JP7171688B2 - medical device - Google Patents

Description

The present invention relates to medical devices for acquiring diagnostic images of biological lumens.

2. Description of the Related Art As a medical device for acquiring a diagnostic image of a lesion such as a stenosis in a living body lumen, a device that acquires a tomographic image using ultrasound or light is known. Further, as this type of medical device, a drive shaft provided with an imaging unit capable of acquiring image information, a flexible sheath portion formed with an imaging lumen through which the drive shaft is inserted, and a sheath portion There is a so-called rapid exchange type, which has a guide wire insertion portion arranged on the outer surface of the tip side of the guide wire (see, for example, Patent Document 1 below).

When an operator such as a doctor acquires a diagnostic image using the medical device as described above, the distal end side of the medical device is placed on the inner peripheral side (inner surface side) of the constriction. At this time, if the distal end of the medical device can be easily placed in the stenotic part, the procedure can be smoothly performed, so that the procedure time can be shortened and the burden on the patient can be reduced. For this reason, medical devices for acquiring diagnostic images are required to have insertability (passability) through the constriction.

WO2013/111700

For example, in the medical device described in Patent Document 1, the distal end surface of the distal end member (reinforcing member) that protrudes toward the distal end side of the sheath portion is formed into a tapered shape that is obliquely inclined toward the guide wire insertion portion side. . On the other hand, the guide wire insertion part arranged in parallel with the sheath part is formed in a shape extending substantially linearly along the axial direction of the sheath part. For this reason, it is difficult to say that the guide wire insertion part side is sufficiently improved in insertability into the stenotic part compared to the sheath part side.

If there is a structural difference between the sheath portion side and the guide wire insertion portion side as described above, it may be difficult to smoothly insert the medical device into the stricture. In such a case, for example, the operator pushes the sheath portion side into the constricted portion to expand the constricted portion, thereby inserting the guide wire insertion portion into the constricted portion together with the sheath portion. However, when the guidewire is inserted through the guidewire insertion portion, the guidewire insertion portion is oriented so as to maintain its linearity due to the physical properties (rigidity, etc.) of the guidewire. Furthermore, since the guidewire insertion part loses its flexibility due to the influence of the physical properties of the guidewire, it becomes difficult to deform when it is inserted into the stenotic part. As a result, it may become even more difficult to pass the guidewire insertion portion through the stenosis.

In view of the above problems, for example, in order to improve the insertability of the guidewire insertion portion into the narrowed portion, a method of forming the guidewire insertion portion in a tapered shape is conceivable. In addition, as an example thereof, a method of gradually decreasing the thickness of the guide wire insertion portion from the proximal side to the distal side can be mentioned. However, if the thickness of the guidewire insertion portion is formed to be extremely small, the rigidity of the guidewire insertion portion is lowered and the pushability of the guidewire insertion portion is lowered. In addition, when the rigidity of the guide wire insertion portion is reduced, the guide wire insertion portion is likely to be turned up or broken when the guide wire is inserted into the stenosis.

The present invention has been made to solve the above-described problems, and provides a medical device for acquiring diagnostic images of a biological lumen that is insertable into a stenotic site while maintaining pushability into the stenotic site. The purpose is to improve

A medical device for achieving the above object is a medical device for acquiring an image of a living body lumen, comprising: a drive shaft provided with an imaging unit capable of acquiring image information; and a drive shaft through which the drive shaft can be inserted. a sheath portion having an imaging lumen; a guidewire lumen through which a guidewire can be inserted; a guidewire insertion portion disposed on the outer surface of the sheath portion on the distal side; and a distal end member disposed so that a distal end portion thereof protrudes from the imaging lumen, and the guide wire insertion portion is disposed inclined toward the imaging lumen side of the sheath portion. The distal end portion of the distal end member is inclined toward the guide wire insertion portion side, and is exposed from the imaging lumen over the proximal end side of the distal end of the sheath portion so that the guide wire can be inserted through the sheath portion. a guide wire lumen that is in contact with the portion and through which the guide wire can be inserted, and that is located on the proximal side of the guide wire insertion portion and on the outer surface of the sheath portion. A guide wire insertion portion is further provided, and the proximal side guide wire insertion portion is provided along the axis of the sheath portion and is separated from the guide wire insertion portion, and the guide wire insertion portion is provided along the axis of the sheath portion. a distal end portion disposed distally of the distal end portion of the distal end member and not fixed to the distal end member and the sheath portion; an intermediate portion axially overlapped with and fixed to the distal end portion of the distal end member protruding from the lumen; and a fixed proximal end, wherein the medical device has a position where the distal end of the guidewire insertion section is arranged, a position where the intermediate section is arranged, and a position where the proximal end is arranged. The outer shape is larger in order of position.

