JP5719275B2 - Ultrasound endoscope system - Google Patents

Description

  The present invention relates to an ultrasonic endoscope system capable of simultaneously observing a living tissue and a puncture needle.

  2. Description of the Related Art Conventionally, an ultrasonic endoscope in which an ultrasonic vibrator is provided at the distal end of an insertion portion to be inserted into the body and an ultrasonic image is obtained by the ultrasonic vibrator has been widely used. In general, in this type of ultrasonic endoscope, a puncture needle introduced into the body through a treatment instrument insertion channel is inserted into a lesioned part or the like under observation by an ultrasonic image, thereby collecting tissue or locally. It is possible to perform treatments such as drug administration and cauterization.

  As a technique for improving the visibility of a puncture needle inserted into a living tissue while ensuring the visibility of the living tissue by an ultrasonic image when performing such a treatment, for example, Patent Document 1 discloses transmission / reception. Each time a scan for one frame is completed, the ultrasonic transmission frequency is switched between a high transmission frequency and a low transmission frequency alternately, and volume data obtained by both scans is synthesized. A technique for generating a single ultrasonic image is disclosed.

JP 2008-12150 A

  However, as in the technique disclosed in Patent Document 1 described above, generating one ultrasonic image by a plurality of scans causes a decrease in frame rate when displaying an ultrasonic image as a moving image. It is unsuitable for observing the operation status of the puncture needle.

  On the other hand, when transmitting and receiving ultrasonic waves of different frequencies for living body observation and puncture needle observation at the same time, the frame rate is improved, but the noise wave of one ultrasonic wave is received as a specular reflection wave of the other ultrasonic wave. Unlike the case of transmitting by switching the frequency for each frame, it is difficult to distinguish between a noise wave and a regular reflection wave, and it is difficult to perform noise removal processing.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultrasonic endoscope system capable of improving the visibility of a puncture needle without reducing the frame rate.

An ultrasonic endoscope system according to an aspect of the present invention includes a first ultrasonic transmission / reception unit, a second ultrasonic transmission / reception unit capable of transmitting / receiving ultrasonic waves toward an observation field of view of the first ultrasonic transmission / reception unit, A driving unit that simultaneously drives the first ultrasonic transmission / reception unit and the second ultrasonic transmission / reception unit to simultaneously transmit ultrasonic waves of different frequencies, and has a predetermined sound velocity in the observation field of view of the second ultrasonic transmission / reception unit; A puncture needle disposed so as to be capable of advancing and retreating, and a plurality of recesses disposed in at least a part of the puncture needle, wherein a transmission center frequency of the first ultrasonic transmission / reception unit satisfies Equation (1) is there.
X = Y + α = ((C / a) × (n / 2)) + α (1)
However,
X: transmission center frequency of the first ultrasonic transmission / reception unit Y: transmission central frequency of the second ultrasonic transmission / reception unit: 3 [MHz] or more C: sound velocity on the puncture needle in the portion where the recess is formed a: recess N is a natural number.

An ultrasonic endoscope system according to another aspect of the present invention includes a first ultrasonic transmission / reception unit and a second ultrasonic transmission / reception unit capable of transmitting / receiving ultrasonic waves toward an observation field of view of the first ultrasonic transmission / reception unit. A driving unit that drives the first ultrasonic transmission / reception unit and the second ultrasonic transmission / reception unit at the same time to transmit ultrasonic waves of different frequencies at the same time; A puncture needle disposed in an observation field so as to be able to advance and retreat, and a plurality of recesses disposed in at least a part of the puncture needle, and the reception center frequency of the second ultrasonic transmission / reception unit is expressed by Equation (2). The transmission center frequency of the first ultrasonic transmission / reception unit satisfies the expression (3).
Y = (C / a) × (n / 2) (2)
However,
Y: central frequency for transmission of the second ultrasonic transmission / reception unit C: speed of sound on the puncture needle in the part where the concave part is formed a: distance n between the concave part and the concave part n: natural number
_{Y 2f <X f12 ... (3} )
However,
Y _2f : Center frequency X _f12 of the second harmonic component of the received wave with respect to the transmission wave from the second ultrasonic transmission / reception unit: Low intensity band effective for image generation in the transmission frequency band of the first ultrasonic transmission / reception unit It is a threshold on the frequency side.

  According to the ultrasonic endoscope system of the present invention, the visibility of the puncture needle can be improved without reducing the frame rate.

Schematic configuration diagram of an ultrasonic endoscope system Perspective view of the distal end of an ultrasonic endoscope Perspective view of ultrasonic array Plan view of ultrasonic transducer element FIG. 4 is a cross-sectional view of an essential part taken along line VV in FIG. Functional block diagram showing the schematic configuration of the ultrasonic observation apparatus Plan view of ultrasonic treatment tool Perspective view of puncture needle Cross section of puncture needle Cross section of puncture needle Frequency characteristics diagram showing the relationship between high and low frequency components of ultrasound Explanatory drawing which shows an ultrasonic image typically

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an ultrasonic endoscope system, FIG. 2 is a perspective view of a distal end portion of the ultrasonic endoscope, FIG. 3 is a perspective view of an ultrasonic array, 4 is a plan view of the ultrasonic transducer element, FIG. 5 is a cross-sectional view of an essential part taken along line VV in FIG. 4, FIG. 6 is a functional block diagram showing a schematic configuration of the ultrasonic observation apparatus, and FIG. FIG. 8 is a perspective view of the puncture needle, FIGS. 9 and 10 are cross-sectional views of the puncture needle, FIG. 11 is a frequency characteristic diagram showing the relationship between the high frequency component and the low frequency component of the ultrasonic wave, and FIG. 12 is an explanatory view schematically showing an ultrasonic image.

  An ultrasonic endoscope system 1 shown in FIG. 1 includes an ultrasonic endoscope 2, an ultrasonic observation device 3, and a monitor 4. The ultrasonic endoscope 2 includes an elongated insertion portion 10 to be inserted into the body, an operation portion 20 connected to the proximal end of the insertion portion 10, and a universal cord extending from a side portion of the operation portion 20. 30.

  Here, a connector 31 connected to a light source device (not shown) is disposed at the base end portion of the universal cord 30. A cable 32 connected to a camera control unit (not shown) via a connector 32a and a cable 33 detachably connected to the ultrasonic observation apparatus 3 via a connector 33a extend from the connector 31. Has been. The ultrasonic endoscope 2 is connected to an ultrasonic observation device 3 via a connector 33a, and further connected to a monitor 4 via the ultrasonic observation device 3.

  The insertion portion 10 is operated in the order from the distal end side, the distal end rigid portion (hereinafter referred to as “the distal end portion”) 11, the bending portion 12 positioned at the rear end of the distal end portion 11, and the rear end of the bending portion 12. A flexible tube portion 13 having a small diameter, a long length, and flexibility reaching the portion 20 is connected to form a main portion.

As shown in FIG. 2, an ultrasonic unit 15 is disposed on the distal end side of the distal end portion 11. Further, on the base side of the ultrasonic unit 15, the distal end portion 11 includes an illumination lens 16 that constitutes an illumination optical system, an observation lens 17 of the observation optical system, and a forceps that is a distal end opening that also serves as a suction port. A mouth 18 and an air / water supply nozzle (not shown) are provided.
The forceps port 18 is a lead-out port for the treatment instrument insertion path. A treatment instrument raising base (not shown) is disposed at the forceps port 18. An operation wire (not shown) is connected to the treatment instrument raising base, and by operating a forceps raising knob (not shown), the operation wire is pulled to adjust the derivation angle of the puncture needle led out from the treatment instrument insertion path. It is like that.

  The operation unit 20 includes an angle knob 21 that controls the bending unit 12 to bend in a desired direction, an air / water supply button 22 that performs air supply and water supply operations, a suction button 23 that performs suction operations, and a treatment that is introduced into the body. A treatment instrument insertion port 24 serving as an instrument entrance is disposed.

