JPS6090542A - Sensor for ultrasonic photographing 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 [Field of Application of the Invention] The present invention relates to a sensor for an ultrasonic imaging device, and particularly to a sensor for an ultrasonic imaging device (hereinafter simply referred to as “sensor ).

[Background of the invention]

In recent years, general-purpose ultrasound imaging devices have become widespread, making it possible to diagnose internal organs non-invasively in real time, but there is a strong demand for ultrasound tissue differentiation using even higher resolution images. . For this purpose, the use of direct frequency ultrasound imaging is considered to be effective.

By the way, in conventional ultrasonic imaging, images are generally taken by transmitting and receiving ultrasonic waves through a sensor that is pressed against the body surface or inserted into a body cavity. FIG. 1 shows an example of a sensor for insertion into a body cavity. In the figure, ■
is a piezoelectric element, 2 is a back sound absorbing material (acoustic backing material), 3 is
Reference numeral 4 indicates a holding member for the piezoelectric element 1 and the backside sound absorbing material 2, 4 a covering case for the holding member 3, and 5 a mechanical unit for performing rotational scanning. The outer diameter of the covering case 4 is approximately 15 mm.
It is mm.

The sensor configured as described above can obtain a radial mode of a cross section perpendicular to the rotation axis of the holding member 3 by inserting the sensor into the body cavity of the subject and rotating the holding member 3.

However, when using such a sensor, it is difficult to obtain a high-resolution image of a deep part of a subject's body by high-frequency ultrasonic imaging. This is because high-frequency ultrasound has large attenuation. To deal with this, the present invention considers a method in which the sensor is significantly miniaturized and inserted into the tissue of the subject like a forceps.

On the other hand, as is well known, in an ultrasonic imaging device, as the resolution increases, the field of view becomes smaller. For example, the ultrasound frequency in a general-purpose linear electronic scanning ultrasound imaging device is 3.5 to 5.0 Ml-1z, and the field of view is 1
00 × 10 (lnm, resolution is about 2 mm (6 dB beam width). On the other hand, the ultrasonic frequency is 100 M lnm.
(In a high-resolution image with z, the field of view is l × 1 mn
+, the resolution is about 10 μm (-6 dB beam width).

Therefore, it is theoretically difficult to simultaneously obtain a wide field of view and high resolution using the same sensor. To deal with this, it is conceivable to capture the general-purpose image and the high-resolution image using separate ultrasound imaging systems, and to associate them with each other.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide a sensor that enables high-resolution imaging of deep parts of a subject's body, which has been impossible with conventional ultrasonic imaging devices. It is in.

[Summary of the invention]

The above-mentioned object of the present invention is to provide a sensor having piezoelectric conversion means for transmitting and receiving ultrasonic waves and a holding means for the piezoelectric conversion means, in which the cross-sectional area of the holding means is made small enough to be press-fitted into a subject, and the tip of the holding means is made small enough to be press fit into a subject. This is achieved by a sensor characterized in that the portion has a sharp shape.

[Embodiments of the invention]

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

FIG. 2 is a sectional view of a sensor (hereinafter referred to as a "needle sensor") that does not show one embodiment of the present invention. In Fig. 2, symbols 1 to 3 indicate the same components as shown in Fig. 1, 4A indicates the covering case of the holding part 3, and 5A indicates the mechanical part that performs rotational scanning and translational movement. There is. Note that the needle-like sensor shown in this example has an extremely compact structure with an outer diameter of approximately 1 mm at the insertion portion into the subject, and thus can be inserted into tissues other than the body cavity of the subject. It has the following characteristics.

As mentioned above, the covering case 4A of this embodiment not only has an extremely thin outer diameter of about 1 m+n, but also has a sharp tip (left side in the figure). It can be easily inserted into the tissue of a subject. The covering case 4A is made of stainless steel, hard plastic, etc., and the - side is marked with the markings shown in Figure 3 (
As shown in FIG. 2 (A-A sectional view), a sulin 1-4B is provided. This sulin 1-4B is for transmitting high-frequency ultrasonic waves emitted from the piezoelectric element 1 into the surrounding tissue of the subject without attenuating them.

FIG. 4 is a sectional view showing details of the mechanism section 5A. In the figure, 6 is a spring, 7 is a rotation translation converter, 8 is a motor, and 9 is a bearing. The spring 6 has the function of pressing the holding member 3 against the rotation translation converter 7 via the bearing 9. The rotation-translation converter 7 has an oblique plane obtained by cutting a cylinder diagonally, and the motor 8
It has a function of reciprocating the holding member 3 in the direction of arrow B in synchronization with the rotation of.

The needle-like sensor of this embodiment configured as described above is inserted into a subject while cutting the tissue thereof, like a hypodermic needle, and
When it reaches the target area, it is set there. Therefore, ultrasonic imaging is performed while rotating and reciprocating as described above.