The medical device configured as described above is inclined toward the distal side so that the guidewire insertion portion and the distal end member face each other. Therefore, the medical device has improved insertability into the constriction. Further, the guide wire insertion part is oriented so as to be inclined toward the distal end side by arranging the guide wire insertion part so as to be inclined toward the imaging lumen side of the sheath part. Therefore, the medical device does not need to excessively reduce the thickness of the guide wire insertion portion in order to impart a tapered shape. As a result, the medical device can preferably maintain pushability into the constriction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing the overall configuration of a medical device according to an embodiment, where (A) is a side view of the medical device before a pullback operation is performed, and (B) is a diagram after the pullback operation is performed; 1 is a side view of a medical device; FIG. It is a perspective view which expands and shows the front-end|tip part of a medical device. FIG. 4 is a cross-sectional view along the axial direction of the distal end portion of the medical device; It is sectional drawing which expands and shows the front-end|tip part of a medical device. It is a figure which shows simply the arrow directional view seen from the arrow 5A direction shown in FIG. It is a figure for demonstrating the effect|action of the medical device which concerns on embodiment.

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

1(A) and 1(B) are diagrams showing a simplified overall configuration of a diagnostic imaging catheter (corresponding to a “medical device”) 100 according to the present embodiment, and FIG. 2 is a diagnostic imaging catheter. 3 is a cross-sectional view of the distal end portion of the diagnostic imaging catheter 100, FIGS. 4 and 5 are diagrams for explaining the distal end portion of the diagnostic imaging catheter 100, and FIG. 4A and 4B are diagrams for explaining the operation of the diagnostic imaging catheter 100. FIG.

In this embodiment, an IVUS catheter for acquiring an image for intravascular ultrasound diagnosis (IVUS) will be described as an example of the diagnostic imaging catheter 100 .

First, the diagnostic imaging catheter 100 will be outlined with reference to FIGS. 1, 2, and 3. FIG. The diagnostic imaging catheter 100 includes a drive shaft 110 provided with an imaging unit 115 capable of acquiring image information, a sheath 120 having an imaging lumen 125 through which the drive shaft 110 can be inserted, and a guide wire 200 through which the guide wire 200 can be inserted. A guide wire insertion portion 130 having a guide wire lumen 135 and arranged on the outer surface of the distal side of the sheath portion 120, a proximal end portion 153 arranged in the imaging lumen 125, and a distal end portion 151 extending from the imaging lumen 125. and a tip member 150 arranged to protrude.

In the description of this specification, the side of the diagnostic imaging catheter 100 that is inserted into the body cavity is referred to as the distal side, the hub 190 side provided on the diagnostic imaging catheter 100 is referred to as the proximal side, and the sheath portion 120 is referred to as the proximal side. The stretching direction is called the axial direction. 2 to 5, the axial direction is indicated by an arrow X, the direction perpendicular to the axial direction and in which the sheath portion 120 and the guide wire insertion portion 130 are arranged side by side is indicated by an arrow Z. An arrow Y indicates a direction orthogonal to each direction indicated by the arrow Z. FIG.

Also, in the description of the embodiments, the distal end means a certain range including the distal end (most proximal end) and its periphery, and the proximal end means a certain range including the proximal end (most proximal end) and its periphery. range.

Next, the overall configuration of the diagnostic imaging catheter 100 will be described.

As shown in FIGS. 1A, 1B, and 3, the drive shaft 110 includes an imaging lumen 125 of the sheath portion 120, an outer tube 160 connected to the proximal side of the sheath portion 120, an outer tube It passes through the inside of the inner shaft 170 inserted into 160 .

Hub 190, inner shaft 170, and drive shaft 110 are configured to move axially together.

For example, when an external drive (not shown) moves hub 190 axially distally, inner shaft 170 connected to hub 190 is pushed into outer tube 160 and unit connector 181 . When the hub 190 moves toward the distal side in the axial direction, the drive shaft 110 connected to the hub 190 and the imaging section 115 provided on the drive shaft 110 move toward the distal side of the imaging lumen 125 of the sheath section 120. .

