JPH0690950A - Ultrasonic probe - Google Patents

Ultrasonic probe

Info

Publication number
JPH0690950A
JPH0690950A JP4267799A JP26779992A JPH0690950A JP H0690950 A JPH0690950 A JP H0690950A JP 4267799 A JP4267799 A JP 4267799A JP 26779992 A JP26779992 A JP 26779992A JP H0690950 A JPH0690950 A JP H0690950A
Authority
JP
Japan
Prior art keywords
axis direction
short axis
vibrator
sound pressure
pressure distribution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP4267799A
Other languages
Japanese (ja)
Other versions
JP3325305B2 (en
Inventor
Shigehiro Odaka
誠弘 小高
Makoto Tanpo
誠 反保
Yasuo Ishikawa
保夫 石川
Akira Sasaki
明 佐々木
Toshihiko Kono
敏彦 河野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Healthcare Manufacturing Ltd
Original Assignee
Hitachi Medical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Medical Corp filed Critical Hitachi Medical Corp
Priority to JP26779992A priority Critical patent/JP3325305B2/en
Publication of JPH0690950A publication Critical patent/JPH0690950A/en
Application granted granted Critical
Publication of JP3325305B2 publication Critical patent/JP3325305B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Landscapes

  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Transducers For Ultrasonic Waves (AREA)

Abstract

PURPOSE:To improve the recessed form on the sound pressure distribution in the short axis direction of the ultrasonic wave to be sent by the attenuation of the ultrasonic wave by an acoustic lens and to improve the directivity in the ultrasonic probe focusing the ultrasonic beam in the direction (short axis direction) to be crossed at right angles in a vibrator alignment direction by a projected acoustic lens. CONSTITUTION:A thin film member 3 with the low acoustic impedance at the center in the short axis direction between an alignment vibrator section 1 and a backing member 3 and with the higher acoustic impedance as it goes to the end section is provided. Thus, the effective impedance of the backing member sewing from a piezo-electric vibrator 11 becomes low at the center and becomes high as it goes to the end section. On the other hand, the vibration effeciency of the vibrator 11 becomes high at the center and becomes low as it goes to the end section. Thus, the sound pressure distribution forms a projected shape. As the sound pressure distribution becomes projected in the short axis direction, the focusing effect of the acoustic lens is not damaged and the directive characteristic is improved. Thus, a good image can be obtained and the S/N can be improved.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は超音波診断装置用の超音
波探触子に係り、特に多数の棒状圧電振動子をアレー状
に配列して成る電子走査型超音波探触子における振動子
の配列方向と直交する方向での超音波の指向性を改善す
る技術に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe for use in an ultrasonic diagnostic apparatus, and more particularly to a vibrator in an electronic scanning ultrasonic probe having a large number of rod-shaped piezoelectric vibrators arranged in an array. The present invention relates to a technique for improving the directivity of ultrasonic waves in a direction orthogonal to the arrangement direction of.

【0002】[0002]

【従来の技術】電子走査型超音波探触子は、各種文献で
も公知のように、細長い棒状の圧電振動子を吸音材(バ
ッキング材ともいう)の上にアレー状に配置し、その圧
電振動子の上面に複数層の音響整合層を設け、さらにそ
の音響整合層の上を音響レンズで覆って構成されている
のが一般的である。
2. Description of the Related Art As is well known in various documents, an electronic scanning ultrasonic probe has piezoelectric rod-shaped piezoelectric vibrators arranged in an array on a sound absorbing material (also called a backing material). Generally, a plurality of acoustic matching layers are provided on the upper surface of the child, and the acoustic matching layers are covered with an acoustic lens.

