JP2009045094A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe which reduces resistance to an oscillator unit by a coupling medium and reduces weight of the ultrasonic probe in the ultrasonic probe having the oscillator unit performing scan mechanically. <P>SOLUTION: A cover 14 is detachably mounted to a lower case 10, and has permeability for making the coupling medium 38 pass through. The coupling medium 38 enters the inside from the outside of the cover 14 and spreads out in a gap between a wave transmitting and receiving surface 36A of an array oscillator 34 and the internal surface 14A of the cover 14. The oscillator unit 22 performs mechanical scan under the state and simultaneously performs electronic scan repeatedly, and consequently, three-dimensional echo data is acquired. A projecting part may be provided on the oscillator unit 22. In addition, a partitioning film may be provided on the periphery of the oscillator unit 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic probe, and more particularly to a structure of an ultrasonic probe having a transducer unit that is mechanically scanned.

  In a mechanical sector scanning ultrasonic probe, an ultrasonic probe for capturing three-dimensional echo data (see Patent Documents 1-3 and the like), etc., the transducer unit is mechanically scanned in the probe case. For example, if the 1D array transducer is scanned in a direction perpendicular to the element arrangement direction, the scanning plane can be moved to form a three-dimensional echo data capturing space. In order to improve the acoustic propagation between the transducer unit and the surface of the living body, or to eliminate the intervention of the air layer, the probe case is filled with a liquid such as physiological saline or oil as an acoustic medium. It is enclosed. On the other hand, a gel-like acoustic jelly is applied as an acoustic medium between the contact surface of the probe case or the living body surface, that is, the gap between the contact surface and the living body surface is filled with the acoustic jelly.

Japanese Patent Laid-Open No. 3-184532 JP-A-4-122358 Japanese Patent Laid-Open No. 6-38962

  However, if an acoustic medium chamber is formed as a sealed space in the probe case and the vibrator unit is moved in the acoustic medium chamber, the resistance and load are large during the movement of the vibrator unit, and thus the vibrator unit is driven. There was a problem that a large mechanism had to be used. In addition, due to the existence of the acoustic medium chamber itself and the use of a large drive source, there is a problem that the ultrasonic probe becomes large and its weight increases.

  An object of the present invention is to reduce a resistance or a load during mechanical scanning of a vibrator unit.

  Another object of the present invention is to reduce the weight of an ultrasonic probe.

  The present invention provides a transducer unit that is provided in a probe case and transmits / receives ultrasonic waves, a mechanical scanning mechanism for mechanically scanning the transducer unit in the probe case, and a living body in the probe case And an permeable cover having a plurality of air gaps that constitute a part of the side and allow a fluid medium having fluidity to pass therethrough, and an ultrasonic probe.

  According to the above configuration, for example, the acoustic medium applied on the living body contact surface (the outer surface of the permeable cover) in the ultrasonic probe or on the surface of the living body is transferred to the ultrasonic probe via the permeable cover. It penetrates into the interior and develops between the wave transmitting / receiving surface of the vibrator unit and the inner surface of the permeable cover. This eliminates the air layer and ensures acoustic propagation. That is, since it is not necessary to form an acoustic medium chamber sealed inside, the weight of the ultrasonic probe can be reduced and the structure can be simplified. The resistance caused by the acoustic medium is also reduced during the movement of the vibrator unit. There is also an advantage that two kinds of acoustic media are not necessarily used. The acoustic medium that has entered the interior is cleaned as necessary.

  Preferably, the permeable cover has a stitch structure, a porous structure, or a multi-slit structure. That is, the permeable cover needs to be configured as a structure that allows passage of the acoustic medium. It can also be composed of an invasive material. In any case, it is desirable to configure as a structure that does not cause or hardly causes an adverse effect on the propagation of ultrasonic waves. The permeable cover can be made of a hard material, but can also be made of a soft member as long as the movement of the vibrator unit can be allowed. It can also be comprised with the film | membrane and the flame | frame holding the shape. Examples of the material include a metal material or a resin material.

