JP2581075B2 - Ultrasound diagnostic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus suitable for giving an image reflecting an ultrasonic attenuation in a living tissue and an evaluation value.

[Conventional technology]

The ultrasonic diagnostic apparatus displays the two-dimensional (B mode) display by making the intensity of the echo reflected from the inside of the ultrasonic pulse emitted into the living body correspond to the luminance.

In the case of a local lesion, the effect of the attenuation characteristic on the B-mode image is observed as an appearance at a location deeper than the lesion due to acoustic shading or acoustic enhancement. For example, when the inside of the cyst in the liver shown in part A of FIG. 3 (a) is a fluid, the attenuation in the vesicle is smaller than that of the surrounding healthy tissue, and the brightness behind the vesicle becomes brighter than the others. A region of acoustic enhancement appears. Conversely, the appearance of an acoustic shadow in which the brightness behind the vesicle is darker than that of the surroundings, as in part B of FIG.

Conventionally, on the B-mode image, the magnitude of the attenuation of the lesion is discriminated from the brightness of the brightness behind the local lesion, and the nature of the lesion is generally discussed. However, in recent years, in ultrasonic diagnosis, a correlation between a disease state of a tissue and an attenuation characteristic is obtained by discriminating an attenuation characteristic peculiar to each tissue of a living body. Many attempts are being made to increase it.

In addition, related to this type of device, for example,
An apparatus disclosed in JP-A-59-218144 can be mentioned.

[Problems to be solved by the invention]

However, discrimination of brightness from light and dark requires considerable skill, and the setting conditions of a device such as TGC (Time Gain Control) and a slight difference in brightness depend on the operator. Moreover, the same acoustic shading may not be affected by attenuation. Part C of FIG. 3 (b) shows an example of this, but the brightness behind it becomes dark due to the scattering by the strong reflector. Absent. This is the first problem.

Among the methods for measuring the attenuation characteristic of a tissue, as a method simple in hardware and suitable for real-time measurement, there is an estimation of the center frequency of an ultrasonic power spectrum by a real crossover method. Regarding this, "Spectrum characteristics and attenuation characteristics in ultrasonic waves" by SW flux etc.
(Ultrasonic Imaging, vol. 5, 95-116 (1983). This method approximates the power spectrum of an ultrasonic pulse in a living tissue to a Gaussian distribution, and attenuates the ultrasonic wave accompanying propagation. Is assumed to be proportional to the frequency, the fact that the number of zero crossings λ per unit time is approximately proportional to the center frequency of the spectrum is used, that is, the power spectrum S ₀ (f) of the incident ultrasonic wave is Here, f ₀ is the center frequency of the probe, σ is the bandwidth of the pulse, and c is the proportionality constant.

In other words, the power spectrum S (f) after propagating in the living body by the distance l is represented by α as a tissue attenuation constant. And change. The above equation (2) is So that f _C = f ₀ −αlσ ² .

That is, by attenuation, the center frequency of the power spectrum of the ultrasound pulse, only Arufaerushiguma ^2, is to shift to the low frequency side. On the other hand, the frequency λ of the zero-crossings per unit time is given by λ = 2 [f _C ² + σ ² ] ^1/2 (3). Usually, since f _C通常 σ, λ ≒ 2f _C = 2 (f ₀ −αlσ ² ) (4)

Therefore, conventionally, in estimating the attenuation characteristic of the living tissue by the zero-crossing method, the depth dependence of the zero-crossing frequency λ of the received RF signal is obtained, and the attenuation constant α is obtained from the gradient. That is, as shown in FIG. 5, a waveform of a fixed time width (indicated by “a” in FIG. 5) is cut out from the received PF waveform, and the number of zero crossings is used as a frequency analysis result. This is repeated while being shifted (indicated by b and c in FIG. 5).

But here is the second problem. In other words, there is a large error that a certain time width for cutting out the waveform must be filled with the ultrasonic RF pulse. FIG. 6 explains this situation. The waveform (a) shows the analysis time width of the received RF signal (see FIG. 6 (c)).
Waveform (b) shows an output waveform of the zero-crossing detector which receives this RF signal as an input.

In section A where no ultrasonic pulse signal exists, there is no output of the zero-crossing detector, so when counting by the analysis time width, the counted value gives a lower value than when all are filled with the RF waveform. This indicates that even if the center frequency of the reflected RF signal does not shift to the lower frequency side, the center frequency of the reflected RF signal shifts to an apparently lower center frequency due to lack of the reflected RF signal. Moreover, such a loss of the reflected RF signal is often found in the echo waveform from the living body.