【0003】上記探触子の構成要素のうち、音響レンズ
は圧電振動子の配列方向と直交する方向(以下、短軸方
向という)へ超音波を集束する目的で設けられている。
そして、通常、音響レンズによる短軸方向への超音波集
束は超音波の伝播速度を利用して行うこと、及び、探触
子を被検体の体表へ密着させ易くすること等から、その
形状は横断面中央部が厚い蒲鉾状に形成されている。こ
の形状によって、細長い棒状の圧電振動子の端部からの
超音波は早く被検体内へ、そして中央部からの超音波は
遅く被検体内へ伝播され、結果的に短軸方向への超音波
ビームの集束が行われるというものである。
Among the constituent elements of the above-mentioned probe, the acoustic lens is provided for the purpose of focusing ultrasonic waves in a direction orthogonal to the arrangement direction of the piezoelectric vibrators (hereinafter referred to as the minor axis direction).
And, in general, the ultrasonic focusing in the short axis direction by the acoustic lens is performed by utilizing the propagation velocity of the ultrasonic waves, and since it is easy to bring the probe into close contact with the body surface of the subject, its shape Is formed in the shape of a semi-cylindrical barb with a thick central cross section. Due to this shape, the ultrasonic waves from the end of the elongated rod-shaped piezoelectric vibrator propagate quickly into the subject, and the ultrasonic waves from the central part propagate slowly into the subject, resulting in ultrasonic waves in the short axis direction. The beam is focused.

【0004】[0004]

【発明が解決しようとする課題】上記従来技術によれ
ば、短軸方向への超音波ビームの集束がなされはする
が、他面、音響レンズの厚みによる減衰により被検体中
での短軸方向での音圧分布が音響レンズの凸形とは逆に
凹形となってしまい、ビーム指向性の面では良い結果を
もたらしているとは言えないものであった。
According to the above-mentioned prior art, although the ultrasonic beam is focused in the short axis direction, on the other side, the attenuation due to the thickness of the acoustic lens causes the short axis direction in the subject. The sound pressure distribution in Fig. 2 was concave, as opposed to the convex shape of the acoustic lens, and it could not be said that it brought good results in terms of beam directivity.

【0005】本発明は上記に鑑みて成されたもので、被
検体へ密着させ易い従来の凸形音響レンズの形状を変え
ることなく、短軸方向への音圧分布を改良し、結果とし
超音波ビームの指向性を改善し良好な超音波像が得られ
る超音波探触子を提供することを目的としている。
The present invention has been made in view of the above, and improves the sound pressure distribution in the short axis direction without changing the shape of the conventional convex acoustic lens that is easily adhered to the subject. It is an object of the present invention to provide an ultrasonic probe capable of improving the directivity of a sound beam and obtaining a good ultrasonic image.

【0006】[0006]

【課題を解決するための手段】本発明は上記目的を達成
するために、細長い棒状圧電振動子をバッキング材上に
多数配列するとともに、前記圧電振動子群の上面に音響
整合層と蒲鉾状音響レンズを積層して成る超音波探触子
において、前記圧電振動子群とバッキング材との間に、
圧電振動子の配列方向に直交する方向にて、中央部が音
響インピーダンスを小さく端部へ行くにしたがい音響イ
ンピーダンスを大きくした薄膜材を設けたものである。
In order to achieve the above object, the present invention arranges a large number of elongated rod-shaped piezoelectric vibrators on a backing material, and at the same time, arranges an acoustic matching layer and a semi-cylindrical sound on the upper surface of the piezoelectric vibrator group. In an ultrasonic probe formed by stacking lenses, between the piezoelectric vibrator group and the backing material,
In the direction orthogonal to the arrangement direction of the piezoelectric vibrators, a thin film material is provided in which the central part has a small acoustic impedance and the acoustic impedance increases as it goes to the ends.

