JPH036960Y2

JPH036960Y2 -

Info

Publication number: JPH036960Y2
Application number: JP1980097085U
Authority: JP
Priority date: 1980-07-10
Filing date: 1980-07-10
Publication date: 1991-02-21
Also published as: JPS5723599U

Description

【考案の詳細な説明】（産業上の利用分野）本考案は、圧電体を用いた超音波探触子に係
り、特に発射される超音波の収束性を改善した超
音波探触子に関する。[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an ultrasonic probe using a piezoelectric material, and particularly to an ultrasonic probe with improved convergence of emitted ultrasonic waves.

（従来の技術）通常の圧電体を用いた超音波探触子は、生体の
内部構造などを探る超音波診断装置用のプローブ
に用いられる。このプローブは、ダンパ材に取付
けられた平板状の圧電振動子を先端に設けた構造
を有し、このプローブを生体の表面に接触させ、
該圧電振動子から超音波を短時間発射し、生体内
部から反射してくる超音波を該圧電振動子で受信
する。受信された反射波は、超音波診断装置内で
処理され、CRT等により生体の内部構造が表示
される。(Prior Art) An ultrasonic probe using a normal piezoelectric material is used as a probe for an ultrasonic diagnostic device to investigate the internal structure of a living body. This probe has a structure in which a flat piezoelectric vibrator attached to a damper material is provided at the tip, and this probe is brought into contact with the surface of the living body.
The piezoelectric vibrator emits ultrasonic waves for a short time, and the piezoelectric vibrator receives the ultrasonic waves reflected from inside the living body. The received reflected waves are processed within the ultrasound diagnostic device, and the internal structure of the living body is displayed on a CRT or the like.

（考案が解決しようとする問題点）このような従来のプローブは、圧電振動子と生
体との間に空気層を作らないこと、しかも圧電振
動子表面を保護する必要があるため、圧電振動子
の表面を凸レンズ状のシリコンゴムで直接に被覆
するようにしていた。ところが、このプローブを
使用したときは、生体とシリコンゴムとの間に反
射が起きて、生体内の音場を大きく乱すため、生
体内部の構造をはつきりと探ることができないと
いう問題があつた。(Problems that the invention aims to solve) Conventional probes like this do not create an air layer between the piezoelectric vibrator and the living body, and the surface of the piezoelectric vibrator must be protected. The surface of the lens was directly covered with silicone rubber shaped like a convex lens. However, when using this probe, reflection occurs between the living body and the silicone rubber, which greatly disturbs the sound field inside the living body, making it impossible to clearly probe the internal structure of the living body. Ta.

本考案は、上記の点に鑑みてなされたもので、
プローブから生体内に超音波を鋭いビームとして
発射するとにより、プローブと生体との境界で超
音波の反射が起きても生体内の音場を大きく乱さ
ない超音波探触子を提供しようとするものであ
る。 This invention was made in view of the above points,
This aims to provide an ultrasonic probe that does not significantly disturb the sound field inside the living body even if the ultrasound is reflected at the boundary between the probe and the living body by emitting ultrasonic waves as a sharp beam from the probe into the living body. It is.

（問題点を解決するための手段）本考案によれば、圧電体の超音波振動を用いて
生体の内部構造を探査する超音波探触子におい
て、ダンパ材と、このダンパ材に接合された平板
状の圧電振動子と、この圧電振動子に接合された
片面平板状凹面形の断面形状を有する第１の固体
レンズと、この第１の固体レンズの凹面部に一方
の主面が密着して接合され他方の主面が生体に直
接に接触する両面凸形の断面形状を有する第２の
固体レンズとから積層して構成され、かつ前記第
１レンズ内の音速をV₁，前記第２レンズ内の音
速をV₂，前記生体内部での音速をV₀とするとき、 V₁＞V₀かつV₁＞V₂ の関係を有することを特徴とする超音波探触子を
提供できる。(Means for solving the problem) According to the present invention, in an ultrasonic probe that uses ultrasonic vibration of a piezoelectric body to probe the internal structure of a living body, a damper material and a A flat piezoelectric vibrator, a first solid lens having a single-sided flat concave cross-sectional shape bonded to the piezoelectric vibrator, and one principal surface of the first solid lens in close contact with the concave surface. and a second solid lens having a convex cross-sectional shape on both sides, the other main surface of which is in direct contact with the living body, and the sound velocity in the first lens is V ₁ , and the second solid lens has a convex cross-sectional shape. It is possible to provide _an ultrasonic probe characterized by having the relationship of V ₁ >V 0 and V ₁ >V ₂ , where the speed of sound inside the lens is V ₂ and the speed of sound inside the living body is V ₀ .

