JP3644876B2 - Ultrasonic probe and ultrasonic diagnostic apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus, and more particularly to improvement of an acoustic lens.
[0002]
[Prior art and problems]
In general, an ultrasonic probe includes an array transducer, a matching layer, an acoustic lens, and the like. The acoustic lens has a function of focusing the ultrasonic wave radiated from the array transducer and the ultrasonic wave reflected from the living body. Specifically, the beam is focused in the elevation direction orthogonal to the array direction of the array transducer. It has an action. Incidentally, the beam focusing action in the array direction is achieved by electronic control such as electronic sector control.
[0003]
In order to perform accurate measurement in the range from short-range measurement to long-range measurement, the width of the transmission / reception aperture in the array direction is widened in the case of long-distance measurement, while in short-range measurement, the transmission / reception aperture is reduced to improve resolution. Increased aperture control is performed.
[0004]
Conventionally, an acoustic lens having the same curvature at any location in the array direction is used in order to improve the beam focusing property in the elevation direction. That is, conventionally, an acoustic lens corresponding to aperture control has not been provided.
[0005]
Japanese Patent Laid-Open No. 6-245931 discloses a configuration in which the curvature of the acoustic lens is changed in the elevation direction. However, there is no change in the curvature in the array direction, in particular, the variable focusing effect associated with variable aperture. Not disclosed.
[0006]
The present invention has been made in view of the above-described conventional problems, and an object thereof is to improve beam focusing in the elevation direction in response to variable control of the transmission / reception aperture in the array direction. is there.
[0007]
[Means for Solving the Problems]
(1) In order to achieve the above object, the present invention provides an array transducer comprising a plurality of transducer elements, and focusing of ultrasonic waves in an elevation direction that is provided on the front side of the array transducer and is orthogonal to the array direction. And an acoustic lens exhibiting an action, wherein the acoustic lens has a characteristic that a focusing action changes along an array direction.
[0008]
According to the above configuration, since the focusing action of the ultrasonic wave is changed along the array direction, for example, an appropriate focusing action can be obtained along with the aperture control, and as a result, the image quality of the ultrasonic image is improved. It can be improved.
[0009]
Preferably, the acoustic lens has a characteristic in which the focusing action is weakened from the center in the array direction to both ends, and particularly preferably, the acoustic lens has a continuously decreasing curvature from the center in the array direction to both ends. Alternatively, the acoustic lens is made of a material whose focusing action is gradually weakened from the center in the array direction to both ends. When changing the collecting action, manufacturing is easy if the shape is variable, and if the material is variable, a uniform curvature can be set in the array direction as in the conventional case to improve the adhesion to the living body.
[0010]
(2) In order to achieve the above object, the present invention provides an ultrasonic diagnostic apparatus to which the above-described ultrasonic probe is connected, and performs scanning for performing transmission / reception aperture variable control and electronic sector scanning control. It has a control means.
[0011]
As is well known, during electronic sector scanning, the theoretical origin of an ultrasonic beam is generally the center in the array direction of the array transducer, and the variable control of the transmission / reception aperture is also centered in the array direction in the array transducer. As symmetric. Therefore, correspondingly, if the curvature is reduced from the center to both ends in the array direction of the acoustic lens (if the radius of curvature is increased), a lens effect suitable for focus depth and aperture control can be expected.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0013]
FIG. 3 conceptually shows the overall configuration of the ultrasonic diagnostic apparatus according to the present invention. This ultrasonic diagnostic apparatus is an apparatus that displays ultrasonic images by transmitting and receiving ultrasonic waves to and from a living body.
[0014]
The ultrasonic diagnostic apparatus is roughly divided into an apparatus main body 20 and an ultrasonic probe 8. The ultrasonic probe 8 is used in contact with the surface of a living body. Of course, it may be inserted into a body cavity. The ultrasonic probe 8 and the apparatus main body 20 are connected by a cable 21.
[0015]
An electronic scanning control unit 22 is provided in the apparatus main body 20. This electronic scanning control unit 22 is means for performing transmission / reception control of ultrasonic waves, and specifically functions as a control unit for executing electronic sector scanning. The electronic scanning control unit 22 includes an aperture control unit 24, and the aperture control unit 24 variably controls a transmission / reception aperture, that is, a transmission / reception range in the array direction in an array transducer described later.
[0016]