【0007】[0007]

【作用】バッキング材と上記薄膜材と圧電振動子とを積
層した場合、圧電振動子から見たバッキング材の実効イ
ンピーダンスが短軸方向の中央部から端部へ行くにした
がって大きくなるため、棒状の圧電振動子の振動効率
(送波効率と言っても良い)は中央部が高く、端部へ行く
にしたがって低下する。したがって、音響レンズが中央
部で凸状となっていることによる音圧分布の中央部での
凹形が補償される。
When the backing material, the thin film material, and the piezoelectric vibrator are laminated, the effective impedance of the backing material seen from the piezoelectric vibrator increases from the central portion to the end portion in the minor axis direction, and thus the rod-shaped Vibration efficiency of piezoelectric vibrator
(It may be called the transmission efficiency) is high in the central part and decreases toward the edges. Therefore, the concave shape in the central portion of the sound pressure distribution due to the convex shape of the acoustic lens is compensated.

【0008】[0008]

【実施例】以下、本発明の一実施例を図1を用いて説明
する。図1は電子走査型超音波探触子の内部構成を説明
するために一部を省略及び断面にして示している。図1
において、1はPZTより成り音響インピーダンスが2
0×106kg/m2・secの圧電振動子11をアレー状に
多数配列して成る振動子部、3はバッキング材で圧電振
動子11の励振時に振動子の背面へ放射される超音波を
吸収・減衰させるもので、材料としては例えば、音響イ
ンピーダンスがZB=7.5×106kg/m2・secのフェ
ライトゴムが用いられるもの、4は音響整合層で超音波
の波長をλとしたとき膜厚がλ/4のものを複数積層し
て超音波が生体へ侵入し易くするもの、5は前にも述べ
た音響レンズである。以上の構成は従来の探触子と同様
である。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a part of the electronic scanning ultrasonic probe with an omission and a cross section for explaining the internal structure. Figure 1
, 1 is made of PZT and has an acoustic impedance of 2
A vibrator unit 3 in which a large number of 0 × 10 6 kg / m 2 · sec piezoelectric vibrators 11 are arranged in an array is a backing material, and ultrasonic waves are radiated to the back surface of the vibrator when the piezoelectric vibrator 11 is excited. For absorbing and attenuating, for example, a ferrite rubber having an acoustic impedance of Z B = 7.5 × 10 6 kg / m 2 · sec is used as a material, 4 is an acoustic matching layer, and is a wavelength of ultrasonic waves. When λ is set, a plurality of films having a film thickness of λ / 4 are laminated to facilitate the penetration of ultrasonic waves into the living body, and 5 is the acoustic lens described above. The above configuration is similar to that of the conventional probe.

【0009】次に本発明の特徴点を説明する。図1にお
いて、2は3種の材料で複合構成された薄膜材で、圧電
振動子から見たバッキング材の実効インピーダンスを短
軸方向に対する位置に応じて変化させるものである。薄
膜材2は厚みがλ/4で、短軸方向の中央部に位置する
ポリウレタン樹脂部21と、その両隣に位置するエポキ
シ樹脂部22と、両端部に位置するフェライトゴム部2
3とから構成している。それらの音響インピーダンスZ
21,Z22,Z23は、Z21<Z22<Z23となるように、例
えばZ21=2.2×106kg/m2・sec,Z22=3.3×
106kg/m2・sec,Z23=7.5×106kg/m2・se
cとする。
Next, the features of the present invention will be described. In FIG. 1, reference numeral 2 denotes a thin film material composed of three kinds of materials, which changes the effective impedance of the backing material viewed from the piezoelectric vibrator according to the position in the short axis direction. The thin film material 2 has a thickness of λ / 4 and has a polyurethane resin portion 21 located at the center in the short axis direction, epoxy resin portions 22 located on both sides of the polyurethane resin portion 21, and ferrite rubber portions 2 located at both ends.
It is composed of 3 and. Their acoustic impedance Z
21 , Z 22 and Z 23 are set so that Z 21 <Z 22 <Z 23 , for example, Z 21 = 2.2 × 10 6 kg / m 2 · sec, Z 22 = 3.3 ×.
10 6 kg / m 2 · sec, Z 23 = 7.5 × 10 6 kg / m 2 · se
Let c.