FIG. 5 is a block diagram of a composite ultrasonic imaging device using the needle-like sensor described above. In the figure, 9 is the main body of the general-purpose ultrasound imaging device, 10 is the sensor of the device, 11 is the display section, 1
Reference numeral 2 indicates a main body of the needle-like sensor ultrasonic imaging device which performs transmission/reception of the needle-like sensor and control of the mechanism section 5A, and 13 indicates a sword-like sensor display section.

The operation of the above compound ultrasonic imaging device is shown in Fig. 6 (A) below.
This will be explained using (C).

FIG. 6(A) is a cross-sectional view of the subject, where 14 indicates the subject's tissue and 15 indicates the field of view obtained by a general-purpose ultrasonic imaging device. FIG. 6(B) is a display image of a general-purpose ultrasound device,
I6 indicates the field of view of the needle sensor.

Moreover, FIG. 6(C) is a display image of the needle-like sensor ultrasonic imaging device.

In this device, the sixth
A wide-field image as shown in Figure (B) is obtained, a needle-like sensor is inserted into the subject while observing the image, and the position of its tip is monitored. Once the position is determined, the mechanism section 5A translates the holding member 3 to obtain the narrow-field image 16, and displays the display section 13.
to be displayed. As mentioned above, the resolution of the display section 11 of the general-purpose device and the display section 13 of the needle-shaped sensor device is 2.
+nm, 10 μm.

FIG. 7 is a sectional view of a needle-like sensor showing another embodiment of the present invention. The difference between the sensor shown in this example and the sensor shown in FIG. 2 is that the sensor shown in FIG. 2 has a covering case, whereas the sensor shown in this example has a covering case. The point is that it does not have. The sensor of this embodiment operates similarly to the sensor shown in FIG. 2 described above to obtain a tomographic image based on translational movement, a so-called B-mode tomographic image.

In each of the above embodiments, a case has been described in which a B-mode tomographic image is obtained by the translational movement of the needle sensor, but the present invention is not limited to this. For example, a three-dimensional tomographic image can be obtained by combining the translational movement with a rotational movement. It goes without saying that by time-gating the so-called A mode signal in the depth direction of the ultrasonic beam, it is also possible to obtain the C mode of the cylindrical surface as shown in FIG. In FIGS. 7 and 8, solid lines indicate the direction of the ultrasonic beam, and broken lines indicate the direction of movement thereof.

It goes without saying that it is also possible to perform tissue discrimination by performing various signal processing from the A-mode signal without moving the needle sensor. It goes without saying that it is also possible to measure the Doppler blood flow velocity from the A-mode signal and use it for diagnosis.

〔Effect of the invention〕

As described above, according to the present invention, in a sensor having a piezoelectric conversion means for transmitting and receiving ultrasonic waves and a holding means for the piezoelectric conversion means, the cross-sectional area of the holding means is made small enough to be press-fitted into a subject. In addition, since the distal end portion is configured to have a sharp shape, it has the remarkable effect of enabling high-resolution imaging of deep parts within the body of the subject, which was impossible with conventional ultrasonic imaging devices.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a conventional sensor for insertion into a body cavity, FIG. 2 is a cross-sectional view showing an embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2, and FIG. 5 is a block diagram of the composite ultrasonic imaging device using the needle-like sensor of the embodiment, FIGS. 6(A) to 6(C) are diagrams explaining its operation, and FIG. FIG. 7 is a sectional view showing another embodiment of the invention, and FIG. 8 is a diagram showing another example of operation of the invention. 1: Piezoelectric element, 2: Back sound absorbing material, 3: Desired member, 4A:
Covering case, 5A: Mechanism section, 6: Spring, 7: Rotation-translation converter, 8: Motor, 9: Bearing, IO = General-purpose ultrasound imaging device sensor, 11° 13: Display section, 12:
Needle-shaped sensor ultrasonic imaging device. Figure 1 Figure 2 Figure 3 Figure 4 Day 4 Figure A Figure 6 (5) (B) 0 Figure 7

Claims (3)

[Claims] (1) In a sensor for an ultrasonic imaging device having a piezoelectric transducer for transmitting and receiving ultrasonic waves and a holding means for the piezoelectric transducing means, the cross-sectional area of the holding means is made small enough to be press-fitted into a subject; A sensor for an ultrasonic imaging device characterized by having a tip portion grown into a sharp shape (1). (2) In a sensor for an ultrasonic imaging device having a piezoelectric conversion means for transmitting and receiving ultrasonic waves fa, a holding means for the 5λ piezoelectric conversion means, and a covering means for the holding means, the cross-sectional area of the covering means can be press-fitted into the subject. 1. A sensor for an ultrasonic imaging device, characterized in that the sensor is relatively small and has a sharp tip. (3) The sensor for an ultrasonic imaging device according to claim 1 or 2, wherein the holding means is configured to move in translation in the direction of the rotation axis of the piezoelectric conversion means.