JPH0975349A - Ultrasonic diagnostic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use the buffer amplifier of delay line as a gain control amplifier by arranging buffer amplifiers at the input and output of an analog delay line and performing weighting in reception while controlling the gains of respective buffer amplifiers. SOLUTION: The delay line buffer amplifier of a delay line circuit is composed of an output buffer mainly composed of transistors TRa2-TRa(n+1) and an input buffer mainly composed of transistors TRb1-TRbn, and a signal inputted in the form of current is converted to a voltage by R21-R(n+1). Besides, the amplifier at the intermediate position is mainly composed of transistors TRc2-TRcn and the signal is converted to the form of current and let flow into the input buffer of transistors TRb1-TRbn. By changing a base potential Vc of the intermediate input amplifier, the level of emitter resistance at the transistor is changed, and weighting is performed while changing the gains as amplifiers.

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 having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition.

[0002]

2. Description of the Related Art In the transmission and reception of an ultrasonic diagnostic apparatus, a technique of obtaining a high quality image of a wide range of test sites by a probe composed of a plurality of transducers has been often used recently.

An ultrasonic diagnostic apparatus of this type having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition is constructed as shown in FIG. FIG. 9 shows the combination of signals when echo signals are received by a plurality of transducers in a linear scan. 1 to 8 are oscillators, 52 to 57 are delay lines, 60 is an adder, and 100 is a reflector.

The operation of FIG. 9 will be described. Reflector 10
When the signals reflected by 0 are received by the transducers 1-8,
Since the distance from the reflector 100 to each transducer is different, a difference occurs in the signal arrival time from the reflector to each transducer. This time difference is corrected by the delay lines 52 to 57 and added by the adder 60 to obtain one output. This method is hereinafter referred to as focusing. By focusing, the beam can be narrowed down, the resolution can be improved, and random noise can be reduced.
/ N ratio can be improved.

An analog type delay line is often used as the delay line, but recently, a digital delay line in which an A / D converter and a digital memory are combined has begun to be used. The switching of the delay time in the analog delay line is generally performed by switching the tap of the analog delay line with an intermediate tap with an analog switch.

In the linear scan, a line (hereinafter referred to as a beam) extending from the reflector to the center of the aperture is perpendicular to the array direction of the transducers. Therefore, the delay time required for the oscillators symmetrical to the center of the aperture, that is, the oscillator 1 and the oscillator 8, the oscillator 2 and the oscillator 7, the oscillator 3 and the oscillator 6, the oscillator 4 and the oscillator 5 is required. Since they are equal to each other, it is possible to reduce the number of delay means to half by adding signals having the same delay time and inputting them to the delay means. This method is called fold over.

An example of foldover is shown in FIG. In FIG. 10, 52 to 54 are delay lines, and 361 to 3
64 is an adder. FIG. 11 shows a delay addition unit of a linear scan that takes the two-dimensional scan into consideration.

In FIG. 11, reference numerals 1 to 16 designate vibrators 21 to 21.
28 is a 2: 1 analog switch, 29 is an 8: 4 crosspoint switch (hereinafter abbreviated as CPS) unit, which is a voltage-current converter 61 to 68, an 8: 4 CPS 70, and a current-voltage converter. 71 to 74. 130
Is a delay adder, which is a variable delay line 30-32 and an adder 33-
35.

Next, the operation in FIG. 11 will be described. The beam movement in the linear scan is performed by sequentially switching the selected transducer with a switch. In FIG. 11, eight of the 16 transducers 1 to 16 are selected, and the transducers 1 to 8 are selected by setting all the analog switches 21 to 28 to the a side, and the position of the beam is selected. Is set between the oscillators 4 and 5. Next, when the analog switch 21 is connected to the b side, the vibrator 9 is selected instead of the vibrator 1, the apertures become the vibrators 2 to 9, and the beam position moves between the vibrator 5 and the vibrator 6. Similarly, the position of the beam can be moved by sequentially switching the analog switches 21 to 28.