For example, when discriminating the attenuation characteristics of the liver, blood vessels such as blood vessels and lymph vessels in an organ do not have an echo source therein, and thus are likely to produce the above-described loss. Conventionally, for this reason, this problem has been avoided by emitting an ultrasonic beam in a direction in which no vessel exists.
For this reason, the target region was to be greatly limited.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to solve the brightness problem described above as the first problem by the ambiguity of brightness behind a local lesion. Another object of the present invention is to provide a means for specifying attenuation characteristics of a local lesion and a means for discriminating whether attenuation of an ultrasonic signal due to a lesion is caused by reflection or attenuation. Further, a second object of the present invention is to provide a discriminating means which is less susceptible to the lack of an ultrasonic reflected signal in discriminating a center frequency of a power spectrum of an ultrasonic pulse by zero crossing with respect to the second problem described above. Is to provide.

[Means for solving the problem]

In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention comprises: (a) an ultrasonic diagnostic apparatus which transmits an ultrasonic pulse into a living body, and generates and displays a B-mode image based on a reflected wave from the living body. In the apparatus, detecting means (analog comparator 20) for detecting the zero-crossing of the reflected wave, and counting means (event counter 21) for repeatedly counting the number of times the zero-crossing is detected by the detecting means until a predetermined threshold is reached.
Each time the number of zero-crossing detections reaches a threshold value, at least a specifying means (signal selection circuit 7) for specifying a position on the B-mode image corresponding to the time when the threshold value is reached. In addition, an iso-zero crossing number line formed at the position specified by the specifying means with the sweep of the ultrasonic pulse is displayed.

(B) In the ultrasonic diagnostic apparatus according to (a), the detecting means comprises an analog comparator 20 having a reference value as a ground potential, and the counting means comprises an event counter.
21.

(C) In the ultrasonic diagnostic apparatus according to any one of (a) and (b) above, the operations of the detecting means, the counting means, and the specifying means are performed during a predetermined period of the ultrasonic pulse sweep. A means (control unit 10) for performing control within the apparatus is provided.

(D) In the ultrasonic diagnostic apparatus according to any one of the above (a) to (c), the operations of the detecting means, the counting means, and the specifying means are performed within a predetermined range of the depth of the living body. A control means (control 10) for performing the control is provided.

(E) In the ultrasonic diagnostic apparatus according to any one of the above (A) to (D), the counting means outputs a pulse each time the number of times of detection of the zero-crossing by the detecting means reaches a threshold, and Switches the signal on the B-mode image to a signal different from the original signal of the B-mode image in response to the pulse output from the counting means, and sets the position on the B-mode image corresponding to the time when the threshold is reached. It is characterized by being specified.

(F) In the ultrasonic diagnostic apparatus according to the above (e), the specifying means expands the width of the pulse output from the detecting means of the counting means, and applies the B mode to the pulse signal having the expanded width of the pulse. It is characterized in that the image original signal is switched.

(G) In the ultrasonic diagnostic apparatus according to any one of (a) to (d), the counting means outputs a pulse each time the number of times of detection of the zero crossing by the detecting means reaches a threshold value, and Corresponds to the pulse output from the counting means, adds a signal different from the original signal of the B-mode image to the signal on the B-mode image, and calculates the position on the B-mode image corresponding to the time when the threshold value is reached. Is characterized.

(H) In the ultrasonic diagnostic apparatus according to the above (g), the specifying means expands the width of the pulse output from the detection means of the counting means, and applies the B-mode to the pulse signal having the expanded width of the pulse. It is characterized in that it is added to an image original signal.

(I) In the ultrasonic diagnostic apparatus according to any one of (a) to (h), the specifying means sets the position on the B-mode image corresponding to the time when the threshold value is reached to the white or black level. It is characterized by a signal.

(Nu) In the ultrasonic diagnostic apparatus according to any one of the above (a) to (li), the specifying means specifies, in color, a position on the B-mode image corresponding to the time when the threshold value is reached. Features.

