JPS61109556A - Convex type ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a computer, a box-type ultrasonic diagnostic device, and especially when displaying a tomographic image of the heart on a display using ultrasonic waves, multiple reflections are detected. The present invention relates to a convex-type ultrasonic diagnostic apparatus configured to obtain high-quality ultrasonic tomographic images, etc. with less noise and a wide field of view.

[Problems to be solved by conventional technology and invention] Conventionally,
As a cardiac ultrasound diagnostic device, as shown in FIG. There is a device that performs so-called sector scanning which determines the observation direction as a result.When observing an image of the 17th layer of the heart using a cardiac ultrasound diagnostic device with this configuration, for example, the In Fig. 6, the ultrasonic waves emitted from the transducer 1-1 in the direction of the reflector 3-1 are reflected, as shown by the dotted line, and the ultrasonic waves returned are detected using the transducer 1-1. This was done by displaying the information on a display.For this purpose, a flat-shaped vibrator placed at the tip of the probe shown in Figure 7 was used.
On the other hand, if there is a reflector 3-2 located in parallel, the ultrasonic waves reflected by the anti-encapsulant 3-214 will be repeatedly reflected between the two, causing the transducer 1-2 and The problem is that the reflector 3-2 is displayed on the display as if it exists as an illustrated virtual image even at positions that are twice, three times, etc. the distance "l" between the reflector 3-2 and the reflector 3-2. was there.

Specifically, a heart with the right ventricle and left ventricle covered by the cardiac abdomen as shown in FIG. The probe 1-2 is used to emit ultrasonic waves, and the reflected signals are detected as shown in FIG. 9th
In the figure, the vertical axis represents the amplitude (intensity) of the ultrasound detected by the transducer 1-1.1-2, and the horizontal axis represents time.
1. The ultrasonic waves emitted from 1-2 toward the heart are
It is strongly reflected in the region where the central membrane of the figure is located.

There should be almost no reflection due to the presence of blood in the right ventricle, but there is a virtual image (reflected between the cardiac abdomen and transducers 1-1 and -2) shown using the dotted line in the figure. ) may be detected. Similarly, since there is blood in the left ventricle, there should be almost no reflection, but a virtual image indicated by the dotted line in the figure may be detected. In this way, if the conventional flat vibrator 1-1.1-2 was used,
There has been a problem in that a virtual image is generated due to repeated reflections between the vibrator 1-1.1-2 and a reflector that causes strong reflection that is present in or near the heart.

On the other hand, a so-called convex type probe in which a transducer 1-3 is disposed in a part of a cylinder as shown in FIG. 10 has come to be used for observing tomographic images of the abdomen and the like. The purpose is to use the linear probe 1-4, which is conventionally used in the abdomen.
As shown by the solid line in Figure 12, an image with a wider field of view can be obtained near the body surface 4 compared to the sector scan shown by the dashed-dotted line. Since there is a drawback that only a wide field of view can be obtained, it is necessary to maintain a wide field of view near the body surface 4 and at the same time secure a wide field of view at a position far away from the body surface 4 in the depth direction as shown by the dotted line in the figure. It is in. Therefore, the ultrasonic diagnostic equipment used to observe tomographic images of the abdomen, etc., by its nature, is used to observe the heart, which is protected like a bird in a cage by the ribs, which is the object of the present invention. Generally, there are few restrictions on the position where the transducer 1-3 contacts the object to be observed (part II'!), and moreover, it is possible to obtain a tomographic image with a wide field of view at a position close to the body surface 4 and a wider field at a deeper position. Since it is desirable to observe tomographic images of the field of view, the radiation center "0" from which the ultrasonic waves are emitted is located above the transducer 1-3, as shown in Figure 1O. When used to observe a tomographic image of the heart, which is the object of the invention, the emission center of the ultrasonic wave is located above the body surface, for example, the emission center "0□", as shown in FIG.
Since it is located at ``0°'' and cannot be approached as close to the body surface as the radiation center ``0°'', the field of view is restricted by the ribs 5 indicated by diagonal lines in the figure, making it difficult to observe. Ta.

