JP2009239976A - Ultrasonic endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic endoscope having a high electrostatic capacity in the capacitor portion of a c-MUT cell and a high transmit-receive sensitivity. <P>SOLUTION: The ultrasonic endoscope inserted into celom to obtain body tissue information by transmitting and receiving ultrasonic waves by an ultrasonic transducer is equipped with: an electrostatic type ultrasonic transducer formed on a semiconductor substrate by a micromachine technique; a lower curved electrode provided on the substrate constituting the electrostatic type ultrasonic transducer by forming a prescribed concavo-convex curved surface on the surface of the substrate; and an upper curved electrode disposed oppositely to the lower curved surface and having a surface shape approximately equal to the above concavo-convex curved surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic endoscope, and more particularly to an ultrasonic endoscope that obtains biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer.

  2. Description of the Related Art In recent years, an ultrasonic diagnostic method that irradiates ultrasonic waves into a body cavity and images and diagnoses the state of the body from the echo signals has become widespread.

  As shown in FIG. 30A to FIG. 30C, as an ultrasonic endoscope apparatus for obtaining an ultrasonic tomographic image in a body cavity, an illumination optical unit 203 and an observation optical unit are provided at a distal end portion 202 constituting an insertion unit 201. There is an ultrasonic endoscope 200 provided with an ultrasonic observation unit 205 together with a unit 204. Reference numeral 206 denotes a balloon placement groove in which a balloon (not shown) is placed.

  In the ultrasonic endoscope 200, ultrasonic transducers 207 and 208 that transmit and receive ultrasonic waves are provided at the distal end portion 205. The ultrasonic transducer 207 shown in FIG. 30B is an electronic scanning type, and this ultrasonic transducer 207 is configured by arranging a plurality of ultrasonic transducer elements 207a,. These ultrasonic transducer elements 207a,..., 207a are linearly or sector-scanned via an ultrasonic observation device (not shown), so that ultrasonic waves are emitted in a direction perpendicular to the axial direction of the ultrasonic endoscope 200, A linear or sector ultrasonic tomographic image is displayed on a display device (not shown).

  On the other hand, the ultrasonic transducer 208 shown in FIG. 30C is a mechanical scanning type, and the ultrasonic transducer 208 has a housing 209. Then, by mechanically rotating the housing 209 by a driving force of a drive motor (not shown), an ultrasonic wave is emitted in a direction orthogonal to the axis of the ultrasonic endoscope 200 along with the rotation of the housing 209. A radial ultrasonic tomographic image is displayed.

  As shown in FIG. 31, the ultrasonic transducer 208 uses, for example, a disk-shaped composite piezoelectric body 211. This composite piezoelectric body 211 is made of a resin such as polyurethane and epoxy around and around a plurality of piezoelectric bodies (not shown) made of PZT piezoelectric ceramics such as lead zirconate titanate Pb (Zr, Ti) O3. The composite piezoelectric body 211 is configured by filling a member (not shown). The composite piezoelectric body 211 is disposed in a metal case body 212.

  The composite piezoelectric body 211 is provided with a first electrode 211a provided on the upper surface and a second electrode 211b provided on the lower surface. The second electrode 211b and the first electrode 211a are electrically separate from each other, and the upper surface side on which the first electrode 211a is provided is an ultrasonic radiation surface. A signal conductor 213 is connected to the second electrode 211b, and a ground line 214 is connected to the first electrode 211a.

  An ultrasonic absorber 215 is disposed on the lower surface side of the composite piezoelectric body 211 disposed in the case body 212, and an acoustic matching layer that covers the top surface of the case body 212 on the upper surface side where the curved surface is formed. An acoustic lens 216 that also serves as an acoustic matching layer that satisfies the amplitude condition of is provided. A resin insulating member 217 for preventing electrical contact between the first electrode 211a and the second electrode 211b is provided on the outer peripheral side of the ultrasonic absorber 215 and the composite piezoelectric body 211. Further, the surface of the ultrasonic transducer 208 is covered with a protective film (not shown) formed of parylene (polyparaxylylene) having excellent water resistance and chemical resistance.

  On the other hand, as shown in FIG. 32, an ultrasonic transducer 207 in which a plurality of ultrasonic transducer elements 207a,..., 207a are arranged is formed of PZT piezoelectric ceramics such as lead zirconate titanate Pb (Zr, Ti) O3. The piezoelectric element 221 and a backing material 222 disposed on the back side of the piezoelectric element 221 are configured. Electrodes 221 a and 221 b are provided on both surfaces of the piezoelectric element 221. A pattern 223a of the flexible printed circuit board 223 is electrically connected to the electrode 221b with solder (not shown).

  The piezoelectric elements 221 are separated at equal intervals in a strip shape in the longitudinal direction by dicing grooves 224 having a depth dimension reaching the backing material 222 in the thickness direction, and a plurality of transducer elements 207a are arranged in the longitudinal direction. The dicing grooves 224 separate the connection portions by solder from the adjacent connection portions, so that each pattern 223a is connected to two sub-element elements 207b that form one transducer element 207, respectively. An acoustic matching layer (not shown) is provided on the front-side electrode 221a, and the front-side electrode 221a is connected to the adjacent electrode 221a by a GND wiring material (not shown) and set to the ground potential.

  However, in the ultrasonic endoscope, regardless of the electronic scanning type or the mechanical scanning type, lead is included in the piezoelectric body constituting the ultrasonic transducer. For this reason, in view of recent environmental problems, there is a demand for lead-free ultrasonic transducers provided in an ultrasonic endoscope that is inserted into a body cavity and used.

  In addition, in the ultrasonic transducer used in the mechanical scanning method, it is difficult to always uniformly fill the resin member in the gaps and the surroundings of the plurality of piezoelectric bodies, and the performance varies depending on the creator or the date of manufacture. . On the other hand, the electronic scanning ultrasonic transducer has a skill in forming a dicing groove, and the performance varies depending on the creator or the date of manufacture.

  Conventionally, in an ultrasonic endoscope that obtains biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer, the c-MUT cell 250 has a void 40 in a vacuum as shown in FIG. Therefore, there is a problem that the upper electrode 37u provided on the membrane 38 bends and deforms when left in the air after the c-MUT is formed.

  The present invention has been made in view of the above circumstances, and in an ultrasonic endoscope that obtains biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer, the capacitance of the capacitor portion of the c-MUT cell is large. An object of the present invention is to provide an ultrasonic endoscope with high transmission / reception sensitivity.

  The ultrasonic endoscope of the present invention is an ultrasonic endoscope that is inserted into a body cavity and receives biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer, and is formed on a semiconductor substrate using micromachine technology. An electrostatic ultrasonic transducer, a curved lower electrode provided by forming a predetermined concave and convex curved surface on the surface of a substrate constituting the electrostatic ultrasonic transducer, and a position facing the curved lower electrode And a curved upper electrode having a shape substantially coinciding with the irregular curved surface.

  As described above, according to the present invention, in an ultrasonic endoscope that obtains biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer, the capacitance of the capacitor part of the c-MUT cell is large and transmission / reception sensitivity is high. It aims to provide a high ultrasound endoscope.