Further, (l) an ultrasonic diagnostic apparatus for transmitting an ultrasonic pulse into a living body and detecting the zero-crossing frequency of a reflected wave from the living body, wherein the detecting means (analog comparator) detects the zero-crossing of the reflected wave 20), a counting means (event counter 21) for counting the number of times of zero-crossing detection by the detecting means for each predetermined period, and an amplitude (intensity) of the reflected wave for each predetermined period. Means for detecting and integrating a period exceeding a predetermined threshold (comparator 24, integrator 25,)
And a means (divider 27) for obtaining a value obtained by dividing the counted number of detected zero-crossings by the integrated value, wherein the value obtained by the division is defined as a zero-crossing frequency. And

(ヲ) In the ultrasonic diagnostic apparatus according to the above (1), a means (detection circuit 5) for detecting the reflected wave is provided, and the amplitude (intensity) of the signal obtained by detecting the reflected wave exceeds a predetermined threshold. It is characterized in that a period is detected and integrated.

(W) In the ultrasonic diagnostic apparatus according to any one of the above (1) and (2), the predetermined period of time is such that the repetition time width of the transmission of the ultrasonic pulse is equally divided into an arbitrary number. It is characterized by becoming.

(F) In the ultrasonic diagnostic apparatus according to any one of (l) to (w) above, a graph is displayed in which the value obtained by dividing as the zero-crossing frequency is associated with the depth of the living body. It is characterized by the following.

(Y) In the ultrasonic diagnostic apparatus according to any one of (1) to (4), means for digitizing the reflected wave, storage means for storing data obtained by digitizing the reflected wave, Based on the created program, processing the data stored in the storage means, detection of the zero-crossing of the reflected wave, counting of the number of times the zero-crossing is detected, detection and integration of a period in which the amplitude of the reflected wave exceeds a predetermined threshold, Processing means for at least dividing the counted number of detected zero-crossings by the integrated value.

[Action]

In the first aspect of the invention, the "equal-zero crossing line" described later is superimposed and displayed on the B-mode image by utilizing the phenomenon that the center frequency of the ultrasonic echo spectrum shifts to the lower frequency side due to attenuation. The attenuation characteristic of the local lesion is determined based on the change in the interval between the iso-zero crossing lines and the deviation of the appearance position. That is, the zero crossing of the received RF signal is detected, and the appearance position is superimposed and displayed on the B-mode image using the white or black level every time the appearance frequency reaches a certain number. When the above procedure is performed two-dimensionally in response to the sweep of the ultrasonic beam, a group of equal zero crossing lines is obtained.

The interval between the iso-zero crossing lines reflects the attenuation characteristic of the preceding region, but the decomposition result will be briefly described below.

In the equation (3) quoted from the report of the SW flux and the like, since f _C ≫σ is usually satisfied, the depth l is equal to l + Δl
Assuming that there are zero crossings N times during
Assuming that the propagation speed is c, You just need to solve The present inventors, from now on, Was obtained. From this, it can be seen that the interval between the isozero crossing lines is inversely proportional to the center frequency of the paraspectrum in that region.

A specific example of the present invention will be described below with reference to the example of the liver described above. FIG. 4 (a) corresponds to FIG. 3 (a). In the fluid cyst of part A, the attenuation in the vesicle is smaller than that of other healthy parts, so that the center frequency of the back of the vesicle is higher than that of the adjacent healthy part. Therefore, the appearance of a certain number of zero-crossings is realized at a shorter distance as compared with other healthy parts. As a result, in the part A, a group of equal zero-crossing lines projecting upward is superimposed and displayed. Also, in part B of FIG.
Since the intracellular attenuation is greater than in other healthy areas, the center frequency of its power spectrum is conversely lower behind the cell. For this reason, a certain number of occurrences of zero crossings appear at longer distances than in other healthy parts. As a result, in the part B, a group of equal zero-crossing lines projecting downward is superimposed and displayed.

As described above, the attenuation characteristics in the cyst, which is a local lesion, are firstly specified as the amount of shift up and down of the group of iso-zero crossing lines, and secondly, the magnitude of the attenuation is determined by other healthy individuals. As a relative value with respect to the part, the magnitude of the shift amount, that is, the size of the line group interval can be clearly evaluated.

Finally, referring to FIG. 4 (b) corresponding to FIG. 3 (b), according to the present invention, it can be determined whether the shadow due to the attenuation of the reflected signal is due to reflection or high attenuation. Show.

