JP7223042B2 - diagnostic imaging equipment - Google Patents

Description

The present invention relates to a diagnostic imaging apparatus using a catheter.

Intravascular ultrasound diagnostic equipment (IVUS: IntraVascular Ultra Sound) and optical coherence tomography diagnostic equipment (OCT: Optical Coherence Tomography) are known as devices for diagnosing the lumen of blood vessels.

Ultrasonic waves have the property of reaching relatively deep regions of vascular tissue, and thus a vascular tomographic image obtained by IVUS is suitable for diagnosing not only the surface of vascular tissue but also deep regions. On the other hand, although light does not reach tissue as deep as ultrasound, the resulting image of the inner wall of a blood vessel can have a much higher resolution than that of IVUS.

As described above, recently, a diagnostic imaging apparatus that uses a catheter containing both an ultrasonic transmission/reception unit and an optical transmission/reception unit, that is, a hybrid type catheter, generates both an ultrasonic tomographic image and an optical tomographic image. has been proposed (Patent Documents 1 and 2).

In this type of device, the catheter is connected to a motor drive unit for rotating and moving the imaging core within it.

JP-A-11-56752 Japanese Patent Application Laid-Open No. 2006-204430

Since the length of the catheter is limited, the motor drive unit will inevitably be installed near the patient during the procedure, so the smaller the size, the better. In addition, since attachment and detachment from the catheter are repeatedly performed depending on the procedure, a material with high durability is desired.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a diagnostic imaging apparatus with a smaller motor drive unit and improved durability.

In order to solve the above problems, for example, the diagnostic imaging apparatus of the present invention has the following configuration. i.e.
It has a motor drive unit (MDU) for connecting a catheter and moving and rotating an imaging core housed in the catheter along the longitudinal direction of the catheter. An optical coherence tomographic image and an ultrasonic tomographic image of
a catheter connector for connecting with the MDU in the catheter,
a first cylindrical member that accommodates an optical fiber that is optically connected to an optical transmission/reception unit provided at the tip of the imaging core and holds an end of the optical fiber that is exposed;
a cylindrical second cylindrical member having a plurality of connection terminals fixed to the first cylindrical member and electrically connected to an ultrasonic transmission/reception unit provided at the tip of the imaging core;
having a connector portion that rotatably supports the first and second cylindrical members;
an MDU connector for connecting with the catheter connector in the MDU,
When the catheter connector is connected, the optical fiber of the first cylindrical member and the optical fiber from the diagnostic imaging apparatus are optically connected, and a photoelectric signal is transmitted from the electrical contact portion and the diagnostic imaging apparatus. having a shape that accommodates the catheter connector for connecting to a wire;
The MDU is characterized by supporting the center position of the end of the optical fiber exposed from the first cylindrical member of the catheter as the rotation center position of the imaging core.

According to the present invention, it is possible to provide a diagnostic imaging apparatus with a smaller motor drive unit and improved durability.

1 is a diagram showing an external configuration of an image diagnostic apparatus according to an embodiment; FIG. It is a figure which shows the structure of the catheter in embodiment. FIG. 4 is a structural cross-sectional view of the distal end of the catheter in the embodiment; FIG. 4 is a diagram showing the structure of the rear end of the catheter (the side connected to the MDU) in the embodiment; FIG. 4 is a diagram showing the structure and connection state of a portion of the MDU that connects to the catheter in the embodiment; FIG. 4 is an exploded view of a portion of an MDU that connects with a catheter in an embodiment;

Hereinafter, each embodiment of the present invention will be described in detail with reference to the accompanying drawings. Since the embodiments described below are preferred specific examples of the present invention, they are subject to various technically preferable limitations. Unless otherwise stated, the invention is not limited to these modes.

The diagnostic imaging apparatus according to the embodiment has an IVUS function and an OCT function.

FIG. 1 is a diagram showing an external configuration of an image diagnostic apparatus 100 according to an embodiment.

