JPH04319662A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To obtain a compact ultrasonic probe capable of performing two-dimensional scanning while keeping high sensitivity, having high durability and capable of obtaining three-dimensional image data in relatively uniform density. CONSTITUTION:An ultrasonic probe has a vibrator driving mechanism constituted of a first motor consisting of stators 11a, 11b for shaking a vibrator support 5 around a first shaft 14 and a rotor 12, a second motor consisting of stators 13a, 13b for shaking the vibrator support 5 around a second shaft 12 and a rotor 14 and the rotor fixing sphere 15 supporting the rotors 12, 14.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an ultrasonic probe used in an ultrasonic imaging device such as an ultrasonic diagnostic device or an ultrasonic flaw detection device. This invention relates to an ultrasonic probe that can scan

0002

[Prior Art] Ultrasonic imaging devices such as ultrasonic diagnostic devices and ultrasonic flaw detection devices use an ultrasonic probe to scan an object with an ultrasonic beam, thereby creating a cross-sectional image that shows the internal structure of the object. I'm getting a statue.

[0003] Scanning methods using ultrasonic beams include electronic scanning, which uses an array probe in which a large number of piezoelectric transducers are arranged, and drives each transducer with an electrical delay, and mechanical scanning, which uses an array probe in which a large number of piezoelectric transducers are arranged. There is also mechanical scanning, which scans by moving. Either method usually yields only one tomographic plane. Therefore, in recent years, attempts have been made to simultaneously obtain tomographic images on a large number of tomographic planes or to obtain two-dimensional tomographic information.

[0004] When attempting to obtain image information on two or more different tomographic planes using an ultrasound imaging device, two or more ultrasound probes that can obtain tomographic images by scanning with ultrasound beams are installed. , each probe needs to be configured to form one tomographic image. However, when a plurality of ultrasonic probes are arranged for one subject, the axes of the respective tomographic planes are inevitably shifted, causing a problem that the same part or adjacent parts cannot be observed.

[0005] When trying to obtain tomographic images on multiple coaxial tomographic planes using an array probe, a two-dimensional array probe is used, or a single array probe (linear scanning array,
(e.g., electronic sector scanning arrays and convex probes). However, two-dimensional array probes have not yet been put into practical use because of the problems of a decrease in sensitivity (S/N) due to the extremely large total number of array elements and a decrease in the size of each probe. In a conventional method of mechanically rotating an array probe, it is necessary to rotate a cable or a flexible printed board connected to a plurality of transducers at the same time as the probe. Therefore, this method has many technical difficulties in terms of durability and the like, and there is also the problem that the density of tomographic image information decreases as the distance from the rotation axis increases.

[0006]

[Problems to be Solved by the Invention] As mentioned above, in the conventional technology, when trying to simultaneously acquire tomographic image information on a large number of tomographic planes or to acquire three-dimensional tomographic image information,
It is necessary to perform two-dimensional scanning by using a two-dimensional array probe or mechanically rotating the array probe, but the former requires an extremely large number of elements and the size of each element. There is a problem of decreased sensitivity due to the smaller size.
The latter has problems with durability because the cable and flexible printed board are rotated at the same time, and the density of tomographic image information decreases as the distance from the rotation axis increases.

The present invention has been made in view of these conventional problems, and is capable of two-dimensional scanning while maintaining high sensitivity, has high durability, and can perform three-dimensional scanning with more uniform density. The purpose of the present invention is to provide an ultrasonic probe that can obtain accurate image information.

[0008]

[Means for Solving the Problems] In order to solve the above problems, the ultrasonic probe of the present invention swings a piezoelectric vibrator that transmits and receives ultrasonic waves or a support that supports the same about a first axis. The piezoelectric vibrator has a first motor that causes dynamic movement, and a second motor that causes the piezoelectric vibrator or support to swing about a second axis that is substantially orthogonal to the first axis. The first and second motors each include a stator and a rotor, each stator being disposed outside a spherical surface, and each rotor being disposed inside the spherical surface and fixed to each other. The first and second axes pass through the center of this spherical surface. According to another aspect, the second motor is configured to rotate in a plane passing through the first and second axes.

