JP2947031B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe which transmits an ultrasonic pulse from an ultrasonic probe to a subject, receives an echo signal from the subject, and gives a predetermined delay time to the echo signal. The present invention relates to an ultrasonic diagnostic apparatus that focuses or deflects a beam while focusing, and processes a echo signal by an image processing unit to obtain a diagnostic image.

[0002]

2. Description of the Related Art An ultrasonic diagnostic apparatus irradiates a living body with ultrasonic pulses from an ultrasonic probe having a plurality of micro-vibrators capable of mutually converting electric signals and ultrasonic signals. A reflected wave from a tissue or a lesion in a living body is received, signal processing is performed, and tomographic images and blood flow information can be displayed.

[0003] Today, the B mode for obtaining a tomographic image of a tissue or a lesion in a living body has been widely used clinically, but a Doppler for obtaining information such as a blood flow direction or a blood flow velocity at a specific position. The clinical role played by modes is also increasing. At present, a phased array type electronic scanning ultrasonic diagnostic apparatus including an array ultrasonic probe in which a plurality of micro transducers are arranged as described above is widely used. In this ultrasonic diagnostic apparatus, a delay line is provided for each micro-vibrator, and by controlling the delay time, reception focus is applied or an ultrasonic beam is deflected to obtain echo information in a specific direction, and phase adjustment is performed. The circuit performs this delay and addition. Hereinafter, an example of this type of conventional electronic scanning ultrasonic diagnostic apparatus will be described with reference to a schematic block diagram shown in FIG.

As shown in FIG. 2, the electronic scanning type ultrasonic diagnostic apparatus includes an ultrasonic probe 12, a transmitting unit 14, a receiving unit 3, a control unit 5, a signal processing unit 2, and a display unit 1. . A plurality of micro transducers 13 are arranged on the ultrasonic probe 12. The receiving unit 3 includes a signal amplifying unit 11, a first matrix switch 9A, a second matrix switch 9B, a first delay circuit 7A, a second delay circuit 7B, and a switch 4.
The first delay circuit 7A has a first input tap 8A,
Are provided with second input taps 8B.

The operation of the above configuration will be described below. An ultrasonic vibrator driving pulse is formed in the transmitting unit 14. This drive pulse is applied to the ultrasonic probe 1
The micro-vibrator 13 in 2 is driven, and the ultrasonic pulse generated by this is transmitted into a subject (not shown). An ultrasonic echo signal reflected from a tissue or a lesion in a living body is received by the micro-vibrator 13 in the ultrasonic probe 12 and sent to the signal amplifier 11 of the receiver 3.

In the configuration shown in FIG. 1, as shown in FIG. 3, a reception dynamic focus for performing focusing at each depth is adopted. For example, in FIG.
Assuming that the dynamic focus is performed in 10 steps from 9 to 9, a predetermined delay time determined from the depth and the scan angle at each focus point for each microvibrator 13 is given independently, and the control signal 5B from the control unit 5 gives First
The matrix switch 9A and the second matrix switch 9B are controlled to transmit the amplified echo signal 10 to the first input tap 8A and the second input tap 8B corresponding to the delay amount. At this time, the two delay circuits 7A,
7B, one of the delay circuits 7A or 7B receives the echo signal while the other delay circuit 7A or 7B receives the echo signal.
The operation of switching the input tap of B or 7A between 8B and 8A is performed alternately at predetermined depths. That is, the first delay circuit 7A is adopted at the even focus points (F0, F2,..., F8) by the control signal 5A from the control unit 5 (that is, the switch 4 is connected to the contact 4A), and the odd focus Points (F1, F
3,. . . , F9), the second delay circuit 7B is employed (that is, the switch 4 is connected to the contact 4B), and delay synthesis is performed.

The echo signal 6 delayed and synthesized as described above
A and 6B are sent to the signal processing unit 2 and subjected to signal processing.
The data is sent to the display unit 1 as image data. Since the data sent to the display unit 1 in this manner has the reception focuses F0 to F9, a diagnostic image with high resolution is displayed from a short distance to a long distance.

As described above, the two delay circuits 7A and 7B
By adopting a method of performing delay synthesis, spike noise generated at the time of tap switching can be prevented from being mixed into the echo signal, and S / N can be improved. Such a configuration is disclosed in, for example,
No. 70139 discloses this.

