JP3243237B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus utilizing non-linear distortion caused by the propagation of ultrasonic waves, and more particularly to an ultrasonic diagnostic apparatus with a reduced frame rate.

[0002]

2. Description of the Related Art In recent years, there has been known an ultrasonic diagnostic apparatus having a harmonic imaging function, that is, an ultrasonic diagnostic apparatus which forms an image using harmonics generated by nonlinear propagation distortion of ultrasonic waves. The configuration is divided into three according to the method of extracting harmonics.

In the first method, a received echo signal is passed through a high-pass filter to attenuate a fundamental wave component and a harmonic is extracted. The operation will be described below with reference to FIG.

[0004] The ultrasonic diagnostic apparatus shown in FIG. 9 includes a pulse generating circuit 101, a control circuit 102, a probe 103, and a receiving circuit 104.
, High-pass filter 105, detector 106, and scan converter
107 and a display unit 108.

Next, the operation of the conventional example will be described. In accordance with a control signal from the control circuit 102, an electric pulse is generated from the pulse generation circuit 101, converted into an ultrasonic pulse by the probe 103, and transmitted to the body (not shown). In the body, part of the energy is converted to harmonics by nonlinear propagation. The probe 103 converts the mixed echo signal of the fundamental wave and the harmonic into an electric signal, and outputs the electric signal to the receiving circuit 104.
After adjusting the amplitude to an appropriate value, the fundamental wave is removed by the high-pass filter 105, and a harmonic component is extracted. The extracted harmonic component is detected by the detector 106, and the scanning converter 1
The information is displayed on the display unit 108 via 07.

A second method is described, for example, in US Pat. No. 5,706,819.
The method is disclosed in US Pat. This method is illustrated in FIG.
0 and FIG. The ultrasonic diagnostic apparatus shown in FIG. 10 includes a pulse generation circuit 101, a control circuit 102,
Probe 103, receiving circuit 104, detector 106, scan converter 107, display unit 108, A / D converter 109, and memory 110
And an adder 111. FIG. 11 shows the internal configuration and operation of the pulse generation circuit 101 of FIG. 10. The pulse generation circuit 101 includes FET switches 112 and 113.

Next, the operation of the conventional example will be described. In the sequence of the conventional example, two transmissions and receptions are performed as one set.
The control circuit 102 sends a control signal to the pulse generation circuit 101. In the first transmission, the pulse generation circuit 101 shown in FIG.
The FET switch 112 of 101 is turned on before the FET switch 113, and the timing is as shown in FIG. The transmission and reception by the probe 103 and the amplification by the reception circuit 104 are the first.
Is the same as the conventional example. The output signal of the receiving circuit 104 is A
The signal is converted into a digital signal by the / D converter 109 and stored in the memory 110. Next, the second transmission / reception is performed. In the second transmission, the FET switch 113 is turned on before the FET switch 112 at the timing as shown in FIG. As a result, the second transmission pulse has a phase opposite to that of the first transmission pulse.

When the echo signals obtained in the two transmissions and receptions as described above are added by the adder 111, the fundamental wave component is canceled and disappears, and only the second harmonic remains. In this conventional example, harmonics are extracted by such a method. The processing after the detector 106 is the same as in the first conventional example.

As a third method, Japanese Patent Application Laid-Open No. 61-27923 is disclosed.
A method described in Japanese Patent Publication No. 5 is known. Hereinafter, the operation principle will be described with reference to the block diagram shown in FIG.

The ultrasonic diagnostic apparatus shown in FIG. 12 comprises a pulse generating circuit 101, a control circuit 102, a probe 103, a receiving circuit 1
04, the subject 105, the detector 106, the scan converter 107,
A display unit 108, an A / D converter 109, memories 114 and 115,
An operation unit 116 and a variable gain unit 119 are provided.