The signals selected by the analog switches 21 to 28 are input to the CPS unit 29. In the CPS unit 29,
The eight signals that have passed through the analog switches 21 to 28 are
Add two signals with the same required delay time,
Fold over is performed to output four types of d. C
The signals input to the PS unit 29 are voltage-current converters 61 to 6
The current signal is converted into a current signal by 8, and the current is added by the connection of the CPS 70.

The signal output from the CPS unit 29 is input to the delay adding unit 130, delayed and added by the delay lines 30 to 32 and the adders 33 to 35, and output. Next, a method of synthesizing received signals from a plurality of transducers in a sector scan will be described with reference to FIG.

In FIG. 12, 1 to 8 are vibrators and 52 to 5
8 is a delay line, 60 is an adder, and 100 is a reflector. Since the beam angle is deflected in the sector scan, the arrangement angle of the transducers and the angle θ formed by the beam are freely changed. Therefore, the foldover that is performed by the linear scan cannot be used, and it is necessary to prepare the delay means for the number of channels, that is, for 8 channels in FIG.

Since the sector scan is performed by changing the deflection angle of the beam, the same transducer group is always used. Although the reception focusing method in the linear scan and the sector scan has been described above, the focusing can be performed also in the transmission by adjusting the pulse generation timing of each transducer.

Next, the gain control of each transducer in the reception beamforming will be described. In the linear scan, it is common to lower the gain at the edge of the aperture with respect to the center of the aperture. This is called weighting and has the effect of reducing the level of the side lobes of the beam. A window function used in fast Fourier transform or the like is used as the weighting function.

In the sector scan, when the beam is deflected, gain correction is performed in order to correct the collapse of the beam shape due to the fact that the distance from each transducer to the focus point is not symmetric with respect to the aperture center as in the linear scan. To do. FIG. 13 shows an example of gain correction when the beam is deflected toward the channel 8 as shown in FIG.

In FIG. 13, the horizontal axis represents the channel number and the vertical axis represents the gain. In FIG. 13, the smaller the channel number, that is, the higher the gain in the element that is farther from the focus point. In FIG. 12, the relationship between the channel number and the delay amount does not increase monotonically, but in reality, the channel pitch is fine and most of the delay time is used for beam deflection. Therefore, the relationship between the channel number and the delay amount increases monotonically. It decreases monotonically, and gain control can be substituted with a straight line. A circuit as shown in FIG. 14 is used for gain control.

In FIG. 14, reference numerals 52 to 58 are delay lines, 60
Is an adder, 100 is a reflector, 151 to 158 are gain control amplifiers that can control the gain with voltage, and 159 is a control circuit that generates an amplifier gain control voltage.

FIG. 15 shows a concrete example of the control voltage generator. Reference numerals 251 to 258 are D / A converters, and 259 is an arithmetic device for weighting data calculation. The weighting data of each channel is calculated by the arithmetic unit 259, sent to the D / A converters 251 to 258 through the data bus, and the D / A
The data analog-converted by the converters 251 to 258 is sent to the gain control amplifiers 151 to 158 as a control voltage.

FIG. 16 shows another example of the control voltage generator. In FIG. 16, reference numeral 259 denotes an arithmetic unit, 251, 252.
Is a D / A converter, and 351 to 357 are resistors. First, the arithmetic unit 259 calculates the weighting data of the center of the aperture and the end of the aperture, and the D / A converter 25
1,252. The data analog-converted by the D / A converters 251 and 252 are added to both ends of the resistor string 358 formed by the resistors 351 to 357. Resistor string 3
The resistance value is set so that the voltage divided by the resistors 351 to 357 of 58 is just a weighting function. Each of the divided voltages is supplied to the gain control amplifier 151-
158 is supplied as a control voltage.

This method requires only two D / A converters,
In addition, there is an advantage that the control data can be calculated using only the center of the aperture and the end. FIG. 1 is a block diagram showing an example in which weighting is performed by linear scanning by the circuit of FIG.
FIG.