The figure explaining the ultrasonic endoscope apparatus which is 1st Embodiment of this invention. The figure explaining the structure of the front-end | tip part of an ultrasonic endoscope The figure explaining an ultrasonic transducer FIG. 3 is an enlarged view of a portion indicated by arrow A and a diagram for explaining a c-MUT cell. The figure explaining the structural example of the cross section of c-MUT cell. Block diagram for explaining configurations of an ultrasonic observation apparatus and an ultrasonic transducer The figure explaining the other structural example of c-MUT The figure explaining the arrangement | sequence and cell shape of c-MUT cell The figure explaining c-MUT which made the ultrasonic wave transmission / reception direction the front The figure which shows c-MUT which made the front shape which made the opening shape of the ultrasonic scanning surface polygonal the ultrasonic wave transmission / reception direction. The figure which shows c-MUT which made the opening shape of the ultrasonic scanning surface the circular shape and made the front and back the transmission / reception direction. The figure which shows c-MUT which made the front which formed the through-hole the transmission / reception direction. The figure explaining c-MUT of a mechanical scanning type ultrasonic endoscope FIG. 14 to FIG. 23 are diagrams for explaining modifications of the c-MUT configured by arranging a plurality of c-MUT cells, and FIG. 14 shows another arrangement configuration of the c-MUT cells constituting the ultrasonic transducer. Figure explaining The figure explaining other arrangement composition of c-MUT cell which constitutes an ultrasonic transducer The figure explaining another arrangement configuration of c-MUT cell which constitutes an ultrasonic transducer The figure explaining the ultrasonic endoscope which provided c-MUT so that it could scan in two directions The figure explaining the structure of c-MUT provided in Fig.17 (a) The figure which shows the ultrasonic endoscope which provided c-MUT in the curved surface part The figure explaining the board | substrate which mounted c-MUT chip | tip. The figure explaining the other structural example of a c-MUT cell The figure explaining the structure of the c-MUT cell which performed the porous process, and the relationship between a porous process time and acoustic impedance The figure explaining another structural example of a c-MUT cell The figure which shows the other structural example of a c-MUT cell. 25 to 29 are related to a second embodiment of the present embodiment, and FIG. 25 is a diagram showing an ultrasonic transducer in which a multifunctional ultrasonic transducer having a silicon light emitting element and a silicon light receiving element provided on a silicon substrate in addition to the c-MUT. Diagram explaining sonic endoscope The figure explaining the structural example of the cross section of a multifunctional ultrasonic transducer The figure explaining the other structural example of the multifunctional ultrasonic transducer which arrange | positioned the silicon light emitting element and the silicon light receiving element. Furthermore, a diagram for explaining the configuration of a multifunction ultrasonic transducer provided with a micro gyro sensor The figure explaining the structure of the multifunctional ultrasonic transducer which provided the cell for capacitance measurement on the silicon substrate The figure explaining the conventional ultrasonic endoscope The figure which shows the structural example of a mechanical scanning type ultrasonic transducer The figure which shows the structural example of an ultrasonic scanning type ultrasonic transducer

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram illustrating an ultrasonic endoscope apparatus according to a first embodiment of the present invention, FIG. 2 is a diagram illustrating a configuration of a distal end portion of the ultrasonic endoscope, and FIG. 3 is a diagram illustrating an ultrasonic transducer. 4 is an enlarged view of a portion indicated by an arrow A in FIG. 3 and a diagram for explaining a c-MUT cell, FIG. 5 is a diagram for explaining a configuration example of a cross section of the c-MUT cell, and FIG. 6 is an ultrasonic observation apparatus FIG. 7 is a diagram for explaining another configuration example of the c-MUT, FIG. 8 is a diagram for explaining the arrangement and cell shape of the c-MUT cell, and FIG. 9 is an ultrasound diagram. FIG. 10 is a diagram for explaining a c-MUT in which the transmission / reception direction is forward, FIG. 10 is a diagram showing a c-MUT in which the front of the ultrasonic scanning surface is a polygonal shape, and the ultrasonic transmission / reception direction is the front, and FIG. C-MUT in which the front side of the ultrasonic scanning surface having a circular shape is a transmission / reception direction Shows, 12 shows a c-MUT was a transducing direction forward of forming the through hole, FIG. 13 is a diagram illustrating a c-MUT the mechanical scanning ultrasonic endoscope.

  8A is a diagram when c-MUT cells are arranged in a grid, FIG. 8B is a diagram showing another cell shape of the c-MUT cell, and FIG. 8C is a diagram showing c-MUT. FIG. 13A is a diagram illustrating another cell shape of a cell, FIG. 13A is a diagram illustrating a mechanical scanning c-MUT, and FIG. 13B is a mechanical scanning ultrasonic endoscope in which the c-MUT is arranged. FIG.

  As shown in FIG. 1, an ultrasonic endoscope apparatus 1 according to this embodiment includes an ultrasonic endoscope (hereinafter abbreviated as an endoscope) 2 including an electrostatic ultrasonic transducer described later, and illumination light. A light source unit (not shown) to be supplied and a signal processing unit that drives an image pickup device (not shown) and performs various signal processing of electric signals transmitted from the image pickup device to generate a video signal for an endoscopic observation image are provided. Endoscope observation device 3 and a signal for generating an image signal for an ultrasonic tomographic image by driving the electrostatic ultrasonic transducer and performing various signal processing of electrical signals transmitted from the electrostatic ultrasonic transducer An ultrasonic observation apparatus 4 including a processing unit and a monitor 5 that displays an image for observation based on video signals generated by the ultrasonic observation apparatus 4 and the endoscope observation apparatus 3 are mainly configured. Has been.

  The endoscope 2 includes an elongated insertion portion 11 that is inserted into a body cavity, an operation portion 12 that is located on the proximal end side of the insertion portion 11, and a universal cord 13 that extends from a side portion of the operation portion 12. And is mainly composed.

  An endoscope connector 14 connected to the endoscope observation apparatus 3 is provided at the base end portion of the universal cord 13. An illumination connector 14a connected to the light source portion of the endoscope observation apparatus 3 is provided at the distal end portion of the endoscope connector 14, and an electric cord (not shown) electrically connected to the signal processing portion is provided on the side portion. An electrical connector 14b is provided to be detachably connected. Further, an ultrasonic cable 15 having an ultrasonic connector 15 a electrically connected to the ultrasonic observation device 4 extends from the proximal end portion of the endoscope connector 14.

  The insertion portion 11 includes a distal end rigid portion 6 formed of a hard member in order from the distal end side, a bendable bending portion 7 continuously provided on the proximal end side of the distal end rigid portion 6, and a proximal end side of the bending portion 7. And a flexible tube portion 8 having a small diameter and a long length that reaches the distal end side of the operation portion 12 and has flexibility.

  The distal end rigid portion 6 is arranged by arranging an observation optical unit that performs endoscopic observation by direct viewing and an endoscope observation unit 20 provided with an illumination optical unit and a plurality of ultrasonic transducer elements that transmit and receive ultrasonic waves. An ultrasonic observation unit 30 having a scanning surface is provided.

  The operation section 12 includes an angle knob 16 for controlling the bending of the bending section 7, an air / water supply button 17a for performing air supply and water supply operations, a suction button 17b for performing suction operations, and a treatment introduced into the body cavity. A treatment instrument insertion port 18 or the like serving as an instrument entrance is provided. Various operation switches 19 are provided for switching a display image to be displayed on the monitor 5 and giving instructions such as freeze and release. Reference numeral 9 denotes a mouthpiece placed in the oral cavity of the patient.

  As shown in FIG. 2, an ultrasonic observation unit 30 for performing ultrasonic observation is disposed on the distal end side of the distal rigid portion 6. In addition, an inclined surface portion 21 is formed on the distal end rigid portion 6, and the inclined surface portion 21 captures an illumination lens cover 22 that constitutes an illumination optical unit that irradiates the observation region with illumination light, and an optical image of the observation region. An observation lens cover 23 constituting an observation optical unit and a forceps outlet 24 which is an opening through which a treatment tool introduced from the treatment tool insertion port 18 protrudes are provided.

  A circumferential balloon groove 25 for attaching a balloon (not shown) formed to be inflatable / shrinkable with latex having ultrasonic permeability, Teflon (registered trademark) (R) rubber or the like, if necessary, on the distal end rigid portion 6. Is formed. In addition, a balloon opening (not shown) is provided in the vicinity of the balloon groove 25 to supply and drain water such as water as an ultrasonic transmission medium into the balloon.

