JPH0984794A - Ultrasonic diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an ultrasonic diagnostic device in which the size and position of an aperture are controlled without adding physical quantity in sector scanning, and the influence of multiple reflection by a costa in diagnosis of the heart from intercosta can be reduced. SOLUTION: In a cross point switch part for performing the selection of oscillator in linear scanning and the addition of signal in sector scanning, the size and position of an aperture are controlled to the signals received by oscillators 1-8, and a delay addition is performed in a delay addition part 50. Thus, an ultrasonic diagnostic device in which the beam position is controlled to reduce the influence of multiple reflection by a costa without increasing physical quantity and focus data can be realized.

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 echo signals by a probe composed of a plurality of transducers and performing delay addition.

[0002]

2. Description of the Related Art Recently, a technique for obtaining a high-quality image of a wide range of regions to be examined by a probe composed of a plurality of transducers in transmission / reception of an ultrasonic diagnostic apparatus has been widely used.

FIG. 7 shows the combination of signals when echo signals are received by a plurality of transducers in a linear scan. The signal reflected by the reflector 100 is applied to the transducer 1 to
When receiving at 8, the distance from the reflector 100 to each of the transducers 1 to 8 is different, so that there is a difference in the arrival time of the signal from the reflector to each of the transducers. This time difference is the delay line 191.
~ 198 to correct, adder 180 to add 1
Get one output.

This process is hereinafter referred to as focusing. By focusing, the beam can be narrowed down, the resolution can be improved, random noise can be reduced, and the S / N ratio can be improved.

As the delay lines 191-198, analog type delay lines are often used, but recently, digital delay lines combining an A / D converter and a digital memory have also 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 by an analog switch. In the linear scan, the beam is perpendicular to the array direction of the transducers. Therefore, the delay time required for the oscillators symmetrical with respect to the aperture center, that is, the oscillator 1 and the oscillator 8, the oscillator 2 and the oscillator 7, the oscillator 3 and the oscillator 6, and the oscillator 4 and the oscillator 5 is required. Therefore, the number of delay lines can be reduced by half by adding the signals having the same delay time by the adders 180 to 184 and inputting them to the delay means as shown in FIG. This method is called fold over.

FIG. 9 shows a linear scan delay addition section in consideration of two-dimensional scanning. Reference numeral 18 denotes a linear scan probe, which is composed of transducers 1 to 16. Reference numerals 21 to 28 are 2: analog switches. 30 is an 8: 4 cross point switch section (hereinafter,
The voltage-current converters 106 to 113 are referred to as CPS units).
And an 8: 4 cross point switch (hereinafter referred to as CPS) 105 and current-voltage converters 114 to 117. 50 is a delay addition unit.

Next, the operation in FIG. 9 will be described. The beam movement in the linear scan is performed by sequentially switching the selected transducer with a switch. In FIG. 9, 8 out of 16 vibrators 1 to 16 are selected, and the analog switches 21 to 28 are selected.
Is set to the side a, the transducers 1 to 8 are selected, and the position of the beam is set between the transducers 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 is between the vibrators 5 and 6. Moving. Similarly, analog switches 21-
The position of the beam can be moved by sequentially switching 28.

The signals selected by the analog switches 21 to 28 are input to the CPS section 30. In the CPS unit 30, the eight signals that have passed through the analog switches 21 to 28 are added with two signals having the same required delay time, and four types of signals are output to perform the fold-over. C
The signal input to the PS unit 30 is the voltage-current converter 106-
After being converted into a current signal by 113 and adding the current by connecting the CPS 105, the current-voltage converter 114-
It is converted into a voltage signal by 117 and is output. CPS
The signal output from the unit 30 is input to the delay addition unit 50, delay-added, 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. 10, when the signals reflected by the reflector 100 are received by the transducers 1 to 8, since the distance from the reflector 100 to each transducer is different, the arrival time of the signal from the reflector to each transducer is different. Occurs. This time difference is corrected by the delay lines 191 to 198 and added by the adder 180 to obtain one output.

