JP3256698B2 - 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 a two-dimensional array structure in which minute piezoelectric vibrators are two-dimensionally arranged in an azimuth direction (scanning direction) and a lens direction as transducers for transmitting and receiving ultrasonic waves to and from a subject. Related to an ultrasonic diagnostic apparatus using a probe of
In particular, the present invention relates to an ultrasonic diagnostic apparatus capable of simultaneously scanning a plurality of diagnostic positions, suppressing an increase in circuit scale, and spatially controlling the focal point of an ultrasonic beam.

[0002]

2. Description of the Related Art Conventionally, as an ultrasonic probe (hereinafter, simply referred to as a probe) of an ultrasonic diagnostic apparatus, various constitutions are used from the viewpoint of diagnosis purpose and scanning performance.

As one type of this probe, one having a structure shown in FIG. 19 is known. The probe 101 shown in FIG. 19 has a plurality of unit transducers 101a, 101b, 1
01c,... Are arranged in the azimuth direction x. When the probe 101 is driven by linear electronic scanning, an arbitrary plurality of transducers in the probe 101 are driven as one set. In this drive, for example, by shifting the drive timing between the transducer located at the center in the scanning direction and the transducer in the lateral direction, the phase difference between the sound waves generated by the transducers can be used, An ultrasonic beam focused on a subject direction orthogonal to the center of the group is formed. Therefore, by driving the plurality of transducers to be driven while shifting them in the azimuth direction x by, for example, one transducer at a time, the transmission point position of the ultrasonic beam can be electronically shifted sequentially in the azimuth direction x. Linear scanning is performed. During reception, the same transducer as the transmitting transducer receives the ultrasonic echo signal and converts it into a voltage signal. The converted voltage signal is sent to a receiving circuit to be reconstructed into ultrasonic image data, and then displayed on a display such as a TV monitor.

In the case of the sector method, the scanning direction of the ultrasonic beam is set to one for one set of transducers to be driven.
The drive timing of each vibrator is changed so that the pulse sequentially changes into a fan shape for each pulse. Thereby, the ultrasonic image of the sector method can be displayed on the display through the same processing as the linear method.

However, when such a probe having a one-dimensional array structure is used, there is an inconvenience that the ultrasonic beam can scan only in the azimuth direction x which is the arrangement direction of the transducers, that is, in the one-dimensional direction. is there.

Therefore, the scanning direction is not limited to one dimension,
A probe having a two-dimensional array structure capable of scanning in a two-dimensional direction including a lens direction y orthogonal to the azimuth direction x has been developed.
FIG. 20 shows an example of a probe having this two-dimensional array structure. The probe 102 shown in FIG.
02a, 102b, 102c, ..., 103a, 103
b, 103c, ..., 104a, 104b, 104c,
..., 105a, 105b, 105c, ..., 106a, 1
06b, 106c,... Are arranged in a predetermined number in the azimuth direction x and the lens direction y.

In order to drive the probe 102 of the two-dimensional array and deflect the received ultrasonic beam in the azimuth direction and the lens direction, switches are separately provided between all the transducers and the transmission / reception unit, and these switches are provided. A configuration is conceivable in which data is obtained by sequentially switching switches.

On the other hand, for the deflection in the lens direction, a conventionally well-known acoustic lens can be used.

[0009]

However, when a probe having a two-dimensional array structure is used, a transmitting and receiving circuit must be separately prepared for each of a plurality of transducers forming the two-dimensional array. Inevitably, the scale of the transmission and reception circuit increases, and the device becomes larger, and the number of arithmetic processes increases, and the real-time performance decreases. Further, in a configuration using an acoustic lens, the directivity in the lens direction is determined in advance, and the focus cannot be changed arbitrarily, and the beam spread cannot be changed by adjusting the aperture area of the transmitting and receiving surfaces.

The present invention has been made in view of such various problems of the prior art. In particular, even when a plurality of diagnostic positions are scanned in parallel, a three-dimensional array of probes is used. An ultrasonic wave that can form a two-dimensional receive beam, can obtain high resolution in the azimuth direction and lens direction, and can suppress an increase in the total memory capacity when performing the phasing addition processing of the ultrasonic transmission / reception circuit scale and the received signal. It is an object to provide a diagnostic device.