In part C of FIG. 3 (b), for example, the ultrasonic wave is attenuated by a strong reflection source such as a gallstone, thereby causing an acoustic shadow behind. However, unlike attenuation due to attenuation, there is no shift of the center frequency in attenuation due to reflection. The frequency dependence of the reflection phenomenon is almost negligible and weak. Therefore, even after the reflection source, the center frequency of the power spectrum is not different from that of the other healthy parts, and therefore, as shown in FIG. 4 (b), the deviation of the iso-zero crossing line is slight.

The above describes the application example of the present invention to a local lesion, but the present invention is also useful for a wider organ. For example, as schematically shown in FIG. 4 (c), according to the two-dimensional distribution of attenuation, the iso-zero crossing line is a polygonal line,
It is also possible to estimate the distribution of the attenuation characteristics in the organ from the shape, which appears while changing the interval.

In the second invention, the amplitude information of the ultrasonic pulse, which has not been used conventionally, is used for detecting the number of zero crossings. In FIG. 6, since the lack of the ultrasonic signal affects the discrimination of the center frequency in that it is normalized in a certain time width, in the present invention, the time width is equivalently reduced by the presence or absence of the signal. , The center frequency is determined by the ratio of the zero-crossing count value to the effective time width.

That is, in FIG. 7, the detected output (shown by a broken line) is obtained for the received RF signal (a), the magnitude is compared with a predetermined threshold, and the count value of the zero-crossing output is calculated. With the ratio of the Hign level of the comparison output to the time,
This is the true zero-crossing output frequency λ.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus showing one embodiment of the first invention. In the figure, reference numeral 1 denotes an array probe for transmitting and receiving ultrasonic waves constituted by arranging a plurality of ultrasonic transducers in parallel. A transmission drive circuit for exciting and driving each transducer of the transmission aperture, 4 is a reception phasing circuit that performs addition in which the phases of the reception signals of each transducer selected as the reception aperture are matched, and performs logarithmic compression of the addition signal. Detection circuit, 6
1 shows a signal processing circuit such as FTC (Fast Time Constant). 7 is a signal selection circuit composed of an analog multiplexer, 8 is an AD converter, 9 is an image memory for storing and storing a B-mode image and the following contour lines, 11 is an image display device, 10
Denotes a processing control unit for controlling the above circuits, 20 denotes an analog comparator, and 21 denotes an event counter. The feature of this embodiment is that the signal selection circuit 7, the analog comparator
20, in that an event counter 21 is provided.

In the ultrasonic diagnostic apparatus of the present embodiment configured as described above, when the signal selection circuit 7 selects the output video signal of the signal processing circuit 6, the reflected ultrasonic waves in the living body are used in the same manner as in a normal diagnostic apparatus. Is displayed on the image display device 11.

The operation when the signal selection circuit 7 selects the output of the event counter 21 will be described below with reference to the signal diagram of FIG. When excited by the processing control unit 10 and the transmission drive circuit 3, the transducer of the array probe 1 emits an ultrasonic beam into a living body, and an ultrasonic reflected signal from the body is received by the transducer. Are added and compressed by the reception phasing circuit 4 (FIG. 2 (b): reception RF signal).

After the reception RF signal is appropriately band-limited, the analog RF signal is converted into a pulse train by the analog comparator 20. Assuming that the reference value of the comparator is the ground potential, the comparator operates as a zero-crossing detector.

The pulse train is counted by the event counter 21, and every time the count value exceeds the maximum count value of the counter, a carry signal value (FIG. 2 (d): counter carry signal) is output.
The carry signal is expanded by a pulse width expanding means (not shown) to a certain width so that it is easy to see at the time of display.
The signal is applied to the selection control terminal of the signal selection circuit 7 (FIG. 2 (e): selection signal).

The signal selection circuit 7 selects the white or black level when the selection signal is at the Hign level, and selects the output of the signal processing circuit 6 when the selection signal is at the Low level, and supplies the output to the AD converter 8. Such a procedure is performed at a constant repetition cycle, and a two-dimensional ultrasonic image is obtained according to the sweep of the ultrasonic beam (FIG. 2 (a): transmission control signal).

According to the above-described embodiment, the image display device 11
In addition to the mode image, a white or black level line group is superimposed and displayed. Since the appearance positions of these line groups correspond to the carry signal generation times of the counter 21, the intervals are inversely proportional to the frequency of the zero crossings of the received RF signal, in other words, the apparent frequency. Of the present invention can be embodied.