In FIG. 12, a pulse generation circuit 101 comprises:
In the first transmission, a drive pulse having an amplitude A is generated to drive the probe 103 to generate an ultrasonic pulse having an amplitude B. In the second transmission, the pulse generation circuit 101 generates a 2A drive pulse whose amplitude is twice the first transmission, drives the probe 103, and generates a pulse having an amplitude of 2B. The ultrasonic pulse generated by the probe 103 propagates in the subject 105.

The ultrasonic pulse increases nonlinear distortion as the propagation distance within the subject 105 increases, and the distortion amount increases as the amplitude of the ultrasonic wave increases. This distortion is based on the generation of harmonic components, and therefore the amplitude of the fundamental wave decreases. In the ultrasonic pulse beam, the distortion is large at the peak portion of the main lobe having a relatively large amplitude, and small at the side lobe portion having a relatively small amplitude. As described above, the distorted ultrasonic pulse is scattered in the subject 105, becomes an echo, and is converted into a received signal by the probe 103.

The variable gain section 119 amplifies the received signal for the first transmission by a factor C,
For the received signal for the second transmission, the variable gain unit 119
Amplifies the received signal at C / 2 times the magnification of half. The first received signal is quantized and discretized by the A / D converter 109, and then stored in the memory 114. The second received signal is quantized and discretized by the A / D converter 109. Thereafter, it is stored in the memory 115. Then, the signals are read from the memories 114 and 115, and the difference between the first received signal and the second received signal is obtained by the arithmetic unit 116 and output.

In this case, comparing the components caused by the side lobes of the first reception signal and the second reception signal, the amplitude ratio is exactly twice since the amplitude is relatively small. It can be said that there is. On the other hand, since the component caused by the main lobe has a relatively large amplitude, the amplitude ratio is not exactly twice for the above-described reason. Therefore, the operation unit 11
By the subtraction by 6, the component due to the side lobe becomes zero, but the component due to the main lobe is not zero. This difference signal can be considered to correspond to a portion where the amplitude of the main lobe is large, that is, a received signal obtained by a very narrow beam. The reception signal thus subtracted is detected by the detector 106, and displayed on the display unit 108 via the scan converter 107 as an image with high resolution and few side lobes.

Of the above three methods, in the first method, that is, the extraction by the filter, if the band of the fundamental wave overlaps with the harmonic, it becomes impossible to extract only the harmonic component by the filter. For this reason, it is necessary to narrow the band of the transmission pulse to some extent, which causes deterioration of the vertical resolution of the image. Therefore, it can be said that the second and third conventional examples are superior in terms of the vertical resolution of the image.

By the way, the amplitude of the harmonic becomes largest at a depth near the focal point of the probe.
It gradually gets smaller. Originally, since the level of the harmonic is smaller than that of the fundamental wave, the harmonic signal is buried in the noise at a deep portion, making it impossible to form an image.

In view of this point, a system as disclosed in Japanese Patent Application Laid-Open No. 10-179589 has been proposed. This method will be described with reference to FIG. An ultrasonic diagnostic apparatus shown in FIG. 13 includes a pulse generation circuit 101, a control circuit 102, and a probe 103.
, Receiving circuit 104, detectors 106 and 117, and scan converter 107
Display unit 108, A / D converter 109, memory 110,
An adder 111 and a mixer 118 are provided.

In the above configuration. The basic operation is the same as that of the second conventional example, except that the memory 110 and the adder 111 are used.
In the mixer 118, the image of the harmonics extracted by the detector 106 and the image of the fundamental frequency detected by the detector 117 from the output of the A / D converter 109 are mixed. Thus, in a deep part, an image is composed of a fundamental wave, thereby blending a harmonic and a fundamental frequency echo in a common image to overcome noise reduction and depth-dependent attenuation.

A case where this method is applied to the third conventional example will be described with reference to FIG. The ultrasonic diagnostic apparatus shown in FIG. 14 includes a pulse generation circuit 101, a control circuit 102, a probe 103, a reception circuit 104, detectors 106 and 117, a scan converter 107, a display unit 108, , A / D converter 109 and memory 1
14, 115, an operation unit 116, and a mixer 118.