  The illumination lens cover 22 faces a light guide fiber (not shown) that transmits illumination light from a light source unit provided in the endoscope observation apparatus 3. A solid-state imaging device (not shown) that extends a signal cable (not shown) is disposed at the imaging position.

  The ultrasonic observation unit 30 mainly includes an ultrasonic transducer 31 that transmits and receives ultrasonic waves and a housing portion 32 that houses the ultrasonic transducer 31 and is fixed to the distal end rigid portion 6. .

  The ultrasonic transducer 31 shown in FIG. 2 and FIG. 3 is also described as an electrostatic ultrasonic transducer (hereinafter referred to as c-MUT (Capacitive Micromachined Ultrasonic Transducer) 31) obtained by processing a silicon semiconductor substrate using a silicon micromachining technology. It is automatically manufactured faithfully and automatically in accordance with the operation sequence in a completely clean environment by a silicon process, without manual operation.

  The c-MUT 31 is formed, for example, as a rectangular sector type by arranging a plurality of c-MUT cells 31a. The c-MUT cells 31a, ..., 31a of the c-MUT 31 and the signal lines 33, ..., 33 are configured to be electrically connected via a cable connection 34. The signal lines 33,..., 33 extending from the cable connection portion 34 are gathered together and extend in the direction of the operation portion 12 in a state of being inserted into, for example, a tube (not shown) that passes through the insertion portion 11. It is electrically connected to the ultrasonic observation apparatus 4.

  A convex portion 32b having a circumferential balloon groove 32a for attaching a balloon (not shown) as needed is provided at the distal end portion of the housing portion 32. Further, the surface of the c-MUT 31 and a part of the housing portion 32 are a protective film (see reference numeral 39 in FIG. 4) formed of parylene (polyparaxylylene) having excellent water resistance and chemical resistance. It is covered.

  As shown in FIG.4 and FIG.7, the cell shape of each c-MUT cell 31a which comprises the said c-MUT31 is formed in hexagonal shape, for example. Then, a plurality of c-MUT cells 31a,..., 31a are arranged in a plurality of rows and rows at a minute predetermined pitch in a honeycomb structure so that the opening shape of the ultrasonic scanning surface is, for example, a rectangular shape.

  The c-MUT cell 31a is mainly composed of a lower electrode 37d, an insulating support 36 for setting an inter-electrode distance, a silicon membrane 38 formed of silicon or a silicon compound, and an upper electrode 37u formed on the silicon substrate 35. It is configured. The lower electrode 37d is provided on the upper surface of the silicon substrate 35, and the upper electrode 37u is provided on the upper surface of the silicon membrane 38. Reference numeral 40 denotes a vacuum gap (hereinafter abbreviated as a gap), which is a braking layer of the silicon membrane 38 in this embodiment.

  On the silicon substrate 35 on which a plurality of c-MUT cells 31a are arranged, an access circuit forming unit 43 provided with an access circuit constituted by a c-MOS integrated circuit and a wiring electrode 44 are provided. The upper electrode 37u provided on the silicon membrane 38 is a ground electrode, and the lower electrode 37d is a signal input / output electrode. The upper surface of the upper electrode 37u is covered with the protective film 39.

  As shown in FIG. 2, a plurality of c-MUT cells 31 a are arranged in the c-MUT 31 shown in FIG. 3 constituting the ultrasonic observation unit 30. These c-MUT cells 31a are driven and controlled based on operation instruction signals output from the CPU 51 provided in the ultrasound observation apparatus 4.

  As shown in FIG. 6, the ultrasonic observation apparatus 4 includes the CPU 51, trigger signal generation circuit 52, selector 53, echo signal processing circuit 54, Doppler signal processing circuit 55, harmonic signal processing circuit 56, ultrasonic image processing unit. 57, a transmission delay circuit 61, a bias signal application circuit 62, a drive signal generation circuit 63, a transmission / reception switching circuit 64, and a c-MUT cell 31a are provided with a preamplifier 65 and a beam former 66.

  The CPU 51 performs various controls by outputting operation instruction signals to various circuits and processing units provided in the ultrasonic observation apparatus 4 and receiving feedback signals from the various circuits and processing units.

The trigger signal generation circuit 52 drives each c-MUT cell 31a and outputs a repetitive pulse signal that is a timing signal for transmission and reception.
The selector 53 transmits a pulse signal to a predetermined c-MUT cell 31a instructed based on the operation instruction signal of the CPU 51.

  The echo signal processing circuit 54 reflects an ultrasonic wave output from each c-MUT cell 31a at an organ in the living body and its boundary, and returns to the c-MUT cell 31a to be received later. Visible image data is generated based on the signal.

  The Doppler signal processing circuit 55 extracts a moving component of the tissue, that is, a blood flow component from the received beam signal output from the c-MUT cell 31a using the Doppler effect, and the blood flow in the ultrasonic tomogram is extracted. Color data for coloring the position is generated.

  The harmonic signal processing circuit 56 extracts and amplifies the signal of the frequency component from the received beam signal output from each c-MUT cell 31a with a filter having the second harmonic frequency or the third harmonic frequency as the center frequency. Then, image data for harmonic imaging diagnosis is generated.

  The ultrasonic image processing unit 57 is based on the image data generated by the echo signal processing circuit 54, the Doppler signal processing circuit 55, the harmonic signal processing circuit 56, and the like, respectively, for a B-mode image, a Doppler image, and a harmonic imaging. Build an image. At the same time, characters such as characters are overlaid via the CPU 51. Then, the video signal constructed by the ultrasonic image processing unit 57 is output to the monitor 5, and an ultrasonic tomographic image that is one of the observation images is displayed on the screen of the monitor 5.

The transmission delay circuit 61 determines the timing for applying the drive voltage to each c-MUT cell 31a and sets it to perform a predetermined sector scan or the like.
The bias signal applying circuit 62 applies a predetermined bias signal to the drive signal generating circuit 63. This bias signal uses the same DC voltage at the time of transmission / reception, is set to a high voltage at the time of transmission and is changed to a low voltage at the time of reception, for example, a signal in which an AC component is superimposed on a DC component for correlation There is.

  The DC bias voltage is necessary for obtaining an ultrasonic transmission waveform having the same waveform as the transmission voltage waveform during transmission. If the DC bias voltage is not superimposed, the frequency of the transmitted ultrasonic signal is twice that of the drive voltage signal and its amplitude is halved.

  On the other hand, it is necessary to apply a bias voltage during reception. If this bias voltage is a DC voltage, it has the same waveform as the received ultrasonic wave. It is also possible to improve the SN by further superimposing the AC voltage signal together with the DC voltage, and filtering it with a bandpass filter of the center frequency of the AC voltage signal by subsequent signal processing. Furthermore, c-MUT cell selection becomes possible as another method of using bias voltage application. This utilizes the fact that a received signal cannot be obtained in principle without a bias voltage, and cell selection is possible by not applying a DC voltage to cells that are not selected. Become. The reception signal on which the DC signal component is superimposed is converted into an rf signal by a DC signal blocking means such as a capacitor, is converted into a reception signal, and is transmitted to the signal processing unit.

The drive signal generation circuit 63 generates a burst wave that is a drive voltage signal corresponding to a desired ultrasonic waveform based on the output signal from the transmission delay circuit 61.
The transmission / reception switching circuit 64 switches one c-MUT cell 31a between a transmission state and a reception state. The drive voltage signal is applied to the c-MUT cell 31a in the transmission state, and the charge signal generated between the electrodes 37u and 37d of the c-MUT cell 31a is received by the preamplifier in the reception state by receiving the echo information. Output.