Note that the counter 2 is preferably a so-called event counter. That is, the enable terminal of the counter is controlled so that the counting operation can be performed for a predetermined time interval from a specific depth. In this embodiment, a variable enable signal of the appearance position Δτ is used based on the rise of the transmission control signal (FIG. 2 (c): enable signal). This makes it possible to measure the deviation of the iso-zero crossing line only at an arbitrary region of interest using an arbitrary depth of the B-mode image as a base line.

In the above embodiment, the comparator and the event counter are used as the means for detecting the center frequency and generating the iso-zero crossing line with an interval inversely proportional thereto, but other digital circuit means, for example, an AD converter and a digital comparator Etc. may be used. Further, in the above embodiment, the signal selection circuit is switched according to the appearance pulse train of the equal zero crossing number line, but the output of the signal processing circuit and this pulse train may be simply added. Further, when a color CRT is used as the image display device, the B-mode image may be displayed as a black-and-white high-gradation gray-scale image, and the equal zero-crossing number line may be displayed in color to superimpose and display both.

 Next, an embodiment of the second invention will be described.

FIG. 8 is a block diagram of an ultrasonic diagnostic apparatus showing one embodiment of the second invention. In the figure, symbols 1 to 6, 8 to 1
1, 20 and 21 indicate the same elements as those of the embodiment shown in FIG. 22 is a DA converter, 23, 26
Is a sample-and-hold circuit, 24 is a comparator for inputting a video detection signal, 25 is an integrator, 27 is a divider, and 28 is an X which displays the output of the divider 27 in two dimensions of λ (zero crossing frequency) -depth. -Y display is shown. Reference numeral 12 denotes a time control unit that performs the display control.

In the ultrasonic diagnostic apparatus of the present embodiment configured as described above, the reception RF signal output of the reception phasing circuit 4 (FIG. 9B)
) Is first applied to an RF comparator 20 (operating as a zero-crossing detector) to generate a zero-crossing output pulse train.
The pulse value is counted by the event counter 21 and the count output is converted by the DA converter 22 into a gradually increasing linear shape (see FIG. 9 (f)).

In the present embodiment, the repetition period of the transmission of the ultrasonic wave is divided into three equal parts, and each time width is defined as a zero-crossing frequency measurement period (see FIGS. 9A and 9E).
21 are reset at the beginning of each.

By configuring as described above, the output of the DA converter 22, that is at the end point of the time width (FIG. 9 t _1, t ₂ and t _3), in proportion to the zero crossing frequency of far Become. At this time, this value is held by the sample and hold circuit 23 until the next end point.

On the other hand, the output of the detector 5 (see FIG. 9 (c)) is applied to a video comparator 24 and compared with a predetermined threshold value.
A comparison output (see FIG. 9 (d)) is generated. This signal
A high level indicates that a received RF signal is present, and a low level indicates that the received RF signal is missing. This comparison output is a polygonal waveform (the ninth
(See FIG. 7G).

This integrated output is also reset at the rise and fall of the count width signal (see FIG. 9 (e)). At the end of this time width, the time during which the received RF signal was present in the count period was calculated. The output is proportional to the sum of At this end time, the value of this output is held by the sample and hold circuit 26 until the next end time. Therefore, the output of the divider 27 (see FIG. 9 (h)) to which the outputs of the sample and hold circuits 23 and 26 are input gives the ratio between the number of zero crossings and the effective counting time width. As described above, an output proportional to the true zero-crossing frequency is obtained regardless of the loss of the received RF signal.

If this output is input to the Y input of the XY display 28 and a sawtooth wave corresponding to the repeated transmission of ultrasonic waves from the time control unit 12 is input to the X input, the XY display 28
Above, a curve is obtained in which the vertical axis represents the zero-crossing frequency and the horizontal axis represents the depth in the living body.

Here, the measured values of the received RF signal shown in FIG. 6 are as follows.

That is, although the center frequency of the RF signal is 3.5 MHz, 3.
For the analysis time width of 6 μm, the zero-crossing output is 17 times,
Therefore, according to the conventional method, Which is significantly different from the true value of 7.0 MHz. On the other hand, according to the apparatus of the present embodiment, the time when the detection comparison output is at the High level is 2.39 μs, and the zero-crossing frequency is Which matches well with the true value.