[0011]

In order to achieve the above object, an ultrasonic diagnostic apparatus according to the present invention comprises a plurality of transducers capable of bidirectionally converting an electric signal and an ultrasonic signal into a first transducer orthogonal to each other. Probes arranged two-dimensionally in a direction and a second direction, and each transducer of the probe is excited by an excitation signal of an electric quantity to transmit an ultrasonic signal to each transducer. Transmitting and receiving means for performing predetermined processing on the received signal of the electric quantity converted by each transducer according to an ultrasonic echo signal and outputting the signal, and passing through each of a plurality of diagnostic positions set in the subject, and A plurality of planes orthogonal to the first direction are simultaneously delayed in a group of reception signals from the plurality of transducers output by the transmission / reception means so that the ultrasonic echo signal is focused on each plane. First arithmetic means for adding the plurality of As each diagnostic position, and,
A plurality of planes orthogonal to the second direction are delayed and added to a group of reception signals output from the first arithmetic unit so that the ultrasonic echo signal is focused on each plane. And a display means for displaying an ultrasonic image based on the signal output by the second calculation means.

[0012] For example, the first arithmetic means includes a number of phasing adders for delaying and adding the received signal group to a number equal to the number of planes orthogonal to the first direction. Further, the second arithmetic means stores a received signal group output by the first arithmetic means, and adds the received signal group output from the storage means with a delay for each diagnostic position. And a phasing adder.

[0013]

According to the ultrasonic diagnostic apparatus of the present application, the received signal group obtained simultaneously by the transmitting and receiving means is delayed and added by the first arithmetic means, so that the plurality of diagnostic positions are respectively included and
The ultrasonic echo signal is focused along each of a plurality of planes orthogonal to the first direction. The signal group output from the first calculation means is then sent to the second calculation means, and similarly, the delay addition processing is performed on each of a plurality of planes each including a plurality of diagnostic positions and orthogonal to the second direction. Is executed. Thereby, the ultrasonic echo signals are focused along each of the plurality of planes orthogonal to the second direction. In this way, even at a plurality of diagnostic positions, it is possible to control the beam focal position three-dimensionally, that is, spatially, simultaneously and simultaneously while performing the two-stage beam focusing processing.

In addition, since a plurality of planes orthogonal to the first direction and then a plurality of planes orthogonal to the second direction are sequentially focused over two stages, it is necessary to provide a reception processing circuit for all the transducers. And the circuit scale is suppressed. Furthermore, the memory scale for focusing control is also suppressed by the two-stage focusing.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment will be described with reference to FIGS. In this embodiment, an ultrasonic receiving beam is formed by focusing on a single diagnostic position α.

The ultrasonic diagnostic apparatus shown in FIG. 1 serves as a probe 1 having a two-dimensional array structure and transmitting and receiving ultrasonic signals via the probe 1 as transmitting and receiving means of the constituent elements of the present invention. Transmission / reception unit 2, a switch circuit group 3 capable of switching a connection state between the transmission / reception unit 2 and the probe 1, a switching controller 4 for instructing switching of the switch circuit group 3, and a reception of the transmission / reception unit 2 A signal processing unit 5 for forming echo data from a signal and a display unit 6 for displaying processing data of the signal processing unit 5 are provided. In the figure, reference numeral 7
Is a timing controller for controlling the operation timing of the entire system, and reference numeral 8 is a subject. Also,
The depth direction of the subject 8 is represented by z.

The probe 1 has a plurality of piezoelectric elements as transducers capable of bidirectionally converting a voltage signal and an ultrasonic signal into transducers, and has an azimuth direction (ie, a scanning direction; corresponding to the first direction of the present invention). X) and a plurality of vibrators P _1y , P _2y , P _3y , P _4y , P _5y , P _6y (y
= 1 to 5), and a plurality of transducers P _x1 , P _x2 , P _x3 , each having the same characteristic in the lens direction y (corresponding to the second direction of the present invention) orthogonal to the azimuth direction x. P _x4 ,
P _x5 (x = 1 to 6) are arranged to form a two-dimensional array.

The transmission / reception unit 2 includes a reference signal generation source 11, a pulser group 12, and a preamplifier group 13. The reference signal generation source 11 has an output circuit of n channels (here, 6 channels), and each output terminal thereof is connected to each of the pulsers 12a,..., 12f of the pulser group 12. Each of the pulsers 12a,..., 12f amplifies the reference pulse signal from the reference signal generation source 11. Pulsars 12a, ..., 12
The output terminal of each switch circuit 3 of the switch circuit group 3
a,..., 3f are respectively connected to one of the input / output terminals,
The input / output terminals are connected to the preamplifiers 13 of the preamplifier group 13.
a,..., 13f.