  Here, the treatment instrument insertion port 24 communicates with the forceps port 18 via a treatment instrument insertion channel (not shown) provided in the insertion portion 10. A sheath 36 of an ultrasonic treatment instrument 35 (see FIG. 6) described later can be inserted into the treatment instrument insertion port 24. Then, by projecting the distal end side of the puncture needle 38 inserted into the sheath 36 from the forceps port 18, the puncture needle 38 can be disposed in an observation field of the ultrasonic unit 15 so as to be able to advance and retreat. .

  As shown in FIG. 3, the ultrasonic array 45 of the ultrasonic unit 15 includes, for example, a plurality of ultrasonic transducer elements 46 having a rectangular shape in plan view, and the long sides of the ultrasonic transducer elements 46 are mutually connected. It is composed of a convex type transducer group that is connected and curvedly arranged in an arc shape. That is, in the ultrasonic array 45, for example, 100 ultrasonic transducer elements 46 having a short side of 0.1 [mm] or less are arranged in a 180-degree direction on the side surface of an arc having a radius of 5 [mm]. Yes. Although the ultrasonic array 45 shown in FIG. 3 employs a convex type, for example, a radial type with a two-dimensional array or a linear type transducer group that is not curved may be employed.

  Lower electrode terminals 51 provided at one end of each ultrasonic transducer element 46 are arranged at one end of the arc-shaped ultrasonic array 45, and these lower electrode terminals 51 are branched from the coaxial cable bundle 47. Each signal line 48 is connected to each other through a flexible substrate (FPC substrate). On the other hand, upper electrode terminals 52 provided at the other end of each ultrasonic transducer element 46 are arranged at the other end of the ultrasonic array 45, and these upper electrode terminals 52 are branched from the coaxial cable bundle 47. The ground lines 49 are connected respectively.

  The coaxial cable bundle 47 is inserted from the distal end portion 11 into each of the bending portion 12, the flexible tube portion 13, the operation portion 20, the universal cord 23, and the ultrasonic cable 26, and is superposed via the ultrasonic connector 26a. The sound wave observation device 3 is connected.

  Next, the configuration of the ultrasonic transducer element 46 will be described with reference to FIGS. Each figure is a schematic diagram for explanation, and the number, thickness, size, size ratio, and the like of patterns are different from actual ones.

  As shown in FIG. 4, in the ultrasonic transducer element 46, for example, a plurality of types of ultrasonic cells 50 (for example, three types of ultrasonic cells 50a to 50c) are arranged in a matrix. Here, each of the ultrasonic cells 50a to 50c is manufactured using, for example, (MEMS (Micro Electro Mechanical Systems) technology), and is a capacitive ultrasonic machine (Capacitive Micromachined Ultrasonic) having a circular shape in plan view. The ultrasonic cells 50a to 50c are set to have different resonance frequencies by appropriately adjusting the effective radius, film thickness, etc. of the membrane, for example. Accordingly, each of the ultrasonic cells 50a to 50c can transmit and receive ultrasonic waves having different band characteristics with respect to the same visual field direction when a predetermined drive signal (electric signal) is applied.

  Among these, for example, the ultrasonic cells 50a and 50b mainly function as a first ultrasonic transmission / reception unit that transmits / receives ultrasonic waves in a high frequency band suitable for living body observation. Specifically, the ultrasonic cell 50a is configured by, for example, a cell in which the resonance frequency of the membrane is set to 5 [MHz]. Thus, the ultrasonic cell 50a transmits an ultrasonic wave having a predetermined bandwidth with a center frequency (frequency at which the intensity reaches a peak) of 5 [MHz] when a predetermined drive signal is applied, and the echo wave thereof. Etc. (for example, a specular reflection wave substantially equivalent to the transmission wave and its harmonics, etc.) can be received.

