Catheters and catheter systems

Abstract

To provide a catheter having a function to observe a form of a living body tissue and a function to treat a lesioned part of the living body tissue.SOLUTION: A catheter A having a lumen 14 includes: a tube 10; a sensor part 25 disposed at the distal end of the tube 10 that can transmit and receive an ultrasonic wave; and an irradiation part 26 disposed at the distal end of the tube 10 that can emit an ultrasonic wave toward a guide wire 15 projected from the distal end of the tube 10 through the lumen 14. The ultrasonic wave is transmitted to a living body tissue from the sensor part 25, and a reflection wave reflected by the living body tissue is received by the sensor part 25 so that the form of the living body tissue can be observed. When the guide wire 15 is irradiated with the ultrasonic wave transmitted from the irradiation part 26, the guide wire 15 vibrates, and by the vibration of the guide wire 15, its passage through a closed part of the living body tissue can be facilitated.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a catheter and a catheter system. [Background technology]

[0002] Patent Document 1 discloses a medical device in which a guidewire is inserted into a catheter and a "spring" is provided as a vibration generating means. The tip of the guidewire protruding from the distal end of the catheter is vibrated by the "spring" to pass through the vascular obstruction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2013-518690 Summary of the Invention [Problem to be solved by the invention]

[0004] The above medical device has a function of facilitating passage of the vascular occlusion by the guidewire, but does not have a function of detecting the morphology of the vascular occlusion. Before performing the procedure of vibrating the guidewire to pass through the vascular occlusion, it is necessary to diagnose the morphology of the vascular occlusion using a separate catheter. Therefore, a device for observing the morphology of the vascular occlusion is required in addition to the medical device for passing through the vascular occlusion.

[0005] The present invention was completed in view of the above circumstances, and aims to provide a catheter capable of observing the morphology of biological tissue and facilitating passage through occluded areas of biological tissue. In particular, when an occluded area in biological tissue has hardened due to calcification or other reasons, making it difficult for a guidewire to pass through the occluded area, the aim is to facilitate the guidewire's passage through the occluded area by crushing the hardened occluded area. [Means for solving the problem]

[0006] (1) This disclosure is A tube having an internal lumen; A sensor unit disposed at a distal end of the tube and capable of transmitting and receiving ultrasonic waves; a catheter including: an irradiation unit disposed at a distal end of the tube and capable of irradiating ultrasonic waves toward a medical device protruding from the distal end of the tube through the lumen; (2) The catheter according to (1), wherein the irradiation unit is configured by arranging a plurality of transducers in a line, and the medical device is disposed on an extension line of the arrangement direction of the plurality of transducers. (3) The catheter according to (2), wherein the irradiation unit has a first transmitting unit and a second transmitting unit arranged to sandwich the lumen, and the plurality of transducers constituting the first transmitting unit and the second transmitting unit are arranged in a straight line. (4) The catheter according to any one of (1) to (3), wherein the irradiation unit is configured to include a transducer that can be controlled independently of a transducer constituting the sensor unit. (5) The catheter according to any one of (1) to (4), wherein a transducer constituting the sensor unit and a transducer constituting the irradiation unit are the same type of component. (6) The catheter according to any one of (1) to (5), wherein the sensor unit is configured to include a transducer capable of transmitting ultrasonic waves toward the medical device. (7) The catheter according to (6), wherein the sensor unit has a mode for irradiating ultrasound toward a lesion and a mode for irradiating ultrasound toward the medical device, and in the mode for irradiating ultrasound toward the lesion, the sensor unit is controlled to switch between ultrasound transmission and reception at predetermined intervals, and in the mode for irradiating ultrasound toward the medical device, the sensor unit is controlled to continuously transmit ultrasound for a period longer than the predetermined period. (8) The catheter according to any one of (1) to (7), wherein the irradiation unit is configured with a transducer capable of transmitting and receiving ultrasonic waves. (9) The catheter according to (8), wherein in a mode in which the irradiation unit transmits and receives ultrasonic waves, the transmission and reception of ultrasonic waves are alternately performed intermittently. (10) A catheter system connected to any one of the catheters (1) to (9) and having a transmission control unit that controls the ultrasonic oscillation of the sensor unit and the irradiation unit, wherein the transmission control unit controls the display on a display device based on the ultrasonic waves received by the sensor unit. Effect of the Invention