  Desirably, an attachment / detachment structure is provided for detachably attaching the permeable cover to the case body of the probe case. It is desirable to adopt such a structure for cleaning, replacement, etc. It is also suitable to use the permeable cover as a disposable type.

  Preferably, the transmission / reception surface of the vibrator unit is mechanically scanned in a state of being opposed to the inner surface of the permeable cover, and the penetration from the living body side into the gap between the transmission / reception surface and the inner surface of the permeable cover. The acoustic medium is introduced through a protective cover. That is, the acoustic medium is naturally introduced into the gap between the transmission / reception surface and the cover inner surface. It is also conceivable to adopt a mode in which such a gap is not provided and the wave transmitting / receiving surface contacts the inner surface of the cover.

  Desirably, the vibrator unit has a projecting portion projecting on both sides of the wave transmitting / receiving surface in the mechanical scanning direction. According to the overhang portion, the acoustic medium can be smoothly deployed. Further, the resistance caused by the acoustic medium to the vibrator unit can be relaxed. The lower end portion (end portion on the living body side) of the transducer unit including the overhang portion may be curved or have a bottom shape in the mechanical scanning direction.

  Desirably, there is provided means for damming the acoustic medium in contact with the wave transmitting / receiving surface at both ends in the mechanical scanning direction of the transducer unit. The acoustic medium is gradually driven to the corner in the mechanical scanning direction with repeated reciprocating scanning of the transducer unit. However, the damming means prevents or reduces the expansion of the acoustic medium to an unnecessary range. it can. In addition, since the acoustic medium can be stopped at a necessary portion, a good acoustic propagation state can be formed.

  As described above, according to the present invention, it is possible to reduce the resistance or load generated during mechanical scanning of the vibrator unit as the movable body. Or according to this invention, an ultrasonic probe can be reduced in weight.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows a preferred embodiment of an ultrasonic probe according to the present invention. In FIG. 1, (A) is a cross-sectional view when the ultrasonic probe is viewed from the front, and (B) is a cross-sectional view when the ultrasonic probe is viewed from the side. This ultrasonic probe is connected to the ultrasonic diagnostic apparatus main body via a cable (not shown). That is, this ultrasonic probe is used when an ultrasonic image of a living body is formed by transmitting / receiving ultrasonic waves to the living body.

  In FIG. 1, the ultrasound probe has a lower case 10 and an upper case 12 that form a main body case. A cover 14 is detachably provided below the lower case 10 as will be described later. The inside of the lower case 10 and the cover 14 is hollow, and a vibrator unit 22 is provided therein. The vibrator unit 22 is driven by a drive mechanism 24 provided inside the lower case 10 and the upper case 12.

  The drive mechanism 24 has a motor 26 as a drive source. An encoder (not shown) for detecting a rotation angle is provided on the rotation shaft of the motor 26. A first gear 28 is connected to the shaft of the motor 26, and the first gear 28 meshes with a second gear 30 provided in the vibrator unit 22 as a movable body. The first gear 28 and the second gear 30 have a bevel gear structure as a whole.

  The second gear 30 is connected to a rotating shaft 32, and an array transducer 36 is attached to the rotating shaft 32 by a frame 34. Incidentally, the structure holding the vibrator unit 22 as a movable body is not shown. The frame 34 is provided with a bearing, and the rotating shaft 32 is rotatably held by the bearing. The rotational motion of the motor 26 becomes the rotational motion of the first gear 28, the second gear 30 and the rotating shaft 32, whereby the array vibrator 36 performs the pendulum motion, that is, the swing motion. In (A), the array transducer 36 moves in the direction perpendicular to the paper surface, and in (B), the array transducer 36 moves in the horizontal direction on the paper surface. The range, speed, period, etc. of the reciprocating motion are controlled by a control unit provided on the ultrasonic diagnostic apparatus side.

  The array transducer 36 is configured by a 1D array transducer in the present embodiment, and is configured by a plurality of transducer elements linearly arranged in the horizontal direction of the paper in (A). Of course, the plurality of vibration elements may be arranged in an arc shape. An electron beam is formed by the array transducer 36, and the electron beam is electronically scanned. As the electronic scanning method, electronic linear scanning, electronic sector scanning, and the like are known.