FIG. 17 shows the configuration of FIG. 11 in which the circuit of FIG. 16 is incorporated. In this example, the CPS unit 29 performs the work of foldover and rearrangement in the order of longer required delay time. In the linear scan, d is the center of the beam and a is the end. Therefore, the gain is increased in the order of d, c, b, a.

[0022]

When such a weighting control circuit is used in a linear scan or sector scan device, the following problems occur.

The first point is that a dedicated gain control amplifier is required, which causes an increase in physical quantity. The second point is a control method of the gain correction amplifier when it is desired to position the gain control amplifier immediately after the vibrator as shown in FIG.
Placing the gain control amplifier at the position shown in FIG. 18 is an effective means for avoiding the influence of jumping noise caused by routing a minute echo signal over a long distance. Since the aperture position is moved by the switch in the linear scan, the gain control amplifiers 151 to 158 are used.
In some cases, the edges 151 and 158 of the edge do not coincide with the edge of the aperture. For example, when selecting the vibrators 5 to 12, the signal at the end of the aperture is the gain control amplifier 15
4 and 155, the control voltage generation circuit by resistance division shown in FIG. 16 cannot be used.

At the third point, in the B-mode image by sector scan, this correction method is effective for adjusting the beam shape, but in applications requiring sensitivity such as Doppler, on the contrary, the S / N ratio is lowered. It is to end up.

The present invention solves such a conventional problem and realizes an ultrasonic diagnostic apparatus which is inexpensive and excellent in quality while preventing an increase in the amount of material.

[0026]

An ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus has a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition. An analog delay line for delaying the output of the oscillator and a buffer amplifier arranged at the input and output of each analog delay line are provided, and the gain of each buffer amplifier is controlled to perform weighting in reception.
The delay line buffer amplifier is used as a gain control amplifier.

An ultrasonic diagnostic apparatus according to a second aspect of the invention is an ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, in a plurality of annularly connected ultrasonic diagnostic apparatuses. A resistor, a buffer amplifier that supplies the terminal voltage of each resistor to the control signal of the gain control amplifier of the echo signal, a D / A converter that generates two voltages of the highest / lowest weighting, and the generated voltage in a ring shape. And a group of switches that can be connected to any of the terminals of the resistor, the dividing resistors are arranged in an annular shape in the resistance voltage dividing type control signal generator, and the dividing resistors are arranged between the D / A converter and the dividing resistors. A multiplexer is provided so that the output can be connected to any terminal of the dividing resistor to the D / A converter.

An ultrasonic diagnostic apparatus according to a third aspect of the invention is an ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition. D / A converter that generates one voltage, a plurality of resistors connected in series that apply the two voltages generated by the D / A converter to both ends, and the terminal voltage of each resistor are input and A switch group connected to one of the outputs, and a buffer amplifier that supplies the voltage signal output from the switch group to the control signal of the gain control amplifier of the echo signal are provided. The weight data is rearranged by using a cross point switch.

An ultrasonic diagnostic apparatus according to a fourth aspect of the invention is an ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, in which the highest / lowest weighting is 2. A D / A converter that generates two voltages, a plurality of resistors connected in series that apply the two voltages generated by the D / A converter to both ends, a plurality of sample and hold circuits, and each of the resistors that are cascaded. A weighting control circuit that is configured by a switch that inputs the selected input signal to the sample hold circuit located next to the sample hold circuit connected to the input, with the terminal as one input and the output of the sample hold circuit as the other input In the linear scan, weighting data is rearranged by a sample hold circuit connected in a ring. That.

An ultrasonic diagnostic apparatus according to a fifth aspect is the ultrasonic diagnostic apparatus according to the second aspect, wherein the number of output lines of the switch group is reduced to 1 / n of the number of channels so that the ultrasonic diagnostic apparatus can be realized by a small-scale circuit. .

An ultrasonic diagnostic apparatus according to a sixth aspect of the invention has a single D / A conversion in the ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition. And a sample hold circuit for the number of channels for taking in the data of the D / A converter, and the echo gain is controlled by the output of the sample hold circuit. The gain is controlled by the output of each sample hold circuit. The data is rearranged in the linear scan by changing the sampling order.

