JPH0675575B2 - Ultrasonic probe for 3D data acquisition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to improvement of an ultrasonic probe for acquiring three-dimensional data capable of acquiring echo data of a three-dimensional region inside a subject.

[Prior Art] An ultrasonic wave is transmitted into a subject such as a living body, and a reflected wave from the inside of the subject is received to obtain a tomographic image of the subject or a motion reflector inside the subject (for example, in a blood vessel). 2. Description of the Related Art An ultrasonic diagnostic apparatus that displays an image of blood flow velocity (Doppler) information and the like is known.

In such an ultrasonic diagnostic apparatus, the data acquisition is performed by an ultrasonic probe provided with an ultrasonic transducer.

In recent years, an ultrasonic three-dimensional image display device that three-dimensionally displays the echo data of the three-dimensional region in the subject has been proposed, and its practical use is desired.

By the way, in the above-mentioned ultrasonic three-dimensional image display device, etc., in order to capture the data of the three-dimensional region inside the subject,
The applicant of the present invention is Japanese Patent Application No. 1-324957 (JP-A-3-184532).
Proposes an ultrasonic probe for 3D data acquisition.

This ultrasonic probe for acquiring three-dimensional data includes a transducer unit including an array transducer configured by arranging a plurality of ultrasonic transducers inside a probe body, and the transducer unit as an electronic unit. The swing mechanism includes a swing mechanism that swings in a direction orthogonal to the scanning direction, and an angle detector that detects the swing angle.

In other words, in this ultrasonic probe, the two-dimensional, for example, fan-shaped, data acquisition area formed by the array transducer of the vibration unit is orthogonal to the surface mechanically formed by using the swing mechanism. The data of the three-dimensional region in the subject is taken in by moving the data in the direction of movement.

Therefore, according to such an ultrasonic probe for three-dimensional data acquisition, it is possible to grasp the three-dimensional position of each data obtained, and also without artificially tilting or moving the ultrasonic probe, It has a feature that data of a three-dimensional region in a subject can be accurately and accurately obtained.

[Problems to be Solved by the Invention] However, in the above-described ultrasonic probe for capturing three-dimensional data, between the tip surface of the transducer unit and the inner bottom surface of the main body case facing the tip surface, There was a problem that the transmitted ultrasonic waves were reflected multiple times.

In other words, a phenomenon in which a part of the ultrasonic wave transmitted from the tip surface of the vibrator unit is reflected by the inner bottom surface of the body case and further reflected by the tip surface of the vibrator unit is repeated,
This causes noise in the captured data, and as a result, there is a problem that noise is mixed in the formed image or the image becomes unclear.

The present invention has been made in view of the above conventional problems,
An object thereof is to provide an ultrasonic probe for taking in three-dimensional data capable of removing multiple reflection of ultrasonic waves generated between the tip surface of the transducer unit and the inner bottom surface of the probe body case. It is in.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a main body case of an ultrasonic probe and an array transducer in a convex-shaped tip portion provided in the main body case. A vibrator unit, and a swing mechanism for swinging the vibrator unit in a direction orthogonal to an array direction of a plurality of ultrasonic vibrators forming the array vibrator, and a tip surface of the vibrator unit The inner bottom surface of the main body case, which is a surface facing with, is formed in a concave shape, and the curvature of the inner bottom surface in the arrangement direction is set to be smaller than the curvature of the transducer unit front end surface, and An ultrasonic wave absorbing member is provided.

[Operation] According to the above configuration, from the curvature of the vibrator unit front end surface,
Since the curvature of the inner bottom surface of the ultrasonic probe body case is smaller, unnecessary ultrasonic waves that are multiple-reflected between the two surfaces are gradually guided to the outside while being repeatedly reflected between the two surfaces. ,
Further, it is absorbed by the ultrasonic wave absorbing member arranged on the side wall in the main body case.

As a result, noise in the captured data is eliminated, and a clear image can be formed.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a preferred embodiment of the ultrasonic probe for three-dimensional data acquisition according to the present invention, and FIG. 1A shows
A cross-section as seen from the front of the probe is shown, and FIG. 1B shows a side cross-section taken along the line BB of FIG. 1A.

In FIG. 1, the body case 10 has a lower part, the subject contact wall 12, which is formed in a gentle convex shape, and the upper part, the grip portion 14, has a side surface direction as shown in FIG. 1B. Is formed so that it can be grasped more easily than the lower part.