  In addition, the ultrasonic cell 50b is configured by, for example, a cell in which the resonance frequency of the membrane is set to 7.5 [MHz]. Thus, the ultrasonic cell 50b can transmit an ultrasonic wave having a predetermined bandwidth with a center frequency of 7.5 [MHz] when a predetermined driving signal is applied, and can receive the echo wave and the like. It is possible.

  In general, it is known that ultrasonic waves in the range of about 5 [MHz] to 20 [MHz] are effective for living body observation. In addition to the ultrasonic cells exemplified above, For example, each ultrasonic cell whose resonance frequency is set to 10 [MHz], 12 [MHz], 20 [MHz] or the like can be appropriately arranged on the ultrasonic transducer element 46.

  On the other hand, the ultrasonic cell 50c functions as a second ultrasonic transmission / reception unit that transmits / receives ultrasonic waves in a low frequency band suitable mainly for puncture needle observation. Specifically, the ultrasonic cell 50c is configured by a cell in which the resonance frequency of the membrane is set to 2 [MHz], for example. Accordingly, the ultrasonic cell 50c can transmit an ultrasonic wave having a predetermined bandwidth with a center frequency of 2 [MHz] when a predetermined drive signal is applied, and can receive the echo wave and the like. It has become.

  Here, each ultrasonic cell 50 is composed of a laminated body having a cross-sectional structure as shown in FIG. 5, for example. That is, the ultrasonic cell 50 includes a lower electrode layer 54 connected to the lower electrode terminal 51, a lower insulating layer (first insulating layer) 55, and an upper insulating layer (second insulating layer) in which a disk-shaped cavity 56 is formed. Insulating layer) 57, upper electrode layer 58 connected to upper electrode terminal 52, and protective layer (third insulating layer) 59, which are sequentially stacked on a silicon substrate 53 as a base. Is configured. The silicon substrate 53 is a substrate in which silicon oxide films 53b and 53c are formed on the surface of the silicon 53a.

  The lower electrode layer 54 includes a lower electrode portion 54a having a substantially circular shape in a plan view and disposed on the lower layer side of each cavity 56, and a plurality of lower wiring portions 54b extending in two directions from the edge of each lower electrode portion 54a. And having. These lower wiring portions 54 b connect the lower electrode portions 54 a adjacent to each other on the same ultrasonic transducer element 46 to each other, and are further connected to the lower electrode terminal 51.

  The upper electrode layer 58 includes an upper electrode portion 58a having a substantially circular shape in plan view, which is disposed on the upper layer side of each cavity 56, and a plurality of upper wiring portions (two upper portions extending in two directions from the edge of each upper electrode portion 58a). (Not shown). The upper wiring portions adjacent to each other on the same ultrasonic transducer element 46 are connected to each other by these upper wiring portions, and are further connected to the upper electrode terminal 52.

  As described above, each ultrasonic cell 50 has the lower electrode portion 54 a and the upper electrode portion 58 a that are disposed to face each other with the cavity 56 interposed therebetween.

  In the ultrasonic cell 50 shown in FIG. 4, the upper insulating layer 57, the upper electrode layer 58, and the protective layer 59 in the region immediately above the cavity 56 constitute a membrane 60 that is a vibrating part.

  Next, functionally showing the outline of the main configuration of the ultrasonic observation apparatus 3, for example, as shown in FIG. 6, the ultrasonic observation apparatus 3 includes a drive signal generation unit 3a as a drive unit, and an echo wave detection. A unit 3b, a biological image generation unit 3c, a needle image generation unit 3d, and a superimposed image generation unit 3e are included.

  The drive signal generation unit 3a generates an ultrasonic signal in a high frequency band (for example, a predetermined band in which the center frequency is in the range of 5 to 12 [MHz]) suitable for ecological observation (that is, generation of a B-Mode image). A driving signal (driving pulse) is generated. Specifically, the drive signal generation unit 3a, for example, according to a preset ultrasonic observation range or the like, a drive pulse adapted to the resonance frequency of the ultrasonic cell 50a or the resonance of the ultrasonic cell 50b. A drive pulse suitable for the frequency is generated selectively or simultaneously.