According to experiments performed by the present inventors, in the conventional method, only half of the true value may be shown due to the effect of missing data, whereas according to the present embodiment, ± 5% of the true value It is confirmed to fit within.

In the above embodiment, for convenience of explanation, the count width signal is set to 1/3 of the transmission repetition time width.
Other widths may be used. In this case, a frequency analysis waveform as shown in the lower part of FIG. 5 is obtained on the XY display 28, and the attenuation constant (α) of the living tissue is obtained from the gradient.

In the above embodiment, the comparator output in the video domain and the RF domain is used for the analog operation, but the present invention is not limited to this. Actually, the RF reception output of the reception phasing circuit is subjected to high-speed AD conversion and stored in a one-line memory, which is transferred to a memory in a personal computer.
Good results have been obtained even if the zero-crossing count for the signal and the calculation of the ratio of the zero-crossing count value to the effective counting time width are processed by software.

Further, in this embodiment, an example has been described in which the B-mode image and the frequency analysis waveform are displayed on separate displays, but this may be superimposed and displayed on one display.

In the calculation of the center frequency, the accuracy depends on the threshold value of the video band comparator that determines the effective counting time. Usually, this threshold is roughly
It is desirable to take the noise level of the signal. However, when this threshold value is set to a large value and an error occurs in the effective counting time width, it is also possible to correct the error with the calculated frequency itself. In example FIG. 9, the value of the center frequency at time t ₂ is, by setting the threshold may deviate significantly from that of t ₁ and t _3. In such a case, t ₁
And the average value of t ₃ I than it is to the value of t _2. Such an operation is considered to be appropriate because the distribution of the attenuation characteristic of the tissue in the living body is continuous, and a sudden change is unlikely.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the attenuation characteristic of a local lesion can be specified regardless of the ambiguity of the brightness behind the local lesion, and the attenuation of the ultrasonic signal due to the lesion may be due to reflection or attenuation. Can also be distinguished.

Further, in discriminating the center frequency of the power spectrum of the ultrasonic pulse by the zero-crossing method, it is possible to reduce the influence of the lack of the ultrasonic reflected signal.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus showing one embodiment of the first invention, FIG. 2 is a time chart of signals in the embodiment shown in FIG. 1, and FIG. 3 is sound in a B-mode image. FIG. 4 is a diagram showing a display form in the embodiment, FIG. 5 is a diagram showing the principle of attenuation measurement by the zero-crossing method, and FIG. 6 is a diagram showing the problems of the conventional zero-crossing method. FIG. 7 is a diagram showing the principle of the second invention, FIG. 8 is a block diagram of an ultrasonic diagnostic apparatus showing one embodiment of the second invention, and FIG. 9 is an embodiment shown in FIG. It is a time chart of the signal in an example. 1: Array probe, 2: Transmission / reception switch, 3: Transmission drive circuit, 4: Reception phasing circuit, 5: Detection circuit, 6: Signal processing circuit, 7: Signal selection circuit, 8: AD converter, 9 : Image memory, 10: Processing control unit, 11:
Image display device, 12: Time control unit, 22, 24: Analog comparator, 21: Event counter, 22: DA converter, 23, 26:
Sample hold circuit, 25: integrator, 27: divider, 28: X-
Y display.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiyoshi Katakura 1-280 Higashi Koigakubo, Kokubunji City, Hitachi, Ltd. Central Research Laboratory Co., Ltd. 56) References JP-A-59-122919 (JP, A) JP-A-62-109553 (JP, A) JP-A-60-173463 (JP, A) JP-A-59-218144 (JP, A)

Claims (15)

