JP2010131068A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact ultrasonic probe which carries out image formation while reducing false images at low cost. <P>SOLUTION: The ultrasonic probe comprises an enclosure having an acoustic window 11 transmitting ultrasonic wave and an oscillator unit 2 arranged within the enclosures 11 and 14 and having a plurality of array oscillators 4. The array oscillators 4 transmit ultrasonic wave to a subject and receive ultrasonic wave reflected by the subject. A part of the ultrasonic wave reaches an inner surface 15 of the enclosure facing an end of the oscillator unit 2 located in the arranging direction of the array oscillators 4. A reflector 16 is arranged on the inner surface 15 of the enclosure for guiding ultrasonic wave radiated from the array oscillators 4 undergoing repeated reflection between the acoustic window 11 and a surface on which the array oscillators 4 of the oscillator unit 2 are arranged to the outside of the oscillator unit 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic probe for reducing artifacts and forming a clear image.

  Conventionally, an ultrasonic probe capable of acquiring three-dimensional ultrasonic image information has been proposed (see, for example, Patent Document 1). FIG. 8 is a cross-sectional view showing a configuration of a conventional ultrasonic probe. The transducer unit 101 is disposed in the main body case 102, and the transducer unit 101 is disposed with an array transducer 104 in which ultrasonic transducer elements 103 are arranged at a convex tip portion. The vibrator unit 101 can be swung in a direction perpendicular to the arrangement direction of the array vibrator 104 by a swing mechanism 105.

  An inner surface 106 of the main body case 102, which is a surface facing the tip surface 107 of the vibrator unit 101, is formed in a concave shape. The inner surface 106 of the main body case 102 is formed such that the curvature in the arrangement direction of the ultrasonic vibration elements 103 is smaller than the curvature of the distal end surface 107 of the transducer unit 101. An ultrasonic absorbing member 108 is disposed on the side wall 109 of the main body case facing the end of the transducer unit 101 in the arrangement direction of the ultrasonic vibration elements 103.

Since the curvature of the inner surface 106 of the main body case 102 is smaller than the curvature of the distal end surface 107 in the arrangement direction of the ultrasonic vibration elements 103, unnecessary ultrasonic waves that are multiple-reflected between the two surfaces are reflected between the two surfaces. Is repeated, the light is guided to the outside of the vibrator unit 101 in the array direction of the array vibrator 104. Further, unnecessary ultrasonic waves are absorbed by the ultrasonic absorbing member 108 disposed on the side wall 109 of the main body case 102. As a result, noise in the captured three-dimensional ultrasonic image data is reduced, and a clear ultrasonic image without a virtual image can be formed.
JP-A-4-122358

  However, in the conventional configuration described above, since the ultrasonic absorbing member 108 is disposed on the side wall 109 in the main body case 102 in order to absorb unnecessary ultrasonic waves, the size of the main body case 102 is increased, and the ultrasonic waves are increased. It becomes difficult to downsize the probe. Further, since the ultrasonic absorbing member 108 is required, the cost is increased.

  An object of the present invention is to solve the above-described conventional problems, and to provide an ultrasonic probe that enables generation of ultrasonic image data that is small in size and low in cost and reduces the virtual image of the ultrasonic image. To do.

  A first ultrasonic probe according to the present invention includes a casing having an acoustic window that transmits ultrasonic waves, and a transducer unit that is disposed in the casing and includes a plurality of array transducers. The vibrator emits ultrasonic waves to the subject and receives the ultrasonic waves reflected from the subject. In order to solve the above-mentioned problem, a part of the ultrasonic waves reaches the inner surface of the casing facing the end of the transducer unit in the arrangement direction of the array transducer, and the inner surface of the casing A reflector for guiding the ultrasonic waves radiated from the array transducer that performs multiple reflections to the outside of the transducer unit is disposed between the surface of the transducer unit on which the array transducer is arranged and the acoustic window. It is characterized by.

  A second ultrasonic probe of the present invention comprises a housing having an acoustic window that transmits ultrasonic waves, and a transducer unit that is arranged in the housing and has a plurality of array transducers arranged. The array transducer emits ultrasonic waves to the subject and receives the ultrasonic waves reflected from the subject. In order to solve the above-mentioned problem, a reflector having a reflective surface with irregularities formed on the inner surface of the casing facing the end of the transducer unit in the arrangement direction of the array transducer. It is characterized by.