In addition, the conventional conhex probe (probe) for
This is done because having a sufficiently small curvature to prevent repeated reflections as shown in FIG. 7 conflicts with the purpose of obtaining a tomographic image with a wide field of view at a position close to the body surface 4.
A curvature of several + mmR is common. This degree of curvature is not sufficient to diffuse the reflected waves and minimize multiple reflections, as shown by the solid line in FIG. however,
Since the abdomen does not have a reflector near the body surface that produces a strong reflection like the ventral region of the heart that covers the heart, there is no practical problem even if the abdomen has the current curvature.

Means for Solving Problem c] In order to solve the above problem, the present invention provides the following steps when displaying a tomographic image of the heart on a display using ultrasound, etc.
By arranging the transducer that emits and detects ultrasonic waves over approximately half the circumference of the cylindrical surface, the center of ultrasonic emission can be lowered and the 10-beam can be made smaller, so that the field of view is not restricted by the ribs and can be multiplexed. We are able to obtain high-quality tomographic images of the heart without reflections. Therefore, the convex-type ultrasonic diagnostic apparatus of the present invention is a convex-type ultrasonic diagnostic apparatus that displays an image on a display using a convex-type probe in which a transducer is arranged on the outer surface of a cylindrical surface. A probe in which each element piece is arranged approximately halfway around the outer surface of a cylindrical surface, and the element pieces within a range of approximately 90° with the center of the cylindrical surface as the scanning center are considered as one group] M and o d d /ev e n scanning, a selection circuit that sequentially selects the predetermined element pieces and supplies power for emitting ultrasonic waves;
It is characterized by being configured to obtain a scanning angle of 0°.

〔Example〕

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

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a block diagram of the main parts of the vibrator shown in FIG. 1, and FIGS. 3 and 4 are explanations explaining the manufacturing method of the vibrator shown in FIG. FIG. 5 shows another main part configuration diagram of the vibrator shown in FIG. 1.

In the figure, 6 is a vibrator, 7 is a display, 8 is a display circuit, 9 is a phase control circuit, 9-1.9-3 is a driver, 9-
2.9-4 is a receiver, 9-5 is a switch, 10 is a scanning selection circuit, 11 is a control circuit, 12 is a power supply, 13-1.1
3-2 is the relay TL scratch, 14 is the adhesive layer, 15 is the contact Vt
membrane, 16 is a Teflon frame, 17 is a matching layer, 1 is a front matching layer, I9 is a back matching layer, 20 is wax, 2I is a sound absorber, 22 is a support frame, 22-1 is an electrode pattern, 23.23
-1 represents an adhesive, 24 represents a support type, and 25 represents a lens.

FIG. 1 shows the configuration of a continuous type cardiac ultrasound diagnostic apparatus that displays tomographic images of the heart, and the transducer 6 in the figure is related to the present invention. As will be described later, the vibrator 6 is arranged to cover approximately half the circumference of the cylindrical surface, and each element (element piece) constituting the vibrator 6 is connected to a scan selection circuit IO.

The cough scanning selection circuit 10 configures the transducer 6 at an approximately 90° angle in response to the illustrated gate signal from the control circuit 11 and the drive signal from the drivers 9-1, 9-3, etc. in the phase control circuit 9. The element groups located within the so-called o d, which will be described later in the order of element group +11 to
d/eve n scanning is being performed. In order to display a tomographic image of the heart, the transducer 6 is arranged to cover approximately half the circumference of the cylindrical surface. The generation of virtual images due to reflections is prevented, and the radiation center of the ultrasound waves emitted from the transducer 6 is lowered and made smaller, resulting in a high-quality tomographic image of the heart with a wide field of view even when inserted between the narrow ribs. etc. can be displayed on the display 7.

Further, among the ultrasonic waves emitted toward the heart from the transducer 6, those that are reflected and returned are detected by the transducer 6, and are detected by the receivers 9-2, 9-4 and 9-4 in the phase control circuit 9. By using the switch 9-5 or the like, the selected delay circuit is turned on at a predetermined tap to determine the desired focus. -), the received ultrasound signal is subjected to known predetermined processing such as amplification, addition, detection, and TGC. Then, the signal subjected to the predetermined processing is supplied to the display circuit 8. The U(
The display circuit 8 receives the power and displays a tomographic image of the heart on the display 7. At this time, o d d from the control circuit 11
/e v e n signal, transmission timing signal, etc. are notified to the phase control circuit 9, and the o d d / e v
A signal for generating a predetermined ultrasonic wave is supplied to each element constituting the transducer 6 so as to perform en scanning, and detection of reflected waves and the like are controlled in a so-called synchronous manner.

Further, the scanning line number signal is notified to the display circuit 8, and control is performed so that a predetermined tomographic image of the heart or the like is displayed. A detailed explanation will be given below.

First, as mentioned above. dd/even scanning will be explained using FIG. 1. Cough o dd /
The e v en scan first includes, for example, approximately 9
A signal is sent to the element group (1) corresponding to the 0° angle to generate ultrasonic waves. Second, a signal is sent to the element group (2) in which an extra element piece is added in the scanning direction of the element group il+ to generate ultrasonic waves. Thirdly, the second
A signal is sent to the element group (3), which is obtained by cutting off one of the rearmost element pieces in the direction opposite to the scanning direction in the element group (2) used during the step , to generate ultrasonic waves.

Thereafter, the first to third steps are sequentially repeated.

1. Generating ultrasonic waves for the element group+11 or n) in which the element pieces are arranged within approximately 90 degrees as a group as described above;
? Since the numbers are supplied sequentially, the relevant o d d / e
・The minimum scanning step width obtained by νen scanning is half the minimum step width of each element piece, and the normal number of scanning lines can be obtained with the half circumference length of the cylindrical surface, which is limited to observing the heart from the ribs. Moreover, it is possible to satisfy the essential conditions for optimizing the vibration mode of each element piece and the grating lobe of the transmitted ultrasonic beam.

FIG. 2 shows a configuration diagram of the essential parts of the vibrator 6 in FIG. 1, and the element pieces constituting the vibrator 6 are arranged over half the circumference of the cylindrical surface. As described above, the element pieces are supplied with signals for emitting ultrasonic waves for each element group corresponding to approximately 90 degrees.

For example, S in the figure, 1. When a signal for emitting ultrasonic waves is supplied to a group of element pieces shown using P, 4. An ultrasonic wave having an envelope indicated by P in the figure is generated.Similarly, when a signal for emitting ultrasonic waves is supplied to a group of element pieces indicated by S0 and S4 in the figure, respectively. and P-4, respectively, are generated.Therefore, the already mentioned 0d d/e
If v a n scanning is performed sequentially over the range of +45° to -45° in FIG. It can be performed over a range of 45° to -45°. In other words, the sector scan is performed from +45° to -45° with a pitch that is twice the number of element pieces that make up the vibrator 6.
can be performed over a range of 90 degrees, and a cardiac sector scan can be performed with a normal number of scanning lines, and an ultrasonic beam with good time resolution and no grating lobes can be achieved. In addition, since the element pieces constituting the transducer 6 are arranged approximately half the circumference of the cylindrical surface, it is small enough to be inserted between the ribs to display a tomographic image of the heart, etc. In addition, since the emission center 0 of the ultrasonic waves is located near the body surface, a high field of view of approximately 90° is not obstructed by the ribs. Further, according to this configuration, the curvature is reduced and a high-quality image without multiple reflections can be obtained, as will be specifically shown below with numerical values.

For example, the center frequency is 3.5MH2, the aperture (l) is 10
mm, the number of scanning lines is approximately 110, and the grating probe is optimized on the condition that it hardly appears in the image. First, the radius a (curvature) of the vibrator is β=2πa/4・・・・・・・・・・・・・+11
From this, approximately 7 mm is obtained. Also, due to the condition that the grating probe does not appear in the image, the aperture was set to 40 to 7
It is desirable to divide the image by 0, and since the number of scanning lines is approximately 110, 48 to 64 divisions are appropriate.

The number of scanning lines n at this time is n=mx2 (m: number of divisions)...
・・・・・・It is calculated by (2), and it becomes about 96 to 128 trees. At this time, as already mentioned. d d / e v e
It uses n-scanning. With the configuration described above, the probe is small enough (about 7 mm radius) and wide field of view (9 mm) to be inserted between the ribs of an adult to display a tomographic image of the heart.
A small conchenox probe with a diameter of about 0°) is obtained.