[0009]

[Operation] When the piezoelectric vibrator is oscillated about the first axis by the first motor, the ultrasonic beam emitted from the vibrator performs so-called mechanical sector scanning within a certain tomographic plane. Further, when the piezoelectric vibrator is oscillated about the second axis by the second motor, the tomographic plane itself on which sector scanning is performed is oscillated in a direction perpendicular to the tomographic plane. Furthermore, when the second motor rotates the first axis within a plane passing through the first and second axes, the tomographic plane itself on which sector scanning is performed rotates.

[0010] Therefore, by combining the rotations of the first and second motors, two-dimensional scanning by the ultrasonic beam is performed. In this case, the transducer can be a single transducer or an annular array transducer, so there is no decrease in sensitivity as in methods using a two-dimensional array probe, and there is no reduction in sensitivity as in methods using a two-dimensional array probe. This also avoids the problem of a decrease in the density of tomographic information in areas away from the rotation axis.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of an ultrasound probe according to an embodiment of the present invention.

In FIG. 1, a liquid tank 3 covered with an acoustic window 2 is placed at the tip of a cylindrical housing 1, and a piezoelectric vibrator 4 is placed within this liquid tank 3. Piezoelectric vibrator 4
In this case, a single vibrator with fixed focus or an annular array vibrator with dynamic focus is used.

The vibrator 4 is supported at the upper end of a vibrator support 5 of a pipe. The support body 5 is connected to a vibrator drive mechanism 6 provided within the housing 1. This transducer drive mechanism 6 is for mechanically moving the transducer 4 to realize two-dimensional scanning. A cable 7 for transmitting drive pulses for the vibrator 4 and reception signals from the vibrator 4 passes through the vibrator drive mechanism 6 and the support body 5 .

FIGS. 2 and 3 are a sectional view and a plan view showing the schematic structure of the vibrator drive mechanism 6. FIG. This vibrator drive mechanism 6 basically includes a first motor consisting of stators 11a, 11b and a rotor 12, and stators 13a, 1
3b and a rotor 14, and a rotor fixing ball 15 formed hollow.

Stators 11a, 11b, 13a, 13b
are arranged outside the rotor fixing ball 15 via bearings 16a to 16d provided at four locations in this example, and are fixed inside the casing 1 in FIG. 1 by fixing means (not shown). Ball bearings are generally used as the bearings 16a to 16d, but they may be of any type, and may be of any type that uses high pressure air or magnetism.

On the other hand, the rotors 12 and 14 are fixed rotor balls 1.
5 and is fixed to the rotor fixing ball 15. The rotors 12 and 14 are formed into rod shapes and are joined together at the center of a rotor fixing ball 15 so as to form a cross shape as a whole. The vibrator support 5 is inserted into the rotor fixing ball 15 through an insertion hole formed at the top of the rotor fixing ball 15, and its lower end is fixed to the joint of the rotors 12 and 14. Note that the cable 7 in FIG. 1 is omitted in FIGS. 2 and 3.

The rotor 12 has both ends facing the stators 11a and 11b through the rotor fixing balls 15, and has the rotor 14 of the second motor as a first shaft.
It can swing around the axis. On the other hand, the rotor 14 also connects the stators 13a and 13 via the rotor fixed ball 15.
b, the rotor 13 of the first motor is used as a second axis, and it can swing around this second axis.

[0018] When electric motors are used as the first and second motors, one of the stators 11a, 11b and rotor 12 constituting the first motor is a magnet, and the other is a coil. Similarly, one of the stators 13a, 13b and rotor 14 that constitute the second motor is a magnet, and the other is a coil. 1st
The second motor is not limited to an electric motor, but may also be an ultrasonic motor, for example.

Next, the operation of the ultrasonic probe of this embodiment will be explained. When the first motor composed of the stators 11a and 11b and the rotor 12 is energized, the rotor 12 swings about the rotor 14 within a certain angular range covered by the stators 11a and 11b. As a result, the vibrator 4
moves in the direction of arrow A together with the vibrator support 5, and mechanical sector scanning is performed within a certain tomographic plane.

