JPH03215253A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE:To enhance the spatial resolving power in a lens direction by making it possible to deeply set focal depth by mounting the ultrasonic probe wholly covered with an acoustic lens and arranging a plurality of vibrator pieces having different calibers in the other direction crossing one direction at a right angle at a predetermined cycle. CONSTITUTION:An ultrasonic probe 1 respectively has effective calibers La, Lb, Lc in a lens direction and three rectangular vibrator pieces 2a, 2b, 2c separated at an interval of a pitch PO are arranged as one set unit so that the effective calibers in the other direction crossing one direction being the arranging direction at a right angle are successively different and an acoustic lens 3 covers the whole of the respective vibrator pieces 2. The focus points F of the respective vibrator pieces are constant because the common acoustic lens 3 is used but the beam width thereof are different because the effective calibers are different. As a result, since the beams shown by broken lines are emitted from the centers or peripheries of the vibrator pieces, the ultrasonic probe 1 forms beam patterns shown by solid lines. By this constitution, focal depth can be deeply set by setting the vibrator pieces as one set unit to selectively change over a control signal.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides an ultrasonic probe in which a plurality of transducer pieces are arranged in one direction and the whole is covered with an acoustic lens. The present invention relates to an ultrasonic diagnostic device equipped with the above-mentioned ultrasonic diagnostic equipment.

(Prior Art) As shown in FIG. 5, a conventional ultrasonic diagnostic apparatus includes a plurality of rectangular transducer pieces 13a, 13b. 13c,...
are pitching each other. It is known that the ultrasonic probes are arranged in one direction X, separated by an interval of , and are entirely covered by an acoustic lens 3 . In order to make the explanation easier to understand, three vibrator pieces 13a, 13b, 13 are shown in the figure.
The structure shown in Fig. c is shown without the acoustic lens. On the surface of each vibrator piece, first electrodes 14a, 14b, 14c,
... are provided and both are connected to the ground line 6, while second electrodes 15a, 15b, 15C, ... are provided on the back surface, respectively.
... are provided and connected to independent signal lines 7, respectively. Further, an acoustic matching layer 8 (8a, 8b, 8c, . . . ) is provided between the acoustic lens 3 and each first electrode 13, and each vibrator piece commonly connects each second electrode 15. It is attached to the packing material 9 via.

Length dimension L of each vibrator piece (La, Lb, Lc,...
) are set to be the same, thereby having the same effective aperture. In addition, the focus point of the ultrasonic waves emitted from each transducer piece in the length direction Y (lens direction) of each transducer piece is determined by the acoustic lens 3, and the effective aperture and focus point of each transducer piece are determined by the acoustic lens 3. Fixed for each probe.

FIG. 6 explains a method of driving the ultrasonic probe shown in FIG. 5. By applying a control signal from the transmission/reception control circuit 11, a beam as shown by a broken line is emitted from the center and periphery of each transducer piece. As a result, the ultrasonic probe forms a beam pattern as shown by a solid line in the direction of the lens. F is the focus point determined by the acoustic lens.

(Problem to be Solved by the Invention) By the way, in the ultrasonic probes provided in conventional ultrasonic diagnostic equipment, the effective aperture and focus point in the lens direction of each transducer are fixed, so basically the focal point is fixed. There is a problem that the depth becomes shallow and the spatial resolution is inferior.

In other words, when the focus point is set at a short distance, the difference in spatial resolution between the focus point and its surroundings becomes large, so when performing ultrasound tomography, it is not possible to uniformly set the thickness of the tomographic plane to be small enough. You will not be able to obtain good image quality.

The present invention has been made in response to the above-mentioned problems.
It is an object of the present invention to provide an ultrasonic diagnostic apparatus in which the depth of focus is set deep to improve spatial resolution in the lens direction.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an ultrasonic probe in which a plurality of transducer pieces are arranged in one direction and the whole is covered with an acoustic lens. The ultrasonic diagnostic apparatus is characterized in that a plurality of transducer pieces having different effective apertures in the other direction orthogonal to the one direction are arranged at a predetermined period.