The preamplifier 65 changes the charge signal output from the transmission / reception switching circuit 64 into a voltage signal and amplifies it.
The beam former 66 outputs a reception beam signal obtained by synthesizing the ultrasonic echo signals output from the preamplifier 65 with a delay time similar to or different from the delay in the transmission delay circuit 61.

  Then, based on the operation instruction signal of the CPU 51, a predetermined phase difference is given, each c-MUT cell 31a is driven, and an ultrasonic wave set at a predetermined focal length from the ultrasonic scanning plane of the ultrasonic observation unit 30 is obtained. Ultrasonic waves generated by ultrasonic waves set at the focal length by transmitting sound waves, synthesizing them with a delay similar to the delay in the transmission delay circuit 61 by the beam former 66 and outputting them as reception beam signals. Can observe.

  The beamformer 66 synthesizes and outputs a desired delay time different from the delay in the transmission delay circuit 61, thereby obtaining a received beam signal corresponding to the delay time of the beamformer 66 and ultrasonic observation. A desired ultrasonic tomographic image can be obtained via the device 4.

  In the present embodiment, the c-MUT 31 having a layered arrangement in which the control circuits and wiring electrodes of the plurality of c-MUT cells 31 a are formed on the first intermediate dielectric layer 41 and the second intermediate dielectric layer 42 of the silicon substrate 35. However, the configuration of the c-MUT 31 is not limited to the layered arrangement, and a c-MUT cell forming unit in which a plurality of c-MUT cells 31a are arranged on one side of the c-MUT 31 as shown in FIG. You may make it comprise the ultrasonic transducer 31A of the in-plane arrangement | positioning which provided 31b and the circuit formation part 31c which formed the said control circuit, a wiring electrode, etc.

  Furthermore, in the present embodiment, the cell shape of the c-MUT cell 31a is formed in a hexagonal shape and arranged in a honeycomb structure, but the shape and arrangement of the c-MUT cell 31a are limited to this. However, a plurality of c-MUT cells 31a are arranged in a grid pattern as shown in FIG. 8A, or a circular shape or an elliptical shape (not shown) as shown in FIG. The c-MUT cell 31d may be formed as shown in FIG. 8, or the c-MUT cell 31e may be formed in a polygonal shape such as an octagonal shape as shown in FIG.

  In this embodiment, the ultrasonic wave emitted from the ultrasonic scanning surface of the c-MUT 31 configured by arranging a plurality of c-MUT cells 31 a is substantially orthogonal to the longitudinal axis direction of the ultrasonic endoscope 2. However, as shown in FIG. 9A, the signal line 33 extending from the c-MUT 31 is extended from the back side of the ultrasonic scanning surface to form the c-MUT 31B. Accordingly, as shown in FIG. 9B, this c-MUT 31B is arranged on the distal end surface 11a of the insertion part having the endoscope observation part 20A of the forward-viewing type, so that the ultrasonic wave emitted from the ultrasonic scanning surface is obtained. Can be configured as a forward-looking square sector electronic scan type ultrasonic endoscope 2A.

  Further, in the present embodiment, a plurality of c-MUT cells 31a are aligned and the opening shape of the ultrasonic scanning surface is a square shape. However, the ultrasonic scanning surface formed by aligning and arranging the c-MUT cells 31a is used. The opening shape, the size of the opening, and the like are not limited to those shown in the drawing, and a c-MUT 31C having a polygonal shape such as an octagonal shape as shown in FIG. You may make it form c-MUT31D, such as circular shape as shown to (a), and the ellipse shape which is not shown in figure.

  Then, these c-MUTs 31C and 31D are arranged on the distal end surface 11a of the insertion portion as shown in FIGS. 10B and 11B to constitute a polygonal sector electronic scan type ultrasonic endoscope 2B in front view. Alternatively, the forward-viewing circular sector electronic scan type ultrasonic endoscope 2C may be configured. At this time, the shape of the cable connecting portion 34 is changed in accordance with the shape of the c-MUT.

The operation of the ultrasonic endoscope provided with the c-MUT configured as described above in the ultrasonic observation unit will be described.
The insertion unit 11 is inserted into the body cavity while observing an endoscope image displayed on the screen of the monitor 5 of the ultrasonic endoscope apparatus 1. If the distal end rigid portion 6 of the insertion portion 11 is disposed in the vicinity of the observation site, for example, a balloon (not shown) is inflated and the ultrasonic observation device 4 is operated to bring the c-MUT 31 into a driving state.

  Then, an operation instruction signal corresponding to the operation instruction of the observer is output from the CPU 51 of the ultrasonic observation apparatus 4, converted into a pulse signal by the trigger signal generation circuit 52, and the c-MUT 31 is configured via the selector 53. The data is output toward a predetermined c-MUT cell 31a.

  This pulse signal is input to the transmission delay circuit 61, a drive voltage signal with a predetermined delay is output via the drive signal generation circuit 63 and the bias signal application circuit 62, and the transmission / reception switching circuit 64 switches to the transmission state. When this is done, this drive voltage signal is applied to the c-MUT cell 31a to emit ultrasonic waves.

  Then, the CPU 51 outputs an operation instruction signal to each c-MUT cell 31a arranged, for example, a large delay is applied to the drive voltage signal for the central c-MUT cell 31a, and the center of the array is arranged. One ultrasonic waveform is formed, for example, by applying a small delay to the drive voltage signal for the c-MUT cell 31 a that is away from the c-MUT cell 31 a, and is output from the ultrasonic scanning surface of the c-MUT 31.

  That is, based on the control of the CPU 51, ultrasonic waves are emitted from each c-MUT cell 31a, and sector scanning in the axial direction and sector scanning in the direction orthogonal to the axial direction can be performed.

  On the other hand, in the c-MUT cell 31a, the transmission / reception switching circuit 64 performs switching control between a transmission state and a reception state. For this reason, when the transmission / reception switching circuit 64 is in a receiving state, a charge signal generated between the electrodes 37 u and 37 d due to reception of echo information by the c-MUT cell 31 a is output to the preamplifier 65.

  The charge signal output to the preamplifier 65 is converted into a voltage signal, amplified, and output to the ultrasound observation apparatus 4 as a reception beam signal with an appropriate delay applied by the beam former 66.

The received beam signals sequentially output from each c-MUT cell 31a are subjected to predetermined processing via an echo signal processing circuit 54, a Doppler signal processing circuit 55, a harmonic signal processing circuit 56, etc., and then subjected to ultrasonic image processing. At the same time as being converted into a standard video signal by the unit 57, overlay is performed via the CPU 51 and output to the monitor 5. Thus, an ultrasonic tomographic image is displayed on the screen of the monitor 5 together with the endoscopic image, or an ultrasonic tomographic image is displayed instead of the endoscopic image.
Thus, ultrasonic observation of the target observation site can be performed.

  As described above, an ultrasonic transducer disposed in an ultrasonic observation unit provided at the distal end portion of the ultrasonic endoscope is arranged by arranging a plurality of c-MUT cells on a silicon semiconductor substrate using silicon micromachining technology. In addition, a lead-free ultrasonic transducer can be realized by using an electrostatic ultrasonic transducer.

  Further, by using silicon micromachining technology, an electrostatic ultrasonic transducer can be automatically created in a clean environment. As a result, it is possible to arrange the fine c-MUT cells without causing dicing distortion and variations, and thus it is possible to provide a highly reliable ultrasonic observation unit at low cost.

  Furthermore, the cell shape of the c-MUT cell and the opening shape of the ultrasonic scanning surface can be set to a desired shape and size, and the ultrasonic observation unit can be reduced in size and accuracy.

  In addition, as shown to Fig.12 (a), ring-shaped c-MUT31E may be formed and the through-hole 24a may be formed in the approximate center part of this c-MUT31E. In the present embodiment, the signal line 33 is extended from the edge side of the cable connecting portion 34 in order to form the through hole 24a.