In sector scanning, scanning is performed by freely changing the angle θ formed by the beam and the array direction of the transducers. Therefore, the delay lines 191 to 198 all have different values, unlike the case of the linear scan. By controlling the delay times of the delay lines 191 to 198, it is possible to variously change the angle θ formed by the beam and the array direction of the transducers. This process will be referred to as deflection hereinafter, and the angle θ between the array direction of the transducers and the beam will be referred to as the deflection angle.

A block diagram for performing a sector scan is shown in FIG. Reference numeral 150 is a delay addition unit. Since all the transducers 1 to 8 are always used in the sector scan, the analog switches 21 to 28 and the CPS unit 30 used in the linear scan are not required. Further, in the sector scan, since the scan is performed by deflection, fold-over is impossible, and it is necessary to prepare as many delay lines as there are oscillators. Also, the delay adder 150 needs a longer delay line than the linear scan in order to deflect the beam.

A method called presuming delay as shown in FIG. 12 is considered as a method for realizing both linear scan and sector scan with one device.
FIG. 12 shows a state in which the sector scan probe 17 is connected to the connector 19. Sector scan probe 1
Reference numeral 7 is composed of transducers 1 to 8 for converting an echo signal into an electric signal. Reference numerals 21 to 28 are 2: 1 analog switches for selecting signals from the transducers 1 to 8, 81 to 84 are variable delay lines, and 30 is two of the four signals that have passed through the variable delay lines 81 to 84. CPS that outputs four types of signals
The unit 50 is a delay addition unit that delays each of the four signals by a necessary delay amount and adds them.

The configuration for performing the linear scan is such that the linear scan probe 18 is connected to the connector 19 and the delay times of the variable delay lines 81 to 84 are set to zero. This has the same configuration as in FIG.

The operation of FIG. 12 will be described. In the linear scan, the vibrators 1 to 8 are connected to the a side of the analog switches 21 to 28, and the vibrators 9 to 16 are connected to the b side of the analog switches 21 to 28.
The variable delay lines 81 to 84 have the delay time set to zero, and
Exactly the same operation is performed.

In the sector scan, the analog switches 21 to 28 select which of two adjacent signals is input to the variable delay lines 81 to 84,
CP for signals that have passed through the delay line and signals that have not passed through the delay line
It is added by the S unit 30. The variable delay lines 81 to 84 are 2
It is used to correct the time difference between two signals.

When the beam direction is A, the oscillator 1 receives the signal at a faster timing, the oscillator 1 receives the signal from the oscillator 2, the oscillator 3 receives the oscillator 4, the oscillator 5 receives the oscillator 6, and the oscillator 7 receives the signal. To do. At this time, the analog switches 21 to 28 select the b side, and the signals of the vibrators 1, 3, 5, and 7 are set to pass through the variable delay lines 81 to 84, and the variable delay lines 81 to 84 are set.
84 is set to a value that corrects the time in each of the two transducers.

When the beam direction is B, the oscillator 2 outputs the signal at a faster timing than the oscillator 1, the oscillator 3 the oscillator 4, the oscillator 6 the oscillator 5, and the oscillator 8 the oscillator 7. For receiving, the analog switches 21 to 24 select the a side, and the analog switches 25 to 28 select the b side. The signals of the oscillators 2, 4, 5, and 7 are variable delay lines 81 to 8
4 and the variable delay lines 81 to 84 are set to values for correcting the time in each of the two transducers.

When the beam direction is C, contrary to A, the oscillator 2 is faster than the oscillator 1, the oscillator 4 is faster than the oscillator 3, the oscillator 6 is faster than the oscillator 5, and the oscillator 8 is faster than the oscillator 7. Since the signals are received at the timing, the analog switches 21 to 2
8 selects the a side, and the signals of the vibrators 2, 4, 6, 8 are set so as to pass through the variable delay lines 81 to 84.
1 to 84 are set to values that correct the time in each of the two transducers.