As shown in FIG. 1, the diagnostic imaging apparatus 100 includes a catheter 101, a motor drive unit (hereinafter referred to as MDU) 102, and an operation control device 103. The MDU 102 and the operation control device 103 are connected by signal lines and optical fibers. They are connected by a cable 104 that is accommodated.

In the operation control device 103, 111 is a main control unit. The main body control unit 111 receives signals (reflected waves of ultrasonic waves emitted toward the vascular tissue and reflected waves of light) obtained by the imaging core accommodated in the catheter 101, and radially from the rotation center position. Generate heading line data. Then, through interpolation processing of the line data, blood vessel tomographic images of respective properties based on ultrasound and optical interference are generated.

Reference numeral 111-1 denotes a printer and a DVD recorder, which print the results of processing in the main control unit 111 and store them as data. It should be noted that the storage destination of the processing result may be a server, a USB memory, or the like, and its type is not limited. Reference numeral 112 denotes an operation panel through which the user inputs various setting values and instructions. A monitor (for example, LCD) 113 serves as a display device, and displays various tomographic images generated by the main control unit 111 . 114 is a mouse as a pointing device (coordinate input device).

Catheter 101 is inserted directly into a blood vessel. Catheter 101 has a structure that accommodates a rotatable imaging core that is movable in its longitudinal direction. At the tip of the imaging core, an ultrasonic transmission/reception unit that generates ultrasonic waves based on signals transmitted from the imaging diagnostic apparatus 100, receives ultrasonic waves reflected from vascular tissue and converts them into electrical signals, and a transmission A housing is provided that houses an optical transmitting/receiving unit that continuously transmits the light (measurement light) that has been received into the blood vessel and that continuously receives the light reflected from the blood vessel. A drive shaft is connected to this housing for transmitting the rotation and movement force of the imaging core from the MDU 102 . In other words, the imaging core consists of this housing and the drive shaft. The diagnostic imaging apparatus 100 uses the catheter 101 containing the imaging core to measure the condition inside the blood vessel.

The MDU 102 has a portion that engages with the connecting portion at the rear end of the catheter 101 , and in a state of being connected to the catheter 101 , the ultrasound transmitting/receiving portion and the optical transmitting/receiving portion in the imaging core within the catheter 101 and the operation control device 103 . It functions as a relay device. Further, the MDU 102 drives a built-in motor to pull the inner hand tube and the drive shaft of the catheter 101 with respect to the outer hand tube of the catheter 101, and also controls the rotation of the drive shaft.

In addition, the MDU 102 is provided with various switches and buttons, which are operated by a user (doctor, etc.) to rotate the imaging core in the catheter 101 and pull back (moving the imaging core). become.

The actual patient blood vessel pullback scan process is well known, but is briefly described here.

While viewing the X-ray image, the user confirms that the tip of the catheter 101 has moved to the position to be diagnosed. Then, the user operates the MDU 102 to instruct pullback. As a result, the housing located at the distal end of the catheter 101 and containing the ultrasonic wave transmitting/receiving section and the optical transmitting/receiving section rotates and moves along the inside of the blood vessel.

The ultrasonic transmission/reception unit transmits and receives ultrasonic waves 512 times during one rotation, for example, and transmits the received signal to the operation control device 103 via the MDU 102 . The operation control device 103 receives this signal and performs predetermined arithmetic processing to obtain 512 line data extending in the radial direction from the rotation center of the transmitting/receiving unit. This line data is dense at the center position of rotation, and becomes coarser with distance from the center of rotation. Therefore, in order to create a two-dimensional image visually recognized by humans, the operation control device 103 performs interpolation processing between lines to generate pixels between the lines. As a result, a blood vessel tomographic image (ultrasound tomographic image) in a direction orthogonal to the axial direction of the blood vessel can be generated.