  Further, the drive signal generation unit 3a is a drive for generating an ultrasonic signal in a low frequency band suitable for observation of the puncture needle 38 (for example, a predetermined band in which the center frequency is in the range of 2 to 3 [MHz]). A signal (driving pulse) is generated. Specifically, the drive signal generation unit 3a generates, for example, a drive pulse that matches the resonance frequency of the ultrasonic cell 50c.

  Then, the drive signal generation unit 3a synthesizes the drive signal for generating the ultrasonic signal in the high frequency band and the drive signal for generating the ultrasonic signal in the low frequency band to generate the ultrasonic unit 15 (the ultrasonic array 45). ).

  Thereby, a drive signal is simultaneously applied to the lower electrode part 54a of each ultrasonic cell 50a-50c on the ultrasonic transducer element 46 at a predetermined timing for each ultrasonic transducer element 46. When a voltage based on the drive signal is applied to the lower electrode portion 54a, the upper electrode portion 58a is attracted to the lower electrode portion 54a side by electrostatic force, and the membrane 60 including the upper electrode portion 58a is deformed. When the voltage application to the lower electrode portion 54a is released, the membrane 60 is restored to its original shape by the elastic force. An ultrasonic wave is generated by the deformation / recovery of the membrane 60. As described above, the ultrasonic cells 50a to 50c on the ultrasonic transducer element 46 are simultaneously driven, and the ultrasonic transducer element 46 outputs an ultrasonic signal in a high frequency band and an ultrasonic signal in a low frequency band at the same time. Is done.

  On the other hand, at the time of ultrasonic reception, the membrane 60 including the upper electrode portion 58a is deformed by the received ultrasonic energy. When the distance between the upper electrode portion 58a and the lower electrode portion 54a changes due to this deformation, the capacitance between them changes.

  The echo wave detection unit 3b converts the capacitance change accompanying the deformation of each membrane 60 into a voltage signal by applying a DC bias between the electrodes, and receives it as an echo signal. Furthermore, the echo wave detection unit 3b performs, for example, well-known FFT processing and bandpass filter processing on the received echo signal, thereby converting the echo signal into a high frequency component echo signal and a low frequency component echo signal. To separate. Then, the echo wave detection unit 3b outputs the separated high frequency component echo signal to the biological image generation unit 3c, and outputs the low frequency component echo signal to the needle image generation unit 3d.

  For example, the biological image generation unit 3c extracts a specular reflected wave component derived from biological tissue from an echo signal of a high frequency component, and generates a normal biological image (B-Mode image) based on the extracted specular reflected wave component. Alternatively, the biological image generation unit 3c extracts, for example, a harmonic component derived from biological tissue (for example, a second harmonic component) from an echo signal of a high frequency component, and generates a biological image (harmonic image) based on the harmonic component. Generate.

  The needle image generation unit 3d extracts a regular reflection wave component derived from the needle from the low frequency component echo signal, and generates an image (needle image) showing the puncture needle 38 based on the extracted regular reflection wave component. Alternatively, the needle image generation unit 3d extracts a needle-derived harmonic component (for example, a second harmonic component) from, for example, a low-frequency component echo signal, and generates a needle image based on the harmonic component.

  The superimposed image generation unit 3e generates a composite image in which the needle image input from the needle image generation unit 3d is superimposed on the biological image input from the biological image generation unit 3c, and outputs the combined image to the monitor 4. Thereby, for example, as shown in FIG. 12, an image of the puncture needle 38 is displayed on the biological image on the monitor 4.

  As shown in FIG. 7, the ultrasonic treatment instrument 35 includes, for example, a sheath 36 that is inserted into the treatment instrument insertion channel of the ultrasonic endoscope 2 and a gripping portion that is disposed at the proximal end of the sheath 36. And an puncture needle 38 formed of an elongated needle tube having a sharp tip formed in a sharp shape with a distal end portion inserted and disposed in the sheath 36 through the operation portion 37 so as to be able to advance and retreat. ing.