According to this method, signals after the CPS unit 30 can be processed by half the number of received signals, many circuits can be shared with the linear scan foldover system, and an ultrasonic diagnostic apparatus having a small circuit scale can be realized. .

In the sector scan, scanning is performed by changing the deflection angle of the beam. For example, in diagnosing the circulatory system, when diagnosing the heart from the intercostal space, reflection occurs due to a part of the ultrasonic signal hitting the rib. , The diagnostic image may be deteriorated.

In order to solve this, a method of limiting the size of the aperture as shown in FIG. 13 so that the ultrasonic signal does not directly hit the ribs is used. 201,
Reference numeral 203 is a path of ultrasonic signals transmitted and received by the transducers 1 and 3, 140 is a rib, 135 is a point where each beam intersects (hereinafter, referred to as beam virtual origin), and 134 is a sector scanning visual field.

When scanning is performed using all the transducers as shown in FIG. 13A, when the beam direction is A, the ultrasonic signal 201 transmitted from the transducer 1 hits the ribs 140 and is reflected. However, this causes deterioration of the diagnostic image.

If the aperture is limited to the transducers 3 to 8 as shown in FIG. 13 (b), the transmitted ultrasonic signal does not hit the ribs 140, and the influence of reflection by the ribs is eliminated.

FIG. 13B shows the scanning visual field when all the transducers are used, and FIG. 13D shows the scanning visual field 134 when the size of the aperture is limited and moved. When the size of the aperture is limited and the position is moved, the center of the aperture moves between the transducer 5 and the transducer 6, so the beam virtual origin 135 is set to the probe as shown in FIG. To the front, that is, inside the subject.

[0027]

It is an effective means to control the size and position of the aperture and move the position of the beam in order to eliminate the influence of reflection by the ribs. However, in order to realize this, a dedicated aperture control circuit and a huge amount of dedicated focus data are required.

It is an object of the present invention to provide an ultrasonic diagnostic apparatus which does not require a dedicated circuit, can control the aperture with a slight increase in control data, and can reduce the influence of reflection due to ribs.

[0029]

An ultrasonic diagnostic apparatus according to claim 1, wherein a probe for linear scan including a plurality of transducers is replaced with a probe for sector scanning including a plurality of transducers. An ultrasonic diagnostic apparatus that can be connected by a cross point switch that inputs and outputs the output signal of the transducer that requires the same delay time in linear scan, and uses the cross point switch in the sector scan. It is characterized by controlling the size and position of the aperture.

Therefore, by controlling the size and position of the aperture in the sector scan by using the CPS portion which has been used only for the linear scan so far, a circuit such as a switch and a focus data are not added, and a small amount can be obtained. The beam position is changed only by increasing the control data, and the influence of reflection due to ribs or the like is reduced.

In the ultrasonic diagnostic apparatus according to the second aspect, the probe for linear scan composed of a plurality of transducers and the probe for sector scan composed of a plurality of transducers can be replaced and connected. An ultrasonic diagnostic apparatus, an analog switch for selecting a transducer, a crosspoint switch for inputting and adding output signals of a transducer that requires the same delay time, and half of the transducers in a sector scan. A delay line is provided, the analog switch selects which received signal of two adjacent oscillators to input to the delay line in a sector scan, and the crosspoint switch outputs the output of the oscillator or the delay line. The output of the oscillator that has passed through the line is input, two adjacent output signals are added, and the size of the aperture is increased by the cross point switch. And controlling the a position.

Therefore, in the device using the presuming delay system, the CPS unit, which has been used only for adding the received signals in the sector scan, is used to control the size and position of the aperture so that the switches and the like are controlled. The beam position is changed by adding a small amount of control data without adding a circuit or focus data, and the influence of reflection due to ribs or the like is reduced.

[0033]

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 connector 19
2 shows a state in which the sector scan probe 17 is connected. When performing a linear scan, the connector 1
A probe 18 for linear scan is connected to 9.

