Diagnostic imaging catheter

Abstract

A diagnostic imaging catheter (100) has: a coil-shaped coil shaft (141) that extends in the axial direction; and a light guide body (143) that is partially inserted in the coil shaft (141) and that has an optical transmission / reception unit (145b) connected to the leading end thereof. The light guide body (143) has, formed therein at a portion in the axial direction, a fragile part (143A) that is more fragile than other portions of the light guide body (143). A high rigidity part (194) having a flexural rigidity higher than that of the coil shaft (141) is provided around the fragile part (143A). Even when a load is applied to the light guide body (143) so as to bend or pull the same, it is possible to suppress breakage thereof starting at the fragile part (143A).

Description

Diagnostic imaging catheters

[0001] The present invention relates to a catheter for diagnostic imaging.

[0002] BACKGROUND ART Conventionally, as a medical device used to acquire tomographic images for diagnosing diseased sites and the like in a living body, there is a diagnostic imaging catheter used in an imaging diagnostic device such as an intravascular ultrasound (IVUS) or an optical coherence tomography (OCT).

[0003] The diagnostic imaging catheter includes a drive shaft provided with a signal transmitting / receiving unit that transmits and receives examination waves, and a sheath with a lumen into which the drive shaft is inserted so as to be movable back and forth. When the diagnostic imaging catheter is in use, the drive shaft is rotated and moved backward to move the drive shaft from the distal end to the proximal end, a so-called pull-back operation (intermediate pulling operation), or a pushing operation to push the drive shaft toward the distal end.

[0004] Among such diagnostic imaging catheters, particularly those with OCT functions, the light guide, which is an optical fiber, may have a weak portion with reduced strength in part of the axial direction due to the processing load during manufacturing (see Patent Document 1 below).

[0005] JP 2024-50454 A

[0006] Generally, the weak part of the light guide is covered by the coil shaft. Because the coil shaft is a relatively flexible material, when the diagnostic imaging catheter is used, the light guide follows the coil shaft and is subjected to bending and tensile loads. If the light guide cannot withstand this load, it may break at the weak part, making it impossible to observe the lesion.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an imaging diagnostic catheter that can prevent a light guide from breaking at a weak portion when the imaging diagnostic catheter is in use.

[0008] The above object of the present invention can be achieved by the following means.

[0009] (1) A catheter for diagnostic imaging, comprising: a coil-shaped coil shaft extending in an axial direction; and a light guide, a portion of which is inserted through the coil shaft and has an optical transmitter / receiver connected to its tip, wherein the light guide has a weak portion formed in a portion of the axial direction that is weaker than other portions of the light guide; and a high-rigidity portion having a bending rigidity higher than that of the coil shaft is provided around the weak portion.

[0010] (2) The diagnostic imaging catheter according to (1), further comprising a housing provided at a distal end of the coil shaft and holding the optical transceiver, wherein the high-rigidity portion is formed in the housing.

[0011] (3) The diagnostic imaging catheter according to (2), wherein a slit is formed in the housing along a circumferential direction between a portion that holds the optical transmitting and receiving unit and the high-rigidity portion.

[0012] (4) The diagnostic imaging catheter according to (2) or (3), wherein a slit is formed in the housing on the proximal end side of the high-rigidity portion along the axial direction.

[0013] (5) The diagnostic imaging catheter according to any one of (2) to (4), wherein an opening is formed in the high-rigidity portion formed in the housing.

[0014] (6) The diagnostic imaging catheter according to (5), wherein the opening is formed at the same position along the axial direction as the weak portion of the light guide, and an adhesive is disposed between the opening and the weak portion.

[0015] According to the diagnostic imaging catheter configured as described above, the high-rigidity portion is provided around the fragile portion, thereby increasing the rigidity of the light guide near the fragile portion, thereby providing a diagnostic imaging catheter that can prevent the light guide from breaking at the fragile portion during use.