An ultrasonic diagnostic apparatus according to a seventh aspect is a ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, in a single D / A conversion. Device, a plurality of sample and hold circuits, a switch that selects either the output of the adjacent sample and hold circuit or the output of the D / A converter, and the input selected by the switch, and the output of the sample and hold circuit It is characterized in that the echo gain is controlled, and the data can be rearranged in the linear scan by enabling the ring connection of the sample and hold circuit.

The ultrasonic diagnostic apparatus according to claim 8 is an ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe formed of a plurality of transducers and performing delay addition, in the sector mode B mode. Performs gain correction to correct attenuation due to the distance between the focus point and each channel,
The feature of the Doppler mode is that the gain of the channel close to the focus point is increased.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. It should be noted that components having the same operation as that of the conventional example will be described with the same reference numerals.

[First Embodiment] FIG. 1 shows a delay line circuit of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention. This delay line circuit replaces the delay addition unit 130 of the ultrasonic diagnostic apparatus shown in FIG. 17, and is configured so that the delay line circuit also performs its function without separately providing the gain control amplifiers 151 to 154. Has been done.

DL1 to DLn are delay lines and TRa1 to TR
an, TRb1 to TRbn, TRc2 to TRcn are transistors, R11 to Rn1, R12 to Rn2, R13 to
Rn3, R24 to Rn4, R25 to Rn5, R26 to R
n6 is a resistance, C1 to Cn, C21 to Cn1, C22 to C
n2 is a capacitor. Input In1, In2, ...
The current-voltage converters 74, 73, ...
The output of ... is connected.

This delay line circuit is composed of a delay line, a delay line buffer amplifier, and an input amplifier from an intermediate tap. The delay line buffer amplifier is composed of an output buffer centered on the transistors TRa2 to TRa (n + 1) and an input buffer centered on the transistors TRb1 to TRbn. The output buffer is an emitter follower and the input buffer is a grounded base circuit. There is a circuit configuration in which a signal input in the form of a current is converted into a voltage by R21 to R (n + 1) 1. R13-Rn3 and R21
~ R (n + 1) 1 is equal to the characteristic impedance Zo of the delay line. The intermediate input amplifier is the transistor TRc2.
.About.TRcn, the signal is converted into a current form and the signal is supplied to the input buffers of the transistors TRb1 to TRbn.

The base potential Va of the intermediate input amplifier and the base potential Vc of the input amplifier are controlled by a control circuit (not shown). By changing the base potential, the size of the emitter resistance of the transistor changes and the gain of the amplifier can be changed.

The base potential of the intermediate input amplifier is fixed at a voltage value Va so that the gain becomes 1 so as to be balanced with the level of the signal that has passed through the delay line in the preceding stage. On the other hand, since the base potential Vc can be changed by control, the value of the emitter resistance fluctuates and the gain of the input amplifier can be changed. That is, it can be said that the signal input from the preceding stage has a higher gain or a lower gain.

Weighting is performed by utilizing this fact. In linear scanning, a delay amount is required closer to the center of the aperture. Therefore, if the gain of each stage is set to be larger than 1, the gain becomes higher as the delay time becomes longer, that is, closer to the center of the aperture, so that weighting can be performed.

In the present embodiment, since the weight can be weighted by the delay line buffer amplifier, the gain control amplifier is not required, and an ultrasonic diagnostic apparatus having a small circuit scale can be realized.

[Second Embodiment] FIG. 2 shows a weighting circuit in the [second embodiment] of the ultrasonic diagnostic apparatus of the present invention. This weighting circuit corresponds to the D / A converters 251 to 258 shown in FIG. 15 or the D / A converters shown in FIG.
It corresponds to the / A converters 251 and 252 and the resistor string 358.