【0010】この場合、圧電振動子11から見たバッキ
ング材の実効インピーダンスはそれぞれの部分で、(Z
21)2/ZB ,(Z22)2/ZB ,(Z23)2/ZBで表わさ
れ、(Z21)2/ZB=0.6×106kg/m2・sec,(Z
22)2=1.5×106kg/m2・sec,(Z23)2=7.5×
106kg/m2・secとなる。これにより、各部分での圧
電振動子の振動効率は、中央部においては20/(20
+0.6)=0.97=97%、中央部に隣接する部分で
は20/(20+1.5)=0.93=93%、両端部では
20/(20+7.5)=0.727=72.7%となる。
In this case, the effective impedance of the backing material viewed from the piezoelectric vibrator 11 is (Z
21 ) 2 / Z B , (Z 22 ) 2 / Z B , (Z 23 ) 2 / Z B , and (Z 21 ) 2 / Z B = 0.6 × 10 6 kg / m 2 · sec , (Z
22 ) 2 = 1.5 × 10 6 kg / m 2 · sec, (Z 23 ) 2 = 7.5 ×
It becomes 10 6 kg / m 2 · sec. As a result, the vibration efficiency of the piezoelectric vibrator in each part is 20 / (20
+0.6) = 0.97 = 97%, 20 / (20 + 1.5) = 0.93 = 93% in the part adjacent to the central part, 20 / (20 + 7.5) = 0.727 = 72 in both ends It becomes 0.7%.

【0011】したがって、単一の細長い棒状圧電振動子
を励振させた場合音圧分布は、中央部では音圧が高く、
端部へ行くにしたがって音圧は低下する。これによっ
て、音響レンズ5から被検体へ侵入する超音波の音圧分
布が従来の凹形から逆に凸形にすることができる。これ
は言葉を替えれば、短軸方向への超音波ビームが細く鋭
くなり、指向性が改善されたことと等価である。
Therefore, when a single elongated rod-shaped piezoelectric vibrator is excited, the sound pressure distribution is high in the central part,
The sound pressure decreases toward the edges. As a result, the sound pressure distribution of the ultrasonic waves entering the subject from the acoustic lens 5 can be changed from the conventional concave shape to a convex shape. In other words, this is equivalent to improving the directivity by making the ultrasonic beam in the short-axis direction narrower and sharper.

【0012】以上、本発明の一実施例を説明したが、本
発明は上記実施例に限定されることなく、要旨を逸脱し
ない範囲で変形が可能である。例えば、上記実施例では
音圧分布を変えるための薄膜材を3種類の異なる音響イ
ンピーダンス部材の複合部材としたが、音圧分布をより
滑らかにするために4種類以上の部材の複合材としても
良い。
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified without departing from the scope of the invention. For example, in the above embodiment, the thin film material for changing the sound pressure distribution is a composite member of three kinds of different acoustic impedance members, but it may be a composite material of four or more kinds of members in order to make the sound pressure distribution smoother. good.

【0013】[0013]

【発明の効果】以上述べたように本発明によれば、振動
子部とバッキング材との間に短軸方向に音響インピーダ
ンスが変化する薄膜材を設けたことにより、探触子から
の超音波の短軸方向への音圧分布を従来の凹形から凸形
へ変えられ、これにより超音波ビームの短軸方向への指
向性を改善することができる。したがって超音波画像は
被検体の薄いスライス厚のものが得られ、画質も良くな
る。更に付随的効果として、サイドローブの減少ももた
らされ、S/N向上も計れる。
As described above, according to the present invention, since the thin film material whose acoustic impedance changes in the minor axis direction is provided between the transducer portion and the backing material, the ultrasonic wave from the probe is The sound pressure distribution in the short axis direction of can be changed from the conventional concave shape to the convex shape, which can improve the directivity of the ultrasonic beam in the short axis direction. Therefore, an ultrasonic image having a thin slice thickness of the subject is obtained, and the image quality is improved. As a side effect, side lobes are reduced and S / N can be improved.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例の超音波探触子の内部構造を
一部断面して示した斜視図。
FIG. 1 is a perspective view showing a partial cross section of an internal structure of an ultrasonic probe according to an embodiment of the present invention.