Inside the main body case 10, a vibrator unit 18 supported by a swing mechanism 16 described later is provided.

As shown in FIG. 1A, the vibrator unit 18 has a convex shape at its tip.

An array oscillator 20 is provided at the tip of the oscillator unit 18. Here, the array transducer 20 is
It is composed of a plurality of harmonic vibration elements 20a arranged along the tip surface 18A of the vibrator unit 18. Although not shown, an acoustic lens for suppressing the spread of the ultrasonic beam is provided on the tip surface 18A of the transducer unit 18, and between the acoustic lens and the array transducer 20. A matching layer for matching acoustic impedance is provided, and a backing layer is provided behind the array transducer 20.

Next, the swing mechanism 16 for swinging the vibrator unit will be described.

A base 22 is provided substantially in the center of the main body case 10. In the vicinity of the side wall of the main body case 10 of the base 22, a spindle serving as a support shaft for swinging the vibrator unit 18 is provided.
A bearing 26 that rotatably supports 24 is provided.

Then, the vibrator unit 18 has arms at both ends.
One end of the arm 27 is fixed, and the other end of the arm 27 is fixed to the support shaft 24.

Therefore, as shown in the figure, the transducer unit 18 is fixed integrally with the support shaft 24 with the tip end surface 18A thereof facing downward (toward the subject).

A motor 28, which is a drive source for swinging the oscillator unit 18 around the support shaft 24 as an axis, is provided near the support shaft 24 on the base. In order to transmit the power of the motor 28 to the support shaft 24, a gear unit 30 composed of a plurality of gears is provided between the motor 28 and the support shaft 24.

In addition, in FIG. 1B, for simplification of the drawing, the motor 2
8, the gear unit 30 and the angle detector 32 are omitted.

As described above, the swing mechanism 16 is composed of the motor 28, the gear portion 30, the support shaft 24, the arm 27, etc., and allows the oscillator unit 18 to swing about the support shaft 24 as an axis.

An angle detector 32 that detects the swing angle of the vibrator unit 18, that is, the rotation angle of the support shaft 24 is provided in the main body case 10. This angle detector 32, in this embodiment,
The slit plate 34 is fixed to the support shaft 24 and rotates integrally with the support shaft 24, and the photo interrupter 36 is fixed to the inner wall of the main body case 10.

In the angle detector 32, light is emitted from one side of the forked portion of the photo interrupter 36 through the slit plate 34, and light passing through the slit of the slit plate 34 is received at the other side of the forked portion. By doing so, the rotation angle of the support shaft 24 is detected.

Next, the medium tank 38 will be described.

The medium tank 38 is filled with an acoustic propagation medium in a space surrounded by an inner bottom surface 12A of the main body case, which is an inner surface of the subject contact wall 12, and a flexible partition film 40 that partitions the inside of the main body case 10. Is formed. The partition film 40 has a substantially central portion in close contact with the front surface of the tip end surface 18A of the vibrator unit 18, and its outer peripheral edge is airtightly joined to the inner peripheral wall of the main body case 10.

The partition film 40 has a slack for allowing the oscillator unit 10 to swing.

Therefore, the space between the partition film 40 and the inner bottom surface 12A is airtightly formed, and the object contact wall 12 and the transducer unit 18 are irrespective of the swing angle of the transducer unit 18. The acoustic matching between and is maintained.

That is, as is well known, ultrasonic waves are extremely attenuated when they pass through an air layer or the like, and thus such medium tank 38 ensures sound propagation.

An acoustic propagation medium is injected into the medium tank 38 from the injection port 42, and a liquid having an acoustic impedance similar to that of the subject such as water or oil is used as the acoustic propagation medium.

Next, the tip surface 18A of the vibrator unit 18 and the main body case 10
The problem of multiple reflection of ultrasonic waves generated between the inner bottom surface 12A and the inner bottom surface 12A will be described.

FIG. 2A shows a comparative example with respect to this example.

In the ultrasonic probe shown in FIG. 2A, the curvature of the tip surface 18A of the transducer unit in the longitudinal direction and the body case 1
The inner bottom surface 12A of 0 is formed to have almost the same curvature in the longitudinal direction.