BF1 to BFn are buffer amplifiers, R1 to
Rn is a resistor and 270 is a 2: n multiplexer.
The gain control voltage Vtop for controlling the gain around the aperture and the gain control voltage Vbot at the aperture end are input to the two inputs of the multiplexer 270, respectively.
The input signal is output from the location selected by the multiplexer, outputs the divided voltage to the terminals of the resistors R1 to n, and is input to the gain control amplifier via the buffer amplifiers Vc1 to Vcn. This embodiment has a feature that the number of control lines can be reduced because only two control lines are required. Further, in the present embodiment, since the connection positions of Vtop and Vbot change, it is desirable that the resistances of R1 to Rn have the same value.

The control of the multiplexer 270 is performed as follows. First, in the linear scan, the highest voltage Vtop is connected to the buffer amplifier that controls the gain of the channel that is the center of the aperture, and the lowest voltage Vbot is connected to the buffer amplifier that is the end of the aperture. As a result, a control signal is generated in which the gain is high at the center of the aperture and becomes lower toward the end. Since the position of the aperture changes in the linear scan, the connection is re-established as described above every time the position of the aperture is changed.

In the sector scan, Vtop is connected to the buffer amplifier BF1 and Vbot is connected to the buffer amplifier BFn, or vice versa, Vtop is connected to the buffer amplifier BFn and Vbot is connected to the buffer amplifier BF1, as shown in FIG. The gain control voltage for weighting is output.

In this embodiment, by using the multiplexer, the weighting in the linear scan can be realized even when the gain control amplifier is positioned immediately after the vibrator.

[Third Embodiment] FIG. 3 shows a weighted gain control voltage generating circuit of the third embodiment of the ultrasonic diagnostic apparatus of the present invention. This weighting circuit corresponds to the D / A converters 251 to 258 shown in FIG.
D / A converters 251 and 252 shown in FIG.
Is equivalent to

BF1 to BFn are buffer amplifiers, R1 to
Rn-1 is a resistor and 271 is an n: n crosspoint switch. The weighting control voltage for each channel generated by being divided by the resistors R1 to Rn-1 is input to the buffers BF1 to BFn after the data order is changed by the cross point switch 271. This solves the problem of moving the aperture in the linear scan.

In the linear scan, the C of the channel that controls the gain of the channel that is the center of the aperture
The PS output terminal is connected to the input terminal of the CPS near Vtop, and is sequentially connected to the input terminal of the CPS near Vbot toward the end of the aperture for weighting. Since the position of the aperture changes in the linear scan, the connection is re-established as described above every time the position of the aperture is changed.

In the sector scan, Vtop is connected to the buffer amplifier BF1 and the buffer amplifiers having the smaller numbers are sequentially connected and Vbot is connected to the buffer amplifier BFn, or Vtop is connected to the buffer amplifier BFn and Vbot is connected to the buffer amplifier BF1. Connected,
The gain control voltage for performing the weighting as shown in FIG. 13 is output.

In this embodiment, the data can be rearranged by the cross point switch, so that the gain correction during the linear scan can be realized even when the gain control amplifier is positioned immediately after the vibrator.

[Fourth Embodiment] FIG. 4 shows a weighted gain control voltage generating circuit of the fourth embodiment of the ultrasonic diagnostic apparatus of the present invention. This weighting circuit corresponds to the D / A converters 251 to 258 shown in FIG.
D / A converters 251 and 252 shown in FIG.
Is equivalent to

BF1 to BFn are buffer amplifiers and S / H
1 to S / H (n + 1) are sample hold circuits, SW1
-SWn are changeover switches, and R1-Rn-1 are resistors. The switches SW1 to SWn are initially connected to the b side. The weighting control voltage for each channel, which is created by dividing by the resistors R1 to Rn-1, is the sample hold circuit S.
/ H1 to S / Hn, and buffers BF1 to BF
It is input to a gain control amplifier (not shown) via n.
In order to cope with the aperture movement in the linear scan, the switches SW1 to SWn are switched to the a side, and the input and output of the sample hold circuit are connected in a ring shape.
In this state, the sample hold circuit S / H (n + 1) performs a sampling operation, and the data of the sample hold circuit S / Hn is copied to the sample hold circuit S / H (n + 1). After that, the sample hold circuit S / H
The weighting data is shifted by sequentially performing sampling operations of n, S / H (n-1), ..., S / H2, S / H1. By repeating this operation, it becomes possible to cope with the aperture movement in the linear scan.

