JPH084587B2 - Ultrasonic diagnostic equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus having a variable focal position for a received ultrasonic wave. In an ultrasonic diagnostic apparatus, the focus position is fixed and the signal received by the transducers in the central part of the transducer group is delayed from the signal received by the transducers in the peripheral part to obtain the signal received by the transducers. It is necessary to match the phases of and extract as clear signals. Conventionally, the delay of the signal received by the vibrator is made by inputting the signal from each vibrator to the multi-stage input point in the delay adding means in which small delay elements are connected in multiple stages, and the delay time is changed by the input point. It was done by switching with a switch.

Therefore, in the conventional ultrasonic diagnostic apparatus, spike noise generated when the switches are switched is mixed into the display screen to deteriorate the image quality. Further, in order to increase the resolution, it is necessary to reduce the unit delay time of the small delay element, which increases the number of input points of the delay adding means, which is difficult to deal with by the conventional method of determining the delay time by the selection switch. It was a thing. It is an object of the present invention to obtain an ultrasonic diagnostic apparatus having a clear image quality and a high resolution by controlling the delay time of a signal without switching a selection switch.

[0003]

2. Description of the Related Art A conventional ultrasonic diagnostic apparatus will be described with reference to FIGS. A focus position adjusting method in the ultrasonic diagnostic apparatus will be described with reference to FIG. Figure (a) shows the relationship between the transducer and the focal position. In the figure, 1 to N represent oscillators, and F
1 to F3 represent focus positions. Consider the case where the focus position is F2. The echo of the ultrasonic wave reflected from the focus position F2 reaches the vibrator N / 2 earliest, and reaches the vibrators 1 and N latest.

Therefore, in order to clearly receive the reflected signal from F2, the delay phase of the signal received by the oscillator N / 2 is larger than that of the signal in the other oscillators and is received by the oscillators 1 and N. Set the delay phase of the signal to be smaller than that of other oscillators,
It is necessary to synthesize and output the signals so that the phases of the signals received by each transducer match. Then, the input point of the delay addition means for inputting the signal from each oscillator is selected by the selection switch group so that the required phase delay can be obtained for each oscillator. Figure 6 (b) shows the relationship between the oscillator and the delay time. As shown in the figure, each focus position F1,
The phase of the signal received by each transducer may be delayed with respect to F2 and F3. FIG. 7 shows an example of the received wave at each transducer. As shown in the figure, it is a pulse signal having an envelope curve in which the carrier frequency of a continuous wave is interrupted.

The structure of a conventional ultrasonic diagnostic apparatus is shown in FIG. In the figure, 71 is a transducer group which receives ultrasonic vibrations and converts it into an electric signal, and T1 to TN are individual transducers. Reference numeral 72 denotes a variable gain amplifier group, which is an amplifier A connected to the vibrators T1, T2, T (N-1) and TN.
1, A2, A (N-1), A (N). A selection switch group 73 includes N input points and M
A switch matrix having a plurality of output points is configured and each amplifier of the variable gain amplifier group 72 is connected.

Reference numeral 74 denotes a delay addition means, which has small delay elements (described later) connected in series in multiple stages and has an addition point for inputting and adding a signal to each small delay element. Reference numeral 75 is a small delay element, a plurality of which are connected in series in multiple stages and have an addition point at both terminals, and 76 is an addition point. IP1,
IP2, ..., IP (M) is the input point, AD2, ...
, AD (M) are addition points corresponding to the input points IP2, ..., IP (M), respectively. Reference numeral 77 is a main signal line for adding and transmitting the signals input to the respective input points. Reference numeral 78 is each amplifier A1 to A of the variable gain amplifier group.
It is a gain control circuit that performs N gain control.

The operation of the configuration shown in FIG. 8 will be described. The received wave is received by each transducer (T1 to TN), converted into an electrical signal, and then connected to each transducer (A1 to A).
Amplified in N). The output from each amplifier is input to each input point of the selection switch group 73. Then, the signal from each transducer is output to the output point corresponding to the input point of the selection switch group determined according to the preset fixed focus position, and the addition point of the delay addition means 74 corresponding to the selected output point. Entered in.

The signals input to the respective input points of the delay addition means 74 are added at the respective addition points of the main signal line 77, delayed by the small delay element and output. For example, the signal input to the i-th addition point is added to the main signal line at the addition point AD (i). Then, the signal added at the addition point AD (i) is delayed by the small delay element 75 between the addition points AD (i) and AD (i + 1) and added to the signal input to the input point AD (i + 1). To be done. The above operation is performed at each addition point and each small delay element, and a signal is output at the addition point AD (M).