  According to the present invention, the reflector that reflects the ultrasonic waves in a direction away from the center line of the array transducer in the arrangement direction of the array transducer is disposed on the inner surface of the housing facing the end of the transducer unit. By doing so, it is possible to provide an ultrasound probe that can form ultrasound image data that is small in size and low in cost and reduced in the virtual image of the ultrasound image.

  The ultrasonic probe of the present invention can take various modes based on the above-described configuration. That is, the first ultrasonic probe of the present invention includes a swing mechanism in which the array transducers are arranged in a one-dimensional manner and the transducer units are swung in a direction orthogonal to the direction of the arrangement. Can be configured.

  The reflector may be configured to reflect the ultrasonic wave in a direction away from the array transducer.

  Moreover, the said reflector can be set as the structure which forms the cylindrical surface. Moreover, the said reflector can also be set as the structure which forms the triangular prism surface.

  Further, in the second ultrasonic probe of the present invention, the reflection surface as a whole has a convex shape having a vertex at the center line of the array transducer in the arrangement direction of the array transducer. You can also.

  Hereinafter, embodiments of an ultrasonic probe according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view showing a configuration of an ultrasound probe 1 according to Embodiment 1 of the present invention. In consideration of legibility, the acoustic window 11, the housing 14, and the convex portion 16 are indicated by broken lines. FIG. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG.

  The ultrasonic probe 1 is configured by disposing a transducer unit 2 inside a housing constituted by an acoustic window 11 and a housing 14. The acoustic window 11 is made of a material that transmits ultrasonic waves.

  The vibrator unit 2 is supported by the swing mechanism 6. In the vibrator unit 2, an end face (hereinafter referred to as a tip face) 3 opposite to the side supported by the swing mechanism 6 is formed in a convex shape, and the array vibrator 4 is arranged on the tip face 3. Has been. The array transducer 4 is configured by arranging a plurality of strip-shaped ultrasonic vibration elements 5. A subject contact wall 12 which is a region in contact with the subject in the acoustic window 11 is formed in a gentle convex shape.

  In the direction (CC line direction) in which the ultrasonic vibration elements 5 shown in FIG. 3 are arranged, a convex portion 16 is formed on the end portion 15 of the acoustic window 11 facing the transducer unit 2. The convex portion 16 is convex on the line (on the CC line) where the ultrasonic vibration elements 5 are arranged when the oscillation angle of the vibrator unit 2 is 0 degree (the state shown in FIGS. 1 to 3). The convex part 16 is not formed with a plane perpendicular to the CC line. The convex portion 16 may be integrally formed with the acoustic window 11.

  As shown in FIG. 2, the swing mechanism 6 includes a motor 7, a shaft 8, and an encoder 9. The vibrator unit 2 is swingably supported on the shaft 8 by a rocking shaft stopper (not shown). The vibrator unit 2 is oscillated in the direction DD in FIG. 3 around the shaft 8 as a result of the rotation of the motor 7 as a drive source being transmitted. In order to transmit the power of the motor 7 to the shaft 8, a gear portion (not shown) composed of a plurality of gears is interposed between the motor 7 and the shaft 8.

  The motor 7 is fixed to the frame 10 via an oil seal (not shown) for liquid sealing, and the oil seal prevents the coupling liquid 13 from entering the motor 7. Detection of the swing angle and the swing origin of the vibrator unit 2 is performed by an encoder 9 attached integrally with the motor 7. The vibrator unit 2 swings in the coupling liquid 13, and the coupling liquid 13 is sealed by the acoustic window 11. For the coupling liquid 13, for example, a liquid having the same acoustic impedance as that of the subject such as water or oil is used to ensure acoustic propagation.

  Further, the frame 10 is fixed to the housing 14 and covers the entire swing mechanism 6.

  Although not shown, an acoustic lens that suppresses the spread of the ultrasonic beam is provided on the distal end surface 3 of the transducer unit 2, and an acoustic impedance is provided between the acoustic lens and the array transducer 4. A matching layer is provided to perform matching. A backing layer is provided behind the array transducer 4.

  The transducer unit 2 has a convex shape in which the array transducers 4 are arranged in a cylindrical shape, but can also be arranged in a linear shape. Moreover, there are various kinds of array transducers, the radius of the cylindrical surface, and the thickness of the ultrasonic vibration element 5, and they can be properly used depending on the purpose of use.