In FIG. 1, a sector scan probe 1 is shown.
Reference numeral 7 is composed of transducers 1 to 8 for converting an echo signal into an electric signal. 130 is an 8: 8 CPS part, and 31 to 38 are C
Input terminals 41 to 48 of the PS unit 130 are CPS units 130
Is an output terminal, and 150 is a delay addition unit, and 51 to 58 are input terminals of the delay addition unit 150.

This [first embodiment] is different from the conventional example shown in FIG. 9 in that the output terminals of the CPS section are doubled. This is because foldover cannot be used in sector scan.

The operation of the linear scan of the first embodiment is exactly the same as that of the conventional example shown in FIG. When performing a linear scan, connect the linear scan probe 18 to the connector 19 and connect the analog switch 2
1 to 28 are provided, and the aperture is moved by sequentially switching the vibrators.

Next, the case where the scanning is performed using all the apertures in the sector scanning will be described with reference to FIG. 120 is an acoustic beam, 134 is a sector scanning field of view, 135 is a beam virtual origin, and θ1 to θ3.
Is the deflection angle of the acoustic beam 120.

The CPS unit 130 in the case where the sector scan is performed using all the vibrators is shown in FIG.
As shown in (c), the terminals are connected to opposite terminals, and the connection state is always constant regardless of the deflection angle of the acoustic beam 120.

Next, the case where scanning is performed with the aperture limited will be described with reference to FIG. 137-
139 is the center of the aperture, D is the beam virtual origin 135
And the surface of the sector scan probe 17.

When the acoustic beam 120 is deflected at the deflection angle θ1 as shown in FIG. 3A, the apertures use the transducers 5-8. This selection is performed by the CPS unit 130. The selected reception signal is input to the delay addition section 150. The terminals of the delay addition section 150 input at this time are terminals to which the vicinity of the center of the aperture is input when all apertures are used, that is, the input terminals 53 to 56. Is. That is, the connection state of the CPS unit 130 is as shown in FIG.

When the acoustic beam 120 is deflected at the deflection angle θ2 as shown in FIG. 3B, FIG.
It is possible to use all transducers as shown in, but to keep the sensitivity of the received signal constant, and
In order to simplify the control of the aperture in the section 130,
The size is limited to the same as that in FIG. That is, the apertures use the transducers 3 to 6. Then, as in the case of FIG. 3A, the signals are input to the input terminals 53 to 56 of the delay addition unit 150. The connection state of the CPS unit 130 at this time is as shown in FIG.

When the acoustic beam 120 is deflected at a deflection angle θ3 as shown in FIG. 3 (c), the apertures use the transducers 1 to 4. Then, as in the case of FIG. 3A, the signals are input to the input terminals 53 to 56 of the delay addition unit. The connection state of the CPS unit 130 at this time is as shown in FIG.

If the deflection angle of the acoustic beam 120 is the same, the delay amount in the delay addition section 150 is constant regardless of the size and position of the aperture. That is, (a) of FIG.
Delay adder 150 and the delay adder 150 of FIG.
Have the same settings. Similarly, the delay adder 15 of FIGS. 2B and 3B, and FIGS. 2C and 3C.
0 is the same setting.

Since the position of the aperture is changed and the position of the beam is changed, each acoustic beam 120 intersects at a point separated from the surface of the sector scanning probe 17 by a distance D. Therefore, the scanning visual field 134 is as shown in FIG.

As described above, the CPS unit 130 for changing the position of the acoustic beam of the linear scan causes the delay addition unit 15
The width and position of the aperture during sector scanning can be changed without changing the delay amount at 0. Therefore, an increase in focus data for controlling the aperture can be suppressed, and the CPS for linear scan can be suppressed.
Since the unit 130 is used, it can be realized without adding a new dedicated circuit such as a switch.

[Second Embodiment] FIG. 4 shows a connector 19
2 shows a state in which the sector scan probe 17 is connected. When performing a linear scan, the connector 1
A linear scanning probe 18 is connected to the variable transmission line 9, and the variable delay lines 81 to 84 set the delay time to zero. This has the same configuration as in FIG.