  Then, the c-MUT 31E having the through hole 24a is disposed on, for example, the distal end surface 11a of the insertion portion as shown in FIG. 12B, so that the through hole 24a becomes a forceps outlet 24 of the treatment instrument channel. The sonic endoscope 2D can be configured.

  In the above-described embodiment, the ultrasonic endoscope provided with the electronic scanning ultrasonic transducer has been described. However, in the mechanical scanning ultrasonic endoscope, the ultrasonic transducer is configured with a c-MUT. It may be.

  Specifically, as shown in FIG. 13A, c-MUT cells 31a are arranged to form an ultrasonic scanning surface in a disk shape to form c-MUT 31F. At this time, the upper electrodes 37u and the lower electrodes 37d constituting the c-MUT cell 31a are electrically connected to each other, and the housing 73 is pivotally supported by a drive member 72 in a housing 73. It arrange | positions and the ultrasonic endoscope 70 is comprised. A signal line (not shown) extending from the c-MUT 31F is inserted through the drive member 72 and electrically connected to the ultrasonic observation apparatus 4.

  While the insertion portion 11 of the ultrasonic endoscope 70 is inserted into the body cavity, the housing 73 is rotated by a driving force of a driving motor (not shown) and an ultrasonic driving signal is transmitted from the ultrasonic observation device 4 to the c- Output to MUT31F. As a result, the c-MUT 31F performs radial scanning while transmitting and receiving ultrasonic waves, converts echo information on the tomographic plane into electrical signals, and outputs the signals to the ultrasonic observation apparatus 4 as received beam signals. The rotation angle of the housing 73 is detected by a rotary encoder 74 that detects the rotation of the drive member 72. That is, the rotation angle of the c-MUT 31F is sequentially output to the ultrasound observation apparatus 4 together with the received beam signal as a rotation angle signal.

  Therefore, the ultrasonic observation apparatus 4 performs various known processes such as envelope detection, logarithmic amplification, A / D conversion, and the like on the received beam signal, and further polar system based on the rotation angle signal. The digital echo data is converted into an orthogonal coordinate system that can be output to the monitor 5, and a video signal for constructing an ultrasonic tomographic image is generated and output to the monitor 5. Thus, an ultrasonic tomographic image can be displayed on the screen of the monitor 5 and ultrasonic observation of the target observation site can be performed.

  Here, a modified example of the c-MUT configured by arranging a plurality of c-MUT cells 31a will be described with reference to FIGS.

With reference to FIG. 14, another arrangement configuration of the c-MUT cells constituting the ultrasonic transducer will be described.
14A is a diagram showing an ultrasonic transducer configured by arranging c-MUT cells whose opening dimensions are changed according to a predetermined rule, and FIG. 14B is an A1-A2 direction of the c-MUT cell. FIG. 14C is a diagram showing an aperture distribution curve that regulates the arrangement, and FIG. 14C is a diagram showing an aperture distribution curve that regulates the B1-B2 direction arrangement of c-MUT cells.

  As shown in FIG. 14A, in the c-MUT 31G of this embodiment, the opening dimensions of the c-MUT cells 31 constituting the c-MUT 31G are regularly changed according to the arrangement direction. In other words, the c-MUT cell 31a is not formed to have all the same opening dimensions as in the above-described embodiment, but according to the arrangement direction, for example, the R value distribution curves shown in FIGS. 14B and 14C. Set based on.

  The R value distribution curves shown in FIGS. 14 (b) and 14 (c) apply that the electrode area in the c-MUT cell is proportional to the capacitance, and as a result, is proportional to the transmitted / received sound pressure. The electrode area is set to a Gaussian distribution function, for example. That is, in the c-MUT 31G of the present embodiment, the opening size of the c-MUT cell 31a located at the center is maximized, and the opening size is the same as that of the curve from the center toward the periphery of the c-MUT 31G. It is getting smaller.

As a result, the directivity characteristic (= the diffraction pattern of the aperture of this element) indicated by the c-MUT cell is multiplied by the interference pattern generated by the mutual interference effect when the c-MUT cells are arranged in an array. Thus, the grating lobe, which is the strength of the directivity, is improved, and artifacts that are pseudo information can be suppressed.
Therefore, a good ultrasonic tomographic image can be obtained.

With reference to FIG. 15, another arrangement configuration of the c-MUT cell constituting the ultrasonic transducer will be described.
FIG. 15A is a diagram showing a configuration example in which the arranged c-MUT cells are divided into a transmitting cell, a receiving cell, and an unused cell, and FIG. 15B is an arranged c-MUT. It is a figure which shows the other structural example which divided | segmented the cell into the cell for transmission, the cell for reception, and the unused cell.

  In the above-described embodiment, the transmission / reception switching circuit 64 is provided to switch between the transmission state and the reception state, so that transmission / reception is performed by one c-MUT cell 31a. The MUT cell is a transmission cell 31f dedicated to transmission, a reception cell 31g dedicated to reception, and a non-use cell 31h that has neither transmission nor reception functions.

  Then, as shown in FIG. 15 (a), a transmitting / receiving cell group 31k and an unused cell 31h constituted by a pair of transmitting cell 31f and receiving cell 31g are formed as an unused cell group 31m which is a band-shaped group, The unused cell group 31m and the transmission / reception cell group 31k are alternately arranged in the column direction, for example, to constitute the c-MUT 31H.

  As a result, between the transmission cell groups 31f arranged in the column direction or between the reception cell groups 31g, the reception cell group 31g and the unused cell group 31h are not used during transmission, and the transmission cell group 31f is not used during reception. By providing the cell group 31h with a predetermined physical interval, crosstalk can be reduced. Therefore, an ultrasonic tomographic image with good image quality can be obtained.

  Instead of configuring the transmission / reception cell group 31k by a pair of transmission cell 31f and reception cell 31g, transmission / reception is performed by two transmission cells 31f and one reception cell 31g as shown in FIG. 15 (b). A cell group 31n is configured, for example, a substantially band-shaped unused cell group 31m is arranged between transmission / reception cell groups 31n arranged in the row direction, and a predetermined physical interval is provided between adjacent transmission / reception cell groups 31n. The c-MUT 31J may be configured in a configuration in which the above is provided.

  In this embodiment, the c-MUT cells constituting the c-MUT are shown as an example of a configuration in which the receiving cell 31g, the transmitting cell 31f, and the unused cell 31h are used. A reception cell group in which electrodes are integrally and electrically connected together, and a transmission cell group in which the electrodes of each of the plurality of transmission cells 31f are electrically connected together to form a group of unused cells. Then, each cell group may be arranged as shown in FIG. 15A and FIG. 15B to constitute a c-MUT.

With reference to FIG. 16, another arrangement configuration of the c-MUT cell constituting the ultrasonic transducer will be described.
16A is a diagram showing a configuration in which the c-MUT cell is divided into a transmission group and a reception group, and FIG. 16B is a transmission cell of the transmission group indicated by an arrow B in FIG. FIG. 16C illustrates the arrangement of the reception cell group and the unused cell group of the reception group indicated by the arrow C in FIG. 16A. It is an enlarged view.

  As shown in FIG. 16A, the c-MUT 31K of this embodiment is provided with two ring-shaped cell groups formed by arranging a plurality of c-MUT cells 31a. Of the two ring-shaped cell groups, for example, the ring-shaped cell group disposed outside is configured as a transmission group 31p, and the ring-shaped cell group disposed inside is configured as a reception group 31s.

  As shown in FIG. 16 (b), in the transmission group 31p, the electrodes of the series of transmission cells 31f are electrically connected to each other from the arranged c-MUT cells 31a. A transmission cell group (hereinafter also referred to as an active group) 31q having a shape as shown by a colored portion is formed, and a plurality of unused cells 31h are shown in FIG. The unused cell group 31r is provided with a physical interval between them. The unused cell group 31r and the transmission cell group 31q are alternately arranged to constitute the transmission group 31p.