  Next, the operation of the ultrasonic probe 1 according to the present embodiment will be described. The ultrasonic probe 1 can perform scanning by an electronic scanning method in the CC direction and a mechanical scanning method in the DD direction shown in FIG. First, an operation in which the ultrasonic probe 1 scans in the CC direction using ultrasonic waves will be described. The ultrasonic probe 1 is connected to an ultrasonic diagnostic apparatus main body (not shown). The ultrasonic diagnostic apparatus main body outputs a transmission signal for emitting an ultrasonic wave from each ultrasonic vibration element 5. The transmission signal is input to the delay circuit before being input to the ultrasonic vibration element 5. The delay circuit varies the delay time according to the ultrasonic transducer 5 corresponding to each transmission signal. Therefore, ultrasonic waves are radiated from the ultrasonic vibration elements 5 at different timings, and the ultrasonic waves are synthesized into an ultrasonic beam having directivity. In addition, the direction of the ultrasonic beam can be changed by changing the delay time in the delay circuit.

  FIG. 4 is a diagram showing an ultrasonic beam emitted from the ultrasonic vibration element 5. Most of the ultrasonic beam is emitted in the set directivity direction, but a part is emitted in an oblique direction. The former is called a main pole (main lobe 21), and the latter is called a sub pole (side lobe 22). Most of the main lobe 21 is transmitted to the outside through the acoustic window 11. The main lobe 21 radiated to the outside of the ultrasonic probe 1 is reflected by the subject and received by the ultrasonic vibration element 5. The received signal received by the ultrasonic vibration element 5 is subjected to signal processing by the ultrasonic diagnostic apparatus body and displayed as an ultrasonic image.

  A part of the main lobe 21 is reflected by the inner surface of the acoustic window 11 and reaches the ultrasonic vibration element 5. A part that reaches the ultrasonic element 3 is received by the ultrasonic element 3, and the rest is reflected. Such reflection is repeated, and multiple reflections are displayed as a plurality of reflectors in the ultrasonic image. In this case, the reflectors are displayed in the ultrasonic image at equal intervals separated by a distance that reciprocates between the ultrasonic vibration element 5 and the acoustic window 11.

  Further, since multiple reflection occurs between the distal end surface 3 of the ultrasonic vibration element 5 and the inner surface of the acoustic window 11, it is received at a relatively early time compared to the ultrasonic wave reflected from the subject. . That is, a virtual image (artifact) due to multiple reflection is displayed in a short distance region, that is, in the upper part of the image on the ultrasonic image. Therefore, by eliminating, for example, signal processing, virtual images that are displayed in a short distance area and displayed at an interval equal to the distance between the ultrasonic vibration element 5 and the inner surface of the acoustic window 11, the influence of multiple reflections is inconspicuous. It is possible to do.

  On the other hand, the ultrasonic side lobe 22 is emitted from the main lobe 21 in a significantly inclined direction. For this reason, the side lobe 22 reflected by the inner surface of the acoustic window 11 is guided to the outside of the transducer unit 2 in the CC direction. The ultrasonic wave guided to the outside of the transducer unit 2 reaches the end 15 of the acoustic window 11 in the CC direction shown in FIG.

  FIG. 5A is a cross-sectional view showing a configuration of a conventional ultrasonic probe. The ultrasonic probe shown in FIG. 5A has a configuration in which the shape of the end portion 15a is a surface perpendicular to the CC direction and no convex portion is arranged. As shown in FIG. 5A, the side lobe 22 guided to the outside of the transducer unit 2 is reflected so as to invert 180 ° at the end 15a in the acoustic window 11, and the ultrasonic vibration element 5 of the transducer unit 2 is reflected. To reach. When this ultrasonic wave is received by the ultrasonic vibration element 5, a virtual image is displayed on the ultrasonic image.

  FIG. 5B is a plan view showing a configuration of another conventional ultrasonic probe. The ultrasonic probe shown in FIG. 5B has a configuration in which the end portion 15b has an elliptic arc concave shape and no convex portion is disposed. In this case, as shown in FIG. 5B, the side lobe 22 guided to the outside of the transducer unit 2 reflects the right component 22a tilted leftward with respect to the CC line when viewed from the traveling direction, and is reflected on the left side. The component 22b is tilted to the right and reflected. That is, the side lobe 22 guided to the outside of the transducer unit 2 is reflected by the end portion 15 b so as to approach the CC line, that is, concentrate on the ultrasonic vibration element 5. When this ultrasonic wave is received by the ultrasonic vibration element 5, a virtual image is displayed on the ultrasonic image.

