between waves scattered by individual corpuscles, and as such the blood flow velocity can be estimated from time-based fluctuation in the amplitude of the echo signals. Thus, the time-based fluctuation in the received echo signals is detected from, for example, the envelope signal thereof and frequency-analyzed, and from the fluctuation frequency thereof the velocity is obtained. Accordingly, without using the conventional ultrasonic Doppler method it is possible to detect velocity and, in particular, to measure with accuracy even low velocities, and it is also possible to detect the velocity of moving members regardless of the direction in which the ultrasonic beam is transmitted.
Inventors
- 👤 Masato Nakajima
- 👤 Takashi Ito
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 06:47
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/06; G; G01; G01N; G01N29/00; G01N29/02; G01N29/032
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
An ultrasonic speckle velocity measurement method comprising: a transmission step in which an ultrasonic wave is transmitted toward a moving measurement object that includes a large number of microscopic scattering bodies; a receiving step in which an echo signal reflected from the measurement object is received; an amplitude detection step in which time-based fluctuation in amplitude of received echo signals is detected; a frequency analysis step in which the time-based fluctuation in amplitude is frequency-analyzed and a fluctuation frequency that shows the degree of said fluctuation is detected; and a velocity conversion step in which the velocity is measured from the fluctuation frequency.
Claim 2
Dependent Claim
103 words
An ultrasonic speckle velocity measurement method comprising: a transmission step in which an ultrasonic wave is transmitted toward a moving measurement object that includes a large number of microscopic scattering bodies; a receiving step in which an echo signal reflected from the measurement object is received; an amplitude detection step in which time-based fluctuation in amplitude of received echo signals is detected; a frequency analysis step in which the time-based fluctuation in amplitude is frequency-analyzed and a fluctuation frequency that shows the degree of said fluctuation is detected; and a velocity conversion step in which the velocity is measured from the fluctuation frequency.
Claim 3
Dependent Claim
42 words
An ultrasonic speckle velocity measurement method according to claim 1 wherein in the said frequency analysis step the degree of time-based amplitude fluctuation is detected from a power spectrum of the time-based echo signal amplitude fluctuation waveform or from the statistics thereof.
Claim 4
Dependent Claim
103 words
An ultrasonic speckle velocity measurement apparatus comprising: a transmission section for transmitting an ultrasonic continuous wave toward a measurement object that includes a large number of microscopic scattering bodies; a receiving section for receiving echo signals reflected by the measurement object; an envelope detection section that amplifies the output of the receiving section and detects the envelope of the echo signals; a frequency analysis section that frequency analyzes the time-based fluctuations of the envelope output by the envelope detection section and detects the envelope fluctuation frequency; and a velocity conversion section that converts frequency values output from the frequency analysis section to velocities.
Claim 5
Dependent Claim
103 words
An ultrasonic speckle velocity measurement apparatus comprising: a transmission section for transmitting an ultrasonic continuous wave toward a measurement object that includes a large number of microscopic scattering bodies; a receiving section for receiving echo signals reflected by the measurement object; an envelope detection section that amplifies the output of the receiving section and detects the envelope of the echo signals; a frequency analysis section that frequency analyzes the time-based fluctuations of the envelope output by the envelope detection section and detects the envelope fluctuation frequency; and a velocity conversion section that converts frequency values output from the frequency analysis section to velocities.
Claim 6
Dependent Claim
124 words
An ultrasonic speckle velocity measurement apparatus comprising: a transmission section for transmitting an ultrasonic pulsed wave toward a measurement object that includes a large number of microscopic scattering bodies; a receiving section for receiving echo signals reflected by the measurement object; an envelope detection section that amplifies the output of the receiving section and obtains the envelope of the echo signals, and by then sample-holding selected signals in the envelope detects time-based envelope amplitude fluctuations at a selected location within the subject; a frequency analysis section that frequency analyzes the time-based fluctuation of the envelope output by the envelope detection section and detects the envelope fluctuation frequency; and a velocity conversion section that converts frequency values output from the frequency analysis section to velocities.
Claim 7
Dependent Claim
124 words
An ultrasonic speckle velocity measurement apparatus comprising: a transmission section for transmitting an ultrasonic pulsed wave toward a measurement object that includes a large number of microscopic scattering bodies; a receiving section for receiving echo signals reflected by the measurement object; an envelope detection section that amplifies the output of the receiving section and obtains the envelope of the echo signals, and by then sample-holding selected signals in the envelope detects time-based envelope amplitude fluctuations at a selected location within the subject; a frequency analysis section that frequency analyzes the time-based fluctuation of the envelope output by the envelope detection section and detects the envelope fluctuation frequency; and a velocity conversion section that converts frequency values output from the frequency analysis section to velocities.
Claim 8
Dependent Claim
59 words
An ultrasonic speckle velocity measurement apparatus according to claim 3 or claim 4 wherein the said frequency analysis section comprises: a differentiator that differentiates the envelope signal; a zero-crossing detector that detects output going to zero from among the outputs of the differentiator; and a counter that counts the number of outputs of the zero-crossing detector per unit time.
Claim 9
Dependent Claim
63 words
An ultrasonic speckle velocity measurement apparatus according to claim 3 or claim 4 wherein the said frequency analysis section comprises: a high-pass filter that removes direct-current components from the envelope signal; a zero-crossing detector that detects output going to zero from among the outputs of the filter; and a counter that counts the number of outputs of the zero-crossing detector per unit time.
Claim 10
Dependent Claim
42 words
An ultrasonic speckle velocity measurement apparatus according to any of claim 3 to 6 applied as an ultrasonic diagnostic apparatus wherein detected velocity information is displayed on the display in numerical form and/or in an image form superimposed on a tomographic image.
References Cited (Backward Citations)
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