In this conventional example, an image based on harmonics extracted by the arithmetic unit 116 and detected by the detector 106 and A
The image of the fundamental frequency detected by the detector 117 from the output of the / D converter 109 is mixed by the mixer 118. This allows
In a deep part, an image is composed of a fundamental wave, thereby blending a harmonic and a fundamental frequency echo in a common image to overcome noise reduction and depth-dependent attenuation.

[0021]

In the second and third prior arts described above, it is not necessary to limit the transmission band, but since the transmission and reception must be repeated twice in the same direction, the frame rate is reduced by half. The problem is that it decreases. In addition, in a moving organ such as a heart, there is a problem in that when the subject moves between two transmissions and receptions, a correct calculation cannot be performed. If the transmission repetition frequency is increased to solve this problem, the next transmission pulse will be generated before the echo of a deep part returns, and the displayable depth will be shallow.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to reduce a decrease in frame rate in an ultrasonic diagnostic apparatus having a harmonic imaging function.

Another object of the present invention is to provide an ultrasonic diagnostic apparatus having a harmonic imaging function in which a reduction in the frame rate is reduced and a display can be made to a deep part.

[0024]

According to an ultrasonic diagnostic apparatus of the present invention, there is provided a probe for transmitting / receiving an ultrasonic wave to / from a subject, and transmitting means for changing the polarity of a driving pulse for driving the probe. A conversion means for discretizing and quantizing the echo signal transmitted to the inside of the subject by the transmission means and reflected and returned to the probe, and corresponding to driving pulses having different polarities,
An adder for detecting a non-linear distortion component in the subject based on an output signal of the converter; and a pulse interval adjuster for adjusting an interval between the drive pulses having different polarities in the transmitter. With this configuration, it is possible to reduce a decrease in the frame rate in the ultrasonic diagnostic apparatus having the harmonic imaging function.

Further, the ultrasonic diagnostic apparatus of the present invention comprises: a probe for transmitting / receiving an ultrasonic wave to / from a subject; transmitting means for varying the amplitude of a driving pulse for driving the probe; A conversion unit for discretizing and quantizing the echo signal transmitted into the subject, reflected and returned to the probe, and an output signal of the conversion unit corresponding to drive pulses having different amplitudes. And a pulse interval adjusting unit for adjusting an interval between the driving pulses having different amplitudes in the transmitting unit. With this configuration, it is possible to reduce a decrease in the frame rate in the ultrasonic diagnostic apparatus having the harmonic imaging function.

Further, in the ultrasonic diagnostic apparatus of the present invention, a mixing means for mixing the nonlinear distortion component and the fundamental wave component is provided. With this configuration, in an ultrasonic diagnostic apparatus having a harmonic imaging function, a decrease in the frame rate can be reduced, and a display can be made to a deep part.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(First Embodiment) FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of driving pulses having different polarities from each other, transmits the generated ultrasonic waves into a subject, adds those echo signals, and extracts a harmonic component. The intervals between drive pulses having different polarities are made variable.

As shown in FIG. 1, the ultrasonic diagnostic apparatus according to the present embodiment has a pulse generation circuit 1 for generating a drive pulse.
A control circuit 2 for controlling the pulse generation circuit 1, a pulse interval adjuster 5 for adjusting the interval between drive pulses generated by the pulse generation circuit 1, and a drive pulse generated by the pulse generation circuit 1 A probe 3 for converting and transmitting the signal to the subject and converting the received echo into an electric signal; a receiving circuit 4 for adjusting the amplitude of a signal received by the probe 3;
A / D converter 9 for discretizing and quantizing the output of receiving circuit 4
A memory 10 for storing the output of the A / D converter 9;
An adder 11 for adding the output of the D converter 9 and the output of the memory 10 to extract a harmonic component;
Detector 6 and detector 17 for detecting the output of A / D converter 9
A mixer 18 for mixing the output of the detector 6 and the output of the detector 17, a scan converter 7 for converting the output of the mixer 18 into image data for display, and displaying the output of the scan converter 7 And a display unit 8 for displaying. In this figure, FIG.
The same names as those used in FIG. 13 are used for components corresponding to the conventional ultrasonic diagnostic apparatus shown in FIG. That is, the basic configuration of the present embodiment is such that the pulse interval adjuster 5 is connected to the conventional device of FIG.