  When a scanning surface having a predetermined shape is formed by scanning the ultrasonic beam as described above, and the scanning surface is moved by mechanical scanning, a three-dimensional echo data capturing space as a three-dimensional space is formed as a result. The technique according to the present embodiment can also be applied to a mechanical sector scanning ultrasonic probe that mechanically scans a single transducer.

  The cover 14 is formed of a permeable member, that is, a member having an action of allowing the coupling medium 38 to pass therethrough. For example, the cover 14 has a stitch structure, a porous structure, or a multi-slit structure. Alternatively, the cover 14 may be configured by an infiltrating member such as a fabric. In FIG. 1, one hole is represented by reference numeral 16. The coupling medium 38 is a so-called echo jelly, and in the present embodiment, the coupling medium 38 is preliminarily applied on the outer surface (biological contact surface) 14B of the cover 14 or is previously preliminarily formed on the biological surface. It is to be applied. After such application, the coupling medium 38 passes through the cover 14 and enters the ultrasonic probe by bringing the outer surface 14B of the cover 14 into contact with the surface of the living body. This state is shown in FIG.

  In this state, the coupling medium 38 is filled between the wave transmitting / receiving surface 36A, which is the front end surface of the array transducer 36, and the inner surface 14B of the cover 14, and the air layer there is eliminated, and good acoustics are obtained. Propagation is formed. Similarly, the outer surface 14B of the cover 14 and the living body surface 20 are in close contact with each other, and even if there is a gap there, the coupling medium 38 is present there, so that the air layer is eliminated and a good condition is obtained. An acoustic propagation path is formed. It is desirable to use a coupling medium 38 having an appropriate amount and moderate viscosity so that such a state is established.

  Incidentally, the cover 14 can also be comprised by members, such as a net-like metal film which makes the biological contact wall of the shaver for shaving, for example. Or it can also be comprised with materials, such as resin which has many space | gap. In any case, it is desirable to employ a material or structure that does not adversely affect the presence of the cover 14 during propagation of ultrasonic waves. In general, in consideration of the relationship with the wavelength of ultrasonic waves, it is possible to effectively reduce the adverse effects on acoustic propagation by making the cover 14 quite thin.

  FIG. 2 shows a plurality of holes formed in the cover 14. In the example shown in (A), a plurality of holes 42 are regularly formed in the vertical direction and the horizontal direction, and the diameter of each hole is, for example, about 5 mm. In the example shown in (B), a plurality of holes 44 are regularly arranged in the vertical and horizontal directions, and each hole 44 is elliptical in this example, and the length in the major axis direction is, for example, about 5 mm. When designing such a structure, it is desirable to determine the size or shape so that hairs and the like existing on the body surface do not enter. In some cases, it is also preferable to form the cover 14 in two layers or multiple layers.

  Returning to FIG. 1, as shown in FIG. 1B, damming members 40 are provided at both ends of the mechanical scanning when the vibrator unit 22 swings. The damming member 40 is a member for accommodating the coupling medium 38 developed on the inner surface 14A of the cover 14 within a certain range, whereby the coupling medium 38 is unnecessarily developed and the ultrasonic probe is used. It is possible to effectively suppress excessive spreading inside. In the configuration example shown in FIG. 1, the damming members 40 are provided at both ends in the machine scanning direction, but may be formed so as to surround the entire inner surface 14A. Incidentally, in the example shown in FIG. 1, the transmitting / receiving surface 36A of the array transducer 36 is gently curved in the mechanical scanning direction, that is, has an arcuate shape. The curvature may be the same as or different from the curvature of the inner surface 14A of the cover 14.

  The engaging portion 17 is a means for detachably attaching the cover 14 to the lower case 10. In the example shown in FIG. 1, the engaging portion 17 is configured by a protrusion 15 provided at the end of the cover 14 and a groove 10B formed in the lower end portion 10A of the lower case 10, and the protrusion 15 is formed in the groove 10B. The cover 14 is attached to the lower case 10 by entering. At least the upper end of the cover 14 can be deformed, and the protrusion 15 can be easily detached from the groove 10B. The groove 10B is formed so as to surround the entire horizontal direction of the probe, and the projection 15 has a ring shape accordingly.