  On the other hand, as shown in FIG. 16C, in the receiving group 31s, the electrodes of the series of receiving cells 31g are electrically connected to each other from the arranged c-MUT cells 31a. The receiving cell group 31t is formed as a receiving cell group 31t (hereinafter also referred to as an active group) as shown by the colored portion, and a plurality of unused cells 31h are shown in FIG. An unused cell group (hereinafter also referred to as an inactive group) 31r having a physical interval between them is formed. The unused cell group 31r and the receiving cell group 31t are alternately arranged to form the receiving group 31s.

Thus, the transmission group 31p for ultrasonic transmission and the reception group 31s for receiving ultrasonic waves can be provided separately in the c-MUT 31K.
In addition, the transmission group 31p and the reception group 31s are configured by alternately arranging active groups and inactive groups, thereby providing a predetermined physical interval between adjacent active groups to prevent crosstalk. Mitigation can be achieved.
Therefore, an ultrasonic tomographic image with good image quality can be obtained.

With reference to FIGS. 17 and 18, another configuration of the ultrasonic observation unit provided in the ultrasonic endoscope will be described.
17A illustrates a configuration of an ultrasonic endoscope provided with a c-MUT capable of scanning in two directions in the ultrasonic observation unit, and FIG. 17B illustrates a scanning direction in the ultrasonic observation unit. FIG. 18A is a diagram for explaining another configuration of an ultrasonic endoscope provided with different c-MUTs, FIG. 18A is a diagram for explaining the configuration of the c-MUT shown in FIG. 17A, and FIG. ) Is an enlarged view for explaining the arrangement of the part indicated by the arrow D of the c-MUT in FIG. 18 (a), and FIG. 18 (c) shows the arrangement of the part indicated by the arrow E of the c-MUT in FIG. 18 (a). It is a figure to do.

  As shown in FIG. 17A, in the ultrasonic endoscope 2E of the present embodiment, the housing portion 32 has a first ultrasonic scanning surface 81 that can perform sector scanning in the axial direction and a sector in a direction orthogonal to the axial direction. A biplane type c-MUT 31L provided integrally with the second ultrasonic scanning surface 82 capable of scanning as an ultrasonic scanning surface is provided.

  As shown in FIGS. 18A and 18B, the second ultrasonic scanning plane 82 is formed in a band shape by electrically connecting the electrodes of the plurality of c-MUT cells 31a for ultrasonic transmission / reception. A cell group for transmission / reception 83 and an unused cell 31h that does not have an ultrasonic transmission / reception function are formed in a band shape, and a predetermined physical interval is provided between adjacent transmission / reception cell groups 83 to thereby prevent crosstalk. It is composed of an unused cell group 84 that is intended to be reduced. These transmitting / receiving cell groups 83 and unused cell groups 84 are alternately arranged in the direction of arrow F.

  On the other hand, as shown in FIGS. 18 (a) and 18 (c), the first ultrasonic scanning surface 81 is formed in a band shape by electrically connecting the electrodes of the plurality of c-MUT cells 31a for ultrasonic transmission / reception. The formed transmission / reception cell group 83 and the unused cell 31h that does not have an ultrasonic transmission / reception function are formed in a band shape, and a physical predetermined interval is provided between adjacent transmission / reception cell groups 83 to cross each other. It is composed of an unused cell group 84 for reducing talk. These transmission / reception cell groups 83 and unused cell groups 84 are alternately arranged in the direction of arrow G.

Thus, an ultrasonic tomographic image scanned in a plurality of directions using a single ultrasonic endoscope can be obtained.
As shown in FIG. 17B, for example, c-MUT 31M in which the scanning direction is the axial direction and c-MUT 31M in which the scanning direction is the axial direction on the distal end surface portion and the side surface portion of the housing portion 32 constituting the ultrasonic observation unit 30. The ultrasound endoscope 2F may be configured by arranging the orthogonal c-MUT 31N. Thus, an ultrasonic tomographic image scanned in a plurality of directions using a single ultrasonic endoscope can be obtained. Further, the scanning direction of the c-MUT disposed on the front end surface portion and the side surface portion of the housing 32 is axial, or orthogonal to the axial direction, or the biplane shown in FIG. By appropriately selecting and providing the type, a desired ultrasonic tomographic image can be obtained and ultrasonic observation of the target site can be performed.

The ultrasonic wave provided in the ultrasonic endoscope with reference to the diagram showing the ultrasonic endoscope provided with the c-MUT on the curved surface portion in FIG. 19 and the diagram illustrating the substrate on which the c-MUT chip is mounted in FIG. Another configuration of the observation unit will be described.
19A is a view showing a convex scanning type ultrasonic endoscope, FIG. 19B is a view showing a radial scanning type ultrasonic endoscope, and FIG. 20A is a c-MUT chip. FIG. 20B is a diagram illustrating an example of the configuration of the mounting substrate, FIG. 20B is a diagram illustrating the operation of the c-MUT chip mounting substrate illustrated in FIG. 20A, and FIG. It is a figure which shows the example of a structure.

  As shown in FIG. 19A, in the ultrasonic endoscope 2G of the present embodiment, the curved surface shape c-MUT 91 is arranged at the distal end portion of the housing portion 32 constituting the ultrasonic observation unit 30 so that convex scanning is possible. Configured. On the other hand, as shown in FIG. 19B, the ultrasonic endoscope 2H of the present embodiment is arranged in the circumferential direction of the distal end portion of the insertion portion so that radial scanning in a direction orthogonal to the insertion direction of the endoscope is possible. A belt-shaped c-MUT 92 is arranged.

As shown in FIG. 20A, the band-shaped c-MUT 92 includes a plurality of c-MUT chips 94 arranged in a chip shape by arranging a plurality of c-MUT cells on a flexible flat substrate 93. , Which is implemented and arranged. The strip-shaped c-MUT 92 is deformed into a predetermined shape as shown in FIG. 20B by mounting and arranging a plurality of c-MUT chips 94 at predetermined intervals. Therefore, by arranging the strip-shaped c-MUT 92 in the circumferential direction at the distal end portion of the insertion portion,
An ultrasonic endoscope 2H capable of obtaining an ultrasonic tomographic image by radial scanning is configured.

  On the other hand, as shown in FIG. 20C, the curved surface shape c-MUT 91 is configured by mounting and arranging a plurality of c-MUT chips 94 at predetermined intervals on a curved substrate 95 formed in a predetermined curved surface shape. By arranging the curved surface shape c-MUT 91 at the distal end portion of the ultrasonic observation unit 30, an ultrasonic endoscope 2G capable of obtaining an ultrasonic tomographic image by convex scanning is configured.

  It should be noted that a curved surface portion having a predetermined shape is formed in advance at the distal end portion of the ultrasonic observation unit 30, and a strip-shaped c-MUT 92 configured to be deformed into the predetermined shape is disposed on the curved surface portion, and an ultrasonic tomographic image obtained by convex scanning. You may make it comprise the ultrasonic endoscope 2G which can be obtained.

  Further, a biplane type ultrasonic endoscope may be configured by disposing a band-shaped c-MUT 92 on the proximal end side of the ultrasonic observation unit 30 of the ultrasonic endoscope 2G as shown by a broken line. Good.

Another configuration example of the c-MUT cell will be described with reference to FIG.
As shown in the figure, in the c-MUT cell 100 of this embodiment, a predetermined thickness having a high dielectric constant is formed in the gap 40 formed between the upper electrode 37u and the lower electrode 37d constituting the capacitor unit. A dielectric film 101 is provided.
As a result, it is possible to increase the capacitance of the capacitor unit and increase the transmission / reception sensitivity.