(Function) By arranging multiple transducer pieces at a predetermined period with different effective apertures in the other direction, the beam pattern formed by the ultrasonic probe is created by combining the beams of each transducer piece. Become something. Therefore, since the depth of focus can be set to a depth, the spatial resolution in the lens direction can be improved.

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

FIG. 1 is a perspective view showing an embodiment of the ultrasonic diagnostic apparatus of the present invention, in which the ultrasonic probe 1 has an effective aperture La in the lens direction,
Lb, Lc (La>Lb>Lc) and pitch P. Three rectangular vibrator pieces 2a, 2b separated by an interval of
, 2c as one group unit, the plurality of units are arranged at a pitch P in one direction. It is arranged in a periodic manner. That is, the three vibrator pieces 2a, 2b, and 2C constituting one set are arranged so that their effective apertures in the pond direction, which is orthogonal to one direction that is the arrangement direction, are successively different. 3 is each vibrator piece 2
It is an acoustic lens that covers the entire area. 4a, 4b. 4c is a first electrode provided on the surface of each vibrator piece 2, 5a, 5b,
5c is a second electrode provided on the back surface of each vibrator piece 2. The first electrode 4 (4a, 4b, 4c) is commonly connected to the signal line 6, and the second electrode 5 (5a .5b,
5c) are each connected to an independent signal line 7.

8a, 8b, 8c are acoustic matching layers provided between the acoustic lens 3 and each first electrode 4; 9 is a packing material to which each vibrator piece 2 is commonly attached via each second electrode 5; It is.

Figure 2 explains the beam pattern formed by three transducer pieces 2a, 2b, 2c, each having a different effective aperture L, a, Lb, Lc, and the focus point F of each transducer piece is Since the common acoustic lens 3 is used, the beam widths are constant, but the beam widths are different because the effective apertures are different. Therefore, a beam as shown by the broken line is emitted from the center and periphery of each transducer piece, and as a result, the ultrasonic probe forms a beam pattern as shown by the solid line. This makes it possible to set the depth of focus deep by selectively switching the control signal for each transducer piece as a unit.

Next, the operation of this embodiment will be explained.

FIG. 3 explains the method of driving the ultrasonic probe in the ultrasonic diagnostic apparatus of the present embodiment shown in FIG. 11 is a transmission/reception circuit that applies a drive signal to the selection switch 10 during transmission and processes the received signal during reception; 12 is a switch control circuit that controls the switching operation of the selection switch 10 for each transducer piece 2a, 2b; , 2c, respectively, control signals 2A., 2c. 2B. Add 2C selectively at the timing shown in the figure. The transmitting/receiving circuit 11 includes delay means for applying a predetermined delay to the transmitted and received signals.

Time t. -tA, the selection switch 10 is controlled to connect the transmission/reception control circuit 11 to the transducer piece 2c by applying the control signal 2C to the switch control circuit 12, so that the ultrasound probe 1 is Transducer piece 2 in Fig. 2
form a beam pattern corresponding to distance d. =C
A beam is emitted to an area corresponding to (t.t.). Note that C is the sound speed of the ultrasound of the subject. Time F'+
tr1? During this period, the selection switch 10 is controlled to connect the transmission/reception control circuit 11 to the pendulum piece 2b by applying the control signal 2B to the switch control circuit 12, so that the ultrasonic probe 1 is Transducer piece 2 in Figure 2
A beam pattern corresponding to b is formed and the distance (d2-
A beam is emitted to a region corresponding to dd)=C (t2-td). Similarly, between 12 and 13, control signal 2
By applying A to the switch control circuit 12, the selection switch 10 is controlled to connect the transmission/reception control circuit 11 to the transducer piece 2a.
forms a beam pattern corresponding to the vibrator piece 2a in FIG. 2, and emits the beam to a region corresponding to the distance (d3-d2')=C(t3 t2). Hours 14-
During time t5t4, the control signal 2B is applied to the transducer piece 2b, and between time t5t4, the control signal 2C is applied to the transducer piece 2b.
control so that it is added to C. In addition, a beam pattern is formed during these periods in the same manner as described above, and the beam is radiated to a region corresponding to the corresponding distance.