The optical transmitter/receiver, like the ultrasonic transmitter/receiver, emits light 512 times and receives reflected light from the vascular tissue during one rotation, and controls the received light (measurement light) via the MDU 102. Send to device 103 . Therefore, an optical fiber is accommodated in the drive shaft of the imaging core, and the optical transmitter/receiver and the operation control device 103 are optically connected via the MDU 102 . The operation control device 103 generates interference light by synthesizing the measurement light from the optical transmitter/receiver and the reference light that has passed through a known length using a photocoupler. The interfering light is then converted into digital data via a photodetector and an A/D converter. Fast Fourier transform is applied to the obtained digital data to obtain line data. Subsequent processing is substantially the same as that of the ultrasonic transmission/reception unit, and interpolation processing is performed to generate a blood vessel tomographic image (optical coherence tomographic image) of a plane orthogonal to the blood vessel axis.

It is also possible to generate a three-dimensional image of the blood vessel using ultrasonic waves by connecting the blood vessel tomographic images at positions on the blood vessel axis for each rotation of the ultrasonic transmission/reception unit. In addition, a three-dimensional image of a blood vessel can be generated using optical interference by connecting blood vessel tomographic images at positions on the blood vessel axis for each rotation of the optical transmitter/receiver. A doctor diagnoses a patient's blood vessels from the images obtained by such scanning.

The above is the outline of the operation during the pullback scan in the embodiment. Next, the catheter 101 according to the embodiment will be described with reference to FIG.

FIG. 2 shows an external configuration diagram of the catheter 101. As shown in FIG. The catheter 101 is composed of an outer tube sheath 200 and an inner tube 201 housed in the outer tube sheath 200 and inserted so as to be freely movable in the feeding direction. A locking portion 200 a is provided at or near the rear end of the outer tube sheath 200 and fixedly supported by the MDU 102 . Also, the MDU 102 pulls the inner tube 201 in the right direction in the figure while gripping the rear end of the inner tube 201 and rotates the drive shaft connected to the inner tube 201 . Reference numeral 201a in FIG. 2 denotes a priming port (injection port for liquid (generally physiological saline) for expelling air from outer tube sheath 200 and inner tube 201).

FIG. 3 shows the cross-sectional structure of the distal end portion (the side inserted into the blood vessel) of the catheter 101 in the embodiment.

The inner tube 201 is inserted into the outer tube sheath 200 . The sheath 310 of the outer tube sheath 200 is made of a transparent material at least at its distal end to maintain the transmission of light. At the tip of the sheath 310, a priming hole 320 is provided for discharging air bubbles in the outer tube sheath 200 and the inner tube 201 and for filling the sheath with a priming liquid. In the case of OCT, even if the medium of the optical path is air, it has little effect when constructing an optical coherence tomographic image. However, if there is air on the propagation path of the ultrasonic wave, the difference in acoustic impedance between the air and the catheter sheath material or blood is large. Therefore, sufficient energy for imaging is not transmitted to the living tissue. Therefore, the ultrasonic wave is diffused and greatly attenuated. Since the inner tube 201 of the embodiment is assumed to be used not only for OCT but also for IVUS, it is provided with a priming hole 320 for discharging air to the outside. Reference numeral 360 in the drawing indicates the priming liquid injected from the priming port 201a in FIG.

Further, an imaging core 350 that is rotatable along the arrow 373 shown in the figure is accommodated within the sheath 310 . At the tip of the imaging core 350, an ultrasonic transmission/reception section 351, an optical transmission/reception section 352, and a housing 353 containing them are provided. This housing 353 is also supported by the drive shaft 330 . The drive shaft 330 is made of a material that is flexible and has characteristics that can transmit the rotation from the MDU 102 well. This drive shaft 330 will have approximately the same length as the inner tube 201 . Further, inside the drive shaft 330, a signal line cable 341 electrically connected to the ultrasonic transmitter/receiver 351 and a single mode fiber 342 optically connected to the optical transmitter/receiver 352 are accommodated in the longitudinal direction. It is