[0007] The morphology of the biological tissue can be observed by transmitting ultrasonic waves from the sensor unit toward the biological tissue and receiving the reflected waves from the biological tissue with the sensor unit. When the ultrasonic waves transmitted from the irradiation unit are irradiated onto the medical device, the medical device vibrates, and the vibration of the medical device can facilitate passage through the obstruction in the biological tissue. The catheter of the present invention can perform the function of observing the morphology of the biological tissue and the function of facilitating passage through the obstruction in the biological tissue. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side cross-sectional view of a catheter system according to a first embodiment. [Diagram 2] Front view of the catheter [Diagram 3] Side cross-sectional view of the catheter [Figure 4] FIG. 1 is a side cross-sectional view of a medical device inserted into a catheter. [Diagram 5] FIG. 1 is a front view of a catheter according to a second embodiment of the present invention; [Figure 6] FIG. 3 is a front view of the catheter of the third embodiment. [Figure 7] FIG. 11 is a front view of the catheter of the fourth embodiment. [Figure 8] FIG. 5 is a front view of the catheter of the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In this embodiment, the irradiation unit may be configured by arranging a plurality of transducers in a line, and the medical device may be disposed on an extension of the line direction of the plurality of transducers. According to this configuration, by shifting the timing of ultrasonic transmission between the plurality of transducers, the wavefronts of the plurality of ultrasonic waves are synthesized, so that the ultrasonic beam can be focused on the medical device. This allows the medical device to be strongly vibrated, so that it is possible to easily pass through the obstruction part of the biological tissue.

[0010] In this embodiment, the irradiation unit may have a first transmitting unit and a second transmitting unit arranged to sandwich the lumen, and the multiple transducers constituting the first transmitting unit and the second transmitting unit may be arranged in a straight line. According to this configuration, the medical device is irradiated with two focused ultrasonic beams, so that the medical device can be vibrated more strongly.

[0011] In the present embodiment, the irradiation unit may be configured to include a vibrator that can be controlled independently of a vibrator constituting the sensor unit. With this configuration, the sensor unit can observe the biological tissue and the irradiation unit can easily pass through the obstruction in the biological tissue at the same time.

[0012] In the present embodiment, the vibrator constituting the sensor unit and the vibrator constituting the irradiation unit may be the same type of component. With this configuration, only one type of vibrator is required to constitute the sensor unit and the irradiation unit, which allows cost reduction.

[0013] In this embodiment, the sensor unit has a mode of irradiating ultrasonic waves toward the biological tissue and a mode of irradiating ultrasonic waves toward the medical device, and in the mode of irradiating ultrasonic waves toward the biological tissue, the sensor unit may be controlled to switch between transmitting and receiving ultrasonic waves at predetermined intervals, and in the mode of irradiating ultrasonic waves toward the medical device, the sensor unit may be controlled to continuously transmit ultrasonic waves for a period longer than the predetermined period. According to this configuration, after observing the biological tissue, it is possible to strongly vibrate the medical device by using the irradiation unit and the sensor unit together.

[0014] In this embodiment, the irradiation unit may be configured with a transducer capable of transmitting and receiving ultrasonic waves. With this configuration, the biological tissue can be observed by the sensor unit and the irradiation unit before passing through the obstruction part of the biological tissue. In this case, the number of ultrasonic transmission positions and reception positions increases compared to the case where observation is performed only by the sensor unit, so that the observation accuracy of the morphology of the biological tissue is improved.

[0015] In the present embodiment, in the mode in which the irradiating unit transmits and receives ultrasonic waves, the transmission and reception of ultrasonic waves may be alternately performed intermittently. With this configuration, the observation of the biological tissue by the irradiating unit can be reliably performed.

[0016] In the embodiment described below, a medical device such as a guidewire passes through the lumen of the catheter and is disposed in front of the irradiation unit. According to this configuration, the medical device passes through the lumen of the catheter and is disposed in front of the irradiation unit, which has the effect of making it easier to focus the ultrasound emitted from the irradiation unit on the medical device.

[0017] The medical device may be disposed in front of the irradiation unit, facing the catheter from the front in the longitudinal direction, or passing beside the catheter. By disposing the medical device in front of the sensor unit and the irradiation unit facing the catheter from the front in the longitudinal direction, or passing beside the catheter, it becomes possible to dispose the catheter and the medical device in different biological tissues, and facilitate the passage of an occlusion in a biological tissue different from the biological tissue in which the catheter is disposed. The configuration of the present invention having a sensor unit and an irradiation unit at the tip of the catheter makes it possible to transmit and receive ultrasonic waves according to the respective purposes of observing the positions of the biological tissue and the medical device, and facilitating the passage of an occlusion.

[0018] <Embodiment 1> A first embodiment of the present invention will be described below with reference to Figs. 1 to 4. Fig. 1 shows a catheter system 1 including a catheter A and a transmission control device 614, and Fig. 2 shows a front view of the catheter A. The catheter system 1 is not limited to this first embodiment, and other embodiments 2 to 5 have a similar configuration. In the following description, with regard to the front-to-rear direction, the upper side in Figs. 3 and 4 is defined as the front. The front end and the distal end of the catheter A are used synonymously.

[0019] The catheter A and catheter system 1 of this embodiment 1 include a flexible tube 10, a lumen 14 formed within the tube 10, four ultrasonic sensors 23, a transmission control device 614 that controls the ultrasonic sensor 23, a display device 615 that displays information obtained from the ultrasonic sensor 23, and a connector 51 that connects the ultrasonic sensor 23 and the transmission control device 614 using a signal line 50 and facilitates the insertion of the catheter A into the body.

[0020] Fig. 2 shows a front view of catheter A. Tube 10 has a long inner tube 11 with a circular cross section housed coaxially within an outer tube 20 with a long outer tube 20 with a circular cross section, with the relative displacement in the radial direction restricted. A flexible guide wire 15 is inserted into lumen 14 (inner cavity) of catheter A.

[0021] Fig. 3 shows a cross-sectional view of the distal end of the catheter A in a state where the guide wire 15 is not inserted, and Fig. 4 shows a cross-sectional view of the distal end of the catheter A in a state where the guide wire 15 is inserted. As shown in Figs. 3 and 4, a pull wire 12 is embedded in the inner tube 11. The pull wire 12 is used to change the direction of the tip of the catheter A. In addition, the inner tube 11 and the outer tube 20 can be rotated relative to each other in the circumferential direction by rotating the inner tube 11 while holding the outer tube 20 at the proximal end of the catheter A, for example, by rotating the connector 51.

[0022] A support tube 21, which is cylindrical and concentric with the inner tube 11 and the outer tube 20, is provided on the outer circumferential surface of the inner tube 11 so as to move integrally with the inner tube 11. A support part 22 is formed at the distal end of the support tube 21, protruding concentrically toward the inner circumferential side. The support part 22 is fitted into the small diameter part 11S on the outer circumferential surface of the distal end of the inner tube 11, and is located slightly behind the distal end of the inner tube 11. The distal end of the inner tube 11 (the front end part of the small diameter part 11S) protrudes forward from the central hole of the support part 22. The inner circumferential surface of the support part 22 is in close contact with the outer circumferential surface of the small diameter part 11S. The outer circumferential surface of the support tube 21 is formed of a low-friction material such as PTFE. The outer circumferential surface of the support tube 21 slides against the inner circumferential surface of the outer tube 20, so that the outer tube 20, the support tube 21, and the inner tube 11 can rotate relatively to each other.

[0023] In addition, as an embodiment different from the first embodiment, the inner surface of the support tube 21 may be formed of PTFE or the like, and the inner surface of the support tube 21 and the outer surface of the inner tube may slide against each other, thereby enabling the outer tube 20 and the inner tube 11 to rotate relative to each other.

[0024] A pressure sensor 13 is built into the support part 22. A wiring (not shown) arranged inside the inner tube 11 is connected to the pressure sensor 13. The pressure sensor 13 detects that the distal end of the tube 10 hits biological tissue (not shown). In this embodiment, a mode in which the pressure sensor 13 detects that the distal end of the tube 10 hits biological tissue will be described, but a mode in which the hitting against biological tissue is detected using an ultrasonic sensor 23 described later and the pressure sensor 13 is not provided may also be used.

[0025] The space inside the inner tube 11 forms a lumen 14 (inner cavity). The cross-sectional shape of the lumen 14 is circular. A guide wire 15 serving as a medical device is inserted into the lumen 14. The guide wire 15 has a core wire 16, a coil body 17 made of a plain wire or a twisted wire, and a distal tip 18. The coil body 17 is disposed so as to surround the front end of the core wire 16, and the rear end of the coil body 17 is fixed to the core wire 16 by brazing. The distal tip 18 is fixed to the front end of the coil body 17 by brazing.

[0026] The guidewire 15 is capable of relative displacement in the longitudinal direction within the lumen 14. When the guidewire 15 is displaced forward, i.e., toward the distal end, the tip 18 protrudes forward beyond the front end of the tube 10. When the guidewire 15 is displaced toward the proximal end, the tip 18 is housed within the tube 10. When ultrasonic waves are applied to the tip 18, it vibrates while elastically deforming the coil body 17.

[0027] Four ultrasonic sensors 23 are attached to the front surface of the support part 22. A signal line 50 connecting the ultrasonic sensors 23 and the transmission control device 614 is inserted or embedded in the support tube 21. As shown in FIG. 2, in a front view of the catheter A seen in the longitudinal direction from the distal end side, the four ultrasonic sensors 23 are concentrically arranged at equal angular intervals in the circumferential direction with the lumen 14 as the center. Each ultrasonic sensor 23 is configured with a plurality of transducers 24 arranged in a row in the radial direction. The plurality of transducers 24 are arranged radially with the lumen 14 as the center.

[0028] Each transducer 24 is made of a piezoelectric element using a piezoelectric material such as lead zirconate titanate (PZT). In addition to PZT, the transducer 24 may be made of a polymer such as PVDF (polyvinylidene fluoride) or a MEMS device such as CMUT. The transducer 24 has a transmission function of transmitting ultrasonic waves forward of the catheter A by applying a voltage, and a reception function of receiving ultrasonic waves from the front of the catheter A to generate a voltage.

[0029] In this embodiment 1, two of the four ultrasonic sensors 23 are used as a sensor unit 25 for observing biological tissue. The transducer 24 constituting the sensor unit 25 is connected to a transmission control device 614. The transmission control device 614 has a circuit (not shown) that applies a voltage to the transducer 24 to transmit ultrasonic waves, and a circuit (not shown) that generates an ultrasonic image based on a voltage generated by receiving ultrasonic waves. The circuit that generates the ultrasonic image is further connected to a display device 615. The two ultrasonic sensors 23 functioning as the sensor unit 25 are arranged to sandwich the lumen 14. The multiple transducers 24 constituting the two ultrasonic sensors 23 functioning as the sensor unit 25 are arranged to be aligned in a straight line with the lumen 14 in between.

[0030] Of the four ultrasonic sensors 23, the two ultrasonic sensors 23 other than the sensor unit 25 are used as an irradiation unit 26 for irradiating ultrasonic waves to the tip 18. The transducer 24 is connected to a circuit that applies a voltage to the transducer 24 to transmit ultrasonic waves, but is not connected to a circuit that generates an ultrasonic image based on the voltage generated by receiving ultrasonic waves.

[0031] The two ultrasonic sensors 23 functioning as the irradiation unit 26 constitute the first transmitter 27A and the second transmitter 27B. The multiple transducers 24 constituting the first transmitter 27A and the second transmitter 27B are arranged in a straight line with the lumen 14 in between. In a front view, the direction in which the multiple transducers 24 functioning as the sensor unit 25 are arranged (the vertical direction in FIG. 2) and the direction in which the multiple transducers 24 functioning as the irradiation unit 26 are arranged (the horizontal direction in FIG. 2) are perpendicular to each other. That is, the transducers 24 of the sensor unit 25 and the transducers 24 of the irradiation unit 26 are arranged in a cross shape so as to intersect at the center of the lumen 14.

[0032] The driving method of the multiple transducers 24 constituting one sensor unit 25 can be a phased array method in which the transmission voltage is applied to each transducer constituting the multiple transducers 24 with a slight difference in timing. The secondary wavefront of the multiple ultrasonic waves transmitted with a time difference is formed as a focused ultrasonic wave with high energy. The driving voltage may be applied to the multiple transducers 24 constituting one irradiation unit 26 with a slight difference in timing, similar to the transducers 24 of the sensor unit 25.

[0033] The focus position where the ultrasonic waves emitted from each of the two sensor units 25 arranged on either side of the lumen 14 are focused can be adjusted by changing the timing of ultrasonic transmission between the multiple transducers 24 constituting each sensor unit 25. Reducing the time difference between ultrasonic transmissions increases the distance from the front end of the catheter A to the focus position. By emitting ultrasonic waves from the transducers 24 on the outer periphery side of the multiple transducers 24 arranged in a row in the radial direction before the transducers 24 on the lumen 14 side, the focus position becomes the position on the lumen 14 side of the sensor unit 25. As a result, when ultrasonic waves are transmitted from the two sensor units 25 sandwiching the lumen 14, the transmission time difference and transmission order between the multiple transducers 24 of each sensor unit 25 are controlled, thereby making it possible to adjust the focus position toward the tip 18 side of the guidewire 15 protruding through the lumen 14.

[0034] The usage form of the catheter A of the first embodiment of the present invention will be described. The purpose is to eliminate a blockage occurring in a tubular biological tissue such as a blood vessel and improve the circulation of blood and the like. When observing a biological tissue, ultrasonic waves are intermittently emitted for a short time from the transducers 24 of the pair of sensor units 25 with the guide wire 15 housed in the tube 10. The pulsed ultrasonic waves emitted from the sensor units 25 are irradiated to the biological tissue as focused ultrasonic waves and are reflected on the surface or inside of the biological tissue. The reflected waves reflected by the biological tissue are received by the transducers 24, which are in a stopped state of emission. The transducers 24 that receive the ultrasonic waves generate a voltage according to the strength of the reflected waves. An ultrasonic image (not shown) of the biological tissue is obtained based on the voltage generated by the transducers 24. The biological tissue is observed in this manner.

[0035] After the observation of the biological tissue is completed, the guidewire 15 is displaced forward, the distal tip 18 is projected forward from the tube 10, and pressed against the obstruction occurring in the biological tissue, while the distal end of the outer tube 20 is pressed against the obstruction or the biological tissue in the vicinity of the obstruction. Whether the outer tube 20 is in contact with the biological tissue in the vicinity of the obstruction is detected by the time from transmission to reception of ultrasonic waves by the pressure sensor 13 or the transducer 24. With the distal tip 18 pressed against the obstruction, ultrasonic waves are transmitted from the transducer 24 of the pair of irradiation units 26. By pressing the outer tube 20 against the obstruction or the biological tissue in the vicinity of the obstruction, the catheter A holds the guidewire 15 when the distal tip 18 of the guidewire 15 vibrates, so that the vibration of the distal tip 18 can be efficiently transmitted to the obstruction.

[0036] The focus position of the emitted ultrasound is set so that the ultrasound is focused at the distal tip 18. The distal tip 18 vibrates at a high frequency when it is irradiated with focused ultrasound with high energy. At this time, if the vibration frequency of the focused ultrasound is set to be the same as the natural vibration frequency of the distal tip 18, the distal tip 18 can be resonated to amplify the amplitude of the distal tip 18. The vibrating distal tip 18 facilitates the crushing and passing through of the occlusion. As a specific example, the distal tip 18 destroys the occlusion in the inner wall of the blood vessel and the guidewire 15 passes through the occlusion, thereby improving the blood flow.

[0037] The irradiation unit 26 is configured with a transducer 24 that is controlled independently of the transducer 24 that constitutes the sensor unit 25. In other words, the sensor unit 25 can transmit and receive ultrasound waves freely without being restricted by the ultrasound transmission of the irradiation unit 26. Therefore, it is possible to simultaneously observe biological tissue by the sensor unit 25 and facilitate passage through an obstruction by the irradiation unit 26.

[0038] The catheter A of the first embodiment includes a tube 10 having a lumen 14, a sensor unit 25, and an irradiation unit 26. The sensor unit 25 is disposed at the distal end of the tube 10 and is capable of transmitting and receiving ultrasonic waves. The sensor unit 25 transmits ultrasonic waves toward biological tissue, and the sensor unit 25 receives the reflected waves reflected by the biological tissue, thereby observing the morphology of the biological tissue. The irradiation unit 26 is disposed at the distal end of the tube 10 and is capable of irradiating ultrasonic waves toward the guidewire 14 that passes through the lumen 14 and protrudes further toward the distal end from the distal end of the tube 10. When the ultrasonic waves transmitted from the irradiation unit 26 are irradiated onto the distal tip 18 of the guidewire 15, the distal tip 18 vibrates, and the vibrating distal tip 18 is pressed against the obstruction, thereby making it easier to pass through the obstruction. The catheter A of the first embodiment can exhibit the function of observing the morphology of biological tissue and the function of facilitating passage through the obstruction of biological tissue.

[0039] The irradiation section 26 is configured by arranging a plurality of transducers 24 in a line, and the lumen 14 through which the guide wire 15 is inserted is arranged on an extension line of the arrangement direction of the plurality of transducers 24. The first transmitter 27A and the second transmitter 27B constituting the irradiation section 26 are arranged to sandwich the lumen 14. The plurality of transducers 24 constituting the first transmitter 27A and the plurality of transducers 24 constituting the second transmitter 27B are arranged to be arranged in a straight line. According to this configuration, when the timing of ultrasonic transmission is shifted between the plurality of transducers 24, the wavefronts of the plurality of ultrasonic waves are synthesized, so that the ultrasonic beam can be focused to the tip tip 18 of the guide wire 15. Moreover, since the tip tip 18 is irradiated with two focused ultrasonic beams, the tip tip 18 can be vibrated more strongly. This makes it easier to pass through the obstruction.

[0040] The transducer 24 constituting the sensor unit 25 and the transducer 24 constituting the irradiation unit 26 are the same type of parts, so only one type of transducer 24 is required to constitute the sensor unit 25 and the irradiation unit 26. This makes it possible to reduce the cost of the catheter A.

[0041] <Embodiment 2> Next, a second embodiment of the present invention will be described with reference to Fig. 5. The catheter B of this second embodiment has a sensor section 30 configured differently from that of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and descriptions of the structures, functions, and effects will be omitted.

[0042] The sensor unit 30 of the second embodiment is configured with one transmitter 31 and one receiver 32 arranged at different positions. The transmitter 31, receiver 32, and two irradiation units 26 are arranged at equal angular pitches in the circumferential direction around the lumen 14 and the guide wire 15, which is separate from the catheter B not shown in FIG. 5, as in the first embodiment. The transmitter 31 and receiver 32 are arranged to sandwich the lumen 14 and the guide wire 15. The multiple transducers 24 constituting the transmitter 31 are arranged in a row in the radial direction. The multiple transducers 24 constituting the receiver 32 are also arranged in a row in the radial direction.

[0043] The transducer 24 constituting the transmitting unit 31 and the transducer 24 constituting the receiving unit 32 are piezoelectric elements having a function of transmitting ultrasonic waves when a voltage is applied thereto and a function of generating a voltage when ultrasonic waves are received. The transducer 24 constituting the transmitting unit 31 is connected to a transmission control device 614. The transmission control device 614 is connected to a circuit (not shown) that applies a voltage to the transducer 24 to transmit ultrasonic waves, but is not connected to a circuit (not shown) that generates an ultrasonic image based on the voltage generated by receiving ultrasonic waves. Therefore, the transducer 24 of the transmitting unit 31 is used as a dedicated component that only transmits ultrasonic waves.

[0044] The transducer 24 constituting the receiving unit 32 is connected to a circuit that generates an ultrasound image based on the voltage generated by receiving ultrasound, but is not connected to a circuit that applies a voltage to the transducer 24 to transmit ultrasound. Therefore, the transducer 24 of the receiving unit 32 is used as a dedicated component that only receives ultrasound.

[0045] When observing the morphology of biological tissue, ultrasonic waves can be continuously emitted from the transmitter 31, and the reflected waves reflected by the biological tissue can be continuously received by the receiver 32. This allows the information received by the receiver 32 to be continuously received, making it easy to recognize the occlusion in the biological tissue and the change in the position of the guidewire 15 in the ultrasonic image. In addition, by emitting ultrasonic waves from the irradiator 26 while emitting and receiving ultrasonic waves from the sensor 30, the observation of the biological tissue and the crushing of the occlusion in the biological tissue can be simultaneously carried out.

[0046] <Embodiment 3> Next, a third embodiment of the present invention will be described with reference to Fig. 6. A catheter C of the third embodiment has a sensor unit 35 and an irradiation unit 36 ​​configured differently from those of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and a description of the structure, action, and effect will be omitted.

[0047] The catheter C of the third embodiment includes four ultrasonic sensors 23. As in the first and second embodiments, the ultrasonic sensors 23 are arranged at equal angular pitches in the circumferential direction around the lumen 14 and the guidewire 15, which is separate from the catheter C and is not shown in FIG. 6. The four ultrasonic sensors 23 include the same type of transducer 24. As in the first and second embodiments, each ultrasonic sensor 23 is composed of a plurality of transducers 24 arranged in a row in the radial direction. The transducers 24 constituting the four ultrasonic sensors 23 are all piezoelectric elements of the same type.

[0048] The transducers 24 constituting the four ultrasonic sensors 23 are all connected to a transmission control device 614. The transmission control device 614 is connected to a circuit (not shown) that applies a voltage to the transducers 24 to transmit ultrasonic waves, and a circuit (not shown) that generates an ultrasonic image based on a voltage generated by receiving ultrasonic waves. Each of the four ultrasonic sensors 23 has both a transmission function of transmitting ultrasonic waves forward of the catheter C by applying a voltage, and a reception function of generating a voltage by receiving ultrasonic waves from the front of the catheter C.

[0049] Therefore, all the ultrasonic sensors 23 are controlled so as to switch between transmitting and receiving ultrasonic waves at predetermined intervals, thereby combining the function of a sensor unit 35 for observing the morphology of the biological tissue located in front of the catheter C and the function of an irradiation unit 36 ​​for irradiating ultrasonic waves toward the distal tip 18 (not shown in FIG. 6) in order to crush an obstruction in the biological tissue located in front of the catheter C.

[0050] A first mode of use of the catheter C will be described. Some (for example, two) of the four ultrasonic sensors 23 are set as the sensor unit 35, and the remaining ultrasonic sensors 23 are set as the irradiation unit 36. When observing the biological tissue and fracturing the obstruction part in separate steps, ultrasonic waves are first emitted from the sensor unit 35 toward the biological tissue, and the biological tissue is observed. At this time, the transducer 24 constituting the sensor unit 35 transmits ultrasonic waves intermittently, and receives reflected waves from the biological tissue at timings when ultrasonic waves are not transmitted. In other words, when ultrasonic waves are irradiated from the sensor unit 35 to the biological tissue, the transmission and reception of ultrasonic waves are switched at predetermined intervals. After the observation of the biological tissue is completed, ultrasonic waves are transmitted from the irradiation unit 36 ​​toward the tip 18 of the guidewire 15, and the tip 18 vibrates to fracturize the obstruction part of the biological tissue.

[0051] The second usage form will be described. As in the first usage form, the four ultrasonic sensors 23 are divided into a sensor unit 35 and an irradiation unit 36. After the observation of the biological tissue is completed, the timing of voltage application to the multiple transducers 24 constituting the sensor unit 35 is set to a different setting from that during the observation. This setting causes the transducers 24 of the sensor unit 35 to emit ultrasonic waves toward the distal tip 18 of the guidewire 15. In other words, the ultrasonic sensor 23 that has performed the observation function as the sensor unit 35 performs the function of the irradiation unit 36 ​​for vibrating the distal tip 18 after the observation.

[0052] In the second use mode, the sensor unit 35 has an observation mode in which ultrasonic waves are irradiated toward the obstructed portion of the biological tissue, and a crushing mode in which ultrasonic waves are irradiated toward the distal tip 18. In the observation mode, the sensor unit 35 is controlled to switch between emitting and receiving ultrasonic waves at predetermined intervals. In the crushing mode, the sensor unit 35 is controlled to continuously emit ultrasonic waves for a period longer than the predetermined period in the observation mode. According to the second specification mode, after observing the biological tissue, ultrasonic waves from not only the irradiation unit 36 ​​but also the sensor unit 35 are emitted toward the distal tip 18, so that the distal tip 18 can be strongly vibrated. In the crushing mode in which the sensor unit 35 irradiates ultrasonic waves toward the distal tip 18, ultrasonic waves are continuously emitted. In this way, the distal tip 18 can be effectively vibrated.

[0053] The third usage form will be described. As in the first and second usage forms, the four ultrasonic sensors 23 are divided into a sensor section 35 and an irradiation section 36. When observing biological tissue, the timing of voltage application to the multiple transducers 24 constituting the irradiation section 36 is set to be different from that during fracturing. This causes the transducers 24 of the irradiation section 36 to emit ultrasonic waves toward the biological tissue, not toward the distal tip 18. In other words, the ultrasonic sensor 23, which should perform the fracturing function as the irradiation section 36, performs the function of the sensor section 35 for observing the biological tissue before fracturing the obstruction section.

[0054] According to this mode of use, before the passage of the obstruction in the biological tissue, the biological tissue can be observed not only by the sensor unit 35 but also by the irradiation unit 36. In this case, the number of ultrasonic transmission positions and reception positions increases compared to when observation is performed only by the sensor unit 35, so the observation accuracy of the biological tissue morphology is improved. In the observation mode in which the irradiation unit 36 ​​transmits and receives ultrasonic waves, the transmission and reception of ultrasonic waves are alternately performed intermittently. In this way, the biological tissue can be reliably observed by the irradiation unit 36.

[0055] <Embodiment 4> Next, a fourth embodiment of the present invention will be described with reference to Fig. 7. A catheter D of the fourth embodiment has a sensor unit 39 and an irradiation unit 40 configured differently from those of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and a description of the structure, action, and effect will be omitted.

[0056] In the fourth embodiment, eight ultrasonic sensors 37 are arranged at equal angular pitches in the circumferential direction around the lumen 14. Each ultrasonic sensor 37 has a plurality of transducers 38 arranged in the radial direction. Each of the plurality of transducers 38 constituting one ultrasonic sensor 37 has an arc shape. The circumferential lengths of the plurality of transducers 38 increase sequentially from the center side to the outer periphery side. The ultrasonic sensors 37 adjacent to each other in the circumferential direction are arranged with a slit-like gap in the radial direction.

[0057] The transducers 38 constituting all the ultrasonic sensors 37 are made of piezoelectric elements. Therefore, all the ultrasonic sensors 37 have both a function as a sensor unit 39 for observing biological tissue and a function as an irradiation unit 40 for fracturing an obstruction in the biological tissue. In this embodiment 4, the eight ultrasonic sensors 37 are divided into a dedicated sensor unit 39 and a dedicated irradiation unit 40. In this embodiment 4, the sensor units 39 and the irradiation units 40 are arranged alternately in the circumferential direction, but the order of the sensor units 39 and the irradiation units 40 can be set arbitrarily. In addition, as a modified example of the embodiment 4, the eight ultrasonic sensors 37 can be configured to serve both as the sensor units 39 and the irradiation units 40.

[0058] <Embodiment 5> Next, a fifth embodiment of the present invention will be described with reference to Fig. 8. A catheter E of the fifth embodiment has a sensor unit 44 and an irradiation unit 45 configured differently from those of the first embodiment. Since the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and a description of the structure, action, and effect will be omitted.