The operation of the ultrasonic diagnostic apparatus configured as described above will be described. The operation of this ultrasonic diagnostic apparatus is basically the same as that of the conventional apparatus shown in FIG. 13 except for a part related to the pulse interval adjuster 5, and therefore, here, the pulse interval adjustment which is a feature of the present embodiment is described. The operation related to the container 5 will be described.

FIG. 2 is a diagram showing a pulse generation trigger signal based on the control of the pulse interval adjuster 5, a transmission pulse of the pulse generation circuit 1, and a timing of a fundamental frequency component and a harmonic component in a reception echo signal. here,
(A) is a pulse generation trigger, (b) is a transmission pulse,
(C) is a fundamental frequency component in the received echo signal,
(D) is a harmonic component in the received echo signal.

As shown in FIG. 2, first, at the timing T _A
In, a transmission pulse trigger signal is output from the control of the pulse interval adjuster 5, a transmission pulse is generated from the pulse generation circuit 1, and an ultrasonic pulse is transmitted from the probe 3 into the subject. Assuming that the subject is a uniform medium, the fundamental wave component of the echo becomes large immediately after the shallow portion, that is, immediately after the transmission pulse, as shown in FIG. 2C, and becomes smaller as time elapses from the deep portion, that is, the transmission pulse. The harmonic components generated in the body gradually increase, become largest near the focus point F, and then become smaller as the depth increases. Here it should be noted, the harmonic component is to signal attenuated at a relatively shallow sites focus point beyond can no longer be detected, the signal after t1 from the timing T _A of the transmitted pulse in this figure detects No longer. At this timing, the signal of the fundamental wave is still detected. Since the extraction of the harmonic components is no problem even if there exists a fundamental wave, in the present embodiment, the timing T _B (T _A from the time t1 after the harmonics from the transmission timing T _A for the first time can no longer be detected ), A second transmission pulse having a phase opposite to that of the first pulse is generated.

From the echo for the second transmission pulse, in addition to extracting the harmonics, a fundamental signal is detected in order to form an image of a deep part. Therefore, the timing T _C (T _B from the time when the echo of the fundamental wave becomes sufficiently small)
After t2. However, wait until t2> t1) and generate the next transmission pulse.

Here, comparing the conventional system shown in FIG. 13 with the present embodiment, the conventional system requires twice as long as t2 for extracting the fundamental wave and the harmonic. On the other hand, in the present embodiment, it can be performed in the time of (t1 + t2).

As described above, in the first embodiment of the present invention, when the harmonic component cannot be detected from the reception echo of the first transmission pulse, the second transmission of a phase opposite to that of the first transmission pulse. When the fundamental wave component of the received echo becomes sufficiently small, a transmit pulse having the same phase as the first transmit pulse is generated, and the pulse is operated periodically thereafter. The time required to extract the waves and construct the image can be reduced. As a result, the harmonic component and the fundamental component can be extracted at a high frame rate, and the harmonic and the fundamental frequency echo can be blended in a common image to reduce noise and overcome depth-dependent attenuation. .

In the first embodiment, a pulse interval adjuster is added to the conventional device shown in FIG. 13; however, the same effect can be obtained by adding a pulse interval adjuster to the conventional device shown in FIG. Thus, a decrease in the frame rate can be prevented.

