JP3462904B2 - Needle-shaped ultrasonic probe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe for an ultrasonic diagnostic apparatus, and more particularly to a needle-shaped ultrasonic probe suitable for diagnosing a tissue property of a deep layer in a subject and for high resolution imaging.

[0002]

2. Description of the Related Art A biopsy is known as a method for diagnosing a lesion occurring in an organ. This is to visualize the internal organs in the body cavity with an ultrasonic imaging device, insert a puncture needle to the lesioned part, introduce living tissue of the lesioned part into the needle and collect it. It is to make a diagnosis. However, this method has a problem that it cannot be diagnosed immediately because the living tissue is removed from the body and then examined, and that the tissue changes from the state in the living body. Therefore, a puncture needle has been proposed in which an ultrasonic transducer is attached to the puncture needle and the puncture needle is directly inserted into the lesion site to measure the tissue properties of the lesion site, specifically, the acoustic characteristics of the lesion site. The puncture needle equipped with an ultrasonic transducer proposed so far is disclosed in Japanese Examined Patent Publication No. 4-7829.
As in No. 9, the needle is provided with a concave portion and an ultrasonic transducer is provided on the wall surface thereof, or as in Japanese Patent Publication No. 5-125, the inner needle of the puncture needle and the ultrasonic transducer can be exchanged.

[0003]

In order to quantitatively measure the acoustic characteristics of living tissue, it is necessary to accurately determine the distance traveled by ultrasonic waves. In this case, it is more accurate to slice the living tissue into a known thickness and measure the transmitted wave thereof than to measure the reflected wave from the living tissue. Further, in order to inspect the fine structure of the lesion, it is necessary to image the living tissue of the lesion, but for this purpose, resolution of at least about several tens of μm is required. In order to obtain high resolution, it is desirable that the center frequency of the transmitted / received waves of the ultrasonic transducer is a high frequency of 50 MHz or higher, but the high frequency ultrasonic waves are largely attenuated in the living body and the reflected waves from the living tissue are Difficult to detect. Therefore, in order to diagnose the living tissue from its acoustic characteristics or to image it with high resolution, the transmitted ultrasonic waves that pass through the living tissue or the pseudo-transmitted ultrasonic waves that pass through the living tissue and are reflected from the reflecting material are measured. It is useful to Also, in the conventional biopsy, the puncture needle is inserted while referring to the image obtained by the ultrasonic probe closely attached to the body surface, but the biopsy is proficient to some extent in order to accurately insert the lesion. There was a need. In order to solve these problems in the prior art, the present invention is a puncture needle-like ultrasonic probe that can be inserted while exploring an observation site (lesion tissue) and that can easily measure transmitted ultrasonic waves or pseudo transmitted ultrasonic waves. The purpose is to provide a tentacle.

[0004]

[Problems to be Solved by the Invention] In order to quickly diagnose a diseased tissue in a subject, in a puncture needle that directly punctures in the subject, a pair of an ultrasonic transducer and an ultrasonic reflector, or At least one pair of the first ultrasonic transducer and the second ultrasonic transducer is installed so as to face each other in a direction perpendicular to the axis of the puncture needle, and the ultrasonic transducer and the ultrasonic reflecting material face each other. Alternatively, the living tissue is introduced between the first ultrasonic transducer and the second ultrasonic transducer. The first and second ultrasonic transducers, the coating layer or the reflecting material that covers the first and second ultrasonic transducers are formed in a curved shape to converge the ultrasonic waves, and the first and second ultrasonic waves. Increase the efficiency of ultrasonic wave transmission / reception of the transducer. Further, in order to simplify the structure of the puncture needle, at least a part of the needle also serves as a back surface sound absorbing material and a reflecting material. In order to facilitate accurate insertion of the puncture needle into the lesion site, the above-mentioned first and second points are provided on the outer surface of the puncture needle or the tip of the inner needle for introducing living tissue into the puncture needle. An ultrasonic transducer different in frequency from the ultrasonic transducer is provided. Also,
In order to image the biological tissue introduced into the needle with high resolution, relative to the tissue introduced into the needle, in the longitudinal axis direction of the puncture needle, or in the rotation direction with the longitudinal axis as the rotation axis,
The ultrasonic transducer can be moved and moved. This movement and movement can be performed simply by moving the needle-shaped ultrasonic probe itself. Further, in order to facilitate the diagnosis, a device for comparing the obtained data with a reference value is provided.

[0005]

The first and second ultrasonic transducers positioned so as to sandwich the living tissue introduced into the inner space of the puncture needle are the tip of the inner needle of the puncture needle or the outer surface of the outer needle of the puncture needle. Since the center frequency of the ultrasonic waves to be transmitted and received is set higher than that of the ultrasonic transducer provided in, the ultrasonic transducer provided on the tip of the inner needle or on the outer surface of the outer needle has a wider range. In contrast to the measurement, the first and second ultrasonic transducers positioned so as to sandwich the living tissue are suitable for measuring the narrower range in detail. Similar to the conventional biopsy, when the puncture needle is inserted while referring to the image by the ultrasonic probe closely attached to the body surface of the subject, it is obtained from the above low-frequency ultrasonic transducer. The puncture needle can be inserted into the subject while monitoring the signal to detect surrounding blood vessels and the like and exploring (monitoring) the biological tissue (lesion site) to be observed. After the tip of the puncture needle reaches the observation site, the inner needle is moved to move the living tissue at the observation site to a high-frequency ultrasonic transducer and an ultrasonic reflecting material, or a first high-frequency ultrasonic transducer. Second
Introduced between the high-frequency ultrasonic transducer. After a while,
With this high-frequency ultrasonic transducer and the first and second high-frequency ultrasonic transducers, the acoustic characteristics of the living tissue at the observation site (attenuation, sound velocity, or their frequency spectrum) are measured,
The result can be compared with a reference value and shown to facilitate a doctor's diagnosis. Further, when the living tissue of the observation site is imaged, the needle-shaped ultrasonic probe is moved in the longitudinal axis direction or the rotation direction around the longitudinal axis as necessary.

[0006]

EXAMPLES Examples of the present invention will be described below. The materials and numerical values shown in the following description are examples, and the values are not necessarily the same.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
7 is a cross-sectional view showing a state in which the needle-shaped ultrasonic probe of the example of FIG. The outer needle has a diameter of 1 mm or less,
The thickness of about 500 μm is suitable because the load on the subject is small. In the present embodiment, the thin film ultrasonic transducers 2 and 2'that face the hollow outer needle wall with the central axis of the outer needle sandwiched therebetween.
A plurality of pairs are provided, and further the tip portion of the solid inner needle 20 is
A low-frequency ultrasonic transducer 3 for monitoring is also provided on the surface of the inner needle in the axial direction. The thin film ultrasonic transducer 2 provided on the wall surface of the outer needle is formed of a thin film of ZnO (zinc oxide),
The center frequency of the transmitted and received waves is 100 MHz, and the distance between the ultrasonic transducer pairs 2 and 2 ′ facing each other is 200 μm.

Further, the ultrasonic transducer 3 for exploration is formed of a thin film of PZT (lead zirconate titanate), and the center frequency of transmission / reception is preferably about 40 MHz. In order to make a diagnosis, first, with the tip positions of the inner needle and the outer needle aligned, a needle-like ultrasonic probe is inserted into the subject in the same manner as a conventional puncture needle. At this time, the ultrasonic transducer 3 for exploration is used to probe the surrounding blood vessels and the boundary between normal tissue and the observation site (lesioned tissue), etc., and insert the probe, and the tip of the inner needle reaches the observation site. To stop. After that, hold the position of the inner needle,
The outer needle 10 is further inserted into the internal observation site. Therefore, the living tissue of the observation site is exclusively introduced into the hollow outer needle,
A plurality of pairs of the ultrasonic transducers 2 facing each other are positioned so as to sandwich them vertically as shown in FIG. In this state, ultrasonic waves are transmitted and received between the ultrasonic transducers forming a pair, and the acoustic characteristics of the living tissue introduced into the outer needle are measured. This corresponds to the state shown in FIG. Each of the ultrasonic transducers is covered with a coating layer 30 that also functions as an acoustic matching layer formed by laminating epoxy resin, polyurethane, or these, and a part of the outer needle that is the back surface of the ultrasonic transducer is It is composed of a sound absorbing material such as butyl rubber mixed with tungsten powder. Signal lines 40 and 40 ′ for transmitting and receiving a transmission / reception signal are connected to each ultrasonic transducer, but for simplicity, only a part thereof is shown in FIG. 1. In this embodiment, ultrasonic waves are transmitted and received between the ultrasonic transducers facing each other, but one of the ultrasonic transducers is an ultrasonic reflecting material such as stainless steel and the transmitted ultrasonic wave is converted. The container may receive the reflected wave from the reflector. Generally, when a living body is irradiated with ultrasonic waves, the transmitted wave has a larger signal amount than the reflected wave. Therefore, the probe of the present invention for detecting the transmitted wave of living tissue can receive even a high-frequency ultrasonic signal with large attenuation. It is possible. In FIG. 1, the ultrasonic transducers 2 and 2 ′ are either flat or curved along the inner circumference of the outer needle.

As a method for introducing living tissue into the outer needle, the tip positions of the inner needle and the outer needle are aligned and a needle-shaped ultrasonic probe is inserted into the diseased tissue of the subject, and then the inner needle is pulled. Thus, the pressure in the outer needle may be lowered, and the biological tissue may be introduced into the outer needle in the same manner as the inhalation principle when blood is collected from the subject with the injection needle. As described above, the pressure between the pair of ultrasonic transducers and the ultrasonic reflectors facing each other or the pressure between the pair of ultrasonic transducers can be lowered to introduce the living tissue between the pairs.

(Second Embodiment) FIG. 2 is a second embodiment different from FIG. 1, and is a sectional view showing the inside of the needle of the needle-shaped ultrasonic probe in detail. 2A is a cross-sectional view taken along the central axis direction including the central axis of the needle, and FIG. 2B is a sectional view taken along a plane orthogonal to the central axis of the needle (AA in FIG. 2A). (Partial cross section)
Indicates. In FIG. 2, the signal wiring is omitted for simplicity. In this embodiment as well, the living tissue at the observation site is introduced into the outer needle in exactly the same way as in FIG. 1, but two ultrasonic transducer pairs 2a, 2 which face each other and have different distance intervals.
b, the biological tissue is simultaneously introduced between any pair thereof. The distance between the pair of ultrasonic transducers 2a and 2b is, for example, 200 μm (in pair 2a) and 10 respectively.
0 μm (in pair 2b). Therefore, the acoustic characteristics of biological tissues having different thicknesses can be simultaneously measured. In the embodiment of FIG. 1, the low-frequency ultrasonic transducer 3 for exploration (monitor) is provided on the axial surface of the inner needle, but as shown in FIG. The ultrasonic transducer 3'for use may be arranged, and on the surface of the transducer 3 ', an epoxy resin, polyurethane, or a coating layer 30' which is formed by laminating these and also serves as an acoustic matching layer is arranged. ing. In FIG. 2, the ultrasonic transducers 2 and 2 ′ have a planar shape, but may have a curved surface configuration.

(Third Embodiment) FIG. 3 is a sectional view of a third embodiment used for the same purpose as in FIGS. 1 and 2. FIG. 3A is a sectional view in the direction of the central axis including the central axis of the needle,
FIG. 3B shows a cross-sectional view (cross-sectional view taken along the line AA ′ in FIG. 3A) taken along a plane orthogonal to the central axis of the needle. In this embodiment,
A plurality of recesses are formed on the outer periphery of the inner needle in a direction substantially orthogonal to the central axis of the inner needle, and ultrasonic transducers 2 and 2 ″ are arranged on the bottom surfaces of these recesses. ,
A coating layer 30 which also serves as an acoustic matching layer is arranged on the 2 ″ surface similarly to the configuration of FIG. 2. Further, similarly to the configuration of FIG. An ultrasonic transducer 3 ″ for a monitor is provided. In the state shown in FIG. 3, the living tissue at the observation site is introduced into the concave portion, after which the inner needle is operated to move the position of the inner needle, and the concave portion is accommodated in the outer needle as indicated by the dotted line. At this time, the biological tissue piece 4 at the observation site is introduced into the space between the inner needle 25 and the outer needle 15. Figure 3
The sectional view of (b) illustrates this state. In this embodiment, the inner needle 25 also serves as the back surface sound absorbing material of the ultrasonic transducer, and the ultrasonic transducers 2 and 2 ″ are arranged at the bottom of the concave portion. The thickness of the removable portion 26 can be changed as 26 to optimize the measurement of the acoustic characteristics of the introduced tissue piece 4. The outer needle 15 opposes the tissue piece of the observation site introduced into the recess. In the present embodiment, the outer needle is, for example, stainless steel and also serves as a sound wave reflecting material,
The transmitted ultrasonic transducer 2 also receives the reflected wave. Contrary to the present embodiment, the effect of the present invention can be obtained even if the outer needle is provided with an ultrasonic transducer and the inner needle is provided with a reflecting material. Needless to say, ultrasonic transducers may be provided on both the inner needle and the outer needle. Also in the present embodiment, the depth of the recess is in two stages, and it is possible to simultaneously measure the biological tissues having different thicknesses in the same manner as the embodiment of FIG. In the embodiments of FIGS. 2 and 3, the ultrasonic wave transducers 3 ′ and 3 ″ for exploration (monitoring) are arrayed, and more detailed exploration is possible.
In FIG. 3, the ultrasonic transducers 2 and 2 ″ have a planar shape, but may have a curved surface configuration.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention, showing a cross section orthogonal to the axis of the needle. In the present embodiment, the biological tissue is introduced into the outer needle so that its cross section is circular, and the plurality of ultrasonic transducers 2 surround it. That is, on the inner peripheral surface of the outer needle 10, a plurality of ultrasonic transducers 2 which are separated from each other and form a curved surface that operate independently are arranged. Each of the ultrasonic transducers 2 has a coating layer 30 which also serves as an acoustic matching layer forming a curved surface. The configuration shown in FIG. 4 has a configuration suitable for obtaining a tomographic image of a biological tissue, like ultrasonic CT which is a known technique. When the number of ultrasonic transducers 2 is not sufficient to obtain a tomographic image, the position of the needle is rotated around the central axis of the needle with respect to the living tissue (observation site) (see the arrow in FIG. 4). Direction, mechanically move and transmit / receive, or electrically select the ultrasonic transducers to be transmitted / received to operate each ultrasonic transducer) and obtain sufficient signals to obtain tomographic images A high quality tomographic image can be obtained. In this embodiment, in order to prevent the transmitted ultrasonic waves from spreading and weakening the strength of the received waves, the ultrasonic transducer 2 has a curved surface and has a structure for converging the ultrasonic waves. .

The center frequency of the ultrasonic transducer is 10
About 0 MHz to 400 MHz is preferable. The obtained azimuth resolution and position resolution are respectively center frequency 100.
30 μm, 20 μm for ultrasonic transducers of MHz, 10 μm, 10 μ for ultrasonic transducers of center frequency 400 MHz
It is about m. While increasing the center frequency improves the resolution, the absorption of ultrasonic waves by the living body increases and the amount of signals that can be obtained decreases, but the dynamic range of the electrical circuit system that transmits and receives ultrasonic waves is set to an appropriate condition. As a result, the ultrasonic signal can be effectively received.

(Fifth Embodiment) FIGS. 4 and 5 show the fourth and fifth embodiments of the present invention. Instead of the coating layer 30 which also serves as the acoustic matching layer in the construction of the above fourth embodiment. In Fig. 5
As in the fifth embodiment shown in FIG. 5, the coating layer 35 also serving as an acoustic lens such as sapphire or quartz is formed on the surface of the planar ultrasonic transducer 2 and the surface of the outer needle 10 so as to form a curved surface. May be. Inside the outer needle, there is not enough space to install an acoustic lens that converges the ultrasonic waves,
This structure is particularly useful. Also in the first to third embodiments, similarly to the present embodiment, the planar ultrasonic transducer and the acoustic lens are arranged on the inner surface of the outer needle in the same manner as in the configuration of FIG. May be configured to converge.

(Sixth Embodiment) An ultrasonic diagnostic apparatus including a needle-like ultrasonic probe according to any of the above-described embodiments and its operation will be described with reference to FIG. Similar to the conventional biopsy, the ultrasonic probe 5 closely attached to the body surface of the subject.
The needle-shaped ultrasonic probe 1 is inserted while referring to the entire image obtained by. Here, the acoustic characteristics of the living tissue at the position of the needle tip are monitored by the ultrasonic transducer for low-frequency exploration in the puncture needle, and the surrounding blood vessels and discontinuities in the acoustic characteristics are investigated (monitored). Information, ultrasonic probe 5
It is displayed on the same screen as the whole image obtained by. The inner needle of the puncture needle is operated at the position reaching the boundary of the observation site to introduce the biological tissue of the observation site into the needle. After that, the ultrasonic transducer provided inside the needle is operated to measure the properties of the introduced tissue, specifically its acoustic characteristics (attenuation, sound velocity, or their frequency spectrum), and compare it with a reference value. This facilitates diagnosis. Here, it is assumed that the reference value is set in advance based on clinical data such as an actual measurement value of the acoustic characteristics of the excised lesioned tissue. Further, the obtained data is processed to image the cross section of the diseased tissue. The comparator for comparing with the reference value does not need to be an independent device, and may be software of a computer. If the needle-shaped ultrasonic probe or the inner needle thereof is removed from the subject, the living tissue can be collected in the same manner as in the conventional puncture needle, and therefore, the tissue discrimination can be performed in the same manner as in the related art.

In FIG. 6, the wave transmitted / received by the ultrasonic probe 5 is transmitted / received by a wave transmitter / receiver 50, and the wave transmitted / received by the probe ultrasonic transducer in the needle-shaped ultrasonic probe 1 is transmitted / received by a wave transmitter / receiver 50 '. The control and signal processing of the respective transmitted / received signals are executed by the signal processing device 52, and the result is displayed on the display device 54 as a whole image. Further, in the needle-shaped ultrasonic probe 1, the position of the ultrasonic transducer provided inside the needle and for measuring the acoustic characteristics of the tissue introduced into the needle is controlled by the moving device 56 to transmit and receive waves. The transmission / reception device 58 controls the signal of the transmission / reception and the signal processing is executed by the signal processing device 62, and the result is displayed on the display device 64 as an image of the lesion tissue. The above reference value is stored in the acoustic characteristic comparator 60 or the signal processing device 62, and the signal transmitted / received from the wave transmitting / receiving device 58 is compared in the acoustic characteristic comparator 60 for comparison with the reference value. Or it is compared with a reference value in the signal processing device 62.

[0017]

As described above, by using the needle-like ultrasonic probe according to the present invention in place of the conventional biopsy puncture needle, it becomes possible to diagnose the tissue property of a lesion during puncture, There is no need to distinguish it separately. It is also possible to image living tissue.

[Brief description of drawings]

FIG. 1 is a sectional view of a needle-shaped ultrasonic probe according to a first embodiment of the present invention inserted into a subject.

FIG. 2 is a sectional view of a needle-shaped ultrasonic probe according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a needle-shaped ultrasonic probe according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a needle-shaped ultrasonic probe according to a fourth embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of a needle-shaped ultrasonic probe according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration example of an ultrasonic diagnostic apparatus including the needle-shaped ultrasonic probe of the present invention.

[Explanation of symbols]

1 ... Needle-like ultrasonic probe, 2, 2 ', 2 "... Ultrasonic transducer 3, 3', 3" ... Ultrasonic transducer for exploration, 4 ... Lesion site, 5 ... Conventional ultrasonic probe Tactile, 10 ... Outer needle, 12 ... Back surface sound absorbing material forming part of the outer needle, 15 ... Outer needle also serving as a reflecting material,
Reference numeral 20 ... Inner needle, 25 ... Inner needle also serving as back surface sound absorbing material, 26 ... Removable portion, 30, 30 ′, 30 ″ ... Coating layer also serving as acoustic matching layer, 35 ... Coating layer also serving as acoustic lens, 40, 4
0 '... signal line, 50, 50' ... wave transmitting / receiving device, 52 ... signal processing device, 54 ... display device, 56 ... moving device, 58 ... wave transmitting / receiving device, 60 ... acoustic characteristic comparator, 62 ... signal processing device, 64 ... Display device.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Ryuichi Shinomura 1-280, Higashi Koigokubo, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Yukio Ito 1-1-14, Uchikanda, Chiyoda-ku, Tokyo Issue Hitachi Medical Co., Ltd. (72) Inventor Kiyoshi Ishikawa 3-19-11 Yushima, Bunkyo-ku, Tokyo Hitachi Construction Machinery Co., Ltd. FA Division (72) Inventor Hiroshi Kanda 1-1-14 Uchikanda, Chiyoda-ku, Tokyo Hitachi Medical Co., Ltd. (56) Reference JP 50-116058 (JP, A) JP 56-103327 (JP, A) JP 59-75047 (JP, A) JP 62-24973 ( JP, A) JP-A-2-107238 (JP, A) JP-A-2-206447 (JP, A) JP-A-7-311184 (JP, A) Actual development Sho-58-37561 (JP, U) (58) ) Fields surveyed (Int.Cl . ⁷ , DB name) A61B 8/00

Claims (4)

(57) [Claims] 1. A puncture needle for puncturing an inside of a subject, and at least one pair of an ultrasonic transducer and an ultrasonic reflector, or at least one pair of a first ultrasonic transducer and a second ultrasonic transducer. and so as to face disposed in a direction perpendicular to the axis of the puncture needle, the puncture needle
A removable part whose thickness can be changed is provided on a part of the inner needle.
The opposite of the ultrasonic transducer and the ultrasonic reflecting material
Pair, or the first ultrasonic transducer and the second ultrasonic wave
The spacing between each component of a transducer pair is different.
Normalize and face the ultrasonic transducer and the ultrasonic reflection
A pair of materials, or the first ultrasonic transducer and the second ultrasonic transducer
The feature is that biological tissue is introduced between the pair of acoustic wave transducers.
A needle-shaped ultrasonic probe to be used. 2. Ultrasonic conversion to a puncture needle for puncturing a subject
Pair of the ultrasonic reflector and the first ultrasonic transducer and the first ultrasonic transducer
Puncturing at least two of the two ultrasonic transducer pairs
Arranged to face each other in the direction perpendicular to the axis of the needle,
Also differ in the spacing between the components that make up each of the two pairs,
Opposing, a pair of the ultrasonic transducer and the ultrasonic reflector,
Alternatively, the first ultrasonic transducer and the second ultrasonic transducer
A needle-like ultrasonic probe , wherein a living tissue is introduced between a pair of vessels . 3. A puncture needle for puncturing the inside of a subject is ultrasonically converted.
Pair of the ultrasonic reflector and the first ultrasonic transducer and the first ultrasonic transducer
Puncturing at least one of two ultrasonic transducer pairs
It is placed facing each other in the direction perpendicular to the needle axis, and the center of transmission and reception
A frequency of the ultrasonic transducer, the first and second
Ultrasonic transducer for monitor, which is lower than the ultrasonic transducer
Is characterized in that the ultrasonic transducer array is further arranged.
Needle-shaped ultrasonic probe to be. 4. The method according to any one of claims 1 to 3.
In a needle-shaped ultrasonic probe, the introduced biological tissue
Relative to the axial direction or around the axis of the puncture needle
Ultrasonic transducer arranged inside the puncture needle in the direction of rotation
A needle-like ultrasonic probe having a mechanism for moving the position of the instrument .