The ultrasonic wave transmitting/receiving unit 351 is because the imaging core 350 of the embodiment functions for IVUS, and transmits ultrasonic waves toward the illustrated arrow 371a according to the signal applied from the signal line cable 341, and reflects from the vascular tissue. When the wave 371b is received, the received ultrasonic wave is transmitted as an electric signal through the signal line 341 toward the MDU 102 (finally the operation control device 103). When the blood vessel is actually inserted and scanned, the drive shaft 330 and the imaging core 350 rotate along the arrow 373. Therefore, the ultrasonic transmission/reception unit 351 transmits ultrasonic waves in a plane orthogonal to the rotation axis. Transmission and reception are repeated. As a result, it becomes possible to obtain a tomographic image perpendicular to the blood vessel axis.

The optical transmitter/receiver 352 is for the imaging core 350 of the embodiment to function for OCT, and is composed of a mirror with an inclination angle of approximately 45 degrees and a hemispherical ball lens with respect to the central axis of rotation shown in the figure. Configured. The light guided through the single-mode fiber 342 is reflected by a mirror in a direction of approximately 90 degrees with respect to the direction of travel, and is directed through a lens toward the vascular tissue indicated by an arrow 372a. The reflected light (arrow 372b) from the vascular tissue is then transmitted through the lens, this time through the single mode fiber 342, toward the MDU 102 (and ultimately the operation control device 103). During scanning, the imaging core 350 rotates, and data for reconstructing a tomographic image of the blood vessel can be acquired, similar to IVUS.

A feature of this embodiment is the structure of the MDU 102 that connects (the inner tube 201 of) the catheter 101 . Therefore, first, the structure of the rear end portion of the catheter 101 connected to the MDU 102 will be described, and then the structure of the connection portion of the catheter 101 in the embodiment will be described.

FIG. 4(a) shows a cross-sectional structural view of the connector portion of the rear end portion 401 (the end portion connected to the MDU 102) of the inner tube 201 of the catheter 101. FIG. 1B is a front view of the connector portion of the inner tube 201 viewed from the MDU 102 side. Note the simplification or partial omission.

First, referring to FIG. 4, the structure of the rear end portion 401 of the inner tube sheath 201 of the embodiment will be described.

A first cylindrical member 410 having a circular cross section is supported at the rear end of the drive shaft 330 . This first cylindrical member 410 is rotatably supported via a rear end portion 401 and a rubber packing 402 . Therefore, at least the surface of the first cylindrical member 410 in contact with the packing 402 has low friction. This maintains a liquid-tight state between the rear end portion 401 and the first cylindrical member 410 .

Also, the first cylindrical member 410 holds the fiber 342 fixedly on its central axis, and the end of the fiber 342 is exposed as a fiber end 342a. Also, the first cylindrical member 410 is provided with a protrusion 411 at one location on the side surface of the distal end thereof. In addition, the first cylindrical member 410 is fixed to a second cylindrical member 423 (integrated structure) for suppressing blurring of the rotation axis and having the same diameter as the first cylindrical member 410 or a larger outer diameter. But it is good). The second cylindrical member 423 is rotatably supported by the rear end portion 401 . As a result, the fiber 342 is supported by the rear end portion 401 so that its center serves as the axis of rotation.

On the side surface of the second cylindrical member 423, electrodes 321a to 321c (three poles) are provided at equal intervals for electrical connection with the ultrasonic transmission/reception section 351 of the imaging core 350. As shown in FIG. The electrodes 312a to 312c may be of any type as long as they are electrically connected to the electrodes on the MDU 102 side when the rear end of the inner tube 201 is inserted into the MDU 102 and connected. The electrodes 321a to 321c in the embodiment are, for example, metal leaf springs. The reason why the electrodes 321a to 321c are arranged at regular intervals is that the center of gravity of the imaging core 350 including the first and second cylindrical portions 410 and 423 is substantially aligned with the center of the fiber 342. This is to eliminate bias and obtain stable rotation. Further, the electrodes are not limited to leaf springs. For example, pin electrodes may be used on the catheter side, and socket pin electrodes may be used on the MDU side.