(Second Embodiment) FIG. 3 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a second embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of driving pulses having different amplitudes from each other, transmits the ultrasonic waves into a subject, and subtracts those echo signals to extract harmonic components. The intervals between drive pulses having different polarities are made variable.

As shown in FIG. 3, the ultrasonic diagnostic apparatus according to the present embodiment has a pulse generation circuit 1 for generating a drive pulse.
A control circuit 2 for controlling the pulse generation circuit 1, a pulse interval adjuster 5 for adjusting the interval between drive pulses generated by the pulse generation circuit 1, and a drive pulse generated by the pulse generation circuit 1 A probe 3 for converting and transmitting the signal to the subject and converting the received echo into an electric signal; a receiving circuit 4 for adjusting the amplitude of a signal received by the probe 3;
Gain control section 19 for variably controlling the gain of the output of receiving circuit 4
An A / D converter 9 for discretizing and quantizing the output of the gain control unit 19; a memory 14 for storing the output of the A / D converter 9;
An arithmetic unit 16 for subtracting the output of the memory 14 from the output of the memory 15 to extract a harmonic component; a detector 6 for detecting the output of the arithmetic unit 16 and the output of the A / D converter 9; Detector
17, a mixer 18 for mixing the outputs of the detector 6 and the detector 17
A scanning converter 7 for converting the output of the mixer 18 into image data for display; and a display unit 8 for displaying the output of the scanning converter 7. In this figure, the components corresponding to those of the conventional ultrasonic diagnostic apparatus shown in FIG. 14 have the same names as those used in FIG. That is, the basic configuration of the present embodiment is such that the pulse interval adjuster 5 is connected to the conventional device of FIG.

The operation of the ultrasonic diagnostic apparatus configured as described above will be described. The operation of this ultrasonic diagnostic apparatus is basically the same as that of the conventional apparatus shown in FIG. 14 except for a part related to the pulse interval adjuster 5. The operation related to the pulse interval adjuster 5 is the same as that of the first embodiment except that the level is alternately increased or decreased instead of alternately changing the transmission pulse in the opposite phase.

As described above, according to the second embodiment of the present invention, when the harmonic component cannot be detected from the reception echo of the first transmission pulse, the level is twice as high as that of the first transmission pulse. Is generated, and when the fundamental wave component of the received echo becomes sufficiently small, a transmission pulse having the same level as the first transmission pulse is generated, and thereafter, the pulse is periodically operated. The time required to extract fundamental waves and harmonics and construct an image can be reduced. As a result, the harmonic component and the fundamental component can be extracted at a high frame rate, and the harmonic and the fundamental frequency echo can be blended in a common image to reduce noise and overcome depth-dependent attenuation. .

In the second embodiment, a pulse interval adjuster is added to the conventional device shown in FIG. 14; however, the same effect can be obtained by adding a pulse interval adjuster to the conventional device shown in FIG. Thus, a decrease in the frame rate can be prevented.

(Third Embodiment) FIG. 4 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a third embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of drive pulses having different amplitudes from each other, transmits the generated ultrasonic waves into a subject, adds those echo signals, and extracts a harmonic component. In addition, the intervals between the drive pulses having different polarities are made variable, and the leakage of the fundamental wave component at the time of extracting the harmonic component is reduced.

As shown in FIG. 4, the ultrasonic diagnostic apparatus according to the present embodiment comprises a pulse generating circuit 1, a control circuit 2, a probe 3, a receiving circuit 4, a pulse interval adjuster 5, It includes detectors 6 and 17, a scan converter 7, a display unit 8, an A / D converter 9, a memory 10, an adder 11, a mixer 18, and a high-pass filter 20. In this figure, the same components as those of the ultrasonic diagnostic apparatus of the first embodiment shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. The configuration of the present embodiment is such that a high-pass filter is provided between the adder 11 and the detector 6 in the ultrasonic diagnostic apparatus of the first embodiment.
20 connected.

