JPS58127642A - Ultrasonic probe - 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] As one of the diagnostic methods using ultrasound, there is a diagnostic method called B mode, which is a pulse reflection method in which all ultrasound pulses are emitted and the internal tissues of the human body are investigated from the echoes. . This is a method of obtaining tomographic images of the human body, and is currently being actively developed as a device that can observe the movements of the abdomen or fetus in real time.

FIG. 1 shows the configuration of an ultrasonic diagnostic apparatus. A pulse generator 2 generates a transmission pulse whose amplitude and phase are controlled by a control signal from a control circuit 1, and a probe 3 consisting of a plurality of piezoelectric vibrating elements (for example, a plurality of barium titanate) is generated.
to drive. As a result, ultrasonic waves are irradiated in a specific direction of the living body, and reflected signals generated due to acoustic impedance mismatch are received by all the vibrating elements of the probe. This received signal is applied to a phaser 5 via a preamplifier 4, and a control circuit obtains a phased and added signal so that the signals are in the same phase. Since the wave frequency component of this addition signal is 11-modulated, an envelope signal is obtained by the detector 6, which becomes the luminance signal (Z signal) of the display. -Since the direction of the ultrasonic beam is determined by the Manjumisaki circuit 1, the X-Y direction is determined by the control circuit 1.
Obtain the signal and input it to a display such as CRT7.

In this way, an ultrasound image of a living organ can be displayed on the display.

Ultrasonic waves can be classified into sector type and linear type depending on the method of transmitting the ultrasonic waves, but there is not much difference in the overall configuration between the two types.

Fig. 2 shows an outline of a method of mechanically scanning the probe 3. Fig. 2(a) shows sector scanning, in which the probe 3 moves along a predetermined arc XC and performs fan-shaped scanning. will be done. In linear scanning, as shown in FIG. 2(b), when the position of the probe 3 rotates to the full center of the focal point of the paraboloid sI, c, the ultrasonic beam reflected by the mirror moves in parallel.

In both cases, the probe 3 repeats pulse emission, echo reception, pulse emission, and echo reception while rotating.

A pulse is emitted in a certain direction, and by the time an echo is returned from that direction, the position of the probe 3 has already shifted. However, since the directivity of the probe 3 is wide, even if an echo is returned from a slightly oblique direction, it can be received.

The probe 3 used in such a device is equipped with a probe 3 so that the emitted ultrasonic beam can be focused in a specific direction.
An acoustic lens is attached to the front of the device.

FIG. 3 is a schematic diagram showing how the ultrasonic beam 9 is focused depending on the shape of the acoustic lens 8.

As a simple shape, the piezoelectric vibrating element 10 is square, and the sound wave emitting surface of the piezoelectric vibrating element 10 has a shape as shown in FIG. 3(a).
When the semicylindrical 1f# lens 8 is attached, the emitted ultrasonic beam 9 is focused in only one direction and is focused in a slit shape at the focusing surface 1i'A, as shown in Fig. 3(b).
It is clear that when a spherical acoustic lens 8' is attached with gold, the ultrasonic beam is focused at one point FB.

In this way, all of the acoustic lenses 8 and 8' having different shapes are attached to the piezoelectric vibrator 10, respectively.
) and (b), each piezoelectric vibrator 10 can emit an ultrasonic beam 9 in the direction of the arrow.

Therefore, when trying to obtain information about the surroundings surrounding the piezoelectric vibrator 10, it is necessary to rotate the piezoelectric vibrator 10 by a quarter of a turn and completely synthesize the information from each piezoelectric vibrator 10. Obtainable.

The present invention enables ultrasonic focusing to be easily carried out in a device whose purpose is to emit the entire ultrasonic beam while rotating the piezoelectric vibrator and obtain information about the surroundings using reflected ultrasonic waves. This paper proposes a piezoelectric vibrator structure and a manufacturing method characterized by the following features.

FIG. 5 shows a jig for making a spherical acoustic lens.

Figure 45(a) shows the two jigs 11 that have a concave hole inside and the apex of the concave hole penetrates in a cylindrical shape.
As shown in , they are fixed so that they are facing each other δ. Next, Figure 5(b)
As shown in the figure, a square pillar is used as the core 12 and inserted into the jig. Next, jig 11 and core 12
As shown in FIG. 5(C), in the space provided between the
Pour and harden.