When the external driving device moves hub 190 proximally, inner shaft 170 is pulled out from outer tube 160 and unit connector 181 as indicated by arrow a1 in FIG. 1(B). At this time, the drive shaft 110 and the imaging section 115 move toward the proximal end side of the imaging lumen 125 of the sheath section 120 as indicated by an arrow a2 in FIG. 1B.

When using the diagnostic imaging catheter 100, the hub 190 is connected to an external drive. Then, a pullback operation is performed in which the drive shaft 110 and the imaging unit 115 are moved backward toward the proximal end side of the sheath portion 120 . At this time, the drive shaft 110 and the imaging unit 115 are rotated (radially scanned) by the driving force provided by the external drive device. In the diagnostic imaging catheter 100, a tomographic image of a body lumen (eg, a blood vessel) can be acquired along the axial direction by moving the imaging unit 115 to the proximal end side of the sheath unit 120 in the axial direction by a pullback operation. can be done.

As shown in FIG. 1A, the distal end of the inner shaft 170 is positioned near the relay connector 182 when the inner shaft 170 is pushed all the way to the distal end. The relay connector 182 is a connector that connects the sheath portion 120 and the outer tube 160 .

As shown in FIG. 1(B), a connector 171 is arranged at the tip of the inner shaft 170 to prevent the inner shaft 170 from slipping out of the outer tube 160 . The disconnection-preventing connector 171 is brought into a predetermined position within the unit connector 181 when the hub 190 is pulled most proximally, that is, when the inner shaft 170 is most pulled out from the outer tube 160 and the unit connector 181. It is designed to be caught.

As shown in FIG. 3, the drive shaft 110 has a flexible tubular body 110a and a signal line 110b inserted through the tubular body 110a.

The tubular body 110a can be composed of, for example, a multi-layered coil with different winding directions around the axis. The coil can be made of, for example, stainless steel, Ni--Ti (nickel-titanium) alloy, or the like.

The imaging unit 115 has an ultrasonic transducer 115a that transmits and receives ultrasonic waves, and a housing 115b that houses the ultrasonic transducer 115a.

The ultrasonic transducer 115a is electrically connected to the signal line 110b. The signal line 110b can be composed of, for example, a twisted pair cable, a coaxial cable, or the like. The ultrasonic transducer 115a emits ultrasonic waves as examination waves into the body cavity. Also, the ultrasonic transducer 115a receives ultrasonic waves reflected from the body cavity.

A distal end member 150 is arranged on the distal end side of the sheath portion 120 . The distal end member 150 functions as a reinforcing member that increases the rigidity of the sheath portion 120 and prevents the sheath portion 120 from being kinked or the like. The tip member 150 is formed with a hole 155 for discharging the priming liquid from the imaging lumen 125 of the sheath 120 .

When the diagnostic imaging catheter 100 is used, the imaging lumen 125 of the sheath 120 is filled with a priming liquid in order to reduce the attenuation of ultrasonic waves by the air in the sheath 120 so that the ultrasonic waves can be transmitted and received efficiently. The priming liquid filled in the imaging lumen 125 of the sheath portion 120 is discharged to the outside of the sheath portion 120 through the hole portion 155 of the tip member 150 together with gas such as air remaining in the imaging lumen 125 .

As shown in FIGS. 2 and 3, a guide wire insertion portion 130 having a guide wire lumen 135 through which the guide wire 200 can be inserted is arranged on the outer surface of the distal end portion of the sheath portion 120 . A proximal side guide wire insertion portion 140 in which a guide wire lumen 145 is formed is arranged on the proximal side of the guide wire insertion portion 130 .

The guide wire insertion portion 130 can be formed, for example, so as to have a tapered shape in which the thickness of the distal end portion 131 gradually decreases toward the distal end side. By forming the distal end portion 131 of the guidewire insertion portion 130 as described above, the insertability of the guidewire insertion portion 130 into the narrowed portion S can be enhanced.

A proximal end opening 133a located at the proximal end 133 of the guide wire insertion portion 130 can be formed, for example, in a tapered shape that is inclined toward the outer surface side of the sheath portion 120 from the distal side toward the proximal side. By forming the base end opening 133 a of the guide wire insertion portion 130 into the shape described above, the guide wire 200 can be easily inserted into the guide wire lumen 135 of the guide wire insertion portion 130 .

The distal opening of the proximal-side guide wire insertion portion 140 has, for example, a tapered shape that is inclined in the direction opposite to the proximal opening 133a of the guide wire insertion portion 130 (the direction that is inclined from the proximal side toward the distal side). can be formed.