According to this embodiment, the data can be rearranged by the sample-hold circuit connected in a ring shape to realize the gain correction during the linear scan even when the gain control amplifier is located immediately after the vibrator. it can.

[Fifth Embodiment] FIG. 5 shows a weighting circuit according to the fifth embodiment of the ultrasonic diagnostic apparatus of the present invention. This weighting circuit is the D / A converter 2 shown in FIG.
51 to 258, or the D / A converters 251 and 252 and the resistor string 358 shown in FIG.

BF1 to BFn are buffer amplifiers and R1 to
Rn is a resistor and 272 is a 2: n / 2 multiplexer. The gain control voltage Vtop at the aperture center and the gain control voltage Vbot at the aperture end are respectively input to the two inputs of the multiplexer. Multiplexer 27
The output of 1 is connected to every other terminal of the dividing resistor. Therefore, the number of changeover switches in the multiplexer 271 is reduced. The smaller the number of outputs of the multiplexer 271 is, the smaller the scale is. However, it is determined in consideration of accuracy.

According to this embodiment, in addition to the second embodiment, the amount of material can be reduced. [Sixth Embodiment] FIG. 6 shows a weighting circuit of the sixth embodiment of the ultrasonic diagnostic apparatus of the present invention. This weighting circuit corresponds to the D / A converters 251 to 258 shown in FIG.
, Or the D / A converter 251, shown in FIG.
252 and a resistor string 358.

Reference numeral 280 is a D / A converter, and SH1 to SHn are sample hold circuits. The D / A converter 280 sequentially converts the weighting data of each channel into an analog signal. The converted analog data is captured by the sample hold circuits SH1 to SHn, but the sequence control circuit (not shown) changes the capturing order.
This solves the problem caused by changing the aperture position in the linear scan.

In this embodiment, by changing the sample order of the sample hold circuit, weighting in the linear scan can be realized even if the gain control amplifier is positioned immediately after the vibrator.

[Seventh Embodiment] FIG. 7 shows a weighting circuit according to the seventh embodiment of the ultrasonic diagnostic apparatus of the present invention. This weighting circuit is the D / A converter 2 shown in FIG.
51 to 258, or the D / A converters 251 and 252 and the resistor string 358 shown in FIG.

Reference numeral 280 denotes a D / A converter, SH1 to SH (n
+1) is a sample hold circuit, BF1 to BFn are buffer amplifiers, and SW1 to SWn are changeover switches.
The D / A converter 280 sequentially converts the weighting data of each channel into an analog signal. Changeover switch SW
1 to SWn are connected to the b side, and the converted analog data are sequentially output from the sample hold circuits SH1 to SHn.
Are input to a gain control amplifier (not shown) via the buffers BF1 to BFn. In order to support the aperture movement in the linear scan, the switch SW1
To SWn are switched to the a side, and the inputs and outputs of the sample hold circuits SH1 to SH (n + 1) are connected in a ring shape. In this state, the sample hold circuit S / H (n + 1)
Performs sampling operation, and sample and hold circuit S / H
The data of n is copied to the sample hold circuit S / H (n + 1). After that, the sample hold circuit S /
The weighting data is shifted by sequentially performing the sampling operation with Hn (n-1), ..., S / H2, S / H1.
By repeating this operation, it becomes possible to cope with the aperture movement in the linear scan.

In this embodiment, by connecting the sample hold circuit in a ring shape, weighting in the linear scan can be realized even if the gain control amplifier is positioned immediately after the vibrator.

[Eighth Embodiment] FIG. 8 shows weighting of the ultrasonic diagnostic apparatus at the time of sector scanning in [Eighth Embodiment] of the present invention.

In FIG. 8, the horizontal axis represents the channel number and the vertical axis represents the gain. Here, as shown in Fig. 12, channel 8
This is the case when the beam is deflected to the side. At this time, in the B mode gain correction, the gain is increased in proportion to the distance from the focus to each transducer, as indicated by the circle in the figure. In contrast, in Doppler (including color flow), conversely × in the figure
Gain is increased for channels closer to the focus as shown by the mark.