Further, the end face of the fiber end 342a exposed from the first cylindrical member 410 is not only perpendicular to the axial direction as shown in the figure, but may also be a face inclined by a predetermined angle θ. The end face of the fiber housed in MDU 102 likewise has not only a right angle, but also an inclined plane at the same angle θ for surface connection with fiber end face 342a. The reason why both fiber end faces have an inclination angle .theta., not only 90 degrees with respect to the axis, is to reduce the influence of reflected light at the connecting face.

As described above, in order to further reduce the influence of reflected light, when the catheter 101 (inner tube 201 thereof) having inclined optical fiber end faces is attached to the MDU 102, the inclined fiber end faces Surface connection, more strictly speaking, connection must be made so as not to generate a phase shift in the direction of rotation. That is, the first cylindrical member 410 must be connected to the MDU 102 in a fixed orientation. For this reason, a protrusion 411 is provided at the tip of the first cylindrical member 410, and a guide groove for guiding the protrusion 411 is provided in the MDU 102 (details will be described later).

The electrodes 321a to 321c (three poles in the embodiment) provided on the second cylindrical portion 423 also have their own properties (one is the ground and the other two are electrodes for transmission and reception of ultrasonic waves). there is That is, the electrodes 312 a - 321 c must be electrically connected to their respective correct electrodes provided on the MDU 102 . The second cylindrical portion 423 is integrated with the first cylindrical portion 410 . Therefore, when the inner tube 201 of the catheter 101 is attached to the MDU 102, the respective fiber end faces are surface-connected, and both can electrically connect the intended electrodes correctly.

The above is the description of the structure of the portion of the inner tube 201 of the catheter 101 in the embodiment that connects to the MDU 102 .

FIG. 5(a) is a partial cross-sectional view of the connector portion of the MDU 102 according to the embodiment, which is connected to the inner tube 201 of the catheter 101, and FIG. 5(b) is a cross-sectional view of the connection state with the catheter 101. .

The MDU 102 is provided with a connector portion 510 that rotates about a one-dot chain line 530 shown in the drawing in accordance with the driving force from the drive motor of the MDU 102 . The connector portion 510 is provided with an opening portion 513 for fitting (accommodating) the first cylindrical member 410 and the second cylindrical member 423 of the inner tube 201 . Also, the MDU 102 has a cylindrical cover 520 for protecting the connector section 510 .

Electrodes 511a to 511c for electrically connecting to the electrodes 321a to 321c provided on the second cylindrical member 423 are provided on the inner surface of the opening 513 of the connector portion 510 when the catheter 101 is connected. ing. These electrodes 511a to 511c are provided at equal intervals like the electrodes 321a to 321c. Signal lines 512a to 512c connected to these electrodes 511a to 511c are housed in the connector portion 501 and led to the right hand side of the drawing.

The connector portion 510 in the embodiment accommodates a detachable adapter portion 550 . This adapter portion 550 has a cylindrical structure.

6A shows a cross-sectional view of the connector portion 501 with the adapter portion 550 removed, and FIG. 6B shows a cross-sectional view of the adapter portion 550. FIG.