After the silicone rubber 13 has sufficiently hardened, the jig 11 and the core 1
When 2 is disassembled and taken out on silicone rubber 13', the 5th
The shape will be as shown in figure (d). If this is all molded, the 5th
A spherical lens 14 made of silicone rubber as shown in Figure (e) can be made. The inside of this spherical lens 14 has a plane of 411M.

, When piezoelectric vibrators 15 are adhered to each of these flat parts as shown in FIG. 6, a spherical lens is attached to the front surface of each piezoelectric vibrator 15, and the piezoelectric vibrator 15
An ultrasonic probe can be realized in which the ultrasonic waves emitted from the probe can be focused on one point at a predetermined position in front of the probe. Note that FIGS. 6(a) and 6(b) are a sectional view and a plan view, respectively.

FIG. 7 shows the mounted shape of the ultrasonic probe completed through the steps described above.

FIGS. 7(a) and 7(b) are a VIfr side view and a plan view, respectively. In the figure, a spherical lens 14 with a piezoelectric vibrator 15 mounted inside a case 20 is pressed down from both ends with a holding fitting 16. A rotating shaft 17 passes through the center of the presser metal fitting 16, and its tip is fixed by a bearing 19, and the other end is supported by a bearing 18.

In such a configuration, the piezoelectric element 15 also rotates when the rotating shaft 17' rotates once.

Is the case 20 made of a material that does not cause any hindrance to the passage of ultrasonic waves, such as mylar? It may be made by molding, and the ultrasonic propagation medium 21? ! −
The ultrasonic waves emitted from the piezoelectric element by filling the
It can be propagated outside the case without loss.

Although the jig 11 has been described above as a perfect spherical surface, the degree of curvature may be adjusted in order to adjust the convergence point 1f.

Regardless of the method, in the ultrasonic probe produced by the above method, a spherical acoustic lens is always attached to the front surface of the piezoelectric vibrator, and the ultrasonic beam can be focused on a single point.

'Furthermore, for convenience of explanation, the cross section of the core 12 has been described as being square, but it does not necessarily have to be a square, and even if it is a polygon such as a triangle, pentagon, hexagon, etc. Of course, the structure always includes a spherical acoustic lens.

In addition, although plate-shaped piezoelectric elements have been described, array-shaped and two-dimensional
The same effect can be obtained with dimensionally arranged piezoelectric elements.

One possible use of the ultrasonic probe with the structure described above is as an endoscope.

FIG. 8 shows an example of an endoscope that combines an ultrasound probe and a solid-state imaging device according to the present invention. A solid-state imaging device 22 configured to form an observation image on the surface of an all-solid-state imaging device 22 is equipped at the tip with an optical lens 24 and a refractive liquid 25, and the configuration described in FIG. 7 is installed at the rear thereof. Place the ultrasonic probe section. This ultrasonic probe section is configured to rotate at a constant rate in a predetermined direction by a scanning drive section 23.

Using an endoscope with the above configuration has the advantage that the morphology of the surface of an organ can be observed optically using a solid-state image pickup tube, while the inside can be observed using ultrasound images, further improving the reliability of diagnosis. do.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the ultrasonic diagnostic equipment, Section 2 is a diagram explaining the scanning method of the ultrasound probe, and Figure 3 is a complete explanation of the focusing state of ultrasound due to the different shapes of the f'1ll lens. Figure 4 is a diagram explaining the state in which multiple focused ultrasonic beams are emitted, Figure 5 is a diagram explaining the entire manufacturing method of a spherical acoustic lens, and Figure 6 is a diagram showing how a piezoelectric element is attached to a spherical acoustic lens. Figure 7 shows the endoscope with a spherical acoustic lens and an ultrasonic probe mounted on the endoscope. Figure 8 shows the endoscope in which the ultrasonic probe and solid-state image sensor are fully assembled. FIG. Agent Patent Attorney Toshi Usuda 1 Country%Z Figure (廄) Figure 3 (Illusion (b) Do' ＼ Figure 4 (^) 0 〒 4 Figure (shi) 'f] 5 (ku) <b) 11' no 1? Fig. 5 15 6 (θ5)
(Puotsu) 5

Claims (1)

[Claims] 1. A plurality of ultrasonic radiation surfaces are arranged within a two-dimensional curved surface,
An ultrasonic probe characterized in that the radiation surface moves while directly facing the curved surface. 2. Claim 1. 1j An ultrasonic probe having a feature of holding the self-contained probe in a liquid container.