The outer diameters of the guidewire insertion portion 130 and the proximal side guidewire insertion portion 140 can be within a range having an inner diameter through which the guidewire 200 can be inserted, from the viewpoint of suppressing an increase in the diameter of the distal end portion of the diagnostic imaging catheter 100. It is preferably formed as small as possible. For example, the outer diameters of the guidewire insertion portion 130 and the proximal guidewire insertion portion 140 can be made smaller than the outer diameter of the sheath portion 120 .

Note that the cross-sectional shape (the shape of the axis-perpendicular cross-section) of the guidewire insertion portion 130 and the proximal side guidewire insertion portion 140 is not particularly limited as long as the guidewire 200 can be inserted therethrough, and may be a shape other than a circle. .

An operator such as a doctor inserts the guide wire 200 into the guide wire lumen 135 of the guide wire insertion portion 130 and the guide wire lumen 145 of the proximal guide wire insertion portion 140 when performing a procedure using the diagnostic imaging catheter 100 . be inserted. By inserting the guide wire 200 through each of the guide wire insertion portions 130 and 140, the operator smoothly moves the diagnostic imaging catheter 100 along the guide wire 200 to the target position (for example, the constricted portion S) of the body lumen. (see Figure 6).

As shown in FIG. 1A, the hub 190 is provided with a priming port 191 that communicates with the imaging lumen 125 of the sheath portion 120 . Inside the hub 190, a predetermined connector (joint) that is mechanically and electrically connected to an external driving device, a connection pipe that holds the drive shaft 110, bearings that rotatably support the connection pipe, and the like are arranged. is doing.

Next, the structure of the distal end portion of the diagnostic imaging catheter 100 will be described.

As shown in FIGS. 2 and 3, the guide wire inserting portion 130 provided on the outer surface of the distal end portion 121 of the sheath portion 120 is arranged so as to be inclined toward the imaging lumen 125 side of the sheath portion 120. . Further, the distal end portion 151 of the distal end member 150 protruding from the imaging lumen 125 of the sheath portion 120 has a shape inclined toward the guide wire insertion portion 130 side. In FIG. 3, the direction in which the guide wire insertion portion 130 is inclined is indicated by an arrow D1, and the direction in which the distal end portion 151 of the distal end member 150 is inclined is indicated by an arrow D2.

The inclination angle θ1 of the guide wire insertion portion 130 shown in FIG. 4 can be set to 2° to 10°, for example. The inclination angle θ1 is determined by a straight line c1 parallel to the axis b1 passing through the approximate center position of the guidewire insertion portion 130 and the axis c2 of the sheath portion 120 in a state where no external force is applied to the distal end portion of the diagnostic imaging catheter 100 . can be defined by the angle formed by

The inclination angle θ2 of the tip portion 151 of the tip member 150 shown in FIG. 4 can be set to 5° to 15°, for example. The inclination angle θ2 is such that a straight line b2 substantially parallel to the end surface 151a of the distal end portion 151 of the distal end member 150 and the axis c2 of the sheath portion 120 are in a state where no external force is applied to the distal end portion of the diagnostic imaging catheter 100. It can be defined by the angle formed.

The magnitude relationship between the inclination angle θ1 of the guide wire insertion portion 130 and the inclination angle θ2 of the distal end member 150 is not particularly limited. However, if the angle difference between the inclination angle θ1 of the guidewire insertion portion 130 and the inclination angle θ2 of the tip member 150 becomes excessively large, there is a possibility that the insertability into the narrowed portion S cannot be effectively improved. Therefore, the angular difference between the inclination angle θ1 of the guide wire insertion portion 130 and the inclination angle θ2 of the tip member 150 is preferably within the range of 0° to 13°, for example.

The inclination angle θ2 of the tip member 150 can be relatively easily set by adjusting the shape of the tip member 150 . On the other hand, since the inclination angle θ1 of the guidewire insertion portion 130 is adjusted by the arrangement (orientation) of the guidewire insertion portion 130, it is difficult to set a steep angle (for example, an angle close to 90°). be. Therefore, for example, the angle difference between the inclination angles θ1 and θ2 can be adjusted by keeping the inclination angle θ1 of the guide wire insertion portion 130 constant within a certain range and adjusting the inclination angle θ2 of the distal end member 150 appropriately. It can be done relatively easily.