A ferrule 551 is fixed to the surface of the adapter portion 550 opposite to the opening surface. Both end faces 551a and 551b of the ferrule 551 are inclined at the same angle as the fiber end face 342a of the catheter 101. FIG. The reason why the end surface 551a of the ferrule 551 in the adapter part 550 is an inclined surface having the same angle as the fiber end surface 342a of the catheter 101 is that the two are surface-connected. Therefore, the inner surface of the adapter portion 550 is provided with a guide groove 552 for guiding the projection portion 411 of the first cylindrical portion 410 of the catheter 101 . Further, the projection 411 of the first cylindrical portion 410 can be guided by the guide groove 552 simply by inserting the catheter 101 into the MDU 102 without worrying about the direction of the catheter 101 (more precisely, the direction of the first cylindrical portion 410). It is desirable to Therefore, a guide wall 553 for restricting the rotation direction of the protrusion 411 is provided in the range from the opening surface of the adapter portion 550 to the guide groove 552 in the embodiment.

FIG. 6(c) shows a partially transparent perspective view of the opening 556 in the adapter section 550. As shown in FIG. As shown in the figure, the guide wall 553 is inclined along both side surfaces with the vertex 554 at the position closest to the opening face, and the guide groove 553 is located on the opposite side of the vertex 554. . Because of the above structure, when the user inserts the catheter 101 into the MDU 102, if the protrusion 411 of the first cylindrical portion 410 is displaced from the apex 554 of the guide wall, simply inserting the catheter 100 will cause the catheter 101 to As the inner tube 201 rotates, the fiber end face 342a and the fiber end face 551a of the adapter portion 550 can finally be surface-connected. It should be noted that when the user inserts the catheter 101 into the MDU 102, the protrusion 411 of the first cylindrical portion 410 may coincide with the apex 554 of the guide wall. However, in this case, the user only has to twist the catheter 101 slightly and insert it into the MDU 102, so the user's operation can be very simple.

As described above, the fiber end surface 342a of the catheter 101 and the fiber end surface 551a of the adapter portion 550 can be surface-connected.

On the other hand, the other fiber end face 551b of the adapter portion 550 and the fiber end face 511a of the connector portion 510 extending from the rotating portion (not shown) of the MDU 102 must also be surface-connected to each other. For this purpose, when housing the adapter portion 550 in the connector portion 510, the direction of rotation of the adapter portion 550 must be in a predetermined direction. Therefore, in the adapter part 550 in the embodiment, a projection part 555 is provided at a position on the outer surface opposite to the opening. A guide groove 502 for guiding the protruding portion 555 is provided on the inner side surface of the connector portion 510 . When exchanging the adapter section 550, the user can perform surface splicing of the fibers only by aligning the protrusion 555 of the new adapter section 550 with the guide groove 502 and inserting it. A guide wall similar to the guide wall 553 of the adapter portion 550 may be provided inside the connector portion 510 .

Here, the reason why the adapter section 550 is interposed when connecting the optical fiber between the catheter 100 and the MDU 102 will be described.

The catheter 100 used for one procedure is treated as discarded in order to prevent infection and the like. Therefore, inserting and withdrawing the catheter from the MDU 102 equals the number of procedures. Therefore, the end surface of the fiber on the MDU 102 side is connected to the fiber of the catheter many times, which inevitably damages the surface, possibly degrading the accuracy of the tomographic image due to optical interference. Once there is a damage that cannot be ignored, it may develop into a situation where the cable 104 connecting the MDU 102 and the control device 103 needs to be replaced.

According to this embodiment, it is the adapter portion 550 described in the above embodiment that directly connects with the fiber end face 342a in the catheter 101 . Moreover, as shown in FIG. 6(b), the adapter portion 550 does not include an electrical signal line or the like, but includes a ferrule 551, but is a simple one that can be made exclusively of resin or the like. Therefore, even if the end face 551a of the ferrule 551 is damaged, by replacing the adapter portion 550, high-precision optical connection can be restored. When installing a new adapter part 550, the projection part 555 is only inserted by aligning it with the guide groove 502, or if the adapter part 550 has a guide wall, it is simply inserted while it is rotated. Since the correct connection can be made with only one operation, the burden on the operator is negligible.

As described above, according to the above embodiment, when the catheter 101 is connected to the MDU 102 , the center of the fiber 342 accommodated by the imaging core 350 in the catheter 101 is held as the rotation central axis of the imaging core 350 . As a result, the structure of the MDU 102 can be made more compact than when the center of the fiber 342 is displaced from the rotation center position.

Further, according to the embodiment, from the user's point of view, by performing a simple operation of inserting the catheter 101 into the MDU 102, the optical fibers in the catheter 101 and the MDU 102 can be connected with high accuracy, and the optical fibers for ultrasonic diagnosis can be used. signal lines can be correctly connected to each other.

Furthermore, according to the embodiment, the portion of the MDU 102 that is optically connected to the optical fiber in the catheter is a simple structure that does not include electrical circuits or signal lines, and is a replaceable adapter portion 550 . Therefore, the optical connection between the catheter 101 and the operation control device 103 can be restored at low cost simply by replacing the adapter 550 as necessary.

The present invention is not limited to the above embodiments, and various modifications and variations are possible without departing from the gist and scope of the present invention. Accordingly, to publicize the scope of the invention, the following claims are included.

DESCRIPTION OF SYMBOLS 101... Catheter 102... MDU 103... Diagnostic imaging apparatus 501... Connector part 550... Adapter part

Claims (4)

It has a motor drive unit (MDU) for connecting a catheter and moving and rotating an imaging core housed in the catheter along the longitudinal direction of the catheter. An optical coherence tomographic image and an ultrasonic tomographic image of
a catheter connector for connecting with the MDU in the catheter,
a first cylindrical member that accommodates an optical fiber that is optically connected to an optical transmission/reception unit provided at the tip of the imaging core and holds an end of the optical fiber that is exposed;
a cylindrical second cylindrical member having a plurality of connection terminals fixed to the first cylindrical member and electrically connected to an ultrasonic transmission/reception unit provided at the tip of the imaging core;
having a connector portion that rotatably supports the first and second cylindrical members;
an MDU connector for connecting with the catheter connector in the MDU,
a first hollow cylindrical portion that optically connects the optical fiber of the first cylindrical member and the optical fiber from the imaging diagnostic apparatus when the catheter connector is connected to the MDU connector;
The second cylindrical member has an electrode connected to the connection terminal of the second cylindrical member when the catheter connector is connected to the MDU connector, and has an opening for accommodating the first hollow cylindrical portion. 2 hollow cylinders;
The first hollow cylindrical portion is detachable from the second hollow cylindrical portion through an opening formed at one end of the second hollow cylindrical portion,
In order to accommodate the first hollow cylindrical portion at a preset angle, guides for guiding protrusions provided on the outer surface of the first hollow cylindrical portion are provided on the inner surface of the second hollow cylindrical portion. grooved
An image diagnostic apparatus characterized by: The first cylindrical member of the catheter is provided with a protrusion for defining the orientation in the rotational direction,
the first hollow cylindrical portion has an opening for accommodating the first cylindrical member;
On the opening side of the first hollow cylindrical portion, there are provided a guide wall that defines the sliding direction of the protrusion when the first cylindrical member enters, and an end portion of the guide wall. 2. The diagnostic imaging apparatus according to claim 1, further comprising: a guide groove for guiding in an intrusion direction when the projection reaches a predetermined angle. The electrode is provided on the inner surface of the second hollow cylindrical portion,
The first hollow cylindrical portion is inserted into the opening from the opening of the second hollow cylindrical portion toward the other end side of the second hollow cylindrical portion to a position beyond the electrode. attached to the second hollow cylindrical portion in the
3. The diagnostic imaging apparatus according to claim 1, wherein: The second hollow cylindrical portion is provided with a guide wall for guiding the projecting portion of the first hollow cylindrical portion to the guide groove on the opening side of the second hollow cylindrical portion. The diagnostic imaging apparatus according to any one of claims 1 to 3, characterized by:

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