（作用）本考案の超音波探触子では、第２の固体レンズ
は、第１の固体レンズの凹面部に一方の主面が密
着して接合されるから、第２レンズ内での音波面
は内側に湾曲し、中心線方向に収束し、かつ生体
に直接に接触する他方の主面を多少凸型にして
も、表面が変形して生体内の音場を大きく乱すお
それもない。(Function) In the ultrasonic probe of the present invention, since one principal surface of the second solid lens is closely bonded to the concave portion of the first solid lens, the acoustic wave surface within the second lens is Even if the other main surface, which is curved inward, converges in the direction of the center line, and directly contacts the living body, is made somewhat convex, there is no risk of the surface deforming and greatly disturbing the sound field inside the living body.

（実施例）以下、本考案の一実施例を図面に従つて詳細に
説明する。(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

図面は、本考案の一実施例を示す断面図であ
り、１は円板状を呈し、PZTなどの圧電物質か
らなる圧電体、２は表面電極、３は裏面電極であ
る。表面電極２と裏面電極３の間に電気信号が印
加されると、これに応じて圧電体１が振動し超音
波が発生する。４はダンパ材、５は圧電振動子１
の前面に設けられた断面平凹形の第１レンズであ
る。６０は第１レンズ５の凹部を埋める形状をな
す両面凸状の第２レンズである。７は生体などの
媒質である。 The drawing is a sectional view showing one embodiment of the present invention, in which 1 is a disk-shaped piezoelectric body made of a piezoelectric material such as PZT, 2 is a front electrode, and 3 is a back electrode. When an electric signal is applied between the front electrode 2 and the back electrode 3, the piezoelectric body 1 vibrates in response to the electric signal, and an ultrasonic wave is generated. 4 is a damper material, 5 is a piezoelectric vibrator 1
A first lens having a plano-concave cross section is provided on the front surface of the lens. Reference numeral 60 denotes a second lens having a convex shape on both sides, which fills the concave portion of the first lens 5. 7 is a medium such as a living body.

第１レンズ５、第２レンズ６０はそれぞれ、エ
ポキシ樹脂、シリコンゴムにより構成され、第１
レンズ５の中を伝わる音の速さは媒質７内を伝わ
る音の速さよりも小さく、かつ第２レンズ６０内
を伝わる音速の方が小さい。このため圧電振動子
１で発生した超音波の一部は、第１レンズ５と圧
電振動子１の境界部分より圧電振動子１方向に少
し反射されるが、残りは中心線ｙと平行に、第１
レンズ５内に入リ、第２レンズ６０に向う。 The first lens 5 and the second lens 60 are made of epoxy resin and silicone rubber, respectively.
The speed of sound that travels through the lens 5 is smaller than the speed of sound that travels through the medium 7, and the speed of sound that travels through the second lens 60 is smaller. Therefore, a part of the ultrasonic waves generated by the piezoelectric vibrator 1 is slightly reflected in the direction of the piezoelectric vibrator 1 from the boundary between the first lens 5 and the piezoelectric vibrator 1, but the rest is reflected parallel to the center line y. 1st
It enters the lens 5 and heads toward the second lens 60.

第１レンズ５と第２レンズ６０との境界部分で
も、一部反射が起るが、大半は境界部分を透過し
て、第２レンズ６０に入る。このとき、第１レン
ズ５を構成している物質内の音速よりも第２レン
ズ６０を構成している物質内の音速の方が大きい
ので、第２レンズ６０内での音波面は内側に湾曲
し、中心線ｙ方向に収束しようとする。更に、第
２レンズ６０から媒質７内に伝わるとき、音波の
一部は第２レンズ６０方向に反射されるが、残り
の超音波はいくぶん分散されながらも、依然とし
て中心線ｙに向つて収束し、R'点で焦点を結ぶ
ことになる。なお、この場合に第２レンズ６０内
を伝わる音の速さが、媒質７内を伝わる音の速さ
よりも遅くなるように、第２レンズ６０を構成す
る物質を選択すると、音の収束性は一層向上す
る。 Although some reflection occurs at the boundary between the first lens 5 and the second lens 60, most of the light passes through the boundary and enters the second lens 60. At this time, the sound speed inside the second lens 60 is higher than the sound speed inside the second lens 60 than the sound speed inside the first lens 5, so the sound wave front inside the second lens 60 is curved inward. and tries to converge in the center line y direction. Furthermore, when the ultrasound waves propagate from the second lens 60 into the medium 7, a portion of the ultrasound waves are reflected toward the second lens 60, but the remaining ultrasound waves are somewhat dispersed but still converge toward the center line y. , will focus at point R'. In this case, if the material constituting the second lens 60 is selected so that the speed of sound that travels through the second lens 60 is slower than the speed of sound that travels through the medium 7, the convergence of the sound will be reduced. Improve further.