  For example, as shown in FIGS. 8 and 9, a concave groove 39 as a concave portion is provided at the distal end portion of the puncture needle 38. The concave groove 39 has, for example, a substantially arc shape in cross section, and is engraved in a spiral shape along the outer peripheral surface of the puncture needle 38. For example, as shown in FIG. 10, the groove 39 may have a substantially rectangular cross section.

  Here, the pitch (distance between the edges a between the grooves 39) when the grooves 39 are spirally engraved is associated with the center frequency Fr of the ultrasonic waves for detecting the puncture needle transmitted from the ultrasonic cell 50c. Is set.

More specifically, when the sound velocity of the ultrasonic wave transmitted through the puncture needle 38 in the portion provided with the recess is C [m / s], the distance a satisfying the relationship of the following expression (4) is set. The natural frequency Fr of the puncture needle 38 can be matched with the center frequency of the puncture needle detection ultrasonic wave.
C / a = Fr (4)

  When the distance a satisfying such a relationship is set and the natural frequency Fr of the puncture needle 38 is matched with the center frequency of the puncture needle detection ultrasonic wave, the puncture needle 38 is resonated with the center frequency Fr. It can be excited efficiently. The vibration of the puncture needle 38 is also transmitted to the human body in which the puncture needle 38 is inserted, and, in the ultrasonic cell 50c, apparently low frequency echo waves (regular reflection wave and its harmonics) derived from the puncture needle. ). As a result, the above-described needle image generation unit 3d can generate a good needle image.

Such a phenomenon can be realized not only for the “λ mode” of the center frequency Fr but also for the “λ / 2 mode”, “3λ / 2 mode”, “4λ / 2 mode”,. is there. In consideration of this point, when the equation (4) is generalized using the natural number n, the relationship of the following equation (5) can be obtained.
C / (2 × n × a) = Fr (5)

  If the distance a is set based on the equation (5), the ultrasonic cell 50c can accurately receive the low-frequency echo wave derived from the needle.

  In consideration of the above, even when the center frequency of the ultrasonic wave for detecting the puncture needle is set to an arbitrary value, the distance a between the concave grooves 39 on the puncture needle 38 is optimized, thereby reducing the low frequency derived from the needle. It can be seen that an echo wave can be accurately received and a good needle image can be generated by the needle image generation unit 3d.

  If the center frequency of the ultrasound for detecting the puncture needle is set to a value that can avoid interference with the frequency band of the ultrasound for biodiagnosis, the ultrasound for living body observation and the ultrasound for detecting the puncture needle are Even when the signals are output simultaneously, the received echo waves can be easily separated without interfering with each other.

  In this case, the center frequency of the ultrasound for detecting the puncture needle transmitted from the ultrasound cell 50c is considered to be excluded from the influence of the second harmonic, for example, with respect to the center frequency of the ultrasound for detecting the living body. Therefore, the minimum margin of 3 [MHz] is set in mind (see FIG. 11).

That is, the center frequency Fr and the distance a are set to values that satisfy the following expression (1).
X = Y + α = ((C / a) × (n / 2)) + α (1)
However,
X: transmission center frequency of the first ultrasonic transmission / reception unit Y: transmission central frequency of the second ultrasonic transmission / reception unit: 3 [MHz] or more C: sound speed on the puncture needle a: distance n between the recesses and the recesses : Natural number.

Alternatively, the transmission center frequency and the distance a of the second ultrasonic transmission / reception unit are set to values satisfying the following expressions (2) and (3).
Y = (C / a) × (n / 2) (2)
However,
Y: transmission center frequency α of the second ultrasonic transmission / reception unit: 3 [MHz] or more C: speed of sound on the puncture needle a: distance between the recesses and the recesses n: natural number,
Y _2f <X _f12 (3)
However,
Y _2f : Center frequency X _f12 of the second harmonic component of the received wave with respect to the transmission wave from the second ultrasonic transmission / reception unit: Low intensity band effective for image generation in the transmission frequency band of the first ultrasonic transmission / reception unit Frequency-side threshold (for example, the value of the portion of the transmission frequency of the first ultrasonic transmission / reception unit where the signal intensity has been reduced to ¼ (the so-called 12 dB drop) and the value on the low frequency side)
It is.