According to this embodiment, it is possible to obtain an excellent S / N ratio in the Doppler mode and an excellent resolution in the B mode.

[0066]

According to the structure of the first aspect, the gain control can be performed by the buffer amplifier of the delay line, and the ultrasonic diagnostic apparatus having the weighting function can be realized without increasing the circuit scale.

According to the structure of claim 2, the use of the multiplexer has an advantage that an ultrasonic diagnostic apparatus having a smaller circuit scale and having a weighting function corresponding to the aperture movement in the linear scan can be realized.

According to the structure of claim 3, by rearranging the data by the cross point switch, the gain correction at the time of the linear scan can be realized even when the gain control amplifier is positioned immediately after the vibrator.

According to the structure of claim 4, by connecting the sample and hold circuit in a ring shape with high accuracy, it is possible to cope with the aperture movement in the linear scan, and the superposition is provided with the weighting function capable of controlling with a small number of control signals. It has an advantage that a sound wave diagnostic apparatus can be realized.

According to the configuration of claim 5, there is an advantage that it is possible to realize an ultrasonic diagnostic apparatus in which the number of output lines of the multiplexer of claim 2 is reduced and the circuit scale of the weighting function is further reduced.

According to the structure of claim 6, a plurality of analog data outputted by a plurality of sequences of one D / A converter are fetched by the S / H circuit corresponding to the number of channels,
There is an advantage that an ultrasonic diagnostic apparatus having a weighting function corresponding to the aperture movement of the linear scan can be realized by changing the capturing order.

According to the structure of claim 7, a plurality of analog data outputted by a plurality of sequences of one D / A converter are fetched by the S / H circuit corresponding to the number of channels,
Further, there is an advantage that the rotation of data is enabled by connecting the sample hold circuit in a ring shape, and the ultrasonic diagnostic apparatus having the weighting function corresponding to the aperture movement of the linear scan can be realized.

According to the structure of claim 8, the gain correction at the time of beam deflection in the sector scan is improved by giving a high gain to the channel having a long distance from the focus point in the B mode, and the beam shape is improved. On the contrary, there is an advantage that it is possible to realize an ultrasonic diagnostic apparatus capable of displaying a high-quality image by a method of increasing sensitivity by giving a high gain to a channel whose distance from the focus point is short.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of a delay line circuit of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a weighting circuit of the ultrasonic diagnostic apparatus according to the second embodiment of the present invention.

FIG. 3 is a schematic block diagram showing a weighting gain control voltage generating circuit of an ultrasonic diagnostic apparatus according to a third embodiment of the present invention.

FIG. 4 is a schematic block diagram showing a weighting gain control voltage generating circuit of an ultrasonic diagnostic apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a schematic block diagram showing a weighting circuit of the ultrasonic diagnostic apparatus according to the fifth embodiment of the present invention.

FIG. 6 is a schematic block diagram showing a weighting circuit of an ultrasonic diagnostic apparatus according to a sixth embodiment of the present invention.

FIG. 7 is a schematic block diagram showing a weighting circuit of an ultrasonic diagnostic apparatus according to a seventh embodiment of the present invention.

FIG. 8 is a gain explanatory diagram showing weighting of the ultrasonic diagnostic apparatus during sector scan according to the eighth embodiment of the present invention.

FIG. 9 is an explanatory diagram of a linear scan of the ultrasonic diagnostic apparatus in the first conventional example.

FIG. 10 is an explanatory diagram of a foldover in a linear scan of the ultrasonic diagnostic apparatus in the second conventional example.

FIG. 11 is an explanatory diagram of a two-dimensional scanning method in linear scanning of an ultrasonic diagnostic apparatus according to a third conventional example.

FIG. 12 is an explanatory diagram of a master-slave system in a linear scan of an ultrasonic diagnostic apparatus according to a fourth conventional example.

FIG. 13 is an explanatory diagram of weighting in sector scan of the ultrasonic diagnostic apparatus in the fifth conventional example.

