Ultrasonographic Device

• US 20090163816A1
• Filed: 11/10/2004
• Published: 06/25/2009
• Est. Priority Date: 05/26/2004
• Status: Active Grant

• Current Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Kamada, Hideyo, Azuma, Takashi, Umemura, Shin-ichiro
• Granted Patent: US 8,353,836 B2
• Time in Patent Office: Days
• US Class Current: 600/454
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00

Abstract

The present invention provides an ultrasonic diagnostic apparatus realizing improved visibility of a contour shape of signal components in an ultrasonic blood flow spectrum display image. The apparatus includes a gray-level correction unit for correcting intensity of an output result of a Doppler processing unit. The Doppler processing unit calculates a Doppler frequency shift in a reception signal output from a receiver and calculates blood flow velocity of a subject on the basis of the Doppler frequency shift. The gray-level correction unit has: a filtering unit for separating a signal and a noise from each other, which are included in a time-varying waveform of the blood flow velocity of the subject obtained by the Doppler processing unit on the basis of continuity on a space defined by the blood flow velocity and time; and a gray-level corrector for performing a gray level correction using, as a parameter, a boundary value between signal intensity and noise intensity obtained by the filtering unit.

Claims

1. An ultrasonic diagnostic apparatus comprising:

an ultrasonic probe;

a transmitter having a transmission signal generating circuit for generating a ultrasonic wave made by continuous wave or pulse wave and selectively transmitting the ultrasonic wave to a subject via the ultrasonic probe;

a receiver for phasing a reception signal received from the subject by the ultrasonic probe;

a Doppler processing unit for calculating Doppler frequency shift in the reception signal output from the receiver and calculating blood flow velocity of the subject on the basis of the Doppler frequency shift;

a display for displaying a waveform of the blood flow velocity;

a controller for controlling the transmitter, the receiver, the Doppler processing unit, and the display; and

a gray-level correcting unit for correcting gray level of an output result of the Doppler processing unit,

wherein the gray-level correcting unit includes;

a filtering unit for separating a signal and a noise from each other, which are included in a time-varying waveform of the blood flow velocity of the subject obtained by the Doppler processing unit on the basis of continuity on a space defined by the blood flow velocity and time; and

a gray-level corrector for performing a gray level correction using, as a parameter, a boundary value between signal intensity and noise intensity obtained by the filtering unit.

2. The ultrasonic diagnostic apparatus according to claim 1, wherein the gray-level correction unit is constructed so as to suppress an intensity signal lower than the boundary value in intensity distribution of the signal and the noise.

3. The ultrasonic diagnostic apparatus according to claim 1, wherein the filtering unit has:

means for defining a peripheral pixel range of a pixel in image data on the blood flow velocity; and

means for determining a weighting function from the difference between the intensity of each of the pixels and the intensity of each of the peripheral pixels,

the weighting function has a maximum point at zero,

an integral value of an absolute value of the function in the range from negative infinity to positive infinity is finite, and

a value obtained by using sum of product of the weighting function and the intensity of each of the peripheral pixels as intensity of a pixel in image data on the blood flow velocity is used as signal intensity of a result of the filtering process.

5. The ultrasonic diagnostic apparatus according to claim 1, wherein the separating process includes a process of separating the signal and the noise as peaks on a histogram from each other.

4. An ultrasonic diagnostic apparatus comprising:

an ultrasonic probe;

a transmitter having a transmission signal generating circuit for generating a ultrasonic wave made by continuous wave or pulse wave and selectively transmitting the ultrasonic wave to a subject via the ultrasonic probe;

a receiver for phasing a reception signal received from the subject by the ultrasonic probe;

a Doppler processing unit for calculating Doppler frequency shift in the reception signal output from the receiver and calculating blood flow velocity of the subject on the basis of the Doppler frequency shift;

a display for displaying a waveform of the blood flow velocity;

a controller for controlling the transmitter, the receiver, the Doppler processing unit, and the display; and

a gray-level correcting unit for correcting gray level of an output result of the Doppler processing unit,

wherein the gray-level correcting unit separates a signal and a noise from each other which are included in a time-varying waveform of the blood flow velocity of the subject obtained by the Doppler processing unit on the basis of a statistical property, and performs an intensity correction by suppressing output intensity equal to or lower than a boundary point between signal intensity and noise intensity obtained as a result of the filtering process.

6. The ultrasonic diagnostic apparatus according to claim 4, wherein the separating process includes a process of separating the signal and the noise as peaks on a histogram from each other.