  Next, a method of using this ultrasonic probe will be described. First, the coupling medium 38 is applied on the outer surface 14 </ b> B of the cover 14 or on the living body surface 20. A coupling medium 38 may be applied to both of them. As an exception, an appropriate amount of coupling medium 38 may be separately applied on the inner surface 14A prior to mounting the cover 14 on the lower case 10.

  In the present embodiment, the plurality of holes 16 are formed over the entire cover 14, but it is also possible to form the plurality of holes 16 only in the central portion or the peripheral portion thereof. In any case, in this embodiment, it is not necessary to form the acoustic medium chamber in the probe case as an airtight space containing the transducer unit, so that the structure of the probe can be simplified and its weight can be reduced. Is possible.

  After the application of the coupling medium 38 as described above, the ultrasonic probe is brought into contact with the living body surface 20, and the reciprocating scanning of the transducer unit 22 is started before or after that. Then, the coupling medium 38 expands in the entire gap between the wave transmitting / receiving surface 36A and the inner surface 14B, and the air existing in such a gap is driven to the outside, and the coupling medium 38 is moved there. Will be satisfied. That is, a good acoustic propagation path is ensured. In this state, ultrasonic diagnosis is executed.

  In other words, by periodically reciprocating the transducer unit 22 while performing electronic scanning of the ultrasonic beam, a three-dimensional echo data capturing area is periodically formed. On the ultrasonic diagnostic apparatus main body side, an ultrasonic three-dimensional image is formed in accordance with the volume data acquired in such a three-dimensional space and displayed.

  After the use of the ultrasonic probe, the cover 14 is removed from the lower case 10, the cover 14 is cleaned, and the main body of the ultrasonic probe itself is also cleaned as necessary. The cover 14 may be replaced for each subject. That is, it may be used as a disposable type.

  Next, another embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to the structure shown in FIG. 1, and the description is abbreviate | omitted.

  In the example shown in FIG. 3, the engaging portion 46 is provided with a screwing structure. Specifically, the fixing ring 50 is provided so as to wrap the ends of the cover 14 and the lower case 10. In this example, a ring-shaped groove is formed inside the fixing ring 50, and a protrusion 48 formed on the upper end portion of the cover 14 is fitted in the groove. Such a protrusion 48 also has a ring shape.

  On the other hand, a screw structure 52 is formed on the upper side of the inner surface of the fixing ring 50, while a screw structure 54 is also formed on the outer side of the lower end of the lower case 10. The fixing ring 50 is screwed and fixed to the lower case 10 by meshing them. In such a state, the cover 14 is securely attached to the lower case 10 via the fixing ring 50. By screwing, the cover 14 can be more reliably attached, and thus there is an advantage that the cover 14 can be effectively prevented from falling off during use of the ultrasonic probe.

  In the example shown in FIG. 4, a partition film 56 is provided around the vibrator unit 22 as a movable body. The partition film 56 has a bellows-like structure in the present embodiment, and itself is configured as a flexible film. That is, it is a deformable membrane. An opening is formed in the central portion of the partition film 56, and a part of the vibrator unit 22 is exposed downward from the opening. The peripheral edge in the opening has a seal structure. The outer periphery of the partition film 56 is fixedly arranged at the upper end of the inner surface of the cover 14 in the example shown in FIG. As a result, a medium chamber 58 is formed in the cover 14. The medium chamber 58 is not an airtight chamber because the cover 14 itself is permeable, but the provision of the partition film 56 unnecessarily expands the coupling medium inside the ultrasonic probe. The problem can be effectively prevented. In other words, the range in which the coupling medium can move can be limited by the partition film 56.

  In the example shown in FIG. 4, the outer periphery of the partition film 56 is fixed to the inner surface of the cover 14, but the outer periphery can also be fixed to the lower case 10. It is desirable that the partition film 56 be made of a flexible material so as not to hinder the movement of the vibrator unit 22 or to give a large resistance thereto, as described above.