[0009]

The change of the focus position in the conventional ultrasonic diagnostic apparatus is performed by changing the connection point of the switch matrix of the selection switch group as described above and inputting the signal from each transducer. This was done by changing the input point (addition point) in the means. Therefore, spike noise generated by the switch operation due to the change of the connection point of the switch matrix is mixed into the display screen every time the focus position is changed, and the display screen is disturbed.

Further, in order to finely set the focus position and improve the resolution, it is necessary to reduce the delay time per stage of the small delay element in the delay adding means.
A large number of multi-stage delay elements of the delay adding means had to be taken (usually, assuming that the center frequency of the received signal is f, τ ≦ 1 / (8
f). Therefore, the number of switches in the selection switch group is increased, and the selection switch group and the control means therefor are enlarged. It is an object of the present invention to obtain an ultrasonic diagnostic apparatus that can perform focus movement without performing a switch operation of a selection switch group after setting a focus at an arbitrary fixed position.

According to the present invention, a signal from an oscillator is input to two amplifiers connected in parallel for each oscillator, and the output of each amplifier connected in parallel is set as a small set. As a configuration for inputting to the addition point of the delay element, we found that the focus can be moved by changing the gain of each amplifier, and the focus position was made variable by such a configuration. FIG. 1 shows the basic configuration of the present invention.

In the figure, 1 is a transducer group, (2-0) to
(2-N) is a vibrator, 3 is a vibrator (2-0) to (2-
N), a first variable gain amplifier group consisting of a first variable gain amplifier for inputting each signal to each transducer, (4-0) to (4-).
N) are first variable gain amplifiers connected to the oscillators (2-0) to (2-N), respectively. 3'is a vibrator (2-
2) Inputting signals from 0) to (2-N) for each transducer
A second variable gain amplifier group consisting of variable gain amplifiers, (4-
0 ')-(4-N') are oscillators (2-0)-
It is a second variable gain amplifier connected to (2-N). The gain (A, A ′, B, B ′) of each variable gain amplifier is individually determined by a gain control unit (described later). Reference numeral 5 denotes a gain controller, which is a variable gain amplifier (4-0) to (4-N), (4-0 ') to (4-) of the first variable gain amplifier group 3 and 3'.
N ') gain is controlled. Reference numeral 6 is a first selection switch group, which constitutes a matrix switch that determines the connection between the input point and the output point. Then, the signal from each amplifier of the first variable gain amplifier group is input to each input point and output to the output point connected by the matrix switch. Reference numeral 8 denotes a delay adding means, which is a series of small delay elements (described later) connected in multiple stages, and an input point and an addition point are provided for each small delay element. Each input point (addition point) is configured so as to correspond to an output point in the first selection switch group 6 and the second selection switch group 6 ′, and is composed of the first selection switch group and the second selection switch group. 9 output is input to the corresponding input point 9
Is a small delay element, 10 and 10 'are addition points, and 11 is a main signal line.

[0012]

The operation of the configuration shown in FIG. 1 will be described. In the present invention, the fixed focus is defined as the connection of matrix switches in the first switch selection group and the second switch selection group, and the variable gain amplifiers (4-0) to (4-N), (4-0 ') to (4. 4-
The focus is moved from the fixed focus by changing the gain of N ′).

Prior to explaining the operation of the configuration in FIG. 1, each variable gain amplifier (4-0) to (4-
The principle by which the focus can be moved by changing the gains of N) and (4-0 ') to (4-N') will be described.

FIG. 2 is a diagram for explaining the principle of the phase delay control method according to the present invention. In the figure, 20 is a first variable gain amplifier, 21 is a second variable gain amplifier, 22 is a small delay element, 23 is an addition point of the signal line in the delay addition means of the output of the first variable gain amplifier (20), and 24 is It is the addition point of the signal line in the delay addition means of the output of the second variable gain amplifier (21).