  Based on the above, in the present embodiment, the center frequency Fr of the ultrasonic wave transmitted from the ultrasonic cell 50c is 2 [MHz] as described above based on the relationship with the ultrasonic wave transmitted from the ultrasonic cells 50a and 50b. ] Is set.

  For example, when the puncture needle 38 is formed of SUS304, the sound velocity C of the ultrasonic wave transmitted on the puncture needle 38 is 5800 m / s, and is transmitted from, for example, the ultrasonic cell 50c. When the center frequency of the ultrasonic wave is set to 2 [MHz], the distance a between the concave grooves 39 is 1.45 [mm] (λ / 2 mode), 2.9 [mm] (λ mode), 4.35 [mm] (3λ / 2 mode),...

According to such an embodiment, the center frequency of the ultrasound for detecting the puncture needle transmitted from the ultrasound cell 50c is transmitted from the ultrasound cells 50a and 50b, and the echo wave of the ultrasound for detecting the puncture needle is transmitted from the ultrasound cells 50a and 50b. By setting the value to a sufficiently low value to avoid interference with echo waves for ecological observation, each echo wave is transmitted even when ultrasonic waves for detecting a puncture needle are transmitted simultaneously with the ultrasonic waves for ecology observation. The received signals can be accurately separated. Then, a spiral concave groove 39 is provided on the puncture needle 38, and by optimizing the distance a between the grooves 39, the natural frequency of the puncture needle 38 and the center of the ultrasonic wave for detecting the puncture needle are detected. By matching the frequency, the puncture needle 38 can be efficiently excited by the ultrasonic waves for detecting the puncture needle so that the vibration of the puncture needle 38 is apparently received as a low frequency echo wave derived from the puncture needle. it can. Thereby, the visibility of the puncture needle can be improved without reducing the frame rate.
When resonance between the concave portions of the needle is used, periodic echo waves derived from the needle may be detected, and the resolution in the depth direction of the needle may be reduced. The living body image generation unit 3c has a function of displaying the highest intensity portion of the echo wave from the needle on one sound ray, so that the needle can be drawn more clearly.

  In addition, this invention is not limited to each embodiment described above, A various deformation | transformation and change are possible, and they are also in the technical scope of this invention.

For example, in the above-described embodiment, an example in which the concave groove 39 is provided on the outer peripheral surface of the puncture needle 38 and the natural frequency of the puncture needle 38 is adjusted by the interval a of the concave groove 39 has been described. For example, a plurality of dimples can be arranged on the outer surface of the puncture needle, and the natural frequency of the puncture needle can be adjusted by the interval between the dimples.
In the above-described embodiment, the puncture needle has been described. However, the present invention is not limited to the puncture needle, and the above-described ultrasonic endoscope is provided with a concave portion on the outer peripheral surface of various known treatment instruments for endoscopes. The same effect can be obtained by using together. Examples of the treatment tool include forceps, sharp scissors, brushes, clips, scissors, knives, and nets.

  Moreover, as a material of the puncture needle, for example, SUS316, NiTi, CoCr, or the like can be suitably applied in addition to SUS304 shown in the above-described embodiment.

  In the above-described embodiment, an example in which an ultrasonic unit is configured using a capacitive ultrasonic cell has been described. However, the present invention is not limited to this, and for example, JP-A-2002-2002 Of course, the ultrasonic unit may be configured by using a piezoelectric element as disclosed in Japanese Patent No. 248100.