The shape (external shape and cross-sectional shape) of the distal end member 150 is not particularly limited as long as the distal end portion 151 inclined toward the guide wire insertion portion 130 side is formed. For example, the end surface 151a of the distal end portion 151 of the distal end member 150 may have a shape extending linearly in the cross section shown in FIG. may be

The axial length of the distal end portion 151 of the distal end member 150 (the axial length of the portion of the sheath portion 120 protruding from the imaging lumen 125) can be set to, for example, 2 mm to 4 mm. In addition, the axial length of the base end portion 153 of the distal end member 150 (the axial length of the portion of the sheath portion 120 disposed in the imaging lumen 125) can be set to, for example, 0.5 mm to 2 mm. .

As shown in FIGS. 4 and 5 , the guidewire insertion portion 130 includes a distal end portion 131 disposed on the distal side of the distal end portion 151 of the distal end member 150 (the portion projecting distally beyond the sheath portion 120), An intermediate portion 132 positioned closer to the proximal side than the distal end portion 131 and disposed so as to overlap the distal end portion 151 of the distal end member 150 in the axial direction, It has a base end portion 133 arranged axially overlying the portion 121 .

As shown in FIG. 4, in the region A2 where the intermediate portion 132 of the guidewire insertion portion 130 is arranged, the distal end portion 151 of the distal end member 150 is arranged along a portion of the outer surface of the guidewire insertion portion 130 in the circumferential direction. be done. In addition, in the region A3 where the base end portion 133 of the guidewire insertion portion 130 is located, the sheath portion 120 having an outer diameter larger than that of the guidewire insertion portion 130 overlaps the guidewire insertion portion 130 in the axial direction. Therefore, the outer shape of the diagnostic imaging catheter 100 shown in FIG. 5 (the outer shape in the plan view viewed from the direction of arrow 5A in FIG. 4) is the position where the distal end portion 131 of the guidewire insertion portion 130 is arranged (area A1 ), the position (area A2) where the intermediate portion 132 of the guidewire insertion portion 130 is arranged, and the area (A3) where the proximal end portion 133 of the guidewire insertion portion 130 is arranged are larger in this order. In other words, the size relationship of the outer shape described above means the size relationship of the dimensions W1 to W3 shown in FIG.

The distal end portion of the diagnostic imaging catheter 100 has an outer shape from the distal end side to the proximal end side according to the positions at which the distal end portion 131, the intermediate portion 132, and the proximal end portion 133 of the guidewire insertion portion 130 are arranged as described above. shape becomes larger. Therefore, the diagnostic imaging catheter 100 can be easily inserted into the stenotic part S from the distal end side of the guidewire insertion part 130, and the insertability into the stenotic part S is improved.

In addition, in the region A2 where the intermediate portion 132 of the guide wire insertion portion 130 is arranged, the intermediate portion 132 and the distal end member 150 are arranged so as to overlap each other in the axial direction. Therefore, the region A2 has greater rigidity than the region A1 where only the distal end portion 131 of the guidewire insertion portion 130 is arranged. Furthermore, in the region A3 where the proximal end portion 133 of the guide wire insertion portion 130 is arranged, the proximal end portion 133, the distal end member 150, and the sheath portion 120 are arranged so as to overlap each other in the axial direction. Therefore, the region A3 has greater rigidity than the region A2. As described above, the image diagnostic catheter 100 increases in rigidity from the distal end side to the proximal end side according to the positions at which the respective portions 131, 132, and 133 of the guide wire insertion portion 130 are arranged. It is possible to suppress the occurrence of abrupt changes in physical properties, and to suitably prevent the occurrence of kink or the like on the distal end side of the sheath portion 120 .

In particular, in this embodiment, since the thickness of the distal end portion 151 of the distal end member 150 gradually increases from the distal end side to the proximal end side, the intermediate portion 132 of the guide wire insertion portion 130 is arranged. The stiffness changes relatively gently from the region A2 where the guide wire insertion portion 130 is located toward the region A3 where the proximal end portion 133 of the guide wire insertion portion 130 is arranged. Therefore, the diagnostic imaging catheter 100 can more preferably prevent kinking or the like from occurring on the distal end side of the sheath portion 120 .

The axial length L1 of the region A1 shown in FIG. 4 can be formed to be 0.5 mm to 2 mm, for example. The axial length L2 of the region A2 can be formed to be 1 mm to 3 mm, for example. The axial length L3 of the region A3 can be formed to be 0.5 mm to 2 mm, for example.

