JPH11128222A - Ultrasonic diagnosis equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set a correlation coefficient in an ultrasonic diagnosis equipment with a frame correlator. SOLUTION: A coefficient calculator 28 automatically calculates a correlation coefficient α based on information to express a frame rate outputted by a send/receive controlling part 24 in this ultrasonic diagnosis equipment. In that case, the action of the frame correlation is determined based on the afterglow time T. Even if the depth of diagnosis or the number of beams are variably set by a user, the coefficient calculator 28 automatically calculates a suitable correlation coefficient α corresponding thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus having a frame correlator.

[0002]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus has a frame correlator for performing a frame correlation process on a received signal.
This performs smoothing in the time axis direction for each pixel between frames. A general frame correlator includes an adder and a frame memory. The output of the adder is temporarily stored in the frame memory and then read out, and the signal and the latest received signal are added with a certain weight. Then, the output is stored again in the frame memory, and this feedback processing is repeated. Therefore,
Increasing the weighting value for past signals output from the frame memory enhances the afterglow effect to enhance the effect of noise removal and missing interpolation, while reducing the weighting value for past signals weakens the afterglow effect. Responsiveness can be improved. In the conventional ultrasonic diagnostic apparatus, several such weighting coefficients are prepared and selected by the user.

[0003]

However, the selection of the weighting coefficient by the user is complicated, and it is not easy to optimize the weighting coefficient to the operating conditions of the apparatus. Therefore, an object of the present invention is to automate setting of weighting coefficients.

[0004]

In order to achieve the above object, the present invention provides a transmitting / receiving means for transmitting / receiving ultrasonic waves, and a frame for performing a frame correlation process on a signal received from the transmitting / receiving means. It is characterized by including correlation processing means and weighting coefficient setting means for adaptively setting weighting coefficients used in the frame correlation processing according to a variably set frame rate.

According to the above configuration, the weighting coefficient in the frame correlation processing can be automatically set by the weighting coefficient setting means according to the frame rate. Therefore, complicated input work by the user is not required, and appropriate correlation processing can always be expected.

Preferably, the frame rate is automatically set according to transmission / reception conditions, or preferably, the frame rate is input by a user.

In a preferred aspect of the present invention, an input means for giving a degree of afterglow is included, and the weighting coefficient setting means adaptively sets a weighting coefficient according to the frame rate based on the degree of afterglow. Set.

[0008] To supplement the explanation, when the frame correlation operation is represented by a simple linear operation, the correlation operation corresponds to the integration of each frame from the past to the present. Assuming that the rate at which past images remain is α (0 ≦ α <1), the complete image time of the B-mode image is τ, and the luminance of information input before time T before the current is I, the current luminance is , Α ^{T /} τ · I
It is represented by Therefore, if the afterglow time T is defined as the time required for the luminance I to become 1 / N, T = τ · logα (1 / N) (1) Therefore, it is understood that T depends on the complete image time of the B-mode image. That is, the value of the coefficient α can be set adaptively according to the frame rate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention. FIG. 1 is a block diagram showing the overall configuration of the ultrasonic diagnostic apparatus.

The probe 10 is an ultrasonic probe for transmitting and receiving ultrasonic waves, and is used by being brought into contact with the surface of a living body and inserted into the living body. The probe 10 includes an array vibrator composed of a plurality of vibrating elements, and electronically scans an ultrasonic beam formed by the array vibrator.
A dimensional data capturing area can be formed. The transmitting and receiving circuit 12 is connected to the probe 10. The transmission / reception circuit 12 supplies a transmission signal to the array transducer included in the probe 10. The received signal output from the probe 10 is
The processing is performed in the transmission / reception circuit 12. A transmission / reception control unit 24 is connected to the transmission / reception circuit 12. The transmission / reception control unit 24 controls the number of ultrasonic beams, the diagnostic depth, and the like according to a frame rate set as described later.

The received signal output from the transmitting / receiving circuit 12 is converted into a digital signal by the ADC 14, and the received signal is input to the frame correlator 16. The frame correlator 16 is a circuit that performs so-called correlation operation between frames to perform smoothing. The received signal output from the frame correlator 16 is input to a DSC (Digital Scan Converter) 18. This DSC18
In this case, a two-dimensional tomographic image, that is, a B-mode image is formed. Of course, the present invention is also applicable to an apparatus on which a Doppler image or the like is formed. The image signal output from the DSC 18 is returned to an analog signal in the DAC 20, and then the signal is output to the CRT 22, and the CRT 2
2 displays a B-mode image or the like.

The operation panel 26 functions as an input device for the user to set the depth of diagnosis, the number of ultrasonic beams, and the like. Of course, the frame rate may be directly input by the operation panel 26.
Further, the afterglow time T, which will be described later, is
And the afterglow time T is calculated by the coefficient calculator 2
8 is input.

The coefficient calculator 28 is a circuit for calculating the correlation coefficient α for the frame correlator 16. The correlation coefficient α
Is calculated based on the frame rate information output from the transmission / reception control unit 24 and the afterglow time T described above. That is, α is determined based on the above-described equation (1).
In this case, if T is set to be large, the effect of the frame correlation can be strengthened accordingly, while if T is reduced, the effect of the frame correlation can be weakened.

The frame correlator 16 has two multipliers 30,
32, an adder 34, and a frame memory 36. The frame memory 36 stores past image data (received signal). The frame memory 36 is a memory for storing image information for one frame. The data output from the frame memory 36 is multiplied by the correlation coefficient α in the multiplier 32. Then, the result of the multiplication is output to the adder 34. On the other hand, the information output from the ADC 14 is multiplied by (1-α) in the multiplier 30. Then, the result of the multiplication is output to the adder 34. The adder 34 achieves frame correlation by adding the two multiplication results. The output of the adder 34 is fed back to the frame memory 36 described above.

Therefore, according to the above embodiment, when the transmission / reception controller 24 determines the frame rate based on various transmission / reception parameters, the coefficient calculator 28 automatically calculates an appropriate correlation coefficient according to the frame rate. . In this case, when the afterglow time T is input as a parameter by the user, a correlation coefficient corresponding to the magnitude of the T is appropriately set.

Accordingly, since it is not necessary for the user to directly set the correlation coefficient, the complexity involved in the setting can be eliminated. In the past, the correlation coefficient was generated stepwise using a ROM table or the like.
According to the above embodiment, the correlation coefficient can be continuously varied, and finer adjustment can be performed.

[0018]

As described above, according to the present invention,
There is an advantage that the setting of the weighting coefficient in the frame correlation can be automated in the ultrasonic diagnostic apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an ultrasonic diagnostic apparatus according to the present invention.

[Explanation of symbols]

10 probe, 12 transmission / reception circuit, 16 frame correlator, 24 transmission / reception control unit, 26 operation panel, 28 coefficient calculator.

Claims (4)

[Claims] A transmitting / receiving means for transmitting / receiving an ultrasonic wave; a frame correlating means for performing a frame correlation process on a signal received from the transmitting / receiving means; And a weighting coefficient setting means for adaptively setting weighting coefficients used in the frame correlation processing. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein said frame rate is automatically set according to transmission / reception conditions. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein the frame rate is input by a user. 4. The apparatus according to claim 1, further comprising: input means for giving an afterglow degree, wherein the weighting coefficient setting means adaptively weights the frame rate based on the afterglow degree. An ultrasonic diagnostic apparatus characterized by setting a coefficient.