  Since the side lobe 22 reflected by the end portions 15a and 15b and received by the ultrasonic vibration element 5 has a propagation path length longer than the multi-reflection path of the main lobe, the virtual image of the subject on the ultrasonic image is It may be displayed overlapping the image. Furthermore, since the reflection path changes depending on the swinging posture of the transducer unit 2, it is difficult to specify the position of the virtual image in the ultrasonic image. Therefore, the virtual image formed by the side lobe 22 is difficult to eliminate by signal processing, unlike the image formed by multiple reflection of the main lobe.

  FIG. 6A is an enlarged cross-sectional view taken along line BB shown in FIG. 1 of the ultrasonic probe 1 according to the present embodiment. The end portion 15 is formed with a convex portion 16 that forms a cylindrical surface as a reflecting surface. The side lobe 22 guided to the outside of the transducer unit 2 is reflected by the convex portion 16 with the right component tilted to the right with respect to the CC line when viewed from the traveling direction, and the left component tilted to the left. And reflected. That is, the side lobe 22 guided to the outside of the transducer unit 2 is reflected by the convex portion 16 in a direction away from the CC line. Accordingly, the multiple reflected ultrasonic waves from the side lobe 22 do not return to the ultrasonic vibration element 5, and therefore it is possible to reduce unnecessary noise in the ultrasonic image.

  As described above, the ultrasonic probe can scan the subject in the CC direction with the ultrasonic beam.

  Next, an operation in which the ultrasonic probe scans in the DD direction using ultrasonic waves will be described. First, the above-described electronic scanning in the CC direction is performed. Next, the motor 7 tilts the vibrator unit 2 by a predetermined angle. Electronic scanning in the CC direction is performed in a state where the transducer unit 2 is tilted by a predetermined angle. Further, the motor 7 tilts the vibrator unit 2 by a predetermined angle. By repeating the above operation, it is possible to scan in the DD direction by ultrasonic waves, and in the ultrasonic diagnostic apparatus main body based on the data scanned in the CC direction and DD direction, three-dimensional ultrasonic waves Image data is formed.

  As described above, the ultrasound probe 1 according to the present embodiment can reduce the virtual image caused by the side lobe in the ultrasound image by arranging the convex portion 16 at the end portion 15.

  Moreover, even if the convex part 16 is comprised with the same material as the acoustic window 11 which is easy to permeate | transmit an ultrasonic wave, it may be comprised with the material which is easy to reflect. That is, the convex part 16 should just be able to prevent the reflected ultrasonic wave from propagating on CC line.

  With the above configuration, the ultrasonic signal information corresponds to the three-dimensional position information by immersing the vibrator unit 2 in the coupling liquid 13 which is an ultrasonic wave propagation body and swinging the vibrator unit 2 at high speed by the motor 7. In addition, it is possible to display the observation site in the body to be diagnosed in three dimensions and in real time.

  Further, by forming the convex portion 16 integrally with the end portion 15, the virtual image can be reduced without increasing the number of parts and the manufacturing process, that is, without increasing the cost.

  Moreover, since only the convex part 16 is arrange | positioned, an ultrasonic probe can be comprised with small size.

  In the present embodiment, the convex portion 16 does not necessarily form a cylindrical surface, and the ultrasonic element unit 2 does not reach the ultrasonic vibration element 5 when the ultrasonic wave reaches the end portion 15. Any structure that reflects outside the area where it is located may be used. For example, as shown in FIG. 6B, a configuration in which a triangular prism surface is formed as the reflection surface may be employed. In this case, the convex part 16 is arrange | positioned so that one vertex of a triangular prism surface may be located on CC line.

(Embodiment 2)
FIG. 7 is a cross-sectional view showing the vicinity of the end 15 of the ultrasonic probe 1b according to Embodiment 2 of the present invention. The ultrasonic probe 1b according to the present embodiment has a configuration in which a concavo-convex portion 17 is arranged at an end portion 15 instead of the convex portion 16 of the ultrasonic probe 1 according to the first embodiment. In the ultrasound probe 1b according to the present embodiment, the same components as those of the ultrasound probe 1 according to Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted. The concavo-convex portion 17 is formed by embossing or the like, and diffuses ultrasonic waves.

  As in the first embodiment, when the side lobe 22 of the ultrasonic beam reaches the end portion 15, the side lobe 22 is irregularly reflected by the uneven portion 17. For this reason, the rate at which the irregularly reflected side lobes 22 are received by the ultrasonic vibration element 5 is reduced, and a virtual image hardly occurs in the ultrasonic image.