【符号の説明】[Explanation of symbols]

1 振動子部 2 薄膜材 3 バッキング材 4 音響整合層 5 音響レンズ 1 Transducer part 2 Thin film material 3 Backing material 4 Acoustic matching layer 5 Acoustic lens

───────────────────────────────────────────────────── フロントページの続き (72)発明者 佐々木 明 千葉県柏市新十余二2番1号 株式会社日 立メディコ大阪工場柏分工場内 (72)発明者 河野 敏彦 千葉県柏市新十余二2番1号 株式会社日 立メディコ大阪工場柏分工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Sasaki 2-1, Shinjuyo, Kashiwa-shi, Chiba Prefecture Nitto Medico Osaka Plant Kashiwabu Plant (72) Inventor Toshihiko Kono 2-2, Shinjuyo, Kashiwa-shi, Chiba Prefecture No. 1 Nitrate Medico Osaka Factory Kashiwabu Factory

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】細長い棒状圧電振動子をバッキング材上に
多数配列するとともに、前記圧電振動子群の上面に音響
整合層と蒲鉾状音響レンズを積層して成る超音波探触子
において、前記圧電振動子群とバッキング材との間に、
圧電振動子の配列方向に直交する方向にて、中央部が音
響インピーダンスを小さく端部へ行くにしたがい音響イ
ンピーダンスを大きくした薄膜材を設けたことを特徴と
する超音波探触子。
1. An ultrasonic probe in which a large number of elongated rod-shaped piezoelectric vibrators are arranged on a backing material, and an acoustic matching layer and a semi-cylindrical acoustic lens are laminated on the upper surface of the piezoelectric vibrator group. Between the transducer group and the backing material,
An ultrasonic probe comprising a thin film material having a low acoustic impedance at the center and a high acoustic impedance as it goes to the end in a direction orthogonal to the array direction of the piezoelectric vibrators.
JP26779992A 1992-09-11 1992-09-11 Ultrasonic probe Expired - Lifetime JP3325305B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP26779992A JP3325305B2 (en) 1992-09-11 1992-09-11 Ultrasonic probe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP26779992A JP3325305B2 (en) 1992-09-11 1992-09-11 Ultrasonic probe

Publications (2)

Publication Number Publication Date
JPH0690950A true JPH0690950A (en) 1994-04-05
JP3325305B2 JP3325305B2 (en) 2002-09-17

Family

ID=17449762

Family Applications (1)

Application Number Title Priority Date Filing Date
JP26779992A Expired - Lifetime JP3325305B2 (en) 1992-09-11 1992-09-11 Ultrasonic probe

Country Status (1)

Country Link
JP (1) JP3325305B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4326372A1 (en) * 1992-08-05 1994-02-10 Mitsubishi Electric Corp Exhaust gas cleaning system for IC engine using catalyser - uses heating system with wind guard to introduce heated air at air inlet pipe upstream of catalyser connected to exhaust gas pipe
US7388317B2 (en) 2003-02-27 2008-06-17 Murata Manufacturing Co., Ltd Ultrasonic transmitting/receiving device and method for fabricating the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4326372A1 (en) * 1992-08-05 1994-02-10 Mitsubishi Electric Corp Exhaust gas cleaning system for IC engine using catalyser - uses heating system with wind guard to introduce heated air at air inlet pipe upstream of catalyser connected to exhaust gas pipe
US7388317B2 (en) 2003-02-27 2008-06-17 Murata Manufacturing Co., Ltd Ultrasonic transmitting/receiving device and method for fabricating the same

Also Published As

Publication number Publication date
JP3325305B2 (en) 2002-09-17

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