JPS6258738B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic diagnostic apparatus having an electronic scanning type ultrasonic probe.

As shown in FIG. 1, an electronic scanning type ultrasonic probe used in a conventional ultrasonic diagnostic device has a drive electrode 2 and a ground electrode 3 formed on both sides of a transducer material (for example, a piezoelectric element) 1. It is equipped with a oscillator. This drive electrode 2 is composed of a plurality of divided electrodes arranged along the longitudinal direction (X-axis direction), each of which is connected to a lead wire 2a, and the other ground electrode 3 is connected to a lead wire 2a. 1
One lead wire 3a composed of two plate-shaped bodies
is connected. Here, the volume portion sandwiched between each divided electrode and the ground electrode functions as an individual vibrator, and is represented by an equivalent circuit as shown in FIG.

According to an ultrasonic probe equipped with a transducer having such a structure, each of the divided transducers is sequentially switched and driven, or a plurality of transducers are grouped into several sets and driven simultaneously. After that, it is possible to control the focus of the ultrasonic beam and the effective aperture of the transducer by shifting and driving the ultrasonic beam one by one, thereby changing the direction of the emitted ultrasonic beam and moving it. become.

However, according to the vibrator used in the ultrasonic probe, the drive electrode is divided into multiple parts in the longitudinal direction (X-axis direction), so the ultrasonic beam is scanned in the X-axis direction. However, in this state, it is not possible to obtain a tomogram in the Y-axis direction. Therefore, if necessary, it is necessary to mechanically or manually move the ultrasound probe so that the longitudinal direction is in the Y-axis direction In order to obtain a tomographic image in the Y-axis direction, it was necessary to rearrange the position so that
For this reason, it takes time to scan, and for example, immediately after first obtaining a tomographic image in the X-axis direction, when trying to obtain a tomographic image in the Y-axis direction of a part perpendicular to this,
There has been a problem in that the relative positions of the two (for example, the position of the center) are shifted, making it impossible to obtain a plurality of diagnostically meaningful tomographic images.

The present invention has been made in view of the above circumstances, and provides an ultrasonic diagnostic apparatus that has a simple configuration and can quickly scan an ultrasonic beam in both the X and Y axes without changing the position of the ultrasonic probe. The purpose is to provide the following.

The present invention will be specifically explained below using Examples.

FIG. 3 is a perspective view showing one embodiment of the transducer of the ultrasonic probe used in the ultrasonic diagnostic apparatus of the present invention. This vibrator is composed of a vibrator material (piezoelectric element) 4 having a rectangular cross section, and a front electrode 5 and a back electrode 6 arranged to sandwich the piezoelectric element. Here, the surface electrode 5 is composed of a plurality of (for example, 64) divided electrodes 5a to 5n arranged at approximately equal intervals along the X-axis direction, as in the conventional device, and each electrode has a lead wire 7. are connected to each other, and the back electrode 6 has a plurality of (for example, the same number as the front electrodes) divided electrodes 6a to 6a arranged along the Y-axis direction (a direction perpendicular to the direction in which the front electrodes are arranged).
6n, and a lead wire 8 is connected to each divided electrode. A vibrator having such a structure is represented by an equivalent circuit as shown in FIG. That is, each surface divided electrode 5a to 5
When n is arranged along the horizontal axis, the back divided electrodes 6a to 6n are arranged and coupled with the piezoelectric element 4 sandwiched between each electrode.

If the vibrator has such a structure, for example, the fifth
When a voltage is applied to one front-surface divided electrode 5c and one back-surface divided electrode 6c as shown in the figure, the shared portion (volume portion) S sandwiched between the two electrodes effectively operates as a vibrator. Become. Therefore, by applying a voltage to each divided electrode individually or simultaneously, the effective area of the vibrator (vibrator aperture) can be arbitrarily controlled. That is, as in the past, by applying an appropriate excitation voltage to the front electrode, it is possible to scan the ultrasonic beam in the X-axis direction, and conversely, by applying an appropriate excitation voltage to the back electrode, the ultrasonic beam can be scanned in the It becomes possible to scan the beam in the Y-axis direction, and as a result, by switching and applying the excitation voltage to both electrodes, the scanning direction of the ultrasonic beam can be arbitrarily controlled. In this case, since each divided electrode is formed by arranging rectangular plate materials at equal intervals, it is equivalent to a case where fine chip-shaped electrodes are arranged in a matrix.