  As described above, the ultrasonic probe 1b according to the present embodiment can reduce the virtual image generated by the side lobe in the ultrasonic image by disposing the uneven portion 17 at the end portion 15.

  Further, the uneven portion 17 can be formed integrally with the end portion 15. With this configuration, the virtual image can be reduced without increasing the number of parts and the manufacturing process, that is, without increasing the cost.

  In addition, since only the uneven portion 17 is disposed, the ultrasonic probe can be configured with a small size.

  The uneven portion 17 may have a surface on which the unevenness is formed perpendicular to the CC line. However, as the entire uneven portion 17, the ultrasonic wave when the oscillation angle of the transducer unit 2 is 0 degree. It is preferable that the convex shape has a vertex located on the line (on the CC line) on which the vibration elements 5 are arranged. By adopting such a configuration, the ratio of the scattered light reaching the ultrasonic vibration element 5 can be further reduced.

  In the first and second embodiments, the three-dimensional scanning ultrasonic probe has been described as an example. However, it can also be used for a two-dimensional scanning ultrasonic probe in which side lobes are generated.

  In Embodiments 1 and 2, the array transducer 4 arranged one-dimensionally has been described. However, the effects of the present invention can be obtained even when the array transducer is arranged two-dimensionally. In this case, the convex portion or the concave-convex portion is disposed at the end portion 15 of the acoustic window 11 facing the transducer unit 2 in each of the two directions in which the array transducers are arranged.

  The ultrasonic probe of the present invention is small, low-cost, capable of forming an ultrasonic image without a virtual image, and capable of capturing echo data of a three-dimensional region inside a subject. Useful as a child.

The perspective view which shows the structure of the ultrasound probe which concerns on Embodiment 1 of this invention. Sectional drawing along the AA line of FIG. Plan view along line BB in FIG. The figure which shows the ultrasonic beam radiated | emitted from an ultrasonic vibration element Sectional drawing which shows the structure of the conventional ultrasonic probe Sectional drawing which shows the structure of another conventional ultrasonic probe Sectional drawing which shows the structure of the ultrasound probe which concerns on Embodiment 1 of this invention. Sectional drawing which shows the structure of another ultrasonic probe which concerns on Embodiment 1 of this invention. Sectional drawing which shows the structure of the ultrasound probe which concerns on Embodiment 2 of this invention. Sectional drawing which shows the structure of the conventional ultrasonic probe

Explanation of symbols

1, 1b Ultrasonic probe 2 Transducer unit 3 Tip surface 4 Array transducer 5 Ultrasonic vibrating element 6 Oscillating mechanism 7 Motor 8 Shaft 9 Encoder 10 Frame 11 Acoustic window 12 Subject contact wall 13 Coupling liquid 14 Housing 15 End portion 16 Convex portion 17 Concavity and convexity portion 21 Main lobe 22 Side lobe

Claims (7)

A housing having an acoustic window that transmits ultrasound;
A vibrator unit disposed in the housing and having a plurality of array vibrators,
The array transducer emits ultrasonic waves to a subject and receives ultrasonic waves reflected from the subject.
A part of the ultrasonic waves reaches the inner surface of the casing facing the end of the transducer unit in the arrangement direction of the array transducer,
On the inner surface of the housing, the ultrasonic waves radiated from the array transducer that is multiply reflected between the surface on which the array transducer of the transducer unit is arranged and the acoustic window are guided out of the transducer unit. An ultrasonic probe comprising a reflector.   The ultrasonic probe according to claim 1, further comprising a swinging mechanism in which the array transducers are arranged in a one-dimensional manner and the transducer units are swung in a direction orthogonal to the direction of the arrangement.   The ultrasonic probe according to claim 1, wherein the reflector reflects the ultrasonic wave in a direction away from the array transducer.   The ultrasonic probe according to claim 3, wherein the reflector forms a cylindrical surface.   The ultrasonic probe according to claim 3, wherein the reflector forms a triangular prism surface. A housing having an acoustic window that transmits ultrasound;
A vibrator unit having a plurality of array vibrators arranged and arranged in the housing,
The array transducer emits ultrasonic waves to a subject and receives ultrasonic waves reflected from the subject.
An ultrasonic probe characterized in that a reflector having a reflecting surface with projections and depressions is disposed on the inner surface of the casing facing the end of the transducer unit in the array direction of the array transducer. Child.   The ultrasonic probe according to claim 6, wherein the reflecting surface has a convex shape having a vertex at a center line of the array transducer in the arrangement direction of the array transducer as a whole.

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