From the viewpoint of improving the insertability of the diagnostic imaging catheter 100 into the stenosis, it is preferable to form the length L1 of the region A1 longer. However, if the region A1 is formed extremely long, the guidewire insertion portion 130 is likely to break or fall off. to increase the contact area (fixed area) between the tip member 150 and the guidewire insertion portion 130 . In this case, the length L3 of the area A3 can be formed shorter than the length L1 of the area A1 and the length L2 of the area A2, for example.

As shown in FIG. 4 , the guide wire insertion portion 130 is fixed to the distal end portion 151 of the distal end member 150 projecting from the imaging lumen 125 of the sheath portion 120 and the distal end portion 121 of the sheath portion 120 . Also, the distal end portion 151 of the distal end member 150 is fixed to the outer surface of the intermediate portion 132 of the guide wire insertion portion 130 . Furthermore, the proximal end portion 153 of the tip member 150 is fixed to the sheath portion 120 within the imaging lumen 125 of the sheath portion 120 .

As described above, the guidewire insertion portion 130 is fixed to both the tip member 150 and the sheath portion 120 . Also, the distal end member 150 is fixed to both the guide wire insertion portion 130 and the sheath portion 120 . In other words, each of the guide wire insertion portion 130, the tip member 150, and the sheath portion 120 is fixed to the two counterpart members to be fixed. Therefore, in the diagnostic imaging catheter 100, the fixing force between the three members of the guide wire insertion portion 130, the tip member 150, and the sheath portion 120 is preferably improved.

In addition, the tip member 150 functions as a fixing member that fixes the guide wire insertion portion 130 and the sheath portion 120 over a certain range in the axial direction. For this reason, the distal end member 150 has a kink at the boundary portion between the guide wire insertion portion 130 and the sheath portion 120 (a portion where the two members transition from a position where they do not overlap to a position where they overlap in the axial direction), where the difference in physical properties tends to be relatively large. It can be suitably prevented from occurring.

The method for fixing each member of the guide wire insertion portion 130, the tip member 150, and the sheath portion 120 is not particularly limited, and for example, adhesion or fusion can be used. When the tip member 150 , the guide wire insertion portion 130 , and the sheath portion 120 are fixed by fusion bonding, the guide wire insertion portion 130 and the sheath portion 120 can be more strongly fixed via the tip member 150 .

As shown in FIGS. 2 and 3, the tip opening 121a formed at the tip of the sheath portion 120 is inclined in the direction opposite to the direction in which the tip portion 151 of the tip member 150 is inclined (the direction indicated by the arrow D2). is doing. That is, the distal end opening 121a of the sheath portion 120 is inclined from the distal side toward the proximal side.

Since the distal end opening 121a of the sheath portion 120 has the above-described shape, the shape of the distal end portion 151 (the shape of the end surface 151a) of the distal end member 150 projecting from the distal end opening 121a is adjusted to the shape of the distal end opening 121a. It becomes easier to form a tapered shape from the lower side (lower side in FIG. 3) to the upper side (upper side in FIG. 3 where the guide wire insertion portion 130 is arranged). In addition, since the amount of exposure (exposed area) of the distal end portion 151 of the distal end member 150 to the upper side of the distal end opening 121a can be made relatively large, the contact area between the distal end member 150 and the guide wire insertion portion 130 is increased. can increase the fixing force between the two.

The sheath portion 120, the guide wire insertion portion 130, and the tip member 150 can be made of, for example, a known resin material. Examples of resin materials include polyethylene, polypropylene, polyisoprene, chlorinated polyethylene, polyvinyl chloride, polybutadiene, polystyrene, impact-resistant polystyrene, acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin). , methyl methacrylate-butadiene-styrene resin (MBS resin), methyl methacrylate-acrylonitrile-butadiene-styrene resin (MABS resin), acrylonitrile-acrylic rubber-styrene resin (AAS resin), acrylic resin, polyester (polyethylene terephthalate, polybutylene terephthalate , polyethylene naphthalate, etc.), polycarbonate, polyphenylene ether, modified polyphenylene ether, aliphatic polyamide, aromatic polyamide, polyphenylene sulfide, polyimide, polyetheretherketone, polysulfone, polyarylate, polyetherketone, polyethernitrile, polythioethersulfone , polyethersulfone, polybenzimidazole, polyamideimide, polyetherimide, polyacetal, liquid crystal polymer, thermoplastic polyurethane, and the like. The sheath portion 120, the guidewire insertion portion 130, and the tip member 150 may be made of different materials, or may be made of the same material.