Each of the switch circuits 3a,..., 3f has the same number of m (here, five) as the number of transducers in the y direction of the probe 1.
, E are built in as shown in FIG. These switching elements a,..., E are, for example, MOS type FETs. One terminal of each of the switching elements a,.
, 12f), and the other terminals are connected to the corresponding transducers P _x1,.
x5 . The switch circuits 3a,.
Each of 3f is supplied with a switching signal from the switching controller 4 at a preset timing. Thus, the switching elements a,..., E are selectively set to the conductive state (ON) according to the switching signal. The switching controller 4 is composed of, for example, a computer,
The switch circuits 3a,.
Is controlled.

As shown, the signal processing unit 5 includes an A / D converter group 15, a memory 16, and a phasing adder 17. The A / D converter group 15 includes preamplifiers 13a,.
Each analog output signal of 3f is converted into a digital signal and output to the memory 16. The memory 16 stores the A / D converter group 1
5 is temporarily stored for a predetermined time for all transducers. The phasing adder 17 is composed of, for example, a digital processing circuit, reads out data stored in the memory 16 at a predetermined timing, sets a diagnostic position α in the subject 8 as a focal point, and sets all the transducers P ₁₁ , P ₂₁ ,. ,
The phasing addition is performed with a delay corresponding to the propagation time to P ₅₅ and P ₆₅ . This phasing addition is performed by delay and addition.

The display section 6 constitutes a display means of the components of the present invention, and includes a detection circuit 21, a frame memory 22, a D / A
A converter 23 and a TV monitor 24 are provided. Detection circuit 2
1 detects a high-frequency signal as a digital signal and stores the detected signal in the frame memory 22. The data stored in the frame memory 22 is read at the display timing of the TV monitor 24 and is converted into an analog signal by the D / A converter 23. This converted signal is supplied to the TV monitor 24 and displayed.

Next, the operation of the first embodiment will be described with reference to FIG.

The reference pulse signal output from the reference signal generating source 11 is amplified by the pulsers 12a,..., 12f, respectively, and then sent to the probe 1 via the switch circuits 3a,. At this time, for example, it is assumed that the switching elements a of the switch circuits 3a,..., 3f are both set to the ON state by the switching controller 4 for a fixed time T (see (a1) in FIG. 3). Thus, the output signals of the pulsars 12a,.
The probe 1 passes through each of the switching elements a,.
Among them, the oscillators P ₁₁ , P ₂₁ , P ₃₁ , P ₄₁ , P ₅₁ , and P ₆₁ in the first row along the azimuth direction x are excited at a time (see (a2) in FIG. 3). This allows
Each transducer _P 11, _..., the ultrasonic signal from the _{P 61} is the subject 8
Sent to This transmit beam includes the diagnostic position α and has a certain spread.

On the other hand, the ultrasonic signal reflected in the subject returns to the probe 1, and the ultrasonic echo signals are converted into voltage signals by the transducers P ₁₁ ,..., P ₆₁ (FIG. 3). (A
3)). However, each of the switch circuits 3a,.
Since only the switching elements a of f are in the ON state, only the voltage signals of the first vibrators P ₁₁ ,..., P _{61 in} the azimuth direction x are taken out to the transmission / reception unit 2, and the preamplifier 13 a ,..., 13f are individually amplified. The amplified echo signal is supplied to A
After being individually converted into digital signals by the / D converter group 15, they are stored in a predetermined area of the memory 16.

When the conduction time T for the first group of transducers elapses in this manner, the switching controller 4 turns on only the switching elements b of the switch circuits 3a,. Only at the same time (see (b1) in FIG. 3). For this reason, this time, the second array of transducers P ₁₂ ,.
₆₂ is excited at a time (see (b2) in Fig. 3), these transducers _P 12, _..., echo signals are received through _{P 62} (see (b3) in FIG. 3).

Thereafter, similarly, when the processing is repeated up to the fifth row of transducers P ₁₅ ,..., P ₆₅ along the azimuth direction x, the phasing adder 17 in the signal processing unit 5 The stored data is read out, and phasing addition is performed with the single diagnostic position α as the focus. In other words, by the calculation after reception,
As shown in FIG. 4, each data is delayed and added so that the received beam converges to the focal point α. The added value obtained in this manner is image data at a certain time at the diagnostic position α. After the image data is stored in the frame memory 22 via the detector 21 of the display unit 6, it is read at a predetermined timing. It is output and displayed on the TV monitor 24.