Next, the operation of FIG. 4 will be described. Since the basic operation of this embodiment is the same as that of the first embodiment, the operation related to the high-pass vitality 20, which is a feature of this embodiment, will be described here. The adder 11 has a memory 10
Of the first transmission pulse output from the A / D
The harmonic component is extracted by adding the echo of the second transmission pulse output from the converter 9. However, since the fundamental wave component is slightly mixed in the adder 11, by removing it with the high-pass filter 20,
In the detector 6, higher-precision harmonics can be extracted.

As described above, according to the third embodiment of the present invention, the harmonic component and the fundamental component are extracted at a high frame rate, and the leakage of the fundamental component at the time of the harmonic extraction is reduced to improve the image quality. Can be improved. .

(Fourth Embodiment) FIG. 5 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a fourth embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of driving pulses having different polarities from each other, transmits the generated ultrasonic waves into a subject, adds those echo signals, and extracts a harmonic component. By monitoring the level of the fundamental wave component in the deep part, the intervals between driving pulses having different polarities are set optimally.

As shown in FIG. 5, the ultrasonic diagnostic apparatus according to the present embodiment comprises a pulse generation circuit 1, a control circuit 2, a probe 3, a reception circuit 4, a pulse interval adjuster 5, It includes detectors 6 and 17, a scan converter 7, a display unit 8, an A / D converter 9, a memory 10, an adder 11, a mixer 18, and a signal level detector 21. . In this figure, the same components as those of the ultrasonic diagnostic apparatus of the first embodiment shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. In the configuration of the present embodiment, a signal level detector 21 for detecting the output level of the A / D converter 9 is connected to the pulse interval adjuster 5 in the ultrasonic diagnostic apparatus of the first embodiment. .

Next, the operation of this embodiment will be described. Since the basic operation of the present embodiment is the same as that of the first embodiment, the operation related to the signal level detector 21 which is a feature of the present embodiment will be described here. The signal level detector 21 detects the level of the echo signal converted into a digital signal by the A / D converter 9 and measures the depth at which the echo signal becomes smaller than the detection level to determine the pulse interval. By feeding back to the controller 5 and determining the time of t2 in FIG. 2, the time of t2 is set to the shortest.

As described above, according to the fourth embodiment of the present invention, by monitoring the level of the fundamental wave component in the deep part of the subject, the interval between the two types of transmission pulses whose polarities are alternately inverted is determined. With proper adjustment, harmonic components and fundamental components can be extracted at a high frame rate.

(Fifth Embodiment) FIG. 6 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a fifth embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of driving pulses having different amplitudes from each other, transmits the ultrasonic waves into a subject, and subtracts those echo signals to extract harmonic components. By monitoring the level of the fundamental wave component in the deep part, the intervals between the drive pulses having different amplitudes from each other are optimally set.

As shown in FIG. 6, the ultrasonic diagnostic apparatus according to the present embodiment has a pulse generating circuit 1, a control circuit 2, a probe 3, Circuit 4
, A pulse interval controller 5, detectors 6 and 17, a scan converter 7, a display unit 8, an A / D converter 9, and memories 14 and 15.
, An operation unit 16, a mixer 18, and a signal level detector 21. In this figure, the same components as those of the ultrasonic diagnostic apparatus of the second embodiment shown in FIG. 3 are denoted by the same reference numerals as those used in FIG. In the configuration of the present embodiment, a signal level detector 21 for detecting the output level of the A / D converter 9 is connected to the pulse interval adjuster 5 in the ultrasonic diagnostic apparatus of the second embodiment. .

Next, the operation of this embodiment will be described. Since the basic operation of this embodiment is the same as that of the second embodiment, the operation related to the signal level detector 21 which is a feature of this embodiment will be described here. The signal level detector 21 detects the level of the echo signal converted into a digital signal by the A / D converter 9 and measures the depth at which the echo signal becomes smaller than the detection level to determine the pulse interval. By feeding back to the controller 5 and determining the time of t2 in FIG. 2, the time of t2 is set to the shortest.