FIG. 14 is a schematic block diagram of a gain control unit of an ultrasonic diagnostic apparatus according to a sixth conventional example.

FIG. 15 is a schematic block diagram of a gain control signal generator of an ultrasonic diagnostic apparatus according to a seventh conventional example.

FIG. 16 is a schematic block diagram of another example of the gain control signal generator of the ultrasonic diagnostic apparatus in the eighth conventional example.

FIG. 17 is a schematic block diagram showing delay addition of an ultrasonic diagnostic apparatus including a weighting circuit in a ninth conventional example.

FIG. 18 is an explanatory diagram showing a problem of the weighting circuit of the ultrasonic diagnostic apparatus in the tenth conventional example.

[Explanation of symbols]

1-16 Oscillator 21-28 2: 1 analog switch 29 8: 4 crosspoint switch part 30-32 Variable delay line 33-35 Adder 52-57 Delay line 60 Adder 61-68 Voltage-current converter 70 8: 4 cross-point switch 71-74 current-voltage converter 100 reflector 130 delay adder 151-158 amplifier capable of controlling gain with voltage 159 control circuit for generating control voltage of amplifier gain 251-258 D / A Converter 259 Arithmetic unit 270 2: n multiplexer 271 n: n crosspoint switch 272 2: n / 2 multiplexer 280 D / A converter 351 to 357 resistor 358 resistor string 361 to 364 adder DL1 to DLn delay line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Hagiwara 4-3-1, Tsunashima-higashi, Kohoku-ku, Yokohama-shi, Kanagawa Matsushita Communication Industrial Co., Ltd.

Claims (8)

[Claims] 1. In an ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, an analog delay line for delaying outputs of the plurality of transducers, An ultrasonic diagnostic apparatus which is provided with a buffer amplifier arranged at the input and output of an analog delay line, and controls the gain of each buffer amplifier to perform weighting in reception. 2. In an ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, a plurality of resistors connected in a ring and a terminal voltage of each resistance. Connect the amplifier to the control signal of the gain control amplifier of the echo signal, the D / A converter that generates the two highest and lowest weighted voltages, and connect the generated voltage to either terminal of the ring resistance An ultrasonic diagnostic apparatus provided with a switch group that can be used. 3. An ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, D / A conversion for generating two voltages of highest / lowest weighting. , A plurality of resistors connected in series that apply two voltages generated at the D / A converter to both ends, and a switch group that inputs the terminal voltage of each resistor and connects it to one of the outputs corresponding to the number of channels And an amplifier for supplying a voltage signal output from a switch group to a control signal of a gain control amplifier of an echo signal. 4. An ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, D / A conversion for generating two voltages of highest / lowest weighting. Device, a plurality of resistors connected in series that apply two voltages generated by the D / A converter to both ends, a plurality of sample and hold circuits, and one terminal of each terminal of the cascaded resistors, a sample and hold circuit And a weighting control circuit including a switch for inputting a selected input signal to a sample and hold circuit located next to a sample and hold circuit connected to the input. 5. The ultrasonic diagnostic apparatus according to claim 2, wherein the number of output lines of the switch group is reduced to 1 / n of the number of channels. 6. An ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, comprising a single D / A converter and the D / A converter. The ultrasonic diagnostic apparatus is provided with sample hold circuits for the number of channels for fetching the data of 1. and the echo gain is controlled by the output of the sample hold circuit. 7. An ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, comprising a single D / A converter and a plurality of sample and hold circuits. , An ultrasonic diagnostic apparatus for selecting either the output of the adjacent sample and hold circuit or the output of the D / A converter, and the input selected by the switch, and controlling the echo gain by the output of the sample and hold circuit . 8. An ultrasonic diagnostic apparatus having a function of receiving an echo signal by a probe composed of a plurality of transducers and performing delay addition, in a sector scan B mode, attenuation by a distance between a focus point and each channel. The ultrasonic diagnostic apparatus is configured to perform gain correction to correct the noise and increase the gain of the channel close to the focus point in the Doppler mode.