As described above, all the transducers P ₁₁ ,
..., the driving of the P ₆₅ is completed, the first row of transducers P ₁₁ of the switching controller 4 again azimuth direction _x, ..., in order to drive the P _61, the process proceeds to the next drive cycle. Thus, the above-described operation is repeated.

As described above, all the transducers P ₁₁ of the probe 1,
..., and P _65, to divide the sequence of azimuth direction x as one group, by driving each the group, the number of receiving channels transmitting and receiving unit 2 may if only vibrator few minutes in the lateral direction x. Therefore, even when the probe 2 having a two-dimensional array structure is driven, the entire circuit scale is significantly reduced as compared with a case where the number of transmission / reception channels for all the transducers is provided.

When the configuration of the above embodiment is applied to Doppler measurement including a Doppler tomography, since the measurement position is a fixed point or the slice thickness does not need to be reduced, the object of the probe 1 An acoustic lens for focusing in the lens direction is installed on the side 8, the phasing adder 17 is set so as to focus only in the azimuth direction, and the switching controller 4 switches the switching elements a of the switch circuits 3 a,. ,…,
e are simultaneously conducted, and all the vibrators P ₁₁ ,..., P ₆₅ are operated. Thereby, the acoustic energy from all the transducers P ₁₁ ,..., P ₆₅ is concentrated at the measurement position, the energy of the echo signal is also increased, and measurement can be performed with a good S / N ratio.

In the above embodiment, although no delay is applied at the time of transmission, the reference signal source 11 and the pulsar 12
The delay circuits are individually inserted between a,..., 12e, and the delay times of these circuits are set so that the transmitted ultrasonic signal is focused along a plane including the diagnostic position α and perpendicular to the azimuth direction x. You may. As a result, the energy of the ultrasonic wave reflected from the diagnosis position α increases, the side lobe decreases, and S
/ N ratio is improved.

Second Embodiment Next, a second embodiment will be described with reference to FIGS. In the second embodiment, phasing addition signal processing for a single diagnostic position α is performed separately in the azimuth direction x and the lens direction y. Here, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

The signal processing unit 3 of the ultrasonic diagnostic apparatus shown in FIG.
0, an azimuth phasing adder 31 is provided on the input side, and an A / D converter 32,
A memory 33 and a lens direction phasing adder 34 are provided. That is, the phasing adder shown in the first embodiment is divided into two stages, the azimuth direction and the lens direction.

As shown in FIG. 6, the azimuth phasing adder 31 is a set (six) of delay circuits 36 for individually inputting the output signals of the preamplifiers 13a,.
, 36f and an adder 37 for adding the output signals of the delay circuits 36a,..., 36f and supplying the result to the A / D converter 32. The delay time of each of the delay circuits 36a,..., 36f is set to a value at a predetermined point on the curve of FIG. 7A, whereby the transducers P _1y , P in the azimuth direction x are set.
_2y , P _3y , P _4y , P _5y , P _6y (y = 1 to 5)
8A has a directivity along a plane perpendicular to the azimuth direction x and including the diagnostic position α by calculation, as shown in FIG. 8A.

The memory 33 stores, as shown in FIG.
It has a three-dimensional matrix of one column in the azimuth direction x, five rows in the lens direction y, and the scanning time t for a single diagnostic position α, and can store data in each direction.

The lens-direction phasing adder 34 performs a circuit configuration equivalent to that of FIG. 6 by digital processing. That is, each delay time of the delay circuit relating to the digital processing is shown in FIG.
8B is set to a value at a predetermined point on the curve of FIG. 8B, and its directivity is calculated along a plane perpendicular to the lens direction y and including the diagnostic position α as shown in FIG. 8B. It has directivity.

Other structures and operations are the same as those of the first embodiment.

In this ultrasonic diagnostic apparatus, transducers P _1y ,..., P _{6y in} the azimuth direction x of the probe 1 (y = 1 to 5)
When each of the received signals is output from the transmission / reception unit 2, the received signals are first delayed by the azimuth direction phasing adder 31 with different delay times and added. This allows
The ultrasonic reception beam is narrowed down in the azimuth direction x by calculation with the diagnostic position α as the focal point for each row of the transducers P _1y ,..., P _6y , and the image data at the diagnostic position α is calculated. This image data is converted from an analog signal to a digital signal by the A / D converter 32 and stored in the first position of the memory 33. Hereinafter, this is repeated for each arrangement of the transducers P _1y ,..., P _6y , and when the first scan is completed, the data of one column in the memory 33 is filled. These one column of stored data are read out at once by the lens direction phasing adder 34,
Digitally delayed and added. That is, the beams of the ultrasonic waves once narrowed down in the azimuth direction x with the diagnosis position α as the focal point by the azimuth direction phasing adder 31 are summed by calculation, and then narrowed down in the lens direction y. For this reason,
The beam corresponding to the calculated value of the lens direction phasing adder 34 has a three-dimensional shape with the diagnostic position α as the focal point as in FIG. 4, and the echo data at the diagnostic position α has a high S / N ratio. The obtained echo data is sent to the display unit.

As described above, by performing scanning for each array of transducers in the azimuth direction x and performing aperture synthesis in the lens direction y, the capacity of the memory 33 can be reduced.

By changing the delay time pattern of each of the phasing adders 31 and 34, the diagnostic position, that is, the focal position of the received ultrasonic beam can be changed to a position at an arbitrary depth and angle from the surface of the subject 8. Can be set to

Third Embodiment A third embodiment will be described with reference to FIG. The third embodiment is an example in which the position of the diagnosis position in the lens direction y is always set to the center position, that is, no deflection is applied to the lens direction y. Here, the same components as those in the above-described second embodiment are denoted by the same reference numerals, and description thereof will be simplified or omitted.

For this purpose, each of the switch circuits 38a,..., 38f of the switch group 38 is connected as shown in FIG. That is, each switch circuit 38a (..., 38f)
The number of terminals on the probe 1 side is set to three, and the terminal can be arbitrarily selectively switched between the common terminal on the transmitting / receiving section 2 side.
Then, a plurality and odd number of transducers _Px1 , _Px2 , _Px3 , _Px4 , _Px5 (x = 1 to
Of 6), pull out the transducer P _x3 at the center position independently,
The vibrators P _x2 and P _x4 on both sides are connected in parallel, and the vibrators P _x1 and P _x5 on both sides are connected in parallel.
These three lead terminals are connected to three input / output terminals of the switch circuit. Note that the lens direction phasing adder 34 of the signal processing unit 30 in the third embodiment has a
The delay time pattern is such that the beam is focused at the center position in the direction. The other configuration is the same as that of the second embodiment.

With this configuration, scanning is performed for each transducer in the azimuth direction x in the same manner as in the above-described embodiments. Thereby, the first (y = 1) transducers P _1y,.
When driving _6y , the fifth (y = 5) transducers P _1y ,..., P _6y are also driven at the same time, and the second (y = 5)
When driving the vibrators P _1y ,..., P _6y arranged in 2), the fourth (y = 4) vibrators P _{1y ,.
6y is} also driven at the same time. Therefore, it is possible to obtain a three-dimensional reception beam that is arbitrarily deflected in the azimuth direction x and is always focused on the center position in the lens direction y. In this case, the number of times of transmission and reception of the ultrasonic wave is reduced to 3/5 as compared with the case of each of the above embodiments, so that the real-time property is improved.

(Fourth Embodiment) A fourth embodiment will be described with reference to FIGS. In the fourth embodiment, the signal processing of the phasing addition for an arbitrary slice plane in the subject, that is, the two-dimensionally arranged diagnostic position α _xy (here, x = 3, y = 2) is performed in the azimuth direction x. And the lens direction y. Here, the first
The same components as those in the embodiment are denoted by the same reference numerals, and description thereof will be simplified or omitted.

The signal processing unit 40 of the ultrasonic diagnostic apparatus shown in FIG. 11 is provided with six azimuth direction phasing adders 41a,..., 41f as first calculating means on the input side, and on the output side. , An A / D converter 42a as a second calculating means,
, 42f, memory 43, and lens direction phasing adder 4
4 is provided.

Each of the azimuth direction phasing adders 41a,..., 41f has a preamplifier 13a,.
The delay circuits 46a, which individually input the output signals of 13f,
, 46f and an adder 47 for adding the output signals of the delay circuits 46a, ..., 46f. Of these, the delay times of the delay circuits 46a,..., 46f are set so as to focus the reception beam along a plane including the _assigned diagnostic position α _xy and perpendicular to the azimuth direction x. The pattern of the delay time is, for example, as shown in FIG.

The azimuth direction phasing adders 41a,.
f are output from the corresponding A / D converters 42a (...,
The signal is converted into a digital signal by 42f) and stored in the memory 43. The memory 43 can store the number of diagnostic positions α _xy , the number of transducers in the lens direction, and three-dimensional echo data on the time axis.

Further, the lens-direction phasing adder 44 performs the same delay and addition circuit configuration as in FIG. 12 by digital processing. That is, the delay time of the delay circuit related to the digital processing is also set, and the setting is made so that the reception beam is focused along a plane that includes the diagnostic position α _xy and is perpendicular to the lens direction y. FIG. 13B shows an example of the delay time pattern.

The other structure is the same as that of the first embodiment.

For this reason, the reception signal obtained by driving the transmission / reception section 2 is first converted into azimuth direction phasing adders 41a,.
At 1f, phasing and addition are performed individually, and a reception beam as shown in FIG. 14A is formed by calculation. The echo data associated with the beam formation is converted into a digital signal and stored at a predetermined position in the memory 43. When the probe 1 is driven for a predetermined time and the entire area of the memory 43 is filled, the stored data is read out from the lens direction phasing adder 44,
The phasing addition is performed individually corresponding to the diagnosis positions α _xy . As a result, the reception beam that has already been narrowed down along the plane perpendicular to the azimuth direction x is narrowed down along the plane perpendicular to the lens direction y as shown in FIG. _The receive beam for _xy is narrowed down to three dimensions. As a result, since a plurality of diagnostic positions can be scanned at the same time, a two-dimensional slice plane passing through the plurality of diagnostic positions in the subject can be scanned with higher real-time performance than when a single diagnostic position is set.

In this embodiment, since no delay is applied during transmission, the transmitted ultrasonic signal is transmitted in the azimuth direction x of the probe 1.
The ultrasonic wave reaches all of the plurality of diagnostic positions α _xy by one transmission. For this reason, the time required for transmission can be saved, and in this respect, the real-time property can be improved.

In the fourth embodiment, the diagnostic position α in the slice plane is changed by changing the number of phasing adders.
The number of _xy can be easily changed. Further, even when the same phasing adder is used, the position to be diagnosed can be easily changed by changing the delay time pattern. Furthermore, even when a plurality of diagnostic positions are arranged in the azimuth direction x or the lens direction y, it can be easily dealt with only by changing the number of phasing adders.

On the other hand, the signal processing unit 4 of the fourth embodiment described above
When all 0s are digitized, the result is as shown in FIG. That is, the signal processing unit 50 relating to the digitization includes A / D converters 51a,..., 51 which individually convert output signals of the preamplifiers 13a,.
f, a first memory 52 for storing the converted signals of the A / D converters 51a,..., 51f, and an azimuth phasing adder for reading the data stored in the memory 52 and performing phasing addition in the azimuth direction. 53, a second memory 54 for storing the addition data of the adder 53, and a lens direction phasing adder 55 for reading the storage data of the memory 54 and performing phasing addition in the lens direction. . Both phasing adders 53,
55 obtains an operation equivalent to that of the fourth embodiment by performing phasing addition in a time-sharing manner according to a plurality of diagnostic positions. Here, the A / D converters 51a,..., 51f, the first memory 52, and the azimuth phasing adder 53 form a first arithmetic unit, and the second memory 54 forms a storage unit. Further, the lens direction phasing adder 55 forms a second calculating means.

The phasing adder in the azimuth direction and the lens direction in each of the above embodiments has been described as being composed of only a delay circuit and an adder. A configuration for changing the opening area over time may be added. That is, as shown in FIG. 16, the phasing adder 60 includes a plurality of delay circuits 61a,.
, 61f, and weighting circuits 62a,..., 62f individually provided on the output side of the delay circuits 61a,. I have. .., 6
1f is a control signal DR output from the depth setting circuit 65
The delay time can be changed according to. Also, the weighting circuit 6
The weight coefficients 2a,..., 62f can be changed according to the control signal DR, and the weight coefficients correspond to the respective transducer positions in the azimuth direction x or the lens direction y. Depth setting circuit 65
Is a depth information generating means, and a reference signal generator 66
A control signal is formed by using the reference pulse signal output by the controller, the control signal DR is output, and a pulse signal for excitation is sent to the transmission / reception unit. Therefore, when the diagnosis depth is deep, the aperture area can be set wide by setting the weighting coefficients of the weighting circuits 62a,..., 62f as shown by a curve CA in FIG. When the diagnostic depth is shallow, the aperture area can be reduced by setting those weighting factors as, for example, a curve CB in FIG. As a result, the aperture area can be controlled in accordance with the focal position of the reception beam to suppress the side lobes of the reception beam, and at the time of diagnosis, a reception area with good directivity is always set even if the depth to be diagnosed differs. it can.

In the above embodiment, the phasing addition is performed in the azimuth direction x and then in the lens direction y. However, the phasing addition is performed in the reverse order. Is also good.

Fifth Embodiment A fifth embodiment will be described with reference to FIG. FIG.
FIG. 9 is a configuration diagram showing a fifth embodiment of the ultrasonic diagnostic apparatus according to the present invention. In the drawing, a vibrator 70 includes a plurality of unit vibrators ya, yb, yc... Arranged in a lens direction y and an azimuth direction x.
Are arranged in a two-dimensional array composed of a plurality of unit transducers xa, xb, xc,. The switches SW ₁ , SW ₂ , SW ₃ ... Are connected to each vibrator, and each switch is connected to one common line. Each of these switches is always one of the switches under the control of the controller 71.
Only one is controlled to be selectively turned on.

In the figure, reference numeral 72 is a reference signal generation source, and reference numeral 7 is
A pulser 3 amplifies the reference signal and selectively drives one vibrator via a switch. Reference numeral 74 denotes a preamplifier for transmitting an ultrasonic wave from the driven transducer to the subject and amplifying an echo signal received by the same transducer, and reference numeral 75 denotes an A / D for converting the echo signal into a digital signal. A converter 76 is a memory for sequentially storing digital echo data corresponding to the received echo signal. Reference numeral 77 denotes an image reconstructing circuit that reconstructs an image by delaying and adding phasing and adding to each obtained echo data after transmission and reception by all the transducers, and reference numeral 78 denotes an image reconstructing circuit. 7
Reference numeral 79 denotes a display for displaying a reconstructed image, and an image detection circuit for detecting the RF signal output from 7.

Next, the operation of this embodiment will be described.

Each switch is selectively turned on based on the control of the controller 71 in advance, so that the vibrators in the x- and y-rows forming the two-dimensional array are sequentially turned on by the pulser 7.
3 to transmit and receive ultrasonic waves to and from the subject. The sequentially received echo signals are converted into digital signals and then stored in the memory 76 as echo data. The echo data stored in this way is taken out by the image reconstruction circuit 77, and the image reconstruction is performed by phasing addition. After the reconstructed image is detected by the image detection circuit 78, it is displayed on the display 79.

According to this embodiment, image reconstruction can be performed only by providing one transmission / reception circuit for applying a drive voltage to each transducer and processing a received echo signal. For this reason, high resolution of image reconstruction can be achieved without increasing the circuit scale.

In this embodiment, the number of times of transmission and reception of ultrasonic waves required to obtain all the images obtained by the transducers may be equal to the number of transducers. In general, since the smoothness of the image is ensured, the number of scanning lines of the image is larger than the number of transducers, so that the real-time property can be improved. In particular, the present embodiment is effective when applied to diagnosis of a site near the body surface.

The above embodiments can be applied to any of the linear scanning method, the sector scanning method, and the convex scanning method.

[0063]

According to the ultrasonic diagnostic apparatus according to the invention described in the claims, for a plurality of diagnostic positions, the ultrasonic wave passes through the diagnostic positions and along a plurality of planes orthogonal to the first direction. Because of the two-stage focusing control in which the echo signals are focused and then passed through their diagnostic location and along their multiple planes orthogonal to the second direction, the ultrasound echo signals are focused. The beam focus position can be controlled dimensionally, that is, spatially, to obtain a good directivity based on a narrower beam, and a first direction (eg, azimuth direction) and a second direction (eg, lens direction). Resolution can be improved.

Further, by the two-stage focusing control, the circuit scale of the reception processing circuit can be suppressed, and the size of the apparatus can be reduced even when a probe having a two-dimensional array structure is used.

[Brief description of the drawings]

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

FIG. 2 is a functional circuit diagram illustrating a configuration of a switch circuit.

FIG. 3 is a timing chart showing transmission / reception timing for each transducer group in the azimuth direction.

FIG. 4 is an explanatory diagram showing a shape of a reception beam focused in a three-dimensional direction.

FIG. 5 is a block diagram of an ultrasonic diagnostic apparatus according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a phasing adder.

FIGS. 7A and 7B are pattern diagrams showing delay time patterns in an azimuth direction and a lens direction with respect to a single diagnosis position, respectively.

FIGS. 8A and 8B are shape diagrams showing shapes of a reception beam in an azimuth direction and a lens direction with respect to a single diagnosis position, respectively.

FIG. 9 is a conceptual diagram illustrating a configuration example of a memory.

FIG. 10 is a block diagram of an ultrasonic diagnostic apparatus according to a third embodiment of the present invention.

FIG. 11 is a block diagram of an ultrasonic diagnostic apparatus according to a fourth embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a phasing adder.

13A and 13B are pattern diagrams showing azimuth and lens direction delay time patterns for a plurality of diagnosis positions, respectively.

FIGS. 14A and 14B are shape diagrams showing shapes of received beams in an azimuth direction and a lens direction with respect to a plurality of diagnostic positions, respectively.

FIG. 15 is a block diagram of a signal processing unit of an ultrasonic diagnostic apparatus according to a modification of the fourth embodiment.

FIG. 16 is a block diagram of a phasing adder according to an application example of the present invention.

FIG. 17 is an explanatory diagram for explaining a difference in a weight coefficient corresponding to a magnitude of a diagnosis depth.

FIG. 18 is a block diagram of an ultrasonic diagnostic apparatus according to a fifth embodiment of the present invention.

FIG. 19 is a perspective view schematically showing a conventional probe having a one-dimensional array structure.

FIG. 20 is a perspective view schematically showing a conventional probe having a two-dimensional array structure.

[Explanation of symbols]

1 probe P _xy transducer 2 transceiver 3 switching circuit group 3a, ..., 3f switching circuit 4 switching controller 5 signal processor 6 the display unit 15 A / D converter group 16 memory 17 phasing adder 30 the signal processing Unit 31 azimuth phasing adder 32 A / D converter 33 memory 34 lens directional phasing adder 36a,..., 36f delay circuit 37 adder 38 switch circuit group 38a,..., 38f switch circuit 40 signal processing unit 41a, , 41f Azimuth direction phasing adder 42a, ..., 42f A / D converter 43 Memory 44 Lens direction phasing adder 46a, ..., 46f Delay circuit 47 Adder 50 Signal processing unit 51a, ..., 51f A / D Converter 52 First memory 53 Azimuth direction phasing adder 54 Second memory 55 Lens direction phasing adder 60 Signal processing unit 6 a, ..., 61f delay circuit 62a, ..., 62f weighting circuit 63 adder 65 depth setting circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61B 8/00-8/15

Claims (3)

(57) [Claims] A probe in which a plurality of transducers capable of bidirectionally converting an electric signal and an ultrasonic signal are arranged two-dimensionally in a first direction and a second direction orthogonal to each other; Each transducer of the probe is excited by an excitation signal of an electric quantity to transmit an ultrasonic signal to each transducer, and a reception signal of the electric quantity converted by each transducer according to an ultrasonic echo signal. Transmitting and receiving means for performing predetermined processing on the plurality of diagnostic positions set in the subject, and for each of a plurality of surfaces orthogonal to the first direction, First computing means for simultaneously delaying and adding the received signal groups from the plurality of transducers output by the transmitting and receiving means so that the ultrasonic echo signal is focused, and passing through each of the plurality of diagnostic positions, And a plurality of surfaces orthogonal to the second direction On the other hand, a second calculating means for delaying and adding a received signal group output from the first calculating means so that the ultrasonic echo signal is focused on each surface thereof; and a second calculating means. And a display unit for displaying an ultrasonic image based on the signal output from the ultrasonic diagnostic apparatus. 2. The apparatus according to claim 1, wherein the first arithmetic means includes a number of phasing adders for delaying and adding the received signal group, the number being equal to the number of planes orthogonal to the first direction. Ultrasonic diagnostic equipment. 3. The storage device according to claim 2, wherein the second operation unit stores the reception signal group output from the first operation unit, and delays the reception signal group output from the storage unit for each diagnostic position. The ultrasonic diagnostic apparatus according to claim 1, further comprising a phasing adder that performs addition by adding.