[0016] 4A is a plan view showing a state in which an external device is connected to a catheter for diagnostic imaging according to an embodiment of the present invention. FIG. 4B is a view schematically showing the overall configuration of a catheter for diagnostic imaging according to this embodiment, and is a side view of the catheter for diagnostic imaging before a pull-back operation (intermediate pulling operation) is performed. FIG. 4C is a view schematically showing the overall configuration of a catheter for diagnostic imaging according to this embodiment, and is a side view of the catheter for diagnostic imaging when a pull-back operation is performed. FIG. 4D is an enlarged sectional view showing the configuration of the distal end side of the catheter for diagnostic imaging according to this embodiment. FIG. 4E is a plan view showing a housing of the catheter for diagnostic imaging according to this embodiment. FIG. 4F is a front sectional view showing the housing of the catheter for diagnostic imaging according to this embodiment. FIG. 4G is a sectional view taken along line 5-5 of FIG. 4A. FIG. 4H is a sectional view taken along line 6-6 of FIG. 4A. FIG. 4H is an enlarged sectional view showing the configuration of the proximal end side of the catheter for diagnostic imaging according to this embodiment. FIG. 4G is a sectional view showing a state in which the catheter for diagnostic imaging has been inserted into a blood vessel. FIG. 4H is a sectional view showing a state in which a catheter for diagnostic imaging is being inserted into a blood vessel.

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0018] FIG. 1 is a plan view showing a state in which an external device 300 is connected to a diagnostic imaging catheter 100 according to an embodiment. FIG. 2A is a diagram schematically showing the overall configuration of the diagnostic imaging catheter 100 according to an embodiment, and is a side view of the diagnostic imaging catheter 100 before a pull-back operation (intermediate pulling operation) is performed. FIG. 2B is a diagram schematically showing the overall configuration of the diagnostic imaging catheter 100 according to an embodiment, and is a side view of the diagnostic imaging catheter 100 after a pull-back operation is performed. FIG. 3 is an enlarged cross-sectional view showing the configuration of the distal end side of the diagnostic imaging catheter 100 according to this embodiment. FIG. 4A is a plan view showing a housing 190 of the diagnostic imaging catheter 100 according to this embodiment. FIG. 4B is a front cross-sectional view showing the housing of the diagnostic imaging catheter 100 according to this embodiment. FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 4. FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 4. FIG. 7 is an enlarged cross-sectional view showing the configuration of the proximal end side of the diagnostic imaging catheter 100 according to this embodiment.

[0019] The diagnostic imaging catheter 100 according to this embodiment is a dual-type catheter that has both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) functions and can be used either by switching between them or simultaneously. As shown in Fig. 1, the diagnostic imaging catheter 100 is driven by being connected to an external device 300.

[0020] The configuration of the diagnostic imaging catheter 100 will be described with reference to FIGS.

[0021] As shown in FIGS. 1 , 2A, and 2B, the diagnostic imaging catheter 100 includes a sheath 110 to be inserted into a body cavity of a living organism, an outer tube 120 provided on the proximal end side of the sheath 110, an inner shaft 130 inserted into the outer tube 120 so as to be movable back and forth, a drive shaft 140 provided on the distal end thereof so as to be rotatable within the sheath 110 and having a signal transmitting / receiving unit 145 for transmitting and receiving signals, a unit connector 150 provided on the proximal end side of the outer tube 120 and configured to receive the inner shaft 130, and a hub 160 provided on the proximal end side of the inner shaft 130.

[0022] In the description of this specification, the side of the diagnostic imaging catheter 100 that is inserted into a body cavity is referred to as the tip or tip side, the side of the hub 160 provided on the diagnostic imaging catheter 100 is referred to as the base end or base side, and the extension direction of the sheath 110 is referred to as the axial direction.

[0023] As shown in FIG. 2A , the drive shaft 140 passes through the sheath 110 , the outer tube 120 connected to the proximal end of the sheath 110 , and the inner shaft 130 inserted into the outer tube 120 , and extends to the inside of the hub 160 .

[0024] The hub 160, inner shaft 130, drive shaft 140, and signal transmitter / receiver 145 are connected to one another so as to move forward and backward in the axial direction as a unit. Therefore, for example, when the hub 160 is pushed toward the distal end, the inner shaft 130 connected to the hub 160 is pushed into the outer tube 120 and the unit connector 150, and the drive shaft 140 and the signal transmitter / receiver 145 move toward the distal end inside the sheath 110. For example, when the hub 160 is pulled toward the proximal end, the inner shaft 130 is pulled out from the outer tube 120 and the unit connector 150 as shown by arrow a1 in Figures 1 and 2B, and the drive shaft 140 and the signal transmitter / receiver 145 move toward the proximal end inside the sheath 110 as shown by arrow a2.

[0025] 2A , when the inner shaft 130 is pushed all the way toward the distal end, the distal end of the inner shaft 130 reaches the vicinity of the relay connector 170. At this time, the signal transmitting / receiving unit 145 is located near the distal end of the sheath 110. The relay connector 170 is a connector that connects the sheath 110 and the outer tube 120.

[0026] 2B , a connector 131 for preventing disengagement is provided at the tip of the inner shaft 130. The connector 131 for preventing disengagement has the function of preventing the inner shaft 130 from disengaging from the outer tube 120. The connector 131 for preventing disengagement is configured to catch at a predetermined position on the inner wall of the unit connector 150 when the hub 160 is pulled all the way toward the base end, that is, when the inner shaft 130 is pulled all the way out from the outer tube 120 and the unit connector 150.

[0027] 3, the drive shaft 140 includes a flexible coil shaft 141, inside which are arranged an electric signal cable 142 connected to a signal transmitter / receiver 145, and a light guide (optical fiber) 143. The coil shaft 141 can be formed, for example, of a multi-layer coil wound in different directions around the axis. Examples of materials for the coil include stainless steel and Ni-Ti (nickel-titanium) alloy.

[0028] 3, the signal transmitting / receiving unit 145 has an ultrasonic transmitting / receiving unit 145a that transmits and receives ultrasonic waves, and an optical transmitting / receiving unit 145b that transmits and receives light. The ultrasonic transmitting / receiving unit 145a is located closer to the tip than the optical transmitting / receiving unit 145b. Note that the positional relationship between the ultrasonic transmitting / receiving unit 145a and the optical transmitting / receiving unit 145b may be reversed.

[0029] The ultrasonic transmitting / receiving unit 145a includes a vibrator and has the function of transmitting ultrasonic waves into the body cavity based on a pulse signal and receiving ultrasonic waves reflected from the living tissue of the body cavity. The ultrasonic transmitting / receiving unit 145a is electrically connected to the electrode terminal 165a (see FIG. 7) via the electric signal cable 142.

[0030] The transducer included in the ultrasonic wave transmitting / receiving unit 145a may be made of a piezoelectric material such as ceramics or quartz crystal.

[0031] The optical transmitter / receiver 145b continuously transmits the transmitted measurement light into the body cavity and continuously receives the reflected light from the biological tissue in the body cavity. The optical transmitter / receiver 145b is provided at the tip of the light guide 143 and has a ball lens (optical element) that has a lens function to condense light and a reflecting function to reflect light.

[0032] The signal transmitting / receiving unit 145 is accommodated inside the housing 190. The base end side of the housing 190 is connected to the coil shaft 141.

[0033] 3 to 6, the detailed configuration of the housing 190 will be described. The housing 190 is provided at the tip of the coil shaft 141. As shown in FIGS. 3 to 6, the housing 190 has a groove 191 provided on the outer circumferential surface so as not to impede the progression of the ultrasonic waves transmitted and received by the ultrasonic transmitting and receiving unit 145a and the light transmitted and received by the optical transmitting and receiving unit 145b, and a main body 192 provided at the base end of the groove 191.

[0034] 3, 4A, and 4B, the groove 191 is formed to open upward in front view. Here, upward means the upward direction in FIG.

[0035] As shown in FIGS. 3 and 4B, the main body 192 is configured to extend along the axial direction, and is configured to be hollow so that the electric signal cable 142 and the light guide 143 can be disposed inside.

[0036] 4A and 4B , the main body 192 has a first low-rigidity section 193 provided at the proximal end of the groove 191, a high-rigidity section 194 provided at the proximal end of the first low-rigidity section 193, and a second low-rigidity section 195 provided at the proximal end of the high-rigidity section 194. Here, the high-rigidity section 194 means having a bending rigidity higher than that of the coil shaft 141, and the first low-rigidity section 193 and the second low-rigidity section 195 mean having a bending rigidity lower than that of the high-rigidity section 194 but approximately the same as that of the coil shaft 141. By forming the high-rigidity section 194 in the housing 190, an increase in the number of parts can be suppressed, and the device configuration of the diagnostic imaging catheter 100 can be simplified.

[0037] Here, when the coating is removed during manufacturing, when heat treatment is performed, or the like, a weak portion 143A that is weaker than other portions of the light guide 143 is formed in a part of the axial direction of the light guide 143. As shown in Fig. 4B , the high rigidity portion 194 is positioned in the main body 192 so that the weak portion 143A is disposed on the inner periphery of the high rigidity portion 194. In other words, the high rigidity portion 194 is provided around the weak portion 143A.

[0038] The first low-rigidity portion 193, the high-rigidity portion 194, and the second low-rigidity portion 195 of the main body portion 192 can be integrally formed by cutting out from a metal block, metal injection molding (MIM), etc. As shown in Figures 4A to 6, the first low-rigidity portion 193 and the second low-rigidity portion 195 have slits S formed in parts of their circumferential direction, thereby reducing their bending rigidity.

[0039] In this embodiment, the first low-rigidity portion 193 has three slits S formed along the axial direction, each slit S being provided along a portion of the circumferential direction.

[0040] At the most distal end of the first low-rigidity portion 193, a slit S is formed over a 90-degree range so as to be open at the top and bottom in cross section as shown in Fig. 5. At a location adjacent to the most distal end and the base end, a slit S is formed over a 90-degree range so as to be open at the left and right in cross section as shown in Fig. 6. At a location further adjacent to the base end, a slit S as shown in Fig. 5 is formed.

[0041] By providing the first low-rigidity portion 193 in this manner, bending deformation between the high-rigidity portion 194 and the groove portion 191 is possible, improving the ability to follow the shape of the blood vessel. Note that the formation pattern of the slits S in the first low-rigidity portion 193 is not limited to the above.

[0042] 4A and 4B, an opening 194H with an open top is formed in the high-rigidity portion 194. This opening 194H is used for observing the inside of the housing 190 or for injecting adhesive. The diameter of the opening 194H is not particularly limited, but is, for example, 0.3 to 0.5 mm.

[0043] The opening 194H is used specifically as a window for confirming (aligning) the placement of the fragile portion 143A when used to observe the inside of the housing 190. This configuration makes it easier to assemble the diagnostic imaging catheter 100.

[0044] On the other hand, when opening 194H is used for injecting adhesive, the positions of high rigidity portion 194 and fragile portion 143A of housing 190 are fixed, thereby preventing damage due to pulling force.

[0045] In this embodiment, the second low-rigidity portion 195 has seven slits S formed along the axial direction, each slit S being provided along a portion of the circumferential direction.

[0046] At the most distal end of the second low-rigidity portion 195, slits S are formed over a 90-degree range so as to be open at the top and bottom in cross section, as shown in Fig. 5. At a location adjacent to the most distal end and the base end, slits S are formed over a 90-degree range so as to be open at the left and right in cross section, as shown in Fig. 6. Further toward the base end, slits S having the cross-sectional shapes shown in Figs. 5 and 6 are formed alternately.

[0047] By providing second low-rigidity portion 195 in this manner, housing 190 can be extended to the base end of high-rigidity portion 194, and this reduces the influence of heat on weak portion 143A of light guide 143 when housing 190 and coil shaft 141 are welded together with solder. Note that the formation pattern of slits S in second low-rigidity portion 195 is not limited to the above.

[0048] 3 , the sheath 110 has a lumen 110a through which the drive shaft 140 is inserted so as to be able to move back and forth. A guidewire insertion member 114 is attached to the distal end of the sheath 110, juxtaposed to the lumen 110a provided in the sheath 110, and having a guidewire lumen 114a through which the guidewire W can be inserted. The sheath 110 and the guidewire insertion member 114 can be integrally formed by thermal fusion or the like. The guidewire insertion member 114 is provided with a marker 115 that is radiopaque. The marker 115 is made of a metal coil that is highly radiopaque, such as Pt, Au, or Ir.

[0049] A communication hole 116 that connects the inside and outside of the lumen 110a is formed at the distal end of the sheath 110. A reinforcing member 117 for firmly joining and supporting the guidewire insertion member 114 is also provided at the distal end of the sheath 110. A communication passage 117a is formed in the reinforcing member 117 that connects the inside of the lumen 110a, which is located on the proximal side of the reinforcing member 117, with the communication hole 116. The reinforcing member 117 does not necessarily have to be provided at the distal end of the sheath 110.

[0050] The communication hole 116 is a priming solution discharge hole for discharging the priming solution. When the diagnostic imaging catheter 100 is used, a priming process is performed in which the sheath 110 is filled with priming solution to reduce attenuation of ultrasound due to air inside the sheath 110 and to efficiently transmit and receive ultrasound. When performing the priming process, the priming solution is released to the outside through the communication hole 116, and gas such as air can be discharged from the inside of the sheath 110 together with the priming solution.

[0051] The tip of the sheath 110, which is the range in which the signal transmitting / receiving unit 145 moves in the axial direction of the sheath 110, forms a window portion formed to be more transparent to inspection waves such as light and ultrasound than other parts.

[0052] The sheath 110, guidewire insertion member 114, and reinforcing member 117 are formed of a flexible material, and the material may be, but is not limited to, various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polyimide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based, and combinations of one or more of these (polymer alloys, polymer blends, laminates, etc.) may also be used. A hydrophilic lubricating coating layer that exhibits lubricity when wet may be disposed on the outer surface of the sheath 110.

[0053] As shown in FIG. 7 , the hub 160 has a hollow hub body 161, a connector case 161a connected to the base end side of the hub body 161, a port 162 that communicates with the interior of the hub body 161, protrusions 163a and 163b for positioning (orienting) the hub 160 when connecting to an external device 300, a connecting pipe 164b that holds the drive shaft 140, a bearing 164c that rotatably supports the connecting pipe 164b, a sealing member 164a that prevents the priming solution from leaking from between the connecting pipe 164b and the bearing 164c toward the base end side, and a connector portion 165 that has an electrode terminal 165a and an optical connector 165b disposed therein that are connected to the external device 300.

[0054] An inner shaft 130 is connected to the tip end of the hub body 161. The drive shaft 140 is drawn out from the inner shaft 130 inside the hub body 161. A protective tube 133 is disposed between the inner shaft 130 and the drive shaft 140. The protective tube 133 functions to prevent damage to the drive shaft 140 due to interference between the inner shaft 130 and the drive shaft 140.

[0055] An injection device D (see FIG. 1 ) that injects priming fluid during priming is connected to port 162. Injection device D includes a connector S1 connected to port 162, a tube S2 connected to connector S1, a three-way stopcock S3 connected to tube S2, and a first syringe S4 and a second syringe S5 that are connected to the three-way stopcock S3 and can inject priming fluid into port 162. The second syringe S5 has a larger capacity than the first syringe S4 and is used as an auxiliary syringe when, for example, the amount of priming fluid injected by the first syringe S4 is insufficient.

[0056] The connection pipe 164b holds the drive shaft 140 in order to transmit the rotation of the electrode terminal 165a and the optical connector 165b, which are rotationally driven by the external device 300, to the drive shaft 140. The coil shaft 141 and the light guide 143 are inserted inside the connection pipe 164b.

[0057] The connector unit 165 has an electrode terminal 165a electrically connected to the ultrasonic transmitter / receiver unit 145a, and an optical connector 165b connected to the light guide 143. A signal received by the ultrasonic transmitter / receiver unit 145a is transmitted to the external device 300 via the electrode terminal 165a, where it is subjected to predetermined processing and displayed as an image. A signal received by the optical transmitter / receiver unit 145b is transmitted to the external device 300 via the optical connector 165b, where it is subjected to predetermined processing and displayed as an image.

[0058] Referring again to FIG. 1, the diagnostic imaging catheter 100 is connected to and driven by an external device 300 .

[0059] As described above, the external device 300 is connected to the connector portion 165 provided on the proximal end side of the hub 160 .

[0060] The external device 300 also has a motor 300a, which is a power source for rotating the drive shaft 140, and a motor 300b, which is a power source for axially moving the drive shaft 140. The rotational motion of the motor 300b is converted into axial motion by a ball screw 300c connected to the motor 300b.

[0061] The operation of the external device 300 is controlled by a control device 301 electrically connected thereto. The control device 301 mainly includes a CPU (Central Processing Unit) and a memory. The control device 301 is electrically connected to a monitor 302.

[0062] Next, an example of use of the diagnostic imaging catheter 100 will be described with reference to Figures 8A, 8B, etc. Figure 8A is a cross-sectional view showing a state in which the diagnostic imaging catheter 100 has been inserted into a blood vessel 900, and Figure 8B is a cross-sectional view showing a state in which a flushing process is being performed.

[0063] First, with hub 160 pulled all the way to the proximal end (see FIG. 2B ), the user connects injection device D, which injects priming solution, to port 162 and pushes the plunger of first syringe S4 to inject the priming solution into lumen 110a of sheath 110. If the amount of priming solution injected by first syringe S4 is insufficient, the user pushes the plunger of second syringe S5 to inject the priming solution into lumen 110a of sheath 110.

[0064] When the priming solution is injected into the lumen 110a, the priming solution is released to the outside of the sheath 110 through the communication passage 117a and the communication hole 116 shown in FIG. 3, and gas such as air can be discharged from the inside of the sheath 110 to the outside together with the priming solution (priming process).

[0065] After the priming process, the user connects the external device 300 to the connector portion 165 of the diagnostic imaging catheter 100, as shown in Fig. 1. Then, the user pushes the hub 160 until it abuts against the base end of the unit connector 150 (see Fig. 2A), and moves the signal transmitting / receiving portion 145 toward the distal end. In this state, the diagnostic imaging catheter 100 is inserted into the lumen 500a of the guiding catheter 500, as shown in Fig. 8A. The guiding catheter 500 is previously inserted into the blood vessel 900 along the guidewire W.

[0066] 8A , the diagnostic imaging catheter 100 is advanced along the lumen 500a and protrudes from the distal end opening of the guiding catheter 500. Thereafter, while the guidewire W is being inserted through the guidewire lumen 114a, the diagnostic imaging catheter 100 is further advanced along the guidewire W and inserted into the blood vessel 900 at a desired position.

[0067] As the guiding catheter 500, a known guiding catheter having a port (not shown) at the base end to which a syringe (not shown) can be connected can be used.

[0068] Next, a flushing process is performed to wash away blood from within the blood vessel 900 with a flushing liquid such as a contrast agent. As in the priming process described above, a syringe containing a flushing liquid is connected to a port of the guiding catheter 500, and the plunger of the syringe is pressed to inject the flushing liquid into the lumen 500a of the guiding catheter 500. As shown by arrow C in Fig. 8B , the flushing liquid passes through the lumen 500a of the guiding catheter 500 and is introduced into the blood vessel 900 via its tip opening. The introduced flushing liquid flushes out the blood around the tip of the sheath 110, and the area around the tip of the sheath 110 becomes filled with the flushing liquid.

[0069] When obtaining a tomographic image at a target position in the blood vessel 900, the signal transmitting and receiving unit 145 moves toward the proximal end while rotating together with the drive shaft 140 (pull-back operation). At this time, the signal transmitting and receiving unit 145 transmits and receives an inspection wave.

[0070] Here, for example, if the high-rigidity portion 194 is not provided around the weak portion 143A of the light guide 143 and a low-rigidity coil shaft is provided around the weak portion 143A of the light guide 143, a bending or tensile load will be applied to the weak portion 143A during the pull-back operation, and the light guide 143 may not be able to withstand this load, causing it to break and making it impossible to observe the lesion. In contrast, in the diagnostic imaging catheter 100 according to this embodiment, the high-rigidity portion 194 is provided around the weak portion 143A of the light guide 143, and therefore bending and tensile stress at the weak portion 143A can be suppressed, thereby preventing the weak portion 143A from breaking.

[0071] The rotation and movement of the drive shaft 140 are controlled by the control device 301. The connector portion 165 provided in the hub 160 is rotated while connected to the external device 300, and the drive shaft 140 rotates in conjunction with this. The rotation speed of the connector portion 165 and the drive shaft 140 is, for example, 1800 rpm.

[0072] Furthermore, the signal transmitting / receiving unit 145 transmits ultrasound and light into the body based on signals sent from the control device 301. Signals corresponding to the reflected waves and reflected light received by the signal transmitting / receiving unit 145 are sent to the control device 301 via the drive shaft 140 and the external device 300. The control device 301 generates a tomographic image of the body cavity based on the signals sent from the signal transmitting / receiving unit 145, and displays the generated image on the monitor 302.

[0073] The diagnostic imaging catheter 100 according to the present invention has been described above through the embodiments, but the present invention is not limited to the configurations described in the embodiments, and can be modified as appropriate based on the claims.

[0074] For example, in the above-described embodiment, the high-rigidity portion 194 is formed in the housing 190. However, the high-rigidity portion does not have to be formed in the housing, and may be formed by, for example, applying heat or material to the coil shaft to partially increase its rigidity.

[0075] In the above-described embodiment, the opening 194H is formed in the high-rigidity portion 194, but the opening 194H does not have to be formed.

[0076] In the above-described embodiment, the diagnostic imaging catheter according to the present invention is described as being applied to a diagnostic imaging catheter having the functions of intravascular ultrasound (IVUS) and optical coherence tomography (OCT). However, the diagnostic imaging catheter according to the present invention may also be applied to a diagnostic imaging catheter having the functions of intravascular ultrasound (IVUS) and optical frequency domain imaging (OFDI). Furthermore, the diagnostic imaging catheter according to the present invention can also be applied to a diagnostic imaging catheter used solely for optical coherence tomography (OCT).

[0077] This application is based on Japanese Patent Application No. 2024-118583, filed on July 24, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0078] 100 Diagnostic imaging catheter, 140 Drive shaft, 141 Coil shaft, 143 Light guide, 143A Weak portion, 145b Light transmitting / receiving portion, 190 Housing, 191 Groove portion, 193 First low rigidity portion, 194 High rigidity portion, 194H Opening, 195 Second low rigidity portion, S Slit.

Claims

1. A catheter for diagnostic imaging, comprising: a coil-shaped coil shaft extending in the axial direction; and a light guide, a portion of which is inserted within the coil shaft and has an optical transmitter / receiver connected to its tip, wherein the light guide has a weak section formed in part of the axial direction that is weaker than other sections of the light guide, and a high-rigidity section having higher bending rigidity than the coil shaft is provided around the weak section.

2. The diagnostic imaging catheter according to claim 1, further comprising a housing provided on the distal end side of the coil shaft and holding the optical transmitter / receiver, wherein the high-rigidity portion is formed in the housing.

3. The diagnostic imaging catheter according to claim 2, wherein a slit is formed in the housing along the circumferential direction between the portion that holds the optical transmitting and receiving portion and the high-rigidity portion.

4. The diagnostic imaging catheter according to claim 2, wherein a slit is formed in the housing along the axial direction on the proximal end side of the high rigidity portion.

5. The diagnostic imaging catheter according to claim 2, wherein an opening is formed in the high-rigidity portion formed in the housing.

6. A diagnostic imaging catheter according to claim 5, wherein the opening is formed at the same location along the axial direction as the weak portion of the light guide, and adhesive is disposed between the opening and the weak portion.

Images