As described above, according to the fifth embodiment of the present invention, by monitoring the level of the fundamental wave component in the deep part of the subject, the interval between two types of transmission pulses whose amplitude alternately increases and decreases can be determined. With proper adjustment, harmonic components and fundamental components can be extracted at a high frame rate.

(Sixth Embodiment) FIG. 7 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a sixth embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of driving pulses having different polarities from each other, transmits the generated ultrasonic waves into a subject, adds those echo signals, and extracts a harmonic component. By monitoring the level of the harmonic component in the deep part, the intervals between the drive pulses having different polarities are set optimally.

As shown in FIG. 7, the ultrasonic diagnostic apparatus according to the present embodiment comprises a pulse generating circuit 1, a control circuit 2, a probe 3, a receiving circuit 4, a pulse interval adjuster 5, It includes detectors 6 and 17, a scanning converter 7, a display unit 8, an A / D converter 9, a memory 10, an adder 11, a mixer 18, and a signal level detector 21. . In this figure, the same components as those of the ultrasonic diagnostic apparatus of the first embodiment shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. In the configuration of the present embodiment, a signal level detector 21 for detecting the output level of the adder 11 is connected to the pulse interval adjuster 5 in the ultrasonic diagnostic apparatus of the first embodiment.

Next, the operation of this embodiment will be described. Since the basic operation of the present embodiment is the same as that of the first embodiment, the operation related to the signal level detector 21 which is a feature of the present embodiment will be described here. The signal level detector 21 detects the level of the harmonic signal extracted by the adder 11, and measures the depth at which the harmonic signal becomes smaller than a predetermined detection level to measure the pulse interval. 5 to determine the time of t1 in FIG. 2 to set the time of t1 to the shortest.

As described above, according to the sixth embodiment of the present invention, by monitoring the level of the harmonic component in the deep part, the interval between two types of transmission pulses having different polarities is appropriately adjusted, Harmonic components and fundamental components can be extracted at a high frame rate.

(Seventh Embodiment) FIG. 8 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a seventh embodiment of the present invention. In this ultrasonic diagnostic apparatus, an ultrasonic diagnostic apparatus that sequentially generates ultrasonic waves by two types of driving pulses having different amplitudes from each other, transmits the ultrasonic waves into a subject, and subtracts those echo signals to extract harmonic components. By monitoring the level of the harmonic component in the deep part, the intervals between the drive pulses having different amplitudes from each other are optimally set.

As shown in FIG. 8, the ultrasonic diagnostic apparatus according to the present embodiment comprises a pulse generating circuit 1, a control circuit 2, a probe 3, a receiving circuit 4, a pulse interval adjuster 5, It comprises detectors 6, 17, a scanning converter 7, a display unit 8, an A / D converter 9, memories 14, 15, an operation unit 16, a mixer 18, and a signal level detector 21. ing. In this figure, FIG.
The same reference numerals as those used in FIG. 3 are used for the same components as those of the ultrasonic diagnostic apparatus according to the second embodiment shown in FIG.
In the configuration of the present embodiment, a signal level detector 21 for detecting the output level of the arithmetic section 16 is connected to the pulse interval adjuster 5 in the ultrasonic diagnostic apparatus of the second embodiment.

Next, the operation of this embodiment will be described. Since the basic operation of this embodiment is the same as that of the second embodiment, the operation related to the signal level detector 21 which is a feature of this embodiment will be described here. The signal level detector 21 detects the level of the harmonic signal extracted by the arithmetic unit 16, measures at which depth the harmonic signal becomes smaller than the detection level, and sends the signal to the pulse interval controller 5. By feedback and determining the time of t1 in FIG. 2,
Set the time of t1 to the shortest.