On the other hand, when deflecting while focusing in FIG. 1, a predetermined delay time determined from the depth and the deflection angle at the focus point for each micro-vibrator 13 by the control signal 5B from the control unit 5 is independent. The control unit 5 controls the two matrix switches 9A and 9B in advance, and sends echo signals to the input taps 8A and 8B corresponding to the delay amount. At this time, only one of the delay circuit outputs 6A and 6B is selected by the control signal 5A from the switch control unit 5.

[0010]

However, in the above-described conventional ultrasonic diagnostic apparatus, when performing focusing requiring a large deflection angle, such as during sector scanning or blood flow measurement, each of the delay circuits 7A and 7B. It is necessary to arrange a large number of delay lines in the system, which leads to an increase in cost. FIG. 4 and FIG. 5 are schematic diagrams of delay combination at the time of focusing and when performing deflection while focusing, respectively. As can be seen from these figures, when scanning is performed using the same number of micro-vibrators 13, the maximum value of the delay amount required for focusing and the maximum value of the delay amount required for focusing while deflecting are the latter. Is clearly large. Therefore, when performing deflection while focusing with the above-described ultrasonic diagnostic apparatus, many delay lines are required, such as providing a delay circuit for deflection at which a large delay time can be obtained in order to obtain a large deflection angle. Therefore, there has been a major problem in terms of cost.

The present invention solves the above-mentioned conventional problems, and does not require the use of a separate delay circuit for obtaining a large delay time, or eliminates the need for additional delay lines to be disposed, thereby providing a large delay. It is an object of the present invention to provide an ultrasonic diagnostic apparatus that can save time and thus reduce cost.

[0012]

The technical means of the present invention for achieving the above object is to provide a micro vibration transmitting / receiving ultrasonic wave.
And an ultrasonic probe in which a plurality of the above-described micro-vibrators are arranged, and an input is connected in parallel to each of the micro-vibrators, and each of the micro-vibrators gives an independent delay time to an echo signal received. First and second delay circuits for focusing or deflecting while focusing, a first switch for selecting one of the outputs of the first and second delay circuits, and an output of the second delay circuit for the first and second delay circuits. A second switch connected to any one input of the one delay circuit; an image processing means for processing an echo signal output from the delay circuit selected by the first switch to generate a diagnostic image ; focus ultrasound or when the delay time for deflecting while focus is less than or equal to the maximum delay time of the first or second delay circuit, said the first and the second delay circuit,
The first switch is alternately switched to the second switch.
Switch off to alternately transmit and receive ultrasound.
When the delay time for focusing or deflecting while focusing exceeds the maximum delay time of the first or second delay circuit, only the output of the first delay circuit is constantly controlled by the first switch. Selection, the second switch is turned on, the output of the second delay circuit is connected to one of the inputs of the first delay circuit, and the output of the first or second delay circuit is Switch control means for obtaining a delay time exceeding the maximum delay time.

[0013]

In each of the above technical means, only the output of the first delay circuit is always selected by the first switch in the Doppler mode, and the output of the second delay circuit is turned on by turning on the second switch. Connecting to one input of the first delay circuit to obtain a delay time exceeding the maximum delay time of the first or second delay circuit, and deflecting the ultrasonic beam while focusing it; There kill in.

[0015]

According to the present invention, the first switch for selecting one of the outputs of the two delay circuits and the output of the second delay circuit for selecting one of the outputs of the first delay circuit. By providing the second switch connected to one input, when the delay time for focusing or deflecting while focusing exceeds the maximum delay time of the first and second delay circuits, one of the outputs is provided. By connecting the two delay circuits in series with only one selected, a delay time exceeding the maximum delay time of the first and second delay circuits can be obtained.

[0016]

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

FIG. 1 is a schematic block diagram showing an ultrasonic diagnostic apparatus according to one embodiment of the present invention. In this embodiment, the same parts as those of the above-described conventional example shown in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG.
The second switch 1 that connects the output of the second delay circuit 7B to any one input of the first delay circuit 7A to the receiving unit 3
5 is different from the above-described conventional example.

The above configuration will be described below in more detail together with its operation. The ultrasonic transducer driving pulse formed by the transmitting unit 14 drives the micro transducer 13 in the ultrasonic probe 12, The generated ultrasonic pulse is transmitted into a subject (not shown). An ultrasonic echo signal reflected from a tissue or a lesion in a living body is received by the micro-vibrator 13 in the ultrasonic probe 12 and sent to the signal amplifier 11 of the receiver 3. The processing of the echo signal 10 amplified by the signal amplifying unit 11 in the receiving unit 3 is divided into the following two methods, and the first switch 4 and the second switch 15 of the receiving unit 3 are controlled accordingly. You. (1) When performing dynamic focus, that is,
Echo signal processing when the delay time for focusing does not exceed the maximum value of the first delay circuit 7A and the second delay circuit 7B. (2) When deflecting while focusing, the first delay circuit 7 delays the time for deflecting while focusing.
E and echo signal processing when the maximum value of the second delay circuit 7B is exceeded.

Hereinafter, the signal processing method in the receiving section 3 of the above (1) and (2) will be described. As for the condition (1), as shown in FIG. 3, the reception dynamic focus for performing the focus for each depth is adopted. For example, assuming that 10 stages of dynamic focus are performed from F0 to F9 in the figure, a predetermined delay time determined from the depth and the scan angle at each focus point is given independently to each microvibrator 13, and the control unit 5 The first matrix switch 9A and the second matrix switch 9B are controlled by the control signal 5B from the controller, and an echo signal is sent to the first input tap 8A or the second input tap 8B corresponding to the delay amount. At this time, since two delay circuits 7A and 7B are provided, one of the delay circuits 7A and 7B is provided.
The operation of switching the input tap 8B or 8A of the other delay circuit 7B or 7A while A or 7B is receiving the echo signal is performed alternately at a constant depth. In other words, even focus points (F0, F2,.
8) employs a first delay circuit 7A, and at odd focus points (F1, F3,..., F9), a second delay circuit 7A is employed.
B is employed for delay synthesis. First delay circuit 7
A when the first switch 4 is set to the contact 4A
When the second delay circuit 7B is employed, the first switch 4 is connected to the contact 4B. The second switch 15 is always connected to the contact 15A.

On the other hand, with respect to the condition (2), the first switch 4 is always operated by the control signal 5A from the control unit 5.
Connect to contact 4A. That is, the output 6A of the first delay circuit 7A is sent to the subsequent signal processing unit 2. Also, the second
The switch 15 is always connected to the contact 15B by the control signal 5C from the control unit 5. As a result, the output of the second delay circuit 7B can be connected to an arbitrary input tap 8A of the first delay circuit 7A, and the maximum delay time of the first delay circuit 7A and the second delay circuit 7B is maintained. It can be doubled. At this time, a predetermined delay time determined from the depth and the scan angle at the focus point or from the deflection angle is given independently to each micro-vibrator 13 by the control signal 5B from the control unit 5, and the control unit 5 The first matrix switch 9A and the second matrix switch 9B are controlled by the signal 5B,
An echo signal is sent to the first input tap 8A or the second input tap 8B corresponding to the delay amount. At this time, the micro vibrator 13 requiring a delay time exceeding the maximum delay time of the first delay circuit 7A and the second delay circuit 7B is connected to the input tap 8B of the second delay circuit 7B, After being delay-synthesized by the second delay circuit 7B,
Further, the required delay amount (ie, the delay amount obtained by subtracting the delay amount in the second delay circuit 7B from the desired delay amount)
The echo signal is sent to the input tap 8A of the first delay circuit 7A corresponding to

After performing any of the delay synthesizing processes under the above conditions (1) and (2), the echo signal is sent to the signal processing unit 2 where it is subjected to signal processing and sent to the display unit 1 as image data. In the display unit 1, in the case of the above (1), since the reception focuses F0 to F9 are generated, a tomographic image with high resolution from a short distance to a long distance is obtained.
In the case of the above (2), a tomographic image focused on a predetermined position or blood flow information is displayed.

That is, in the case of the linear scanning or the convex scanning in the B mode, the delay synthesizing process under the condition (1) is employed, and in the case of the sector scanning, the delay synthesizing process under the condition (2). Processing is employed. When the deflection is performed in the Doppler mode, the delay synthesis processing under the condition (2) is adopted.