By controlling the power supply to the first motor, it is possible to stop the rotor 12 at a predetermined angular position within the range covered by the stators 11a and 11b. When the second motor composed of the stators 13a and 13b and the rotor 14 is energized with the rotor 12 stopped and fixed in this manner, the rotor 14 swings around the rotor 12. As a result, the vibrator 4 swings together with the vibrator support 5 in a direction perpendicular to arrow A, that is, in a direction perpendicular to the tomographic plane. Thereby, a tomographic plane for mechanical sector scanning can be selected.

Further, at this time, the rotor 12 is replaced by the rotor 14.
If the vibrator support 5 is rocked slowly enough relative to the rocking motion of the rotor 14, the vibrator support 5 can swing the rocking surface of the rotor 14 in a direction perpendicular to the rocking surface of the rotor 14.

[0022] In this way, the first and second motors can perform mechanical sector scanning within a plurality of desired tomographic planes, thereby making it possible to realize two-dimensional scanning.

[0023] In this embodiment, the rotors 12 and 14 are fixed within the rotor fixing ball 15 and have the same diameter (length), but it is only necessary that their rotation centers are the same; It doesn't have to be.

FIGS. 4 and 5 are a side view and a plan view showing a schematic configuration of a vibrator drive mechanism according to another embodiment of the present invention. In this embodiment, stators 13a, 13b
The second motor consisting of the rotor 14 and the rotor 14 is similar to the previous embodiment, except that the first motor is different. The first motor in this embodiment includes stators 21a and 21b and a rotor 22, which have the same shape as the second motor.

That is, in this embodiment, the first and second
Both of the motors are configured to be able to function as a motor for swinging the vibrator 4 within the fault plane and as a motor for stopping and fixing the axis of this swing movement. Therefore, the stators 21a, 21b, 13 of each motor
a and 13b have the shapes shown in the figure so as to cover an area greater than the minimum area necessary for the movement of the rotors 22 and 14.

With such a configuration, according to this embodiment, the oscillating motion of the vibrator can be performed in directions perpendicular to each other, thereby making it possible to take the fault plane in two directions perpendicular to each other. , it becomes possible to swing each tomographic plane in a direction perpendicular to each other or to fix it at an arbitrary position.

FIGS. 6 and 7 are a side view and a plan view showing a schematic configuration of a vibrator drive mechanism according to still another embodiment of the present invention. In this embodiment, a rod-shaped stator 31
and a rotor 32 having a spherical shape with the top and bottom removed, constitute a first motor, and a rod-shaped stator 33 and an annular rotor 34 constitute a second motor. Rotor 32,3
4 are joined together at the center of the rotor fixed ball 15 to form a cross shape, and the vibrator support 5 is integrated with the rotor fixed ball 15.
The lower end thereof is fixed to the joint of the rotors 32 and 34.

When the first motor composed of the stator 31 and the rotor 32 is energized, the rotor 32 swings about the rotor 34, which is the first shaft. As a result, the vibrator moves together with the vibrator support 5 to perform mechanical sector scanning.

On the other hand, when the second motor composed of the stator 33 and the rotor 34 is energized, the rotor 34 rotates along the circumferential direction of the stator 33. That is, the rotor 34 has a first axis, which is the rotor 34, and a second axis, which is perpendicular to the first axis.
The rotor 32 rotates in a plane passing through the rotor 32, which is the axis of the rotor 32.

Here, by controlling the power supply to the second motor, the rotor 34 is fixed at an appropriate position inside the stator 33, so that the rotor 34 of the first motor is fixed.
The axes of the two rocking movement surfaces can be fixed at arbitrary positions. Therefore, according to this embodiment, the vibrator support 5 can be rocked in any plane that passes through the center of the rotor fixed sphere 15 and includes an axis perpendicular to the plane of the paper of FIG. Thereby, a tomographic plane for mechanical sector scanning can be selected.