  The porous treatment of the c-MUT cell of FIG. 22 will be described. As shown in FIG. 22A, the porous treatment is performed on the membrane 38 to provide a porous acoustic matching layer 117 whose acoustic impedance is as small as that of the resin material. -The MUT cell 103 may be configured. As shown in FIG. 22B, in the chemical conversion treatment process of the porous treatment, the acoustic impedance greatly changes depending on the treatment time. That is, since the acoustic impedance strongly depends on the chemical conversion processing time, the transmission / reception sensitivity can be increased by controlling the chemical conversion processing time and providing the porous acoustic matching layer 117.

With reference to FIG. 23, another configuration example of the c-MUT cell will be described.
FIG. 23A is a diagram showing a configuration of a conventional c-MUT cell, and FIG. 23B is a diagram showing a configuration of a c-MUT cell having a characteristic on the upper surface of the substrate.

  As shown in FIG. 23 (a), in the conventional c-MUT cell 250, the gap 40 is formed in a vacuum, and therefore, when the c-MUT is formed and left in the atmosphere, it is provided on the membrane 38. The upper electrode 37u was bent and deformed. In this embodiment, as shown in FIG. 23B, a predetermined concave surface 110 is provided in advance on the upper surface of the silicon substrate 35 in consideration of the bending deformation, and the gap 112 is formed in the c-MUT cell 101. Yes.

  As a result, the distance between the upper electrode 37u and the lower electrode 37d can be formed to be uniform and narrow, the capacitance of the capacitor portion can be increased, and transmission / reception sensitivity can be increased.

  Note that, as shown in FIG. 24 showing another configuration example of the c-MUT cell, a concave and convex curved surface 113 having a predetermined concave and convex shape is formed on the surface of the silicon substrate 35 and the curved lower electrode 114 is provided. The area of the curved upper electrode 115 and the curved lower electrode 114 is increased by configuring the upper electrode provided on the membrane 38 disposed opposite to the curved surface upper electrode 115 substantially matching the concave and convex curved surface 113 as shown in FIG. The transmission / reception sensitivity can be increased by increasing the capacitance of the capacitor portion of the MUT cell 102. Reference numeral 116 denotes a curved space.

(Second Embodiment)
25 to 29 are related to a second embodiment of the present embodiment, and FIG. 25 is a diagram showing an ultrasonic transducer in which a multifunctional ultrasonic transducer having a silicon light emitting element and a silicon light receiving element provided on a silicon substrate in addition to the c-MUT. FIG. 26 is a diagram illustrating a cross-sectional configuration example of a multifunction ultrasonic transducer, FIG. 27 is another configuration of the multifunction ultrasonic transducer in which a silicon light emitting element and a silicon light receiving element are disposed. FIG. 28 is a view for explaining an example, FIG. 28 is a view for explaining the configuration of a multifunction ultrasonic transducer in which a micro gyro sensor is further provided, and FIG. 29 is a multifunction ultrasonic transducer in which a capacitance measuring cell is provided on a silicon substrate. FIG.

  FIG. 27A is a diagram for explaining the configuration of a multifunctional ultrasonic transducer having a different outer shape, and FIG. 27B is another arrangement example when the silicon light emitting element and the silicon light receiving element are arranged in the central portion. FIG. 27 (c) is a diagram showing another arrangement example when the silicon light emitting element and the silicon light receiving element are arranged outside, and FIG. 29 (a) is provided with a dummy c-MUT cell for capacitance measurement. FIG. 29B is a flowchart illustrating the operation and function of the dummy c-MUT cell.

  As shown in FIG. 25, in the ultrasonic endoscope 120 of the present embodiment, a multifunction ultrasonic transducer 122 is disposed on the distal end surface 121 a of the insertion portion 121. The multi-function ultrasonic transducer 122 includes a c-MUT 131 in which an opening shape of an ultrasonic scanning surface formed by using silicon micromachining technology is formed in a ring shape, and is positioned at a substantially central portion of the ring-shaped c-MUT 131. On the same surface, a light emitting unit 123 composed of a silicon light emitting element and a light receiving unit 124 composed of a silicon light receiving element are provided.

  As shown in FIG. 26, in the c-MUT 131 of this embodiment, a silicon substrate 35 on which a plurality of c-MUT cells 131a are arranged is formed of, for example, a first intermediate dielectric layer 41 and a second intermediate dielectric layer 42. In addition to the access circuit forming unit, the dielectric layers 41 and 42 include various control circuits 43a that control the light emitting unit 123 and the light receiving unit 124 that are configured by a c-MOS integrated circuit that performs the predetermined control. 43b, 43c,... And wiring electrodes 44a, 44b, 44c, 44d,.

  The lower electrode 37d and the wiring electrode 44a, the wiring electrode 44a and the wiring electrode 44b, the wiring electrode 44b and the wiring electrode 44c, the wiring electrode 44c and the control circuit 43c, the wiring electrode 44d and the control circuit 43b, the wiring electrode 44d and the control circuit 43c, etc. Are electrically connected to each other by a via hole 45.

  An electric cable (not shown) extends from the light emitting unit 123 and the light receiving unit 124 and is electrically connected to the endoscope observation apparatus 3. Therefore, in the ultrasonic endoscope apparatus 1 according to the present embodiment, a lamp that emits illumination light as a light source unit is not required for the endoscope observation apparatus, and a light guide fiber that transmits the illumination light to the ultrasonic endoscope 120 is used. Is no longer needed.

  Note that a forceps outlet through-hole 125 may be formed at a predetermined position of the multi-function ultrasonic transducer 122 as indicated by a broken line in the figure. The light emitting unit 123 is, for example, a light emitting diode or a laser diode, and the light receiving unit 124 is, for example, any one of a C-MOS, a CCD, and the like. Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals and description thereof is omitted. Reference numeral 126 denotes a buffer area.

  In the present embodiment, the c-MUT 131 of the multi-function ultrasonic transducer 122 is formed in a ring shape, and the light emitting unit 123 and the light receiving unit 124 disposed in the center are shown in a circular shape. The c-MUT shape of the multi-function ultrasonic transducer and the shapes and arrangement positions of the illumination unit and the light receiving unit are not limited to these. For example, as shown in FIG. The rectangular multi-functional ultrasonic transducer 127 may be formed by providing the central light emitting portion 123 at the four corners of the c-MUT 131.

  In addition, as shown in FIG. 27B, a polygonal light receiving part 124 is provided at the center of the ring-shaped c-MUT 131, and a plurality of polygonal light emitting parts 123 are provided around the polygonal light receiving part 124. Thus, the multi-function ultrasonic transducer 128 may be formed.

  Furthermore, as shown in FIG. 27C, a circular c-MUT 31 is formed, and for example, a polygonal light emitting unit 123 and a light receiving unit 124 are regularly provided around the c-MUT 31, and multifunctional ultrasonic waves are provided. The transducer 129 may be formed.

The operation of the ultrasonic endoscope 120 configured as described above will be described.
First, the observation region is illuminated by the light emitting unit 123 provided in the multifunction ultrasonic transducer 122 disposed on the distal end surface of the insertion unit 121 of the ultrasonic endoscope 120, and the observation region illuminated by the light emitting unit 123 is illuminated. Are received by the light receiving unit 124. As a result, an endoscopic image is displayed on the screen of the monitor 5. Thus, the surgeon inserts the insertion portion 121 into the body cavity while observing the endoscopic image.

  And if the front-end | tip part of this insertion part 121 is arrange | positioned in the object observation site | part vicinity, while making a front-end | tip part submerged with the water which is an ultrasonic transmission medium, for example, the ultrasonic observation apparatus 4 will be operated and it will be multifunctional. The c-MUT 131 of the ultrasonic transducer 122 is set in a driving state.