  In the embodiment shown in FIG. 5, the transducer unit 22 has protruding portions 62 at both ends in the mechanical scanning direction. The lower end portion of the transducer unit 22 has an arc shape or a ship bottom shape as a whole, and the curvature of the wave transmitting / receiving surface 66 is substantially the same as the curvature of the inner surface of the cover 14. The overhanging portion 62 exerts an action of expanding the transmission / reception surface (the effective transmission / reception surface and the surface connected thereto) shown in FIG. 1 in the mechanical scanning direction, that is, restricts a gap generated between the transmission / reception surface 66 and the cover inner surface. It is possible to effectively suppress the problem that the coupling medium stays or rises on the side surface of the vibrator unit 22.

  6 shows a part of FIG. 5 as an enlarged view. A lower end portion of the lower case 10 faces inward to form a squeegee 64. The squeegee 64 functions as a scraping structure, and scrapes off the coupling medium adhering to the wave transmitting / receiving surface 66 to restrict the movement of the coupling medium upward. The squeegee 64 has a sharp tip, which contacts the wave transmitting / receiving surface 66 intermittently or constantly. In the illustrated example, the tip of the squeegee 64 comes into contact with the wave transmitting / receiving surface 66 when the transducer unit 22 swings by a certain angle or more. When the vibrator unit 22 further swings, the coupling medium attached to the wave transmitting / receiving surface is scraped off by the squeegee 64, and unnecessary development of the coupling medium is suppressed. The squeegee 64 can be made of a resin member or a rubber material, and it is desirable to form the squeegee 64 at a position that does not adversely affect the ultrasonic wave propagation even when the vibrator unit 22 swings. Reference numeral 60 has a vibrator assembly, and an array vibrator is provided at the lower end thereof. A pair of overhang portions 62 are provided in the mechanical scanning direction of the transducer assembly 60, and the above-described various advantages can be obtained by such overhang portions 62.

It is sectional drawing which shows suitable embodiment of the ultrasound probe which concerns on this invention. It is a figure for demonstrating the structure of a cover. It is sectional drawing which shows the other structure of an ultrasonic probe. It is sectional drawing which shows other structure of an ultrasonic probe. It is sectional drawing which shows other structure of an ultrasonic probe. FIG. 6 is a partially enlarged view of the configuration shown in FIG. 5.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Lower case, 12 Upper case, 14 Cover, 17 Engagement part, 22 Vibrator unit, 24 Drive mechanism, 38 Coupling medium.

Claims (6)

A transducer unit provided in the probe case for transmitting and receiving ultrasonic waves;
A mechanical scanning mechanism for mechanically scanning the transducer unit in the probe case;
A part of the probe case on the living body side, and a permeable cover having a number of voids allowing passage of a fluid acoustic medium;
An ultrasonic probe comprising: The ultrasonic probe according to claim 1,
The ultrasonic probe according to claim 1, wherein the permeable cover has a stitch structure, a porous structure, or a multi-slit structure. The ultrasonic probe according to claim 1 or 2,
An ultrasonic probe, characterized in that an detachable structure for detachably attaching the permeable cover to a case main body of the probe case is provided. In the ultrasonic probe according to any one of claims 1 to 3,
The transmission / reception surface of the transducer unit is mechanically scanned in a state of being opposed to the inner surface of the permeable cover,
The ultrasonic probe, wherein the acoustic medium is introduced from a living body through the permeable cover into a gap between the wave transmitting / receiving surface and the inner surface of the permeable cover. In the ultrasonic probe according to any one of claims 1 to 4,
The ultrasonic probe according to claim 1, wherein the transducer unit has a protruding portion that protrudes on both sides of the transmission / reception surface in the mechanical scanning direction. The ultrasonic probe according to any one of claims 1 to 5,
An ultrasonic probe comprising means for damming the acoustic medium in contact with the transmission / reception surface at both ends in the mechanical scanning direction of the transducer unit.

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