As described above, according to the seventh embodiment of the present invention, by monitoring the level of the harmonic component in the deep part of the subject, the two types of transmission pulse intervals whose amplitude alternately increases and decreases can be appropriately adjusted. , And the harmonic component and the fundamental component can be extracted at a high frame rate.

[0062]

As described above, according to the present invention,
In an ultrasonic diagnostic apparatus having a harmonic imaging function, a repetition interval of transmission and reception of ultrasonic waves can be shortened, a decrease in a frame rate in harmonic imaging can be reduced, and the degree of image quality deterioration in a moving organ can be reduced. In addition, by mixing the harmonic component and the fundamental component, it is possible to display a deep part.

[Brief description of the drawings]

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

FIG. 2 is a timing chart for explaining the first embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a second embodiment of the present invention;

FIG. 4 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a third embodiment of the present invention;

FIG. 5 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a fourth embodiment of the present invention;

FIG. 6 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a fifth embodiment of the present invention;

FIG. 7 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a sixth embodiment of the present invention;

FIG. 8 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to a seventh embodiment of the present invention;

FIG. 9 is a block diagram showing the configuration of a first conventional example of an ultrasonic diagnostic apparatus;

FIG. 10 is a block diagram showing the configuration of a second conventional example of an ultrasonic diagnostic apparatus;

FIG. 11 is an explanatory diagram showing an operation of a pulse generation circuit of an ultrasonic diagnostic apparatus according to a second conventional example;

FIG. 12 is a block diagram illustrating a configuration of a third conventional example of an ultrasonic diagnostic apparatus.

FIG. 13 is a block diagram showing a configuration of a fourth conventional example of an ultrasonic diagnostic apparatus.

FIG. 14 is a block diagram showing a configuration of a fifth conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 Reference Signs List 1 pulse generation circuit 2 control circuit 3 probe 5 pulse interval adjuster 9 A / D converter 11 adder 16 operation unit 18 mixer 20 high-pass filter 21 signal level detector

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 8/00

Claims (7)

(57) [Claims] A probe for transmitting / receiving ultrasonic waves to / from the subject; a transmitting unit having a variable polarity of a driving pulse for driving the probe; and a transmitting unit transmitting the ultrasonic wave into the subject by the transmitting unit.
A converting means for discretizing and quantizing the echo signal reflected and returned to the probe; and a non-linear distortion in the subject based on an output signal of the converting means corresponding to driving pulses having mutually different polarities. An ultrasonic diagnostic apparatus comprising: an adding unit that detects a minute; and a pulse interval adjusting unit that adjusts an interval between driving pulses having different polarities in the transmitting unit. 2. A probe for transmitting and receiving an ultrasonic wave to and from a subject, transmitting means for varying the amplitude of a drive pulse for driving the probe, and transmitted into the subject by the transmitting means,
Converting means for discretizing and quantizing the echo signal reflected and returned to the probe; and non-linear distortion in the subject based on an output signal of the converting means corresponding to drive pulses having mutually different amplitudes. An ultrasonic diagnostic apparatus comprising: subtraction means for detecting a minute; and pulse interval adjustment means for adjusting an interval between drive pulses having different amplitudes in the transmission means. 3. An ultrasonic diagnostic apparatus according to claim 1, wherein a high-pass filter is provided on an output side of said adding means. 4. An ultrasonic diagnostic apparatus according to claim 1, further comprising a level detecting means for monitoring an output of said converting means, wherein the generation timing of the driving pulse is changed by an output of said level detecting means. . 5. An ultrasonic diagnostic apparatus according to claim 1, further comprising a level detecting means for monitoring an output of said adding means, wherein a timing of generating a driving pulse is changed by an output of said level detecting means. 6. An ultrasonic diagnostic apparatus according to claim 2, further comprising a level detecting means for monitoring an output of said subtracting means, wherein a generation timing of a driving pulse is changed by an output of said level detecting means. 7. The ultrasonic diagnostic apparatus according to claim 1, further comprising mixing means for mixing the non-linear distortion component and the fundamental wave component.