FIG. 8 is a sectional view showing a schematic configuration of an ultrasonic probe according to another embodiment of the present invention, in which a cylindrical housing 1 and a liquid tank 3 surrounded by an acoustic window 2 are connected. A partition wall 8 is arranged in between,
A ball-shaped joint portion 9 is provided at the center of the partition wall 8 . The vibrator support 5 passes through this joint portion 9. An elastic member 1 for relaying is provided at the lower part of the partition wall 8 of the vibrator support 5.
0 is provided, and the support body 5 can be bent freely at the position of the elastic member 10.

According to this embodiment, the vibrator drive mechanism 6 is not directly exposed to the liquid tank 3, improving reliability and durability. Further, by adjusting the lengths of the portions of the vibrator support 5 on both sides of the elastic member 10, the swing angle of the vibrator 4 can be adjusted.

[0033]

According to the present invention, mechanical sector scanning can be performed on any plurality of tomographic planes using a single vibrator or an annular array vibrator. Therefore, there is a decrease in sensitivity as when using a two-dimensional array probe, a decrease in the density of tomographic information in the peripheral area as seen in the method of mechanically rotating the array probe, and At the same time, two-dimensional scanning by ultrasonic beams can be realized without problems of durability caused by rotating cables and the like.

Furthermore, since the ultrasonic probe of the present invention uses a motor composed of a stator and a rotor arranged inside and outside the spherical surface as the transducer drive mechanism, the entire probe can be constructed compactly.

[Brief explanation of drawings]

[Fig. 1] A cross-sectional view showing a schematic configuration of an ultrasound probe according to an embodiment of the present invention.

[Figure 2] Schematic sectional view of the vibrator drive mechanism in the same example

[Figure 3] Schematic plan view of the vibrator drive mechanism in the same example

FIG. 4 A schematic side view of a vibrator drive mechanism in another embodiment of the present invention.

[Figure 5] Schematic plan view of the vibrator drive mechanism in the same example

FIG. 6 A schematic side view of a vibrator drive mechanism in another embodiment of the present invention.

[Figure 7] Schematic plan view of the vibrator drive mechanism in the same example

[Fig. 8] A cross-sectional view showing a schematic configuration of an ultrasound probe according to another embodiment of the present invention.

[Explanation of symbols]

1...Housing
2...Acoustic window 3...Liquid tank

4... Piezoelectric vibrator 5... Vibrator support
6... Vibrator support mechanism 7... Cable
8...Partition wall 9...Joint part
10
...Elastic members 11a, 11b...Stator of the first motor 12...Rotor 13a, 13b of the first motor...Stator of the second motor 14...Rotor 15 of the second motor...Rotor fixing ball
16a-16b...Bearings 21a, 21b...Stator of the first motor 22...Rotor of the first motor 31...Stator of the first motor
32...Rotor of the first motor 33...Stator of the second motor
34... Rotor of second motor

Claims (2)

[Claims] 1. A piezoelectric vibrator that transmits and receives ultrasonic waves, a first stator disposed outside a predetermined spherical surface, and a first rotor disposed inside the spherical surface, the piezoelectric vibrator or the a first motor that swings a support supporting the spherical surface around a first axis passing through the center of the spherical surface; a second stator disposed outside the spherical surface or a spherical surface having the same center as the spherical surface; A second rotor is disposed inside the spherical surface and is fixed to the first rotor. An ultrasonic probe comprising: a second motor that causes a swinging movement about a second axis passing through the probe. 2. A piezoelectric vibrator that transmits and receives ultrasonic waves; a first stator disposed outside a predetermined spherical surface or a spherical surface having the same center; and a first stator disposed inside the spherical surface.
a first motor comprising a rotor for swinging the piezoelectric vibrator or a support supporting the same about a first axis passing through the center of the spherical surface; and a second motor disposed outside the spherical surface. a stator and a second rotor disposed inside the spherical surface and fixed to each other with the first rotor, the first axis being substantially perpendicular to the first axis and the second rotor disposed inside the spherical surface. An ultrasonic probe comprising: a second motor that rotates within a plane passing through a second axis passing through the center.