In addition, when displaying tomographic images of children's hearts, etc., an even smaller device is required, but the diagnostic depth can be increased from 50 to 1
Since the depth can be as shallow as 00 mm and the center frequency can be set to 5 to 7 MH2, the aperture can be narrowed and the probe can be further miniaturized.

FIGS. 3 and 4 each show a method of manufacturing the vibrator 6,
The former shows one in which the front matching layer is used as a support for the vibrator 6, and the latter shows one in which the back matching layer is used as a support for the vibrator 6. This will be explained below.

FIG. 3(A) shows a plan view, and FIG. 3(B) shows a front view.

In the figure, the vibrator (for example, PZT) 6 is a flat plate, and is on both sides of the flat plate? 1i12 are provided in a circle. Relay electrodes Fi13-1 and 13-2 made of ceramic, glass, epoxy, or the like are bonded to both ends of the vibrator 6 with an adhesive layer (epoxy or the like) 14. Then, the vibrator 6 and the relay electrode plate 13-1, 13-2, which are bonded together by the adhesive layer 14, are shaped as shown from the surface using diagonal lines in FIG. An electrically conductive connecting film 15 is formed in a staggered pattern, and the connecting film 15 is formed on the entire back surface. The connection film 15 is formed by sputtering 1. This is done by vapor deposition, plating, etc.

FIG. 3(c) shows the state in which the front matching layer N1B and the front matching layer 19 are formed.

In the figure, the Teflon frame 16 is connected to the relay electrode 13-1.1 as shown.
3-2, and in order to form a matching layer 17 in the middle, a matching material made of epoxy mixed with metal powder and adjusted to an appropriate acoustic impedance is poured. After the epoxy is cured, it is cut and polished at a position indicated by a dotted line in the figure, that is, at a distance d corresponding to 1/4 of the wavelength λ of the ultrasonic wave to be generated. This results in
A front matching layer 18 is produced. Similarly, back matching layer 1
9 is generated on the back surface of the vibrator 6.

FIG. 3(d) shows how the vibrator 6 is separated into each element (element piece).

In the figure, the generated front matching layer 1B of the vibrator 6 is fixed to a workbench using wax 20. Then, a cut is made from the upper part of the figure, that is, from the side of the back matching layer 19 to the position indicated by the dotted line on the front matching layer 18 using a dike/manufacturer. The incisions are made at the positions indicated by the arrows in FIG. 3(a), and 1) IEI1g15 is also separated in a staggered manner. As a result, lead wires are connected to the staggered layered positions and connected to the scan selection circuit 10 in FIG. 1, as described above.
dd/even scans can be performed.

FIG. 3(E) shows the completed probe housed in the support mold 24. The probe is constructed by placing the vibrator 6 produced in FIG.
It is bent along the curve, sandwiched between separately prepared sound absorbers 21 via adhesive 23, and cured. The adhesive 23 is reduced so that it does not get between the elements 6
In the above manufacturing process, the front matching layer 18 left uncut in the operation shown in FIG. 3(D) is arranged so as to be located on the outer surface of the cylindrical surface as shown in FIG. Each element constituting the front matching +! 11B, it does not fall apart and has high workability.

FIG. 4(a) shows how the vibrator 6 is separated into each element (element piece), and corresponds to the one shown in FIG. 3(d), and in this manufacturing example, wax 20 is used to The difference is that it is fixed to the workbench.

The rest is the same as in the case of FIG. 3(d).

Figure 4 (b) shows the completed probe;
C) is a sectional view taken along line 8-8 of FIG. 4(B). The probe includes each element piece constituting the vibrator 6 generated as shown in FIG. Solder by bending it according to the shape. The soldering is performed between the solder-plated parts of the relay electrode plate 13-1 and 13-2 of the vibrator 6 and the electrode pattern placed on the cylindrical support frame 22 that holds the vibrator 6. 22-1
The middle m electrode plate 13-1 is held in a state of defeat.
, l3-2 and the support frame 22 are heated to a temperature higher than the melting temperature of the solder. By the soldering,
The vibrator 6 is fixed to a support frame 22. Next, a sound absorber 21 made of a mixture of epoxy, metal oxide, etc. is poured and hardened. At this time, before pouring the sound absorber 21, apply adhesive 23 such as epoxy to prevent the sound absorber 21 from leaking.
It is best to seal it using As above, Figure 4 (a)
Since the back matching layer 19 left uncut in the process is arranged so as to be located on the inner surface as shown in FIG. 1
9 and does not fall apart, making it easy to work with.

The probes shown in FIGS. 3 (e) and 4 (b) obtained from the above results are made into practical probes by bonding a lens 25 for focusing the ultrasonic beam in the so-called thickness direction perpendicular to the scanning direction. Become. At this time, it is desirable to apply the adhesive 23.23-1 as thinly as possible. In particular, in the case shown in FIG. 4(b), the adhesive 23-1 is prevented from entering between the elements.

FIG. 5 shows the characteristics of a probe configured so that an air gap exists without using a sound absorber 21 or the like to fill the area around the vibrator 6. By adopting this configuration, Interference between the elements constituting the vibrator 6, particularly interference due to the influence of lateral vibrations of adjacent elements, is reduced. For this reason, the directivity characteristic when the space between the vibrators 6 is conventionally filled with the sound absorber 21 is as shown by the solid line in FIG. However, in this embodiment, an air gap is provided to acoustically isolate each element constituting the vibrator 6. Therefore, as shown by the dotted line in FIG. 5, the side lobes do not occur, so a smooth continuous curve is obtained, and the side lobes are
High-resolution images can be obtained using ultrasound beams that are not located in the lobes.

〔Effect of the invention〕

As explained above, according to the present invention, when displaying a tomographic image of the heart, etc. on a display using ultrasound waves, the transducer that emits and detects the ultrasound waves is arranged over approximately half the circumference of the cylindrical surface. Therefore, the radiation center of the ultrasonic waves emitted from the transducer is lowered and the transducer is miniaturized.
It is possible to obtain high-quality tomographic images of the heart that have a wide field of view and do not cause multiple reflections.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of one embodiment of the present invention, FIG. 2 is a configuration diagram of main parts of the first illustrated vibrator, and FIGS. 3 and 4 are explanations explaining the manufacturing method of the vibrator illustrated in FIG. 1. 5 is a configuration diagram of other essential parts of the transducer shown in FIG. 1, FIG. 6 is an explanatory diagram illustrating the operation of a conventional convex type cardiac ultrasound diagnostic apparatus, and FIGS. 7 to 9 are Fig. 6 is an explanatory diagram that captures the operation of the configuration shown in the diagram, Fig. 10 is an explanatory diagram that explains the operation of another conventional convex type cardiac ultrasound diagnostic device, and Fig. Ti is an explanatory diagram that captures the operation of the transducer shown in Fig. 1. Explanatory drawings, Fig. 12 and Fig. 1
FIG. 3 is an explanatory diagram illustrating the operation of a conventional convex-type ultrasound diagnostic apparatus for the abdomen. In the figure, 6 is a vibrator, 7 is a display, 8 is a display circuit,
9 is a phase control circuit, 9-1.9-3 is a driver, 9-2
．． 9-4 is a receiver, 9-5 is a switch, IO is a scanning selection circuit, 11 is a control circuit, 12 is an electrode, 13-1.13
-2 is a relay electrode plate, 14 is an adhesive layer, 15 is a connection l19.
16 is a Teflon frame, 17 is a matching layer, 1st is a front matching layer,
19 is a back matching layer, 20 is wax, 21 is a sound absorber, 2
2 is a support frame, 22-1 is an electrode pattern, 23.23-1
24 represents an adhesive, 24 represents a support type, and 25 represents a lens.

Claims (1)

[Claims] In a convex-type ultrasonic diagnostic device that displays an image on a display using a convex-type probe in which a transducer is arranged on the outer surface of a cylindrical surface, each element piece constituting the transducer is placed on the outer surface of the cylindrical surface approximately half a circumference. The probe is placed at approximately 90° with the center of the cylindrical surface as the scanning center.
The element pieces within the range of are selected as one group, and od
and a selection circuit that sequentially selects predetermined element pieces to perform d/even scanning and supplies power for emitting ultrasonic waves, and is configured to obtain a scanning angle of approximately 90°. Convex type ultrasound diagnostic device.