(57) [Claims] 1. An ultrasonic diagnostic apparatus for transmitting an ultrasonic pulse into a living body and generating and displaying a B-mode image based on a reflected wave from the living body, a detecting means for detecting a zero crossing of the reflected wave. Counting means for repeatedly counting the number of times the zero-crossing is detected by the detecting means until the number of times the zero-crossing is detected reaches the threshold. And a specifying means for specifying a position on the B-mode image corresponding to
An ultrasonic diagnostic apparatus characterized by displaying, on a mode image, an equal zero-crossing number line formed at a position specified by the specifying means with the sweep of the ultrasonic pulse. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein said detecting means comprises an analog comparator having a reference value as a ground potential, and said counting means comprises an event counter. Ultrasound diagnostic device. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein the operation of the detecting unit, the counting unit, and the specifying unit is performed by the ultrasonic diagnostic device. An ultrasonic diagnostic apparatus comprising means for controlling pulse sweeping within a predetermined period. 4. An ultrasonic diagnostic apparatus according to claim 1, wherein the operations of said detecting means, said counting means, and said specifying means are performed in a predetermined manner. An ultrasonic diagnostic apparatus, comprising: means for performing control within a depth range of a living body. 5. The ultrasonic diagnostic apparatus according to claim 1, wherein said counting means comprises:
Each time the number of times the zero-crossing is detected by the detecting means reaches the threshold value, a pulse is output, and the specifying means outputs a signal on the B-mode image in accordance with the pulse output from the counting means. An ultrasonic diagnostic apparatus characterized by switching to a signal different from the original signal of the B-mode image and specifying a position on the B-mode image corresponding to the time when the threshold value is reached. 6. An ultrasonic diagnostic apparatus according to claim 5, wherein said specifying means expands a width of a pulse output from said detection means of said counting means, and expands a width of said pulse. An ultrasonic diagnostic apparatus characterized in that the original signal of the B-mode image is switched to the pulse signal obtained. 7. The ultrasonic diagnostic apparatus according to claim 1, wherein said counting means comprises:
Each time the number of times of detection of the zero-crossing by the detection means reaches the threshold value, a pulse is output, and the specifying means outputs a signal on the B-mode image corresponding to the output of the pulse from the counting means. A signal different from the original signal of the B-mode image is added,
An ultrasonic diagnostic apparatus, wherein a position on the B-mode image corresponding to the time when the threshold value is reached is specified. 8. The ultrasonic diagnostic apparatus according to claim 7, wherein said specifying means expands a width of a pulse output from said detecting means of said counting means, and expands a width of said pulse. An ultrasonic diagnostic apparatus, wherein the pulse signal obtained is added to the original signal of the B-mode image. 9. The ultrasonic diagnostic apparatus according to claim 1, wherein said specifying means comprises:
An ultrasonic diagnostic apparatus, wherein a position on the B-mode image corresponding to the time when the threshold is reached is also specified by a signal of a white or black level. 10. The ultrasonic diagnostic apparatus according to claim 1, wherein said specifying means sets a position on said B-mode image corresponding to a time when said threshold value is reached. An ultrasonic diagnostic apparatus characterized by being clearly indicated by a color. 11. An ultrasonic diagnostic apparatus for transmitting an ultrasonic pulse into a living body and detecting a zero-crossing frequency of a reflected wave from the living body, comprising: detecting means for detecting a zero-crossing of the reflected wave;
Counting means for counting the number of times the zero-crossing is detected by the detecting means at predetermined intervals, and detecting a time period at which the amplitude of the reflected wave exceeds a predetermined threshold value at each predetermined time period And a means for calculating a value obtained by dividing the counted number of zero-crossings detected by the integrated value, and setting the value obtained by the division as the zero-crossing frequency. Ultrasound diagnostic device characterized by the following. 12. An ultrasonic diagnostic apparatus according to claim 11, further comprising means for detecting said reflected wave, and detecting a period in which the amplitude of a signal obtained by detecting said reflected wave exceeds a predetermined threshold value. An ultrasonic diagnostic apparatus characterized in that the sum is integrated. 13. The twelfth or twelfth aspect of the present invention.
7. The ultrasonic diagnostic apparatus according to claim 1, wherein the predetermined time period is obtained by equally dividing a repetition time width of the transmission of the ultrasonic pulse into an arbitrary number. . 14. The ultrasonic diagnostic apparatus according to any one of claims 11 to 13, wherein the value obtained by dividing the value as the zero-crossing frequency is added to the depth of the living body. An ultrasonic diagnostic apparatus characterized by displaying an associated graph. 15. An ultrasonic diagnostic apparatus according to claim 11, wherein said reflected wave is digitized, and storage means for storing data obtained by digitizing said reflected wave. Means, processing the data stored in the storage means based on a program created in advance, detecting the zero-crossing of the reflected wave, counting the number of times the zero-crossing is detected, and setting the amplitude of the reflected wave to a predetermined threshold. An ultrasonic diagnostic apparatus, comprising: a processing unit that performs at least detection and integration of a time period that is exceeded and division of the counted number of times of zero-crossing detection by the integrated value.