このように、第２レンズ６０の表面が凸形をし
ているので、生体のように軟らかい物質と接触し
たとき、媒質７の表面が第２レンズ６０の表面と
良く密着するため、この間に隙間ができにくく、
かつ第２レンズ内での音波面は第１レンズとの間
ですでに中心線方向に収束しているから、生体内
の音場を大きく乱さないという利点を有する。 In this way, since the surface of the second lens 60 has a convex shape, when it comes into contact with a soft substance such as a living body, the surface of the medium 7 comes into close contact with the surface of the second lens 60, so there is no gap between them. It is difficult to
In addition, since the sound wave front within the second lens has already converged in the center line direction between the second lens and the first lens, it has the advantage that the sound field within the living body is not significantly disturbed.

（考案の効果）以上説明したように、本考案の超音波探触子
は、ダンパ材と、このダンパ材に接合された平板
状の圧電振動子と、この圧電振動子に接合された
片面平板状凹面形の断面形状を有する第１の固体
レンズと、この第１の固体レンズの凹面部に一方
の主面が密着して接合され他方の主面が生体に直
接に接触する両面凸形の断面形状を有する第２の
固体レンズとから積層して構成され、かつ前記第
１レンズ内の音速をV₁，前記第２レンズ内の音
速をV₂，前記生体内部で音速をV₀とするとき、 V₁＞V₀かつV₁＞V₂ の関係を有する固体レンズとして形成したので、
音の収束性が良くなつて圧電振動子から発せられ
た超音波は効率良く短い焦点を結び、音場の大き
な乱れがなくなる。又、第２レンズは、従来のシ
リコンゴムを直接に貼着するものとは異なり、第
１の固体レンズの凹面部と密着して接合されるか
ら、凸形をなす表面が変形することなく、媒質と
なる生体表面に直接接触し、超音波の伝達効率も
向上する。(Effects of the invention) As explained above, the ultrasonic probe of the invention consists of a damper material, a flat piezoelectric vibrator bonded to the damper material, and a single-sided flat plate bonded to the piezoelectric vibrator. A first solid lens having a concave cross-sectional shape, and a double-convex solid lens having one main surface closely bonded to the concave surface of the first solid lens and the other main surface directly contacting the living body. A second solid lens having a cross-sectional shape is laminated, and the speed of sound in the first lens is V ₁ , the speed of sound in the second lens is V ₂ , and the speed of sound inside the living body is V ₀ Since it is formed as a solid lens with the relationship of V ₁ > V ₀ and V ₁ > V ₂ ,
With improved sound convergence, the ultrasonic waves emitted from the piezoelectric vibrator efficiently focus on a short distance, eliminating large disturbances in the sound field. In addition, unlike conventional silicone rubber that is directly attached, the second lens is closely bonded to the concave surface of the first solid lens, so the convex surface does not deform. Direct contact with the biological surface serving as a medium improves ultrasound transmission efficiency.

[Brief explanation of the drawing]

第１図は、本考案の一実施例を示す断面図であ
る。１…圧電体、２…表面電極、３…裏面電極、４
…ダンパ材、５…第１レンズ、６０…第２レン
ズ、７…媒質。 FIG. 1 is a sectional view showing an embodiment of the present invention. 1... Piezoelectric body, 2... Surface electrode, 3... Back electrode, 4
...damper material, 5...first lens, 60...second lens, 7...medium.

Claims

[Claims for Utility Model Registration] An ultrasonic probe that probes the internal structure of a living body using ultrasonic vibrations of a piezoelectric material, comprising: a damper material; a flat piezoelectric vibrator bonded to the damper material;
a first solid lens having a single-sided flat concave cross-sectional shape bonded to the piezoelectric vibrator;
a second solid lens having a double-convex cross-sectional shape, one main surface of which is closely bonded to the convex surface of the solid lens, and the other main surface of which is in direct contact with a living body, and The speed of sound inside the first lens is
Ultrasonic waves characterized by having the relationship V ₁ > V ₀ and V ₁ > V ₂ , where V ₁ is the sound speed inside the second lens, V ₂ is the sound speed inside the living body, and V ₀ is the sound speed inside the living body. probe.