By the way, besides the conditions (1) and (2), when deflecting while focusing, the delay time for deflecting while focusing is determined by the first delay circuit 7A and the second delay circuit. When the maximum value of the signal 7B is not exceeded, in the delay synthesis processing under the condition (2), a method of inputting all the echo signals 10 from the signal amplifying unit 11 to the first input tap 8A can be adopted. It is also possible to do it. That is, the first switch 4 is always set to the contact 4A by the control signal 5A from the control unit 5,
The second switch 15 is always connected to the contact 15A. As a result, only the first delay circuit 7A is used for echo signal processing. At this time, the control signal 5B from the control unit 5
As a result, a predetermined delay time determined from the depth and the deflection angle at the focus point is given independently for each micro-vibrator 13, and the first matrix switch 9A is controlled to input the tap 8A corresponding to the delay amount. Is sent an echo signal.

According to the above embodiment, the first switch 4 and the second switch 15 are controlled, and the first delay circuit 7A is provided at every constant focus depth during dynamic focus.
And the output of the second delay circuit 7B is alternately selected, and when one of the delay circuits 7A or 7B is receiving an echo signal, the input tap of the other delay circuit 7B or 7A is set to 8B or 8A. When switching and obtaining a tomographic image with high resolution over a wide area from a short distance to a long distance and deflecting while focusing, the first delay circuit 7A and the second delay circuit 7B with a desired delay time
Exceeds the maximum delay time of the first delay circuit 7A.
And the second delay circuit 7B are connected in series to increase the maximum delay time, thereby enabling focusing at a large deflection angle and obtaining tomographic images or blood flow information.

[0026]

As described above, according to the present invention, 2
A first switch for selecting one of the outputs of the two delay circuits, and a second switch for connecting the output of one of the two delay circuits to the input of one of the other delay circuits Accordingly, a large delay time is secured by connecting two delay circuits in series, and focusing at a large deflection angle is enabled. This eliminates the necessity of adding a delay circuit or a delay line that obtains a large delay time, which has conventionally been separately secured, when performing focusing that requires a large degree of deflection, such as during sector scanning or blood flow measurement. . Therefore, it can be provided at low cost.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing an example of a conventional ultrasonic diagnostic apparatus.

FIG. 3 is a schematic diagram showing a receiving dynamic focus method.

FIG. 4 is a schematic diagram showing delay synthesis at the time of focusing;

FIG. 5 is a schematic diagram showing a delay synthesis method when deflecting while focusing.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 display unit 2 signal processing unit 3 reception unit 4 first switch 5 control unit 7A first delay circuit 7B second delay circuit 8A first input tap 8B second input tap 9A first matrix switch 9B first 2 matrix switch 11 signal amplifying unit 12 ultrasonic probe 13 microvibrator 14 transmitting unit 15 second switch

Continuation of front page (56) References JP-A-59-28682 (JP, A) JP-A-2-164348 (JP, A) JP-A-61-162938 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) A61B 8/00-8/14

Claims (2)

(57) [Claims] An ultrasonic probe for transmitting and receiving ultrasonic waves, an ultrasonic probe having a plurality of said microvibrators arranged therein, and an input connected in parallel to each of the microvibrators, A first and a second delay circuit for giving an independent delay time to the echo signal received by the micro-vibrator to focus or deflect while focusing, and one of the outputs of the first and the second delay circuit is selected. A first switch, a second switch for connecting the output of the second delay circuit to one of the inputs of the first delay circuit, and an output from the delay circuit selected by the first switch image processing means for generating a diagnostic image by processing the echo signal, a focus ultrasound,
Alternatively, when the delay time for deflecting while focusing is shorter than the maximum delay time of the first or second delay circuit, the first and second delay circuits are switched to the first switch.
Switch alternately, and turn off the second switch.
When the delay time for deflecting while performing focusing or focusing while performing transmission and reception of ultrasonic waves alternately exceeds the maximum delay time of the first or second delay circuit, the first switch is used. While always selecting only the output of the first delay circuit, turning on the second switch and connecting the output of the second delay circuit to one of the inputs of the first delay circuit An ultrasonic diagnostic apparatus comprising: switch control means for obtaining a delay time exceeding the maximum delay time of the first or second delay circuit. 2. In the Doppler mode, only the output of the first delay circuit is always selected by the first switch, and the output of the second delay circuit is turned on by turning on the second switch. Or one input to obtain a delay time exceeding the maximum delay time of the first or second delay circuit,
The ultrasonic diagnostic apparatus according to claim 1, wherein the deflecting while focusing the ultrasonic beam.