Next, an embodiment of the apparatus of the present invention using the ultrasonic probe having the above structure is shown in FIG. 6 and will be described in detail. In the description of this embodiment, for convenience of explanation, there will be four divided front electrodes and four divided electrodes on the back surface, and the electrode to which the excitation voltage is applied will be referred to as the related electrode, and the electrode to be grounded will be referred to as the indifferent electrode. call. In the figure, the front divided electrodes 5a to 5d are connected to the four switches SW1 _{to SW4} of the first switch 9A, and the back divided electrodes 6a to 6d are connected to the four switches of the second switch 9B. SW ₁ to SW ₄ are respectively connected, and the a contact of each switch in the first switching device 9A is connected to each exciter 1 in the next stage exciter group 10.
0a to 10d, and the b contacts are grounded, and the a contacts of the switches SW ₁ to SW ₄ in the second switching device 9B are grounded, and the b contacts are connected to the exciters 10a to 10d. 10d, respectively. Each of these exciters 10a to 10
The time phase of d to be excited is controlled by the phase control oscillator 11. In the illustrated state, each of the switches 9A and 9B is connected to the contact a side, but if necessary, only a desired switch can be connected to the b contact side by a control means (not shown). It is now possible to switch to

In such a device, when the exciters 10a to 10d are driven in the illustrated state, an excitation voltage is applied to the surface dividing electrodes 5a to 5d via the first switch 9A, so that the ultrasonic beam is not transmitted. It is possible to scan in the X-axis direction. In this case, the surface divided electrode 5
a to 5d act as separation electrodes, and the back divided electrodes 6
Since a to 6d are grounded, they act as indifferent electrodes. Next, in this state, each switch in the first and second switching devices 9A and 9B is simultaneously switched to the b contact side to drive the exciters 10a to 10d, and this time the ultrasonic beam is scanned in the Y-axis direction. can do. In this case, the back divided electrodes 6a to 6
d becomes a related electrode, and the surface divided electrode becomes an indifferent electrode. It is also possible to partially scan the ultrasonic beam in the X-axis direction or the Y-axis direction by appropriately switching the switches at arbitrary positions of the first and second switching devices 9A and 9B. Furthermore, immediately after applying an excitation voltage to one front surface segmented electrode 5a to perform beam scanning, an excitation voltage is then applied to the back surface segmented electrode 6a to perform beam scanning, and this process may be repeated alternately. Alternatively, by grounding both opposing electrodes, they do not act as electrodes, and by appropriately combining the switching of each electrode, it is possible to scan an arbitrary area with the ultrasonic beam. Note that the control means for the switching device at this time may be a mechanical one or an electrical one that performs switching control based on a preset program.

The present invention is not limited to the embodiments described above, and various modifications can be made. For example, split electrodes formed on the front and back sides are not limited to being arranged orthogonally to each other;
The two may be arranged at an appropriate angle (that is, they may intersect).

According to the present invention as described above, beam scanning in both the X and Y axes can be performed quickly and easily by simply switching between the related and indifferent electrodes without changing the position of the ultrasound probe. It is possible to provide an ultrasonic diagnostic apparatus that can obtain a tomographic image of a desired tomographic plane and that can obtain a plurality of diagnostically meaningful tomographic images.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the structure of a conventional vibrator, Fig. 2 is its equivalent circuit diagram, Fig. 3 is a perspective view showing an embodiment of the vibrator used in the device of the present invention, and Fig. 4 is its equivalent circuit diagram. FIG. 5 is a schematic diagram illustrating the effective volume of the vibrator, and FIG. 6 is a block diagram of an embodiment of the device of the present invention using the vibrator. 4... Piezoelectric element, 5... Surface electrode, 6... Back electrode,
5a to 5d, 6a to 6d...divided electrodes, 9A, 9B
...Switcher, 10a to 10d...Exciter, 11...Phase control signal generator, _SW1 to _SW4 ...Switch.

Claims (1)

[Claims] 1 An ultrasonic probe having a plurality of divided electrodes arranged in a row on a surface sandwiching a piezoelectric element, a plurality of divided electrodes arranged in a row in a direction crossing the divided electrodes on the surface, and a switching circuit. An ultrasonic diagnostic apparatus characterized in that switching control is performed so that an excitation voltage is applied to one electrode and the electrode on the opposite side is grounded.