DESCRIPTION OF SYMBOLS 1 ... Ultrasound endoscope system 2 ... Ultrasound endoscope 3 ... Ultrasound observation apparatus 3a ... Drive signal generation part 3b ... Echo wave detection part 3c ... Living body image generation part 3d ... Needle image generation part 3e ... Superimposition image generation Section 4 ... Monitor 10 ... Insertion section 11 ... Tip section 12 ... Bending section 13 ... Flexible tube section 15 ... Ultrasound unit 16 ... Illumination lens 17 ... Observation lens 18 ... Forceps port 20 ... Operation section 21 ... Angle knob 22 ... Air / water button 23 ... Suction button 23 ... Universal cord 24 ... Treatment instrument insertion port 26 ... Ultrasonic cable 26a ... Ultrasonic connector 30 ... Universal cord 31 ... Connector 32 ... Cable 32a ... Connector 33 ... Cable 33a ... Connector 35 ... Ultrasound treatment tool 36 ... sheath 37 ... operation part 38 ... puncture needle 39 ... Grooves 45 ... ultrasonic array 46 ... ultrasonic transducer element 47 ... coaxial cable bundle 48 ... signal line 49 ... capacitance detection line 50 ... ultrasonic cell 50a ... ultrasonic cell (first ultrasonic transmitter-receiver)
50b ... Ultrasonic cell (first ultrasonic transmission / reception unit)
50c ... Ultrasonic cell (second ultrasonic transmission / reception unit)
DESCRIPTION OF SYMBOLS 51 ... Lower electrode terminal 52 ... Upper electrode terminal 53 ... Silicon substrate 53a ... Silicon 53b, 53c ... Silicon oxide film 54 ... Lower electrode layer 54a ... Lower electrode part 54b ... Lower wiring part 56 ... Cavity 57 ... Upper insulating layer 58 ... Upper Electrode layer 58a ... Upper electrode part 59 ... Protective layer 60 ... Membrane

Claims (2)

A first ultrasonic transmission / reception unit;
A second ultrasonic transmission / reception unit capable of transmitting / receiving ultrasonic waves toward an observation field of view of the first ultrasonic transmission / reception unit;
A driving unit that simultaneously drives the first ultrasonic transmission / reception unit and the second ultrasonic transmission / reception unit to transmit ultrasonic waves of different frequencies;
A puncture needle having a predetermined sound velocity and arranged to be able to advance and retreat in the observation visual field of the second ultrasonic transmission / reception unit;
A plurality of recesses disposed in at least a part of the puncture needle,
The ultrasonic endoscope system according to claim 1, wherein a transmission center frequency of the first ultrasonic transmission / reception unit satisfies formula (1).
X = Y + α = ((C / a) × (n / 2)) + α (1)
However, X: Center frequency for transmission of the first ultrasonic transmission / reception unit Y: Center frequency for transmission of the second ultrasonic transmission / reception unit α: 3 [MHz] or more C: Sound velocity on the puncture needle a: Between the concave portion and the concave portion Distance n: a natural number. A first ultrasonic transmission / reception unit;
A second ultrasonic transmission / reception unit capable of transmitting / receiving ultrasonic waves toward an observation field of view of the first ultrasonic transmission / reception unit;
A driving unit that simultaneously drives the first ultrasonic transmission / reception unit and the second ultrasonic transmission / reception unit to transmit ultrasonic waves of different frequencies;
A puncture needle having a predetermined sound velocity and arranged to be able to advance and retreat in the observation visual field of the second ultrasonic transmission / reception unit;
A plurality of recesses disposed in at least a part of the puncture needle,
The reception center frequency of the second ultrasonic transmission / reception unit satisfies the formula (2),
The ultrasonic endoscope system, wherein the transmission center frequency of the first ultrasonic transmission / reception unit satisfies the expression (3).
Y = (C / a) × (n / 2) (2)
Where Y: transmission center frequency of the second ultrasonic transmission / reception unit C: speed of sound on the puncture needle a: distance between the recesses and the recesses n: a natural number,
Y _2f <X _f12 (3)
However, _Y2f : Center frequency of the second harmonic component of the received wave with respect to the transmission wave from the second ultrasonic transmission / reception unit _Xf12 : Intensity band effective for image generation in the transmission frequency band of the first ultrasonic transmission / reception unit Is a threshold on the low frequency side.