In FIG. 4, the sector scan probe 1
Reference numeral 7 is composed of vibrators 1 to 8. 21 to 28 are 2: 1 analog switches for selecting the vibrators 1 to 8, 8
1 to 84 are variable delay lines, 30 is an 8: 4 CPS unit, 31
˜38 are input terminals of the CPS section, 41-44 are output terminals of the CPS section, 50 is a delay addition section, and 51-54 are input terminals of the delay addition section 50.

First, in the linear scan, the oscillators 1 to 8 are connected to the a side of the analog switches 21 to 28, the oscillators 9 to 16 are connected to the b side, and the delay time of the variable delay lines 81 to 84 is set to zero. Then, exactly the same operation as in FIG. 9 is performed.

Next, a case where the scanning is performed using all the apertures in the sector scanning will be described with reference to FIG. The CPS unit 30 in the case where scanning is performed using all the transducers is shown in FIG.
It is used only for adding two adjacent signals as shown in (c), and the connection state of the switch is the acoustic beam 12
It is constant regardless of the deflection angle of 0.

Next, the case where scanning is performed with the aperture limited will be described with reference to FIG. 137-
139 is the center of the aperture. When the acoustic beam 120 is deflected at the deflection angle θ1 as shown in FIG. 6A, the apertures use the transducers 5 to 8. This selection is performed by the CPS unit 30. The selected received signals are added to adjacent signals and input to the delay addition unit 50. The terminal of the delay addition unit 50 input at this time is a terminal to which the vicinity of the center of the aperture is input when all the apertures are used. ,
That is, the input terminals 52 and 53. That is, the CPS unit 3
The connection state of 0 is as shown in FIG.

When the acoustic beam 120 is deflected by the deflection angle θ2 as shown in FIG. 6B, FIG.
Although it is possible to use all transducers as shown in FIG. 6, in order to make the sensitivity of the received signal constant and to simplify the control of the aperture in the CPS unit 30, FIG.
It is limited to the same size as (a). That is, the apertures use the transducers 3 to 6. Then, as in the case of FIG. 6A, the signals are input to the input terminals 52 and 53 of the delay addition unit. The connection state of the CPS unit 30 at this time is as shown in FIG.

When the acoustic beam 120 is deflected at a deflection angle θ3 as shown in FIG. 6C, the apertures use the transducers 1 to 4. Then, as in the case of FIG. 6A, it is input to the input terminals 52 and 53 of the delay addition unit. The connection state of the CPS unit 30 at this time is as shown in FIG.

The delay amount in the delay addition section 50 is constant regardless of the size and position of the aperture if the deflection angle of the acoustic beam 120 is the same. That is, the delay addition unit 50 of FIG. 2A and the delay addition unit 50 of FIG. 3A have the same settings. Similarly, FIG. 2 (b) and FIG. 3 (b),
The delay addition unit 50 of FIG. 2C and FIG. 3C have the same settings.

Since the position of the aperture is changed and the position of the beam is changed, the acoustic beams 120 intersect at a point separated from the surface of the sector scanning probe 17 by a distance D. Therefore, the scanning visual field 134 is as shown in FIG.

As described above, the CPS unit 30 for changing the beam position of the acoustic beam of the linear scan does not change the delay amount in the delay addition unit 50 and the settings of the analog switches 21 to 28, and the width of the aperture during the sector scan. And you can change the position. Therefore, an increase in focus data for controlling the aperture can be suppressed, and since the CPS unit 30 for linear scan is used, it can be realized without adding a new dedicated circuit such as a switch.

[0057]

According to the first aspect of the present invention, in an apparatus capable of performing both linear scan and sector scan, a linear scan beam selection CPS unit which is not used in conventional sector scan is used in sector scan. By controlling the size and position of the aperture, there is no increase in circuits such as switches and focus data, and the size and position of the aperture in the sector scan can be controlled by a slight increase in data for controlling the CPS section. It is possible to realize an ultrasonic diagnostic apparatus that can change the position of the beam. This device can realize a sector scan in which the influence of rib reflection is reduced especially in the diagnosis of the heart from the intercostal space.

According to the structure of claim 2, in the apparatus using the presuming delay system, the CPS portion for beam selection of the linear scan which is used only for addition of two signals in the sector scan is controlled in the sector scan. By controlling the size and position of the aperture, there is no increase in circuits such as switches and focus data, and it is possible to change the size and position of the aperture in the sector scan with a slight increase in data for controlling the CPS section. Therefore, an ultrasonic diagnostic apparatus capable of changing the position of the beam can be realized. This device can realize a sector scan in which the influence of rib reflection is reduced especially in the diagnosis of the heart from the intercostal space.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing delay addition in a first embodiment of an ultrasonic diagnostic apparatus of the invention.

FIG. 2 is an explanatory diagram showing an operation when all the vibrators of the same embodiment are used.

FIG. 3 is an explanatory diagram showing an operation when controlling an aperture according to the same embodiment.

FIG. 4 is a schematic block diagram showing delay addition of the second embodiment of the ultrasonic diagnostic apparatus of the invention.

FIG. 5 is an explanatory diagram showing an operation when all the vibrators of the same embodiment are used.

FIG. 6 is an explanatory diagram showing an operation when the aperture of the embodiment is controlled.

FIG. 7 is an explanatory diagram of a linear scan of the ultrasonic diagnostic apparatus in the conventional example.

FIG. 8 is an explanatory diagram of foldover in a linear scan of the ultrasonic diagnostic apparatus in the conventional example.

FIG. 9 is an explanatory diagram of a two-dimensional scanning method in a linear scan of an ultrasonic diagnostic apparatus in a conventional example.

FIG. 10 is an explanatory diagram of sector scan of the ultrasonic diagnostic apparatus in the conventional example.

FIG. 11 is an explanatory diagram of a two-dimensional scan in a sector scan of the ultrasonic diagnostic apparatus in the conventional example.

FIG. 12 is an explanatory diagram of a presuming delay method in sector scanning of the ultrasonic diagnostic apparatus in the conventional example.

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

[Explanation of symbols]

 1 to 16 transducer 17 probe for sector scan 18 probe for linear scan 19 connector 21 to 28 analog switch 30 CPS unit 31 to 38 input terminal of CPS unit 41 to 48 output terminal of CPS unit 50 delay addition unit 51 -58 Input terminal of delay addition part 81-84 Variable delay line 105 CPS 106-113 Voltage-current converter 114-117 Current-voltage converter 120 Acoustic beam 130 CPS part 134 Sector scanning field of view 135 Beam virtual origin 137-139 Aperture Center 150 Delay adder 180 Adder 181-184 Adder 191-198 Variable delay line

Claims (2)

[Claims] 1. An ultrasonic diagnostic apparatus capable of connecting a linear scanning probe composed of a plurality of transducers and a sector scanning probe composed of a plurality of transducers by replacing them. An ultrasonic diagnostic apparatus is provided with a crosspoint switch for inputting and adding output signals of transducers requiring the same delay time in scanning, and controlling the size and position of the aperture by the crosspoint switch in sector scanning. 2. An ultrasonic diagnostic apparatus in which a linear scanning probe including a plurality of transducers and a sector scanning probe including a plurality of transducers can be replaced and connected to each other. The analog switch for selecting the child, the crosspoint switch for inputting and adding the output signals of the oscillators requiring the same delay time, and the delay line for half of the oscillators in the sector scan are provided. Selects which received signal of two adjacent oscillators to input to the delay line in the sector scan, and the crosspoint switch outputs the output of the oscillator or the output of the oscillator passing through the delay line. Ultrasound diagnosis that inputs and adds two adjacent output signals, and controls the size and position of the aperture by the cross point switch apparatus.