Therefore, in such a case, the ultrasonic wave radiated from the tip surface 18A is first partially reflected by the inner bottom surface 12A and further reflected by the tip surface 18A. As a result, multiple reflections occur, which adversely affects the captured data.

Therefore, in the present invention, in order to solve this problem, first, the tip surface 18A of the vibrator unit 18 is
The curvature in the longitudinal direction of the inner bottom surface 12A is smaller than the curvature in the longitudinal direction of the.

Secondly, as shown in FIG. 2B, an ultrasonic absorbing member 44 is arranged on the side peripheral wall of the medium tank 38.

That is, as shown in FIG. 2B, the ultrasonic waves radiated from the ultrasonic transducers 20a of the array transducer 20 have a curvature of the tip surface 18A of the transducer unit 18 and a curvature of the inner bottom surface 12A of the main body case 10. Therefore, the ultrasonic absorption member is finally guided while repeatedly reflecting outward.
It will be absorbed at 44.

Therefore, the tip surface 18A of the vibrator unit 18 and the body case 10
Multiple reflections of ultrasonic waves between the inner bottom surface 12A and the inner bottom surface 12A can be absorbed, and unnecessary noise generated in the formed image can be removed.

In the present embodiment, the radius of curvature of the tip surface 18A of the vibrator unit 18 is 60R, and the inner bottom surface of the main body case 10 is
The radius of curvature of 12A is 100R. Of course, if the radius of curvature of the inner bottom surface 12A is larger than the radius of curvature of the tip surface 18A, the above effect can be obtained.

Incidentally, according to the experiments conducted by the present inventors, it has been confirmed that the multiple reflection wave can be effectively removed by the above-mentioned configuration.

In the present embodiment, the above-mentioned ultrasonic wave absorbing member 44 is made of, for example, sillin rubber, and the ultrasonic wave absorbing member 44 may be any other member as long as it absorbs ultrasonic waves. is there.

Further, in the present embodiment, the ultrasonic wave absorbing member 44 is provided on the entire circumference of the side wall in the main body case 10 in order to absorb and remove the unnecessary ultrasonic wave to the maximum, but of course, the present invention is not limited to this, and unnecessary. It is also suitable to dispose only in the ultrasonic wave guiding direction.

Further, the tip surface 18A of the vibrator unit 18 and the body case 10
If the curvatures of the inner bottom surface 12A in the longitudinal direction are extremely different from each other, the ultrasonic waves emitted from the transducer unit 18 may be excessively reflected by the inner bottom surface 12A. The difference between these two curvatures is It can be said that it is preferable to set within a practically appropriate range.

[Effects of the Invention] As described above, according to the ultrasonic probe for taking in three-dimensional data according to the present invention, the multiple reflection of ultrasonic waves generated between the front end surface of the transducer unit and the inner bottom surface of the main body case is prevented. Since it can be suppressed, it is possible to effectively remove unnecessary noise related to data acquisition and to form a clear image.

[Brief description of drawings]

FIG. 1A is a front sectional view of an ultrasonic probe for acquiring three-dimensional data according to the present invention, FIG. 1B is a side sectional view showing a sectional view taken along the line BB of FIG. 1A, and FIG. 2A is the present embodiment. FIG. 2B is a partial front sectional view showing a comparative example, and FIG. 2B is a partial front sectional view of the present embodiment for explaining removal of multiple reflection of ultrasonic waves. 10 …… Main body case 12 …… Subject contact wall 16 …… Swing mechanism 18 …… Vibrator unit 18A …… Tip surface 20 …… Array transducer 20a …… Ultrasonic transducer 44 …… Ultrasonic absorber

Claims (1)

[Claims] 1. A main body case of an ultrasonic probe, a transducer unit provided in the main body case and having an array transducer inside a convex-shaped tip portion, and a plurality of ultrasonic transducers constituting the array transducer. A swinging mechanism that swings the transducer unit in a direction orthogonal to the array direction of the acoustic wave vibrating elements, and the inner bottom surface of the main body case, which is a surface facing the tip end surface of the transducer unit, has a concave shape. The three-dimensional shape is characterized in that the curvature of the inner bottom surface in the arrangement direction is set to be smaller than the curvature of the transducer unit front end surface, and an ultrasonic wave absorbing member is disposed on the side wall in the main body case. Ultrasonic probe for data acquisition.