  Then, as described in the first embodiment, the operation instruction signal corresponding to the operation instruction of the observer is output from the CPU 51 of the ultrasonic observation apparatus 4 to the c-MUT 131. Then, the c-MUT cell 131a is switched between a transmission state and a reception state to emit ultrasonic waves, while receiving reflected ultrasonic waves and displaying an ultrasonic tomographic image on the screen of the monitor 5. Thus, ultrasonic observation of the target observation site can be performed.

  In this way, an ultrasonic endoscope is configured by arranging a multi-function ultrasonic transducer in which an illumination unit and a light receiving unit are formed using silicon micromachining technology in addition to c-MUT on the distal end surface of the insertion unit. Thus, the ultrasonic endoscope can be configured without providing the observation optical unit and the illumination optical unit in the ultrasonic endoscope.

  As a result, the diameter and size of the ultrasonic endoscope can be reduced.

In addition, by appropriately setting the arrangement of the c-MUT cells, the aperture shape of the ultrasonic transducer can be set to a desired shape and size, and the shape, size, and quantity of the illumination unit and the light receiving unit can be set as appropriate. Thus, by creating a multi-function ultrasonic transducer, the degree of freedom in designing an ultrasonic endoscope increases, such as miniaturization and high accuracy.
Other operations and effects are the same as those in the first embodiment.

Here, a modified example of the multifunction ultrasonic transducer will be described with reference to FIGS.
In the multi-function ultrasonic transducer 132 shown in FIG. 28, in addition to the c-MUT 131, the light emitting unit 123, and the light receiving unit 124, the movement of the distal end portion of the ultrasonic endoscope is detected and position detection is performed. Electrostatic micro gyro sensors 133 and 134 arranged to correspond to the Y direction are also provided.

  As a result, the position detection signals output from the electrostatic micro gyro sensors 133 and 134 are processed by a calculation unit (not shown), thereby constantly and quantitatively grasping the position of the distal end portion of the ultrasonic endoscope. be able to.

  In the multi-function ultrasonic transducer 135 shown in FIG. 29A, a plurality of c-MUT cells at arbitrary positions constituting the c-MUT 131 are used as the capacitance measuring cell 136. Based on the electrical signal output from the capacitance measuring cell 136, the ultrasonic drive signal is corrected and output.

  That is, when an instruction for measuring the capacitance is output by the ultrasonic observation device 4, the data during operation is sequentially transferred from each capacitance measurement cell as shown in step S1 of FIG. Input to the capacitance measurement correction unit. Then, the capacitance measurement correction unit calculates the average value of the input data as shown in step S2, and then proceeds to step S3 to compare the calculated value with a preset reference value. Go to evaluate the difference and move to step S4. In step S4, the c-MUT drive signal is corrected based on the evaluation result in step S3. As a result, a corrected ultrasonic drive signal is output to the c-MUT cell.

  In this way, by providing a part of the c-MUT cell constituting the c-MUT as a capacitance measuring cell, the ultrasonic drive that is always optimally corrected in the c-MUT cell constituting the c-MUT cell. An ultrasonic diagnostic image can be obtained by outputting a signal.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

[Appendix]
According to the embodiment of the present invention as described above in detail, the following configuration can be obtained.

(1) An ultrasonic endoscope that obtains biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer inserted into a body cavity, and a signal of an electrical signal related to biological tissue information transmitted from the ultrasonic endoscope In an ultrasonic endoscope apparatus comprising an ultrasonic observation apparatus that performs processing and drive control of the ultrasonic transducer,
An ultrasonic endoscope apparatus in which an ultrasonic transducer mounted on the ultrasonic endoscope is formed of a silicon semiconductor substrate.

(2) The ultrasonic endoscope apparatus according to appendix 1, wherein the ultrasonic transducer is an electrostatic ultrasonic transducer processed using a silicon micromachining technique.

(3) The ultrasonic endoscope apparatus according to appendix 2, wherein the electrostatic ultrasonic transducer has an array structure in which a large number of ultrasonic transducer elements are linearly arranged. FIG.
(4) The ultrasonic endoscope apparatus according to appendix 2, wherein the electrostatic ultrasonic transducer has an array structure in which a large number of ultrasonic transducer elements are two-dimensionally arranged.

(5) The ultrasonic endoscope apparatus according to appendix 2, wherein the electrostatic ultrasonic transducer has an array structure in which a large number of ultrasonic transducer elements are arranged in a ring shape.

(6) The ultrasonic endoscope apparatus according to any one of supplementary notes 3 to 5, wherein the ultrasonic transducer elements are distributed based on a predetermined rule to form a predetermined opening shape.

(7) The ultrasonic endoscope device according to any one of appendix 3 to appendix 5, wherein the ultrasonic transducer element has different functions and is configured by at least two groups. The ultrasonic endoscope apparatus according to appendix 7.

(9) The ultrasonic endoscope apparatus according to appendix 7, wherein the group is further divided into subdivided groups, and the subdivided groups are alternately arranged.

(10) The ultrasound endoscope apparatus according to appendix 7, wherein the group is configured by alternately arranging every other ultrasonic transducer element constituting each group.

(11) The ultrasonic endoscope apparatus according to appendix 7, wherein at least one of the groups has a function of transmitting an ultrasonic wave, and at least one of the other groups has a function of receiving an ultrasonic wave. .

(12) The ultrasonic endoscope apparatus according to appendix 5, wherein a through hole is formed in the arrayed ultrasonic transducer arranged in a ring shape.

(13) The ultrasonic endoscope apparatus according to appendix 12, wherein the through hole is configured as a forceps outlet communicating with a treatment instrument channel.

(14) The ultrasonic endoscope according to appendix 2, wherein a dielectric film having a high dielectric constant is formed in a gap portion that constitutes a capacitor portion by an upper electrode and a lower electrode constituting the electrostatic ultrasonic transducer. apparatus.

(15) The ultrasonic endoscope apparatus according to appendix 2, wherein an uneven surface is formed on a surface of a substrate constituting the electrostatic ultrasonic transducer.

(16) The ultrasonic endoscope apparatus according to appendix 4, wherein the two-dimensional array ultrasonic transducer is arranged on a curved surface portion of an ultrasonic endoscope.

(17) The ultrasonic endoscope apparatus according to supplementary note 16, wherein the two-dimensional array ultrasonic transducer is arranged in a circumferential direction in an ultrasonic endoscope insertion portion.

(18) The ultrasonic endoscope apparatus according to appendix 2, wherein the ultrasonic transducer is configured as a chip-shaped ultrasonic transducer, and the chip-shaped ultrasonic transducer is mounted on a substrate.

(19) The ultrasonic endoscope apparatus according to appendix 18, wherein the substrate is a flexible planar substrate.

(20) The ultrasonic endoscope apparatus according to appendix 18, wherein the substrate is a curved substrate formed in a predetermined curved shape.

2 ... Ultrasound endoscope 30 ... Ultrasound observation unit
31 ... Electrostatic ultrasonic transducer (c-MUT)
31a ... c-MUT cell 35 ... Silicon substrate 37d ... Lower electrode 37u ... Upper electrode 38 ... Silicon membrane 40 ... Vacuum gap 44 ... Wiring electrode

Claims (1)

In an ultrasonic endoscope that is inserted into a body cavity and receives biological tissue information by transmitting and receiving ultrasonic waves with an ultrasonic transducer,
An electrostatic ultrasonic transducer formed on a semiconductor substrate using micromachine technology;
A curved lower electrode provided by forming a predetermined concave and convex curved surface on the surface of the substrate constituting the electrostatic ultrasonic transducer;
A curved upper electrode disposed at a position facing the curved lower electrode, and having a shape substantially matching the concave and convex curved surface;
An ultrasonic endoscope characterized by comprising: