Patent ID: 12193877

DETAILED DESCRIPTION

An exemplary embodiment of an ultrasound endoscope and an endoscope system according to the disclosure is described below with reference to the accompanying drawings. However, the disclosure is not limited by the embodiment described below. Moreover, the disclosure can be applied in general to an ultrasound endoscope including an ultrasound transducer, and to an endoscope system.

Meanwhile, in the drawings, identical or corresponding elements are referred to by the same reference numerals. Moreover, each drawing is schematic in nature, and it needs to be kept in mind that the relationships among the dimensions of the elements or the ratio of the elements may be different than the actual situation. Among the drawings too, there may be portions having different relationships among the dimensions or having different ratios among the dimensions.

Embodiment

FIG.1is a diagram that schematically illustrates the endoscope system including the ultrasound endoscope according to the embodiment of the disclosure. As illustrated inFIG.1, an endoscope system1includes an ultrasound endoscope2, an ultrasound imaging apparatus3, an endoscope imaging apparatus4, a display device5, and a light source device6.

The ultrasound endoscope2converts electrical pulse signals, which are received from the ultrasound imaging apparatus3, into ultrasound pulses (acoustic pulses) using an ultrasound transducer installed at its front end, and irradiates the subject with the ultrasound pulses; and then converts the ultrasound echo reflected from the subject into electrical echo signals expressed in terms of voltage variation, and outputs the electrical echo signals.

The ultrasound endoscope2includes an imaging optical system and an imaging element. The ultrasound endoscope2is inserted into the alimentary tract (the esophagus, the stomach, the duodenum, or the large intestine) or into a respiratory organ (the trachea or the bronchus), and is capable of capturing images of the alimentary canal or the respiratory organ. Moreover, the ultrasound endoscope2includes a light guide for guiding an illumination light that is thrown onto the subject at the time of imaging. The light guide has the front end thereof reaching the front end of the insertion portion of the ultrasound endoscope2that is to be inserted into the subject, and has the proximal end thereof connected to the light source device6that generates the illumination light. Furthermore, the ultrasound endoscope2sends ultrasound waves to the surrounding organs of the alimentary tract or the respiratory organ (such as to the pancreas, the gallbladder, the biliary duct, the biliary tract, the lymph node, the mediastinal organs, and the blood vessels), and receives the ultrasound waves reflected from those surrounding organs.

As illustrated inFIG.1, the ultrasound endoscope2includes an insertion portion21, an operating unit22, a universal cord23, and a connector24. The insertion portion21gets inserted into the subject. As illustrated inFIG.1, the insertion portion21is positioned at the front end, and has a front end portion212holding an ultrasound transducer211; has a curved portion213that is connected to the proximal end of the front end portion212and is bendable in nature; and a flexible tube214that is connected to the proximal end of the curved portion213and that has flexibility.

The ultrasound transducer211includes a plurality of piezoelectric elements arranged along the long side of the insertion portion21. More particularly, the ultrasound transducer211is a convex transducer in which a longitudinal direction of the plurality of piezoelectric elements is orthogonal to the longitudinal direction of the insertion portion21, and the piezoelectric elements are arranged to form a curved surface. Moreover, to the piezoelectric elements, a flexible shaft211a(seeFIG.5) (explained later) and a plurality of signal lines211b(seeFIG.5) (explained later) are connected. Moreover, to the piezoelectric elements, an acoustic matching layer (not illustrated) is attached as may be necessary, an acoustic lens211c(seeFIG.4) is attached, and a backing member (not illustrated) is attached. The ultrasound waves generated in each piezoelectric element are irradiated toward the subject through the acoustic lens211c. The configuration including a plurality of piezoelectric elements is housed in a housing211d(seeFIG.2). Meanwhile, alternatively, the ultrasound transducer211can be a linear transducer in which a plurality of piezoelectric elements is arranged in a plane. Meanwhile, when the ultrasound transducer211is a convex transducer, the ultrasound waves are irradiated in a radial manner from a plurality of piezoelectric elements, and hence a wide observable range is achieved. On the other hand, when the ultrasound transducer211is a linear transducer, the front end of the insertion portion21can be made thinner as compared to a convex transducer. The ultrasound endoscope2performs electronic scanning by electronically switching among the piezoelectric elements involved in transmission and reception and by applying delays in the transmission and reception performed by the piezoelectric elements. Regarding the front end of the insertion portion21, the detailed explanation is given later.

The operating unit22is connected to the proximal end of the insertion portion21, and receives various operations from the operator such as a doctor. As illustrated inFIG.1, the operating unit22includes a curved knob221that is meant for bending the curved portion213, and includes a plurality of operating members meant for performing various operations. Moreover, in the operating unit22, an instrument channel port223is formed which is communicated with an instrument channel and through which a treatment tool is inserted in the instrument channel.

The universal cord23extends from the operating unit22, and represents a cable in which a plurality of signal cables is laid for transmitting various signals and an optical fiber is laid for transmitting the illumination light supplied from the light source device6.

The connector24is installed at the front end of the universal cord23. The connector24includes a first connector unit241to a third connector unit243to which an ultrasound cable31, a video cable41, and the light source device6are respectively connected.

The ultrasound imaging apparatus3is electrically connected to the ultrasound endoscope2via the ultrasound cable31(seeFIG.1); sends electrical pulse signals to the ultrasound endoscope2via the ultrasound cable31; irradiates the ultrasound endoscope2with ultrasound waves; receives electrical echo signals obtained as a result of conversion of the ultrasound echo received by the ultrasound endoscope2; and generates ultrasound images.

The endoscope imaging apparatus4is electrically connected to the ultrasound endoscope2via the video cable41(seeFIG.1) and receives input of image signals from the ultrasound endoscope2via the video cable41. Then, the endoscope imaging apparatus4performs predetermined processing with respect to the image signals and generates endoscope images.

The display device5is configured using liquid crystals or organic EL (Electro Luminescence), or using a projector, or using a CRT (Cathode Ray Tube); and displays the ultrasound images generated by the ultrasound imaging apparatus3and displays the endoscope images generated by the endoscope imaging apparatus4.

The light source device6is connected to the ultrasound endoscope2, and provides an illumination light to the ultrasound endoscope2for illuminating the inside of the subject.

Given below is the explanation of a detailed configuration of the insertion portion21.FIG.2is a diagram illustrating a lateral view of the front end of the ultrasound endoscope. As illustrated inFIG.2, the ultrasound endoscope2includes a first rigid portion2121that is positioned at the front end of the insertion portion21which gets inserted inside the subject; a supporting portion2122that is connected to the proximal end of the first rigid portion2121; and a second rigid portion2123that is connected to the proximal end of the supporting portion2122.

In the first rigid portion2121and the second rigid portion2123, a first band groove2121aand a second band groove2123aare respectively formed to lock balloon bands provided in a balloon, so that the balloon gets attached to the ultrasound endoscope2.

FIG.3is a diagram illustrating the state attained by attaching a balloon to the state illustrated inFIG.2. As illustrated inFIG.3, of a tubular balloon2127, a balloon band2127aat the front end is fit in the first band groove2121a, and a balloon band2127bat the proximal end is fit in the second band groove2123a; and hence the balloon2127gets attached to the front end of the insertion portion21and covers the ultrasound transducer211. In the state in which the balloon2127is attached to the insertion portion21, when a liquid such as water is filled in the balloon2127from balloon water supply/water drainage conduits2123d, the balloon2127expands. When the ultrasound transducer211is driven under the control of the ultrasound imaging apparatus3; as illustrated inFIG.3, an ultrasound image can be generated in a region A having the cross-sectional surface along the direction of arrangement of a plurality of piezoelectric elements.

FIG.4is a perspective view of the front end of the ultrasound endoscope illustrated inFIG.1, when viewed from the front end side.FIG.5is a perspective view of the front end of the ultrasound endoscope illustrated inFIG.1, when viewed from the proximal end side.FIG.6is an exploded view ofFIG.4.FIG.7is an exploded view ofFIG.5.

At the front end of the first rigid portion2121, the following units are installed: an imager2124that captures images along the longitudinal direction of the insertion portion21; an illuminating unit2125that illuminates the inside of the subject with the illumination light supplied from the light source device6; and a nozzle2126that is used to spray a liquid such as water from the front end of the insertion portion21toward the imager2124with the aim of removing dirt attached to the imager2124.

As illustrated inFIG.5, the ultrasound transducer211has the flexible shaft211aconnected thereto for transmitting the power of a rotation mechanism. In the flexible shaft211ais inserted a plurality of signal lines211bthat is electrically connected to the piezoelectric elements of the ultrasound transducer211. The flexible shaft211ais, for example, a coil-shaped metallic member that rotates due to the power of the rotation mechanism and causes rotation of the ultrasound transducer211that is fixed to the front end of the flexible shaft211a. At that time, the flexible shaft211aand a plurality of signal lines211brotate in an integrated manner. As a result of inserting the signal lines through the inside of the flexible shaft211a, the internal space of the flexible shaft211acan be effectively utilized, thereby making it possible to make the insertion portion21thinner. Meanwhile, the signal lines211bneed not always be inserted through the flexible shaft211a, and can alternatively be placed on the outside of the flexible shaft211a. That eliminates the need to perform the task of inserting a plurality of signal lines211bthrough the elongated flexible shaft211a. Meanwhile, a rotation supporting member such as a shaft bearing can be disposed in between the flexible shift211aand the second rigid portion2123, so that the flexible shaft211acan smoothly rotate with respect to the second rigid portion2123.

The first rigid portion2121is made of, for example, resin. However, there is no particular restriction on the material of the first rigid portion2121. Thus, the first rigid portion2121can be made of a metal or an alloy. In the ultrasound endoscope2, in the state in which the ultrasound transducer211is covered by the balloon2127and a liquid such as degassed water is filled in the balloon2127, the balloon2127is brought into contact with the body tissue, so that the ultrasound waves are transmitted more easily from the ultrasound transducer211toward the body tissue. At the proximal end of the first rigid portion2121, a depressed portion2121b(seeFIG.7) is formed in which the front end of the supporting portion2122fits. In between the supporting portion2122and the depressed portion2121b, a rotation supporting member such as a shaft bearing is disposed so that the ultrasound transducer211can rotate smoothly.

The supporting portion2122is a rod-like member that has the long side along the longitudinal direction of the insertion portion21. The supporting portion2122is made of, for example, a metal or an alloy; but there is not particular restriction on the material of the supporting portion2122. To the supporting portion2122, the flexible shaft211ais attached in such a way that the supporting portion2122rotates accompanying the rotation of the flexible shaft211a. Moreover, the supporting portion2122has the ultrasound transducer211fixed thereto. Thus, accompanying the rotation of the flexible shaft211a, the supporting portion2122and the ultrasound transducer211can be rotated in an integrated manner. At the front end of the supporting portion2122, a salient portion2122ais formed to fit in the depressed portion2121bof the first rigid portion2121. Meanwhile, alternatively, a salient portion can be formed on the first rigid portion2121, and a depressed portion can be formed in the supporting portion2122.

The second rigid portion2123is made of, for example, resin. However, there is no particular restriction on the material of the second rigid portion2123. Moreover, in the second rigid portion2123, an instrument channel outlet2123bis formed through which the treatment tool inserted from a side of the proximal end is made to protrude along the longitudinal direction of the insertion portion21. The instrument channel outlet2123bis formed to be communicated with an instrument channel. Moreover, in the instrument channel outlet2123b, a forceps standup mechanism (not illustrated) can be disposed so that the orientation of the treatment tool, which is protruding from the instrument channel outlet2123b, can be guided in the direction in which the ultrasound transducer211radiates the ultrasound waves. Furthermore, in the second rigid portion2123, an oscillator conduit2123cis disposed in which the proximal end of the supporting portion2122is inserted. In between the supporting portion2122and the oscillator conduit2123c, a rotation supporting member such as a shaft bearing can be disposed so as to ensure smooth rotation.

FIG.8is a diagram illustrating the second rigid portion when viewed from the front end side. As illustrated inFIG.8, the following components are formed in the second rigid portion2123: the oscillator conduit2123cthrough which the flexible shaft211aand the signal lines211bare inserted; the balloon water supply/water drainage conduits2123dthat are used for supplying a liquid into the balloon attached to cover the ultrasound transducer211and for draining the liquid from the inside of the balloon; an imaging signal line conduit2123ethrough which signal lines for imaging that are connected to the imaging element of the imager2124are inserted; a light guide conduit2123fthrough which the light guide that is used to transmit light to the illumination lens of the illuminating unit2125is inserted; and a water supply conduit2123gthat is used to supply a liquid to the nozzle2126. Meanwhile, the two balloon water supply/water drainage conduits2123dillustrated inFIG.8include a conduit for supplying a liquid into the balloon and a conduit for draining the liquid from the inside of the balloon. However, alternatively, only a single conduit can be configured to supply the water as well as drain the water.

Moreover, as illustrated inFIG.6, the second rigid portion2123includes a columnar portion2123hthat extends up to the first rigid portion2121. Inside the columnar portion2123hare formed the imaging signal line conduit2123e, the light guide conduit2123f, and the water supply conduit2123g. The front end of the columnar portion2123his fixed to the first rigid portion2121. Hence, even when the flexible shaft211aand the supporting portion2122rotate, the first rigid portion2121and the second rigid portion2123do not rotate. Meanwhile, either the columnar portion2123hcan be formed in an integrated manner with the second rigid portion2123, or the columnar portion2123hformed as a separate portion from the second rigid portion2123can be fixed to the second rigid portion2123.

The openings of the balloon water supply/water drainage conduits2123dcan for formed at any positions in between the first band groove2121aand the second band groove2123a. At the front end of the columnar portion2123h, the openings of the imaging signal line conduit2123e, the light guide conduit2123f, and the water supply conduit2123gare formed. The columnar portion2123hand the first rigid portion2121are paired in such a way that the positions of those openings are coincident with the imager2124, the illuminating unit2125, and the nozzle2126in the first rigid portion2121, respectively.

Meanwhile, it is desirable that the flexible shaft211a, which extends from the second rigid portion2123to the proximal end of the insertion portion21, is placed to pass through the inside of a tube. That is desirable for the reason that, since the insertion portion21has a light guide placed therein, the rotating flexible shaft211ais to be prevented from interfering with the light guide and damaging it.

FIG.9is a schematic configuration diagram of the connector. Inside the connector24, a motor224is installed for rotating the ultrasound transducer211. As the motor224, it is possible to use a stepping motor that can be rotated at an arbitrary angle according to the drive pulse current, or to use a servo motor that is combined with a detection device meant for detecting the rotation angle and the rotation count. The motor224has a shaft228installed therein, and the shaft228has a first gear225attached thereto. Moreover, at the end of the flexible shaft211a, a second gear227is attached. The first gear225and the second gear227are configured to mesh with each other and rotate in tandem. Thus, when the motor224is rotated, the power can be transmitted to the flexible shaft211avia the shaft228, the first gear225, and the second gear227. In the present working example, the configuration includes two gears for transmitting the power. However, that is not the only possible case, and the number of gears can be increased or reduced as may be necessary. Besides, as long as the power of the motor224can be transmitted to the flexible shaft211a, it is not required to use a gear and alternatively, for example, a dynamic belt can be used. As explained above, inside the connector24, a rotation mechanism is housed that includes the motor224meant for rotating the ultrasound transducer211and includes a transmission mechanism configured with the first gear225and the second gear227. Moreover, the shaft228has a lever226attached thereto. When the lever226is manually rotated, the shaft228rotates and, in tandem with the rotation of the shaft228, the ultrasound transducer211can be rotated via the flexible shaft211a.

FIG.10is a view taken along an arrow B illustrated inFIG.9. As illustrated inFIG.10, the lever226includes an indicator2261as an angle display portion for displaying the angle of the ultrasound transducer211in the direction of its rotation. For example, when the indicator2261is oriented in the direction of a first mark229, it is indicated that the orientation of the ultrasound transducer211is such that the insertion portion21is easily insertable into the body of the subject. On the other hand, when the indicator2261is oriented in the direction of a second mark230, it is indicated that the orientation of the ultrasound transducer211is such that, even when a treatment tool is made to protrude from the instrument channel outlet2123b, the treatment tool and the ultrasound transducer211do not come in contact with each other.

FIGS.11and12are front views of the front end of the ultrasound endoscope. When at the angle illustrated inFIG.11, the ultrasound transducer211overlaps, in the longitudinal direction of the insertion portion21, with the portion that is bulging due to the instrument channel outlet2123bof the second rigid portion2123. Hence, a projection area that is obtained by projecting the insertion portion21in the longitudinal direction of the insertion portion21is the smallest. In other words, the acoustic lens of the ultrasound transducer211gets oriented in the direction in which the distance from the center of the oscillator conduit2123cof the second rigid portion2123to the outer periphery of the second rigid portion2123is the longest. Thus, by adjusting the angle of the ultrasound transducer211, it can be oriented in such a way that the cross-sectional area of the front end portion212, which has the orthogonal orientation to the longitudinal direction of the insertion portion21, is the smallest. As a result, the insertion portion21can be made easily insertable into the body of the subject and easily removable from the body of the subject.

On the other hand, when the ultrasound transducer211is at the angle illustrated inFIG.12, the treatment tool protruding from the instrument channel outlet2123bdoes not make contact with the ultrasound transducer211.

Given below is the explanation of an observation method implemented using the ultrasound endoscope2. Firstly, the ultrasound endoscope2is operated and, in the state in which the insertion portion21having the balloon2127attached thereto is inserted into the body of the subject, the ultrasound transducer211is placed in the vicinity of the site of lesion by referring to an optical observation image taken using the imaging optical system. Then, while maintaining that state, degassed water is sent into the balloon2127using the balloon water supply/water drainage conduits2123d, so that the balloon2127expands. Subsequently, in the state in which the expanded balloon2127is pressed against the body wall of the subject, the ultrasound imaging apparatus3is operated and electrical signals are sent to the ultrasound transducer211, so that ultrasound waves are generated by the ultrasound transducer211. Moreover, the ultrasound imaging apparatus3is operated so as to supply the power for driving the motor224. As a result of driving the motor224, the ultrasound transducer211rotates via the flexible shaft211a.

FIG.13is a diagram illustrating the rotation of the ultrasound transducer. As illustrated inFIG.13, the ultrasound transducer211rotates by a predetermined angle R from the position illustrated inFIG.11. In other words, the ultrasound transducer211oscillates at a certain angle R. Herein, the angle R can be set in the range from 30° to 180°. With such a configuration, in addition to electronically scanning the ultrasound transducer211in the direction of arrangement of the piezoelectric elements, the ultrasound transducer211is mechanically scanned around the axis of the supporting portion2122. Regarding the mechanical scanning, by establishing association with the information about a detection device that detects the pulse current and the rotation angle at the time of driving the motor224, three-dimensional echo information included in the angle R can be obtained as illustrated inFIG.13. The ultrasound imaging apparatus3in which such information is sequentially obtained and stored becomes able to generate a three-dimensional image based on that information.

Meanwhile, the ultrasound endoscope2is not limited to the embodiment described above. Alternatively, a rotation mechanism such as a motor can be installed in the operating unit22. In that case, the flexible shaft211ais no more required to be placed up to the inside of the universal code23, and hence can be shortened in length. As a result of shortening the length of the flexible shaft211a, the distance between the motor224and the ultrasound transducer211can be reduced. That enables achieving enhancement in the transmissibility of the torque.

Moreover, the motor224can be disposed in the connector24, and a detection device for detecting the rotation angle can be disposed in the operating unit22or the front end portion212. In this way, by placing the detection device close to the ultrasound transducer211, the rotation angle of the ultrasound transducer211can be detected with more accuracy.

As another working example, a rotation mechanism such as a motor can be disposed in the front end portion212. In that case, the configuration need not include the flexible shaft211a. As a result, a more preferable rotation action can be achieved without any effect of the flexure of the flexible shaft211a.

The ultrasound imaging apparatus3can have the function of displaying the angle, which is detected by an angle sensor, in the display device5. Moreover, the ultrasound imaging apparatus3can have the function of displaying, in the display device5, the angle of the ultrasound transducer211at which the projection area obtained by projecting the insertion portion21in the longitudinal direction of the insertion portion21is the smallest. Furthermore, the ultrasound imaging apparatus3can have the function of displaying, in the display device5, the angle of the ultrasound transducer211at which there is no contact between the treatment tool, which is protruding from the instrument channel outlet2123b, and the ultrasound transducer211.

The operator becomes able to observe two-dimension ultrasound images as well as to observe three-dimensional ultrasound images at arbitrary timings. Regarding the two-dimensional ultrasound images obtained in a conventional ultrasound endoscope, the observation area is narrow and there are not many clues enabling identification of the observed body part. On the other hand, in the ultrasound endoscope2according to the disclosure, there is a wide observable range, and the ultrasound images can be confirmed in the three-dimensional display too. Hence, it becomes easier to understand the site of lesion.

Modification Example

The ultrasound endoscope according to a modification example includes an imager that is installed in the second rigid portion and that takes images in the direction intersecting with the longitudinal direction of the insertion portion. Thus, the ultrasound endoscope is not limited to the direct viewing type as explained in the embodiment, and can alternatively be an oblique-viewing endoscope in which the imager is positioned at the proximal end of the ultrasound transducer.

Moreover, in the first rigid portion of the ultrasound endoscope, an instrument channel outlet is formed for enabling protrusion of a treatment tool, which is inserted from the proximal end, along the longitudinal direction of the insertion portion. Thus, in the ultrasound endoscope, although a treatment tool can be made to protrude from the proximal end of the ultrasound transducer as explained in the embodiment, it can alternatively be made to protrude from the front end of the ultrasound transducer. Furthermore, in the ultrasound endoscope, although a treatment tool can be made to protrude along the longitudinal direction of the insertion portion21, it can alternatively be made to protrude in the direction intersecting with the longitudinal direction of the insertion portion21.

Meanwhile, in the embodiment described above, the first rigid portion2121is made of resin. Hence, in case the ultrasound transducer211is damaged, it can be removed by breaking the first rigid portion2121, and can be repaired or replaced.

According to the disclosure, it becomes possible to implement an ultrasound endoscope and an ultrasound system that have a wider observable range in ultrasound images.

Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.