According to this method of driving an ultrasound probe, the time t.

The combination of the beam patterns emitted during the period -t4 is as shown by the solid line in Figure 3, and as is clear from the comparison with the conventional case in Figure 6, from the distance do to d2 and from d3 to d.
, the beam width can be narrowed within the range of . In other words, since the depth of focus can be increased, the spatial resolution in the lens direction can be improved. This reduces the difference in spatial resolution between the focus point and its surroundings, making it possible to set the thickness of the tomographic plane to be sufficiently small when performing ultrasonic tomography, making it possible to obtain uniform image quality.

Here, the arrangement pitch P of each vibrator piece. From the relationship between the vibration modes of each vibrator piece, the width W and thickness t of the vibrator piece corresponding to one signal line are (w/t)<0.6 to 0.
It can be divided into multiple parts to satisfy the relationship 7.
P=P. , xn (P is the arrangement pitch of the transducer piece group corresponding to the signal line, n is the number of divisions).

In addition, in the explanation of the main text, three transducer pieces with different effective apertures are used.
Although the example is shown in which groups are used as units, this is just an example, and any combination is possible.

FIG. 4 shows an example of the manufacturing method of the ultrasonic probes having different effective apertures shown in this embodiment. First, as shown in (a), the transducer 15 is prepared, The shaded area (\\\\) that should be the effective aperture is set as the polarization range, and the polarization process is performed, and the electrode (////) 1 6 a. 1
6 b. Next, as shown in (C), each vibrator piece is cut along the boundary portion 17 in the vertical direction in the figure, so that each La. The vibrator pieces 2a, 2b, and 2c having effective apertures of Lb and Lc can be separated.

According to such a manufacturing method, each vibrator piece can be easily manufactured by setting a region to be a polarization range in advance using a well-known patterning technique and cutting it after polarization processing.

[Effects of the Invention] As described above, according to the present invention, since a plurality of vibrator pieces having different effective apertures are arranged at a predetermined period,
Since the depth of focus can be set deep, the spatial resolution in the lens direction can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the ultrasonic diagnostic device of the present invention, FIG. 2 is an explanatory diagram of the functions and configuration of the main parts of the device of this embodiment, and FIG. 3 is a diagram illustrating the driving method of the device of this embodiment. Explanatory diagram, Figure 4 (
a) to (d) are explanatory diagrams of an example of the manufacturing method of the device of this embodiment, FIG. 5 is a perspective view showing a conventional example, and FIG. 6 is an explanatory diagram of a conventional driving method. DESCRIPTION OF SYMBOLS 1... Ultrasonic probe, 2a, 2b, 2c... Vibrator piece, 3... Acoustic lens, 4a, 4b, 4c...-First electrode, 5a, 5b, 5c--- 2nd electrode, 10... selection switch, 11... transmission/reception control circuit,
12...Switch control circuit.

Claims (2)

[Claims] (1) In an ultrasonic diagnostic device equipped with an ultrasonic probe in which a plurality of transducer pieces are arranged in one direction and the whole is covered by an acoustic lens, the effective aperture in the other direction perpendicular to the one direction is An ultrasonic diagnostic device characterized in that a plurality of different transducer pieces are arranged at a predetermined period. (2) The ultrasonic diagnostic apparatus according to claim 1, further comprising a control means for selectively switching and driving a plurality of transducer pieces so that transducer pieces having the same effective diameter are driven simultaneously.