[0059] The catheter E of the fifth embodiment has a plurality of rectangular transducers 42 arranged vertically and horizontally in a front view. The plurality of transducers 42 are arranged in a circular region from the outer periphery of the lumen 14 to the inner periphery of the outer tube 20. Therefore, all of the transducers 42 can function as a sensor unit 44 for observing biological tissue and as an irradiation unit 45 for fracturing an obstructed portion of the biological tissue.

[0060] The sensor unit 44 is composed of one vibrator 42 or a plurality of vibrators 42. The irradiation unit 45 is also composed of one vibrator 42 or a plurality of vibrators 42. That is, the plurality of vibrators 42 are divided into a dedicated vibrator 42 that constitutes only the sensor unit 44 and a dedicated vibrator 42 that constitutes only the irradiation unit 45. In the fifth embodiment, the plurality of sensor units 44 and the plurality of irradiation units 45 are arranged alternately in the circumferential direction, but the order of the sensor units 44 and the irradiation units 45 can be set arbitrarily. As a modified example of the fifth embodiment, all of the plurality of vibrators 42 can be used as both the sensor unit 44 and the irradiation unit 45.

[0061] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention. In the above-mentioned first embodiment, the pair of sensor units are arranged so as to sandwich the medical device, but the pair of sensor units may be arranged in a positional relationship that does not sandwich the medical device. In the above-mentioned first and second embodiments, the pair of irradiation units is arranged so as to sandwich the medical device, but the pair of irradiation units may be arranged in a positional relationship that does not sandwich the medical device. In the above-mentioned first and second embodiments, two irradiation units are provided, but the number of irradiation units may be one or three or more. In the above first to fifth embodiments, the vibrator constituting the sensor unit and the vibrator constituting the irradiation unit are the same type of component, but the vibrator constituting the sensor unit and the vibrator constituting the irradiation unit may be different types of vibrators. In the above first to third embodiments, four ultrasonic sensors are provided, but the number of ultrasonic sensors may be three or less, or five or more. In the above embodiment 5, an example was shown in which multiple transducers were arranged on the cross section of the tip of the catheter, but the catheter may have a layer in which multiple transducers are arranged within the cross section, and the transducer constituting the irradiation unit irradiates ultrasound toward a medical device arranged to the side of the long axis of the catheter, and the transducer constituting the sensor unit observes the position of the medical device and the biological tissue in the same direction. [Explanation of symbols]

[0062] A, B, C, D, E…Catheter 10…Tube 14…Lumen 15...Guidewire (medical device) 24, 38, 42...Transducers 25, 30, 35, 39, 44...Sensor section 26, 36, 40, 45…Irradiation section 27A…First transmitter 27B…Second transmission section

Claims

1. A tube having an internal lumen; a sensor unit disposed at a distal end of the tube and capable of irradiating an ultrasonic wave toward a lesion located in front of the tube; an irradiation unit that is disposed at a distal end of the tube and is capable of irradiating ultrasonic waves toward a medical device that passes through the lumen and protrudes from the distal end of the tube; The sensor unit is capable of irradiating ultrasonic waves toward the medical device, the sensor unit has a mode of irradiating ultrasonic waves toward the lesion and a mode of irradiating ultrasonic waves toward the medical device, In the mode of irradiating the lesion with ultrasound, the ultrasound transmission and reception are switched at predetermined intervals, In a mode in which ultrasound is irradiated toward the medical device, the ultrasound is controlled to be continuously emitted for a period longer than the predetermined period; The sensor unit irradiates ultrasonic waves capable of vibrating the medical device, The irradiation unit is a catheter that irradiates ultrasonic waves capable of vibrating the medical device.

2. When viewed from the front of the tube in the longitudinal direction from the distal end side, the irradiation unit is configured by arranging a plurality of transducers in a line, The catheter according to claim 1 , wherein the lumen through which the medical device is inserted is disposed on an extension line of an arrangement direction of the plurality of transducers.

3. The irradiation unit has a first transmitting unit and a second transmitting unit arranged to sandwich the lumen, The catheter according to claim 2 , wherein the plurality of transducers constituting the first transmitting section and the second transmitting section are arranged in a straight line.

4. 4. The catheter according to claim 1, wherein the irradiation unit is provided with a transducer that can be controlled independently of a transducer that constitutes the sensor unit.

5. The catheter according to claim 1 , wherein the irradiation unit is configured to include a transducer capable of transmitting and receiving ultrasonic waves.

6. 6. The catheter according to claim 5, wherein in a mode in which the irradiation unit transmits and receives ultrasonic waves, the transmission and reception of ultrasonic waves are alternately performed intermittently.

7. A catheter described in any one of claims 1 to 6, wherein the sensor portion has a first sensor portion and a second sensor portion arranged to sandwich the inner cavity.

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