The signal from the vibrator is Vin = COS (ω
t), the gain of the first variable gain amplifier (20) is A, the gain of the second variable gain amplifier is B, the output from the small delay element 22 is Vout, and the delay time in the small delay element 22 is τ. Vout = ACOS (ω (t−τ) ) + BCOS (ωt) = A (COS (ωt) COS (ωτ) + SIN (ωt) SIN (ωτ)) + BCOS (ωt) where φ is a parameter and COS (φ) ) = ACOS
Let (ωτ) + B, SIN (φ) = ASIN (ωτ). A = SIN (φ) / SIN (ωτ) ... B = COS (φ) −SIN (φ) COS (ωτ) / SIN (ωτ) = (SIN (ωτ) COS (φ) −SIN ( φ) COS (ωτ)) / SIN (ωτ) = SIN (ωτ−φ) / SIN (ωτ) ... where SIN (ωτ) ≠ 0, that is, ωτ = 2πfτ ≠ kπ
(F is the center frequency of the signal, k is an arbitrary integer) Therefore, by τ ≠ k / (2f) ······· above, Vout = COS (φ) COS (ω t) + SIN (φ) SIN ( ωt) = COS (ωt−φ) ...

If the delay time τ between the two input points and the center frequency f of the received signal are known and the condition is satisfied, the above equation is obtained with the gains A and B using φ as a parameter.
By calculating and setting the gains of the variable gain amplifier A (20) and the variable gain amplifier B (21) to the calculated values, the output phase can be made variable. In particular, if τ = 1 / (4f), then ωτ = 2πf / (4f) = π / 2, so A = SIN (φ) from the equation and B = COS (φ) from the equation. Therefore, if A = 1 and B = 0, the configuration becomes the same as the conventional fixed focus configuration described above with reference to FIG. 8, and the fixed focus position can be focused by setting the connection point of the selection matrix. it can. In this way, A = 1, B
After setting the fixed focus position at = 0, the gain control unit 5 controls the gains of the variable gain amplifiers A and B using φ as a parameter, and the phase of the signal at an arbitrary addition point in the delay addition means is in the entire signal line. If they are always in phase, the focus can be moved around the fixed focus position.

Based on the above principle, the operation of the configuration in FIG. 1 in which the focus is moved will be described. The gain of the first variable gain amplifier (4-i) connected to the i-th oscillator is A (i), and the second variable gain amplifier (4-I ′).
Let B (i) be the gain of.

The ultrasonic waves received by the vibrator group 1 are converted into electric signals by the vibrators (2-0) to (2-N),
Variable gain amplifiers (4-0) to (4
-N), (4-0 ') to (4-N'). The outputs of the first variable gain amplifiers (4-0) to (4-N) are the first
It is input to the selection switch group 6, and the second variable gain amplifier (4
The outputs of −0 ′) to (4-N ′) are input to the second selection switch group 6 ′.

The first selection switch group 6 sets a fixed focus so that the focus is at an arbitrary position when each gain A (i) (i = 0 to N) of the first variable gain amplifier is set, for example. . The configuration of the connection point of the matrix switch of the second selection switch group is also the same as that of the first variable gain amplifier. Then, each output point is input to each addition point 10, 10 ′ of the delay addition means 8. Then, the first variable gain amplifiers (4-0) to (4-N) connected to the respective oscillators (2-0) to (2-N)
And second variable gain amplifiers (4-0 ') to (4-N')
A pair of outputs from the first variable gain amplifier and the second variable gain amplifier, which are connected to the same oscillator, are input to both ends of the small delay element. For example, variable gain amplifiers (4-0) and (4-
The output of 0 ') is input to both ends of the small delay element 9. In this way, the signals from the transducers (2-0) to (2-N) are added at the addition points on the main signal line 11 to which they are input.

In the above operation, when the signal waveform shown in FIG. 7 is in focus at the set fixed focus position, it is moved away from the fixed focus position corresponding to the time of 1 to 2 cycles at the carrier frequency. By changing the gains of the first variable gain amplifier and the second variable gain amplifier so that the signals reflected at the different points are focused on their respective positions, the connection points of the switch matrix of each selection switch group are changed. It is possible to move the focus without moving.

FIG. 3 shows a first embodiment of the present invention. In the figure, reference numeral 30 is a vibrator group, which is composed of vibrators T1 to TN, 31 is a first variable gain amplifier group, which is composed of variable gain amplifiers A1 to AN, and 31 'is a second variable gain amplifier. The amplifier group is composed of variable gain amplifiers B1 to BN. Reference numerals 32 and 32 'are a first selection switch group and a second selection switch group, respectively, which form a switch matrix of N input (M-1) outputs. 33 is a gain control circuit, 34 is delay adding means, 3
Reference numeral 5 is a small delay element, and 36 is a main signal line.

Received signals from the vibrators (T1 to TN) of the vibrator group 30 are divided into two systems, one of which is connected to each of the first variable gain amplifiers (A1 to AN) of the first variable amplifier group 31. , N input (M-1) output via a first selection switch group 32 composed of a switch matrix,
Input points of the delay addition means 34 (IP1 to IP (M-1))
Connected to. The other of the received signals from each transducer group (T1 to TN) is connected to each second variable gain amplifier (B1 to BN) of the second variable gain amplifier group 31 ', and has N inputs (M-1).
It is connected to the input points (IP2 to IP (M)) of the delay adding means 34 via the second selection switch group 32 'composed of the output switch matrix. Reference numeral 36 is a main signal line for adding signals from each transducer.

The delay adding means 34 uses the M input points (IP
1-IP (M)) corresponding to addition points (AD2-AD)
(M)), of which any input point IP (i)
The signals input to (i = 1 to M) are added to the main signal line at the addition point AD (i). Addition point AD on the main signal line 36
A small delay element 35 is connected between (i) and the addition point AD (i + 1), and the output of the delay addition means 34 is made from AD (M).

If the switch connection states of the first selection switch group 32 and the second selection switch group 32 'are the same, as shown in the figure, the i-th first variable gain amplifier A in the first variable gain amplifier group 31 is shown. The output of (i) is the delay addition means 34.
, I-th variable gain amplifier B of the second variable gain amplifier group, if it is connected to the j-th input point IP (j) of
The output of (i) comes to be connected to IP (j + 1).

By doing so, the delay time τ of the j-th small delay element DL (j) of the delay adding means 34 becomes τ.
If ≠ k / (2f) (k is an integer), the gain control circuit 3
3, each variable gain amplifier A of the first variable gain amplifier group
The gain of (i) is G (i) SIN (ωτ−φi) / SIN (ω
τ), each variable gain amplifier B of the second variable gain amplifier group
If the gain of (i) is G (i) SIN (φi) / SIN (ωτ), the focus can be moved by changing the gains of A (i) and B (i) according to φi.

Particularly, if τ = 1 / (4f), then A
The gain of each variable gain amplifier may be determined so that the gain of (i) becomes G (i) SIN (φi) and the gain of B (i) becomes G (i) COS (φi).

FIG. 4 shows a second embodiment of the present invention. In the figure, reference numeral 40 is a vibrator group, which is composed of vibrators T1 to TN, and 41 is a first variable gain amplifier group,
Variable gain amplifiers A1 to AN, 41 'is a second
A variable gain amplifier group, the second variable gain amplifier B1 to
It consists of BN. 42 and 42 'are the first
The selection switch group and the second selection switch group respectively constitute a switch matrix of N inputs and M outputs. Reference numeral 43 is a gain control circuit, and 44 is a delay adder, which is a 2M input point (IPA1, IPB1, ..., I).
PA (M) and IPB (M)) and addition points (ADA1, ADB1, to ADA (M), corresponding to the respective input points
ADB (M)). 45 is a small delay element (DL01 to DL0M), and 45 'is a small delay element (DL0
1 to DL0M).

Received signals from the vibrators (T1 to TN) of the vibrator group 40 are divided into two systems, one of which is connected to each of the first variable gain amplifiers (A1 to AN) of the first variable amplifier group 41. , N inputs and M outputs via a first selection switch group 42 composed of a switch matrix, which is connected to the input points (IPA1 to IPA (M)) of the delay addition means 44. The other of the received signals from the respective transducers (T1 to TN) is the second variable gain amplifier (B) of the second variable gain amplifier group 42.
1 to BN), and via the second selection switch group 42 ′ composed of a switch matrix of N inputs and M outputs, input points (IPB1 to IPB) of the delay addition means 44.
(M)). 46 is a main signal line.

The delay adding means 44 uses the 2M input points (I
PA1, IPB1, to IPA (M), IPB (M)) and corresponding addition points (ADA1, ADB1, to ADA)
(M), ADB (M)), the signal input to the i-th input point IPA (i) (i = 1 to M) is sent to the main signal line at the i-th addition point ADA (i). And the i-th input point input point IPB (i) is added to the i-th addition point ADB
It is added to the main signal line in (i).

On the main signal line 46, a small delay element 45 (DL0 is provided between the addition point ADA (i) and the addition point ADB (i).
(I)) are connected in series, and the addition points ADB (i), ADB
The small delay elements DL1 (i) are connected in series between (i + 1). And the addition point ADB
The signal is output from (M).

In the present embodiment, the first selection switch group 4
2 and the switch connection state of the second selection switch group 42 'are made the same. By doing so, for example, the output of the i-th first variable gain amplifier A (i) in the first variable gain amplifier group 41 is the j-th input point IPA (j) of the delay adding means 44.
Is connected to i of the second variable gain amplifier group.
The output of the second variable gain amplifier B (i) is the IPB
(J) is connected.

Further, the delay time τ0 of the j-th small delay element DL0 (j) of the delay adding means 44 is τ0 ≠ k / (2
f) (k is an integer), the gain control circuit 43 determines the gain of each variable gain amplifier A (i) of the first variable gain amplifier group as G (i) SIN (ωτ-φi) / SIN (ωτ), The gain of each variable gain amplifier B (i) of the second variable gain amplifier group is set to G
(I) If SIN (φi) / SIN (ωτ), then φi
The focus can be moved by changing the gains of A (i) and B (i) according to the above.

Particularly, if τ 0 = 1 / (4f), then A
It suffices to find the gain of each variable gain amplifier so that the gain of (i) becomes G (i) SIN (φi) and the gain of B (i) becomes G (i) COS (φi).

The small delay element 45 '(DL1 (j)) is for forming a specific focus serving as a reference when moving the focus together with the small delay element 45 (DL0 (j)). The sum of delay times τ1 and τ0 is usually 1 of the received signal.
The time may be about the cycle (1 / f). Therefore, if the total delay time (delay time received from the input signal from IPA (1) until output) of the delay time is the same as in the case of the conventional method, τ ≦ 1 / (8f) required conventionally In comparison with the first selection switch group 42 and the second selection switch group 4
The number M of outputs of 2'can be reduced.

FIG. 5 shows a third embodiment of the present invention. In the figure, reference numeral 50 is a vibrator group, which is composed of vibrators T1 to TN, 51 is a first variable gain amplifier group, which is composed of first variable gain amplifiers A1 to AN, and 51 'is a second variable gain amplifier. A group of gain amplifiers, the second variable gain amplifiers B1 to B
It consists of N. 52 and 52 'are a first selection switch group and a second selection switch group, respectively.
The switch matrix has N / 2 inputs and M outputs. Reference numeral 53 is a gain control circuit, 54 is a delay addition means, and 2M input points (IPA1, IPB1, ..., I).
PA (M), IPB (M)) and addition points (ADB1, ... ADA (M), ADB) corresponding to the respective input points.
(M)). 55 is a small delay element (DL0
1 to DL0M) and 55 'are small delay elements (DL01 to DL0).
0M). 56 is a main signal line.

The embodiment of FIG. 5 is different from the embodiment of FIG. 4 in that the oscillators T (i) and T (i + 1) (i is an odd number,
i = 1, 3, 5, ...) A of the first variable gain amplifiers A
(I), A (i + 1) outputs are added and input to the first selection switch group, and similarly, outputs of the second variable gain amplifier groups B (i), B (i + 1) are added. It is different in that it is input to the second selection switch group.
As a result, the first selection switch group and the second selection switch group
The relationship between the number of inputs and the number of outputs of the selection switch group is (N / 2):
The only difference is that it becomes M.

Normally, the time difference between the signals received by the adjacent transducers is small, and it is sufficient to add only the phases.
Further, even if the addition is performed as described above, A (i + 1), B (i) and A (i + 1), B (i +
1) The phases of the signals (i = 1 to N) can be controlled independently. In the configuration of FIG. 5, the number of input lines of the first selection switch group and the second selection switch group can be halved.

[0038]

According to the present invention, the focus can be moved without changing the input point of the delay addition means, so that the disturbance of the screen caused by the switching of the switch for changing the input point can be eliminated. . Further, the delay time given to the small delay element is also about 1 / (4f), and an ultrasonic diagnostic apparatus having a good resolution can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of the present invention.

FIG. 2 is a diagram illustrating the principle of phase delay control according to the present invention.

FIG. 3 is a diagram showing a first embodiment of the present invention.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a third embodiment of the present invention.

FIG. 6 is a diagram showing a focus position adjusting method in the ultrasonic diagnostic apparatus.

FIG. 7 is a diagram showing an example of a reception waveform.

FIG. 8 is a diagram showing a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 1: Oscillator group, 2-0 to 2-N: Oscillator, 3: First variable gain amplification group, 3 ': Second variable gain amplification group, 4-0 to 4-N: Variable gain amplifier, 4- 0 ′ to 4-N ′: variable gain amplifier, 5: gain control unit, 6: first selection switch group, 6 ′: second selection switch group, 8: delay addition means, 9: small delay element, 10, 10 ': Additional points,

Claims (6)

[Claims] 1. An ultrasonic wave is radiated into a subject by driving a transducer group (1) composed of a plurality of transducers (2-0 to 2-N), and a reflected wave from the inside of the subject is generated as described above. An ultrasonic wave that is received by a transducer group, converted into an electrical signal, and then delayed and added to each other to obtain a scanning signal and focus on an arbitrary position inside the subject. In the diagnostic device, the oscillator (2-0
~ 2-N) connected to each first variable gain amplifier (4-0
˜4-N), a first variable gain amplifier group (3) and the first variable gain amplifiers (4-0 to 4-N) provided in parallel, and a vibrator (2-0 to 2-N). A second variable gain amplifier group (3 ') provided for each transducer, which is composed of the second variable gain amplifiers (4-0' to 4-N ') connected to each other, and an addition point (10) for inputting an external signal. , 10 ') at both ends, and a delay adding means (8) constituted by connecting a plurality of small delay elements (9) in series, and the first variable gain amplifier (4-0 to 4-).
N) has an input point corresponding to each output and an output point corresponding to a plurality of addition points (10, 10 ') of the delay addition means (8), and selectively selects an output point connected to the input point. A first selection switch group (6) defined in 1., input points corresponding to respective outputs of the second variable gain amplifiers (4-0 ′ to 4-N ′), and a plurality of delay addition means (8). A second selection switch group (6 ') having an output point corresponding to the addition point (10, 10') and selectively determining an output point connected to the input point; ~ 2-N) for the output from the first variable gain amplifier (4-0-4-
N) and the second variable gain amplifier (4-0'-4)
-N ') is output to the output point selected in the selection switch group, and the output from the first variable gain amplifier and the output from the second variable gain amplifier in the arbitrary oscillator are combined as a set for delay addition. The first variable gain amplifier (4-0 to 4-N) and the second variable gain amplifier (4) are respectively input to the sets of arbitrary different addition points in the means (8).
An ultrasonic diagnostic apparatus characterized in that the focus position of a received signal is changed by changing the gain of −0 ′ to 4-N ′ respectively. 2. The delay addition means according to claim 1, wherein the delay addition means has M input points, and is connected to the i-th vibrator with a first variable gain amplifier and the i-th vibrator is connected with the first variable gain amplifier. An ultrasonic diagnostic apparatus, wherein the outputs of the two variable gain amplifiers are input to adjacent input points in the delay addition means. 3. The input according to claim 2, wherein the output of the first variable gain amplifier connected to the i-th oscillator and the output of the second variable gain amplifier connected to the i-th oscillator are input. The delay time of the small delay element between the points is 1 / (4f) (where f is the center frequency of the received wave), φi is the phase for delaying the signal from the i-th oscillator, and the gain of the first variable gain amplifier is An ultrasonic diagnostic apparatus, wherein G (i) COS (φi) and the gain of the second variable gain amplifier are G (i) SIN (φi). 4. The vibration according to claim 1, wherein the outputs of the first variable gain amplifier connected to the i-th vibrator and the second variable gain amplifier connected to the i-th vibrator are set as one set. N sets are set for each sub-element, and the delay addition means has one set of input sets at two adjacent input points, and N sets of outputs from each variable amplifier group can be connected to any input sets in the delay addition means. An ultrasonic diagnostic apparatus characterized by: 5. The delay time between two input points in delay adding means for inputting outputs from M sets of variable gain amplifiers according to claim 4, 1 / (4f) (f is a center frequency of a received wave) And φi is a phase for delaying the signal from the i-th oscillator, and the gain of the first variable gain amplifier is G
(I) COS (φi), and the gain of the second variable gain amplifier is G (i) SIN (φi). 6. The method according to claim 4 or 5, wherein i (i =
The first variable gain amplifier A (i) and the first variable gain amplifier A ((1) connected to the transducer T (i + 1) adjacent to the (1, 3, 5, ... Odd) -th transducer T (i), respectively. The output of i + 1) is added to the second variable gain amplifier B (i) connected to the i-th oscillator T (i) and input to the delay addition means, and connected to the oscillator T (i + 1). An ultrasonic diagnostic apparatus, wherein outputs of a second variable gain amplifier B (i + 1) in a group of two variable gain amplifiers are added and input to a delay addition means.