In the ultrasonic probe 8, an array transducer 16 is provided in the probe main body 10. The array vibrator 16 is formed by arranging a plurality of vibration elements, and a cross section in the array direction is shown in the figure. The acoustic lens 12 is provided on the front side of the array transducer 16, that is, on the ultrasonic wave transmission side, with a matching layer 14 interposed. The acoustic lens 12 performs an ultrasonic focusing function in a direction orthogonal to the array direction, that is, in the elevation direction. In this embodiment, the curvature changes from the center to both ends in the array direction as will be described in detail later. Has the form. This is to achieve an appropriate ultrasonic focusing effect for each focus depth, assuming that the transmission / reception aperture is controlled by the aperture controller 24. In FIG. 3, a backing layer 18 for absorbing unnecessary ultrasonic waves is provided on the back side of the array transducer 16.
[0017]
In FIG. 3, a scanning plane 100 is formed by scanning an ultrasonic beam 102 with an electronic sector. In forming the ultrasonic beam 102, dynamic focus or multi-stage focus is executed at the time of reception, and the aperture controller 24 switches the transmission / reception aperture stepwise or continuously. Also, at the time of transmission, the aperture control unit 24 performs appropriate aperture setting at the time of transmission according to the focus depth.
[0018]
FIG. 1 is a perspective view of the probe main body 10. In the figure, the X direction is the array direction, the Y direction is the elevation direction, and the Z direction is the axial direction of the probe body 10.
[0019]
As shown in the figure, the curvature of the acoustic lens 12 is set gradually smaller from the center 12A in the array direction of the acoustic lens 12 to both end portions 12B. In other words, the radius of curvature is gradually increased from the center 12A to both ends 12B, that is, the ultrasonic focusing action is weakened at both ends.
[0020]
FIG. 2 shows a change in the radius of curvature in the array direction of the acoustic lens. As shown in the figure, the radius of curvature is gradually increased from the center in the array direction to both ends. In FIG. 2, reference numerals 100 to 104 denote transmission / reception apertures. The aperture 100 is used for short-distance diagnosis, the aperture 102 is used for medium-distance diagnosis, and the aperture 104 is used for long-distance diagnosis. Is done. Therefore, for example, in the case of short-distance diagnosis, it is used only for the vibration element near the center of the array transducer, and the ultrasonic beam formed thereby is more strongly focused on the portion with a large curvature in the acoustic lens, It is possible to improve the image quality of the ultrasonic image. In the case of long-distance diagnosis, a large opening 104 is used. In this case, the radius of curvature at both ends of the acoustic lens is set to be large, so that the ultrasonic power can be concentrated in a deeper portion. . Therefore, on the premise of aperture variable control, it is possible to realize appropriate ultrasound beam focusing from a short distance to a long distance.
[0021]
In the above embodiment, the focusing function is changed by changing the form of the acoustic lens 12, but the curvature of the acoustic lens 12 is made uniform in the array direction, and the material constituting the acoustic lens 12 is continuously changed. By doing so, a focusing action of the ultrasonic beam equivalent to the change in the radius of curvature shown in FIG. 2 may be obtained.
[0022]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the beam focusing property in the elevation direction corresponding to the variable control of the transmission / reception aperture in the array direction.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an acoustic lens according to the present invention.
FIG. 2 is a diagram showing changes in the radius of curvature of an acoustic lens.
FIG. 3 is a conceptual diagram showing a configuration of an ultrasonic diagnostic apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Probe main body, 12 Acoustic lens, 20 Apparatus main body, 22 Electronic scanning control part, 24 Opening control part.

Claims (5)

An array vibrator comprising a plurality of vibration elements;
An acoustic lens that is provided on the front side of the array transducer and exhibits an ultrasonic focusing function in an elevation direction orthogonal to the array direction;
Including
The ultrasonic probe is characterized in that the acoustic lens has a characteristic that a focusing action changes along an array direction. The ultrasonic probe according to claim 1,
The ultrasonic probe according to claim 1, wherein the acoustic lens has a characteristic that the focusing action is weakened from the center to both ends in the array direction. The ultrasonic probe according to claim 1,
The ultrasonic probe according to claim 1, wherein the acoustic lens has a form in which the curvature continuously decreases from the center in the array direction to both ends. The ultrasonic probe according to claim 1,
2. The ultrasonic probe according to claim 1, wherein the acoustic lens is made of a material whose focusing action is gradually weakened from the center to both ends in the array direction. An ultrasonic diagnostic apparatus to which the ultrasonic probe according to claim 1 is connected,
An ultrasonic diagnostic apparatus comprising: scanning control means for executing transmission / reception aperture variable control and electronic sector scanning control.

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