Next, the operation of the diagnostic imaging catheter 100 according to this embodiment will be described.

As shown in FIG. 6, an operator such as a doctor delivers an image diagnostic catheter 100 along a guide wire 200 that has been inserted prior to a narrowed portion S formed in a biological lumen B such as a blood vessel. . At this time, the operator inserts the guide wire 200 through the guide wire lumen 135 of the guide wire insertion portion 130 and the guide wire lumen 145 of the proximal guide wire insertion portion 140 .

For example, if the guidewire insertion portion 130 is not disposed inclined toward the sheath portion 120 side, the guidewire insertion portion 130 maintains its shape so as to extend linearly due to the rigidity of the guidewire 200 . For this reason, it becomes difficult to smoothly insert the guide wire insertion portion 130 side into the narrowed portion S on the inner peripheral side (inner surface side). In particular, in the diagnostic imaging catheter provided with the proximal guidewire insertion portion 140, the rigidity of the guidewire 200, which is arranged substantially linearly from the guidewire insertion portion 130 toward the proximal guidewire insertion portion 140, increases. As a result, the guidewire insertion portion 130 is more strongly straightened. As a result, the deterioration in insertability of the diagnostic imaging catheter 100 into the stenosis S becomes even more pronounced.

In order to address the above problems, the diagnostic imaging catheter 100 of the present embodiment is inclined so that the guidewire insertion portion 130 and the tip member 150 face each other. Therefore, when inserting the distal end portion of the diagnostic imaging catheter 100 into the stenotic portion S, the operator easily inserts the guide wire insertion portion 130 side and the distal end member 150 side into the stenotic portion S on the inner circumference side. be able to. Further, the guide wire 200 inserted through the guide wire insertion portion 130 directs the direction of the guide wire insertion portion 130 toward the inner peripheral side of the narrowed portion S due to its rigidity. Therefore, the distal end portion of the diagnostic imaging catheter 100 can enter the inner peripheral side of the narrowed portion S more smoothly.

As described above, the diagnostic imaging catheter 100 according to the present embodiment includes the driving shaft 110 provided with the imaging unit 115 capable of acquiring image information, and the sheath unit including the imaging lumen 125 through which the driving shaft 110 can be inserted. 120, a guide wire lumen 135 through which the guide wire 200 can be inserted, the guide wire insertion portion 130 arranged on the outer surface of the distal side of the sheath portion 120, and the proximal end portion 153 are arranged in the imaging lumen 125. , and a tip member 150 positioned such that a tip portion 151 protrudes from the imaging lumen 125 . The guide wire insertion portion 130 is arranged to be inclined toward the imaging lumen 125 side of the sheath portion 120, and the distal end portion 151 of the distal end member 150 is inclined toward the guide wire insertion portion 130 side. there is

The diagnostic imaging catheter 100 configured as described above is inclined toward the distal side so that the guide wire insertion portion 130 and the tip member 150 face each other. Therefore, the diagnostic imaging catheter 100 can be inserted into the stenosis S more easily. Further, the guide wire insertion portion 130 is oriented so as to be inclined toward the distal end side by arranging the guide wire insertion portion 130 so as to be inclined toward the imaging lumen 125 side of the sheath portion 120 . Therefore, the diagnostic imaging catheter 100 does not need to excessively reduce the thickness of the guide wire insertion portion 130 in order to impart a tapered shape. As a result, the diagnostic imaging catheter 100 can preferably maintain the ability to be pushed into the narrowed portion S.

In addition, the guide wire insertion portion 130 includes a distal end portion 131 disposed on the distal side of the distal end portion 151 of the distal end member 150 and a proximal end portion of the distal end portion 131 positioned on the distal end side of the distal end portion 151 of the distal end member 150 . and a proximal end portion 133 located on the proximal side of the intermediate portion 132 and axially overlapping the distal end portion 121 of the sheath portion 120. there is The diagnostic imaging catheter 100 has a position (region A1) where the distal end portion 131 of the guidewire insertion portion 130 is arranged, a position (region A2) where the intermediate portion 132 is arranged, and a position where the proximal end portion 133 is arranged. The outer shape becomes larger in order of (area A3).

In the diagnostic imaging catheter 100 configured as described above, the distal end portion 131, the intermediate portion 132, and the proximal end portion 133 of the guide wire insertion portion 130 have an outer shape that increases in order from the distal end side to the proximal end side. It becomes easier to push the wire insertion portion 130 into the constricted portion S from the distal end side, and the insertability into the constricted portion S is improved. Furthermore, since the image diagnostic catheter 100 increases in rigidity from the distal end side to the proximal end side according to the positions at which the respective portions 131, 132, and 133 of the guide wire insertion portion 130 are arranged, a sharp difference in physical properties occurs. can be suppressed, and the occurrence of kink or the like on the distal end side of the sheath portion 120 can be suitably prevented.

Further, the guide wire insertion portion 130 is fixed to the distal end portion 151 of the distal end member 150 protruding from the imaging lumen 125 of the sheath portion 120 and the distal end portion 121 of the sheath portion 120 . Therefore, the fixing force between the three members, ie, the guide wire insertion portion 130, the distal end member 150, and the sheath portion 120 can be preferably improved.

Further, the tip opening 121a formed in the tip 121 of the sheath part 120 is inclined in the direction opposite to the direction in which the tip 151 of the tip member 150 is inclined. Therefore, the shape of the distal end portion 151 of the distal end member 150 protruding from the distal opening portion 121a can be easily formed into a tapered shape that is inclined toward the guide wire insertion portion 130 side. Moreover, the contact area between the distal end portion 151 of the distal end member 150 and the guide wire insertion portion 130 can be increased, and the fixing force between the two can be increased.

The diagnostic imaging catheter 100 also includes a guidewire lumen 145 through which the guidewire 200 can be inserted, which is located on the proximal side of the guidewire insertion portion 130 and on the outer surface of the sheath portion 120. It has a proximal side guide wire insertion portion 140 . Since the diagnostic imaging catheter 100 is inclined toward the distal side so that the guide wire insertion portion 130 and the tip member 150 face each other, the guide wire 200 is inserted through the guide wire insertion portions 130 and 140. Also, the insertability into the narrowed portion S is favorably maintained.

Although the medical device according to the present invention has been described above through the embodiments, the present invention is not limited to the configurations described in the embodiments, and can be appropriately modified based on the description of the claims. is.

An IVUS catheter has been described as an example of a medical device, but the medical device includes, for example, the functions of an optical coherence tomography diagnostic device, an intravascular ultrasound diagnostic device, and an optical coherence tomography diagnostic device. It is also possible to apply to a dual-type diagnostic imaging catheter that can be used by switching or simultaneously, a diagnostic imaging catheter that uses an optical frequency domain imaging method, and the like. Also, the configuration of each part of the medical device is not limited to the one illustrated in the drawings, and can be changed as appropriate.

100 diagnostic imaging catheters (medical devices),
110 drive shaft;
120 sheath portion,
121 the tip of the sheath,
121a tip opening of the sheath,
125 imaging lumens,
130 guide wire insertion part,
131 tip of the guide wire insertion part,
132 intermediate part of the guide wire insertion part,
133 proximal end of the guide wire insertion part,
135 lumen for guide wire,
140 proximal side guide wire insertion part,
145 lumen for guide wire,
150 tip member,
151 the tip of the tip member,
153 the proximal end of the tip member;
200 guide wire,
θ1 inclination angle of guide wire insertion part,
θ2 inclination angle of the tip member,
B a biological lumen,
S constriction.

Claims (2)

A medical device for acquiring images of a biological lumen, comprising:
a drive shaft provided with an imaging unit capable of acquiring image information;
a sheath portion comprising an imaging lumen through which the drive shaft can be inserted;
a guidewire insertion portion provided with a guidewire lumen through which a guidewire can be inserted, and disposed on the outer surface of the sheath portion on the distal end side;
a distal end member disposed such that a proximal end portion is disposed in the imaging lumen and a distal end portion protrudes from the imaging lumen;
The guide wire insertion portion is disposed so as to be inclined toward the imaging lumen side of the sheath portion,
A distal end portion of the distal end member is inclined toward the guide wire insertion portion side, and is exposed from the imaging lumen over a proximal end side of the distal end of the sheath portion to be connected to the guide wire insertion portion. are in contact with
A guide wire lumen through which the guide wire can be inserted is further provided, and a proximal side guide wire insertion portion is disposed on the outer surface of the sheath portion and is proximal to the guide wire insertion portion. death,
The proximal side guide wire insertion portion is provided along the axis of the sheath portion and is separated from the guide wire insertion portion ,
The guide wire insertion portion is arranged on the distal side of the distal end portion of the distal end member and is not fixed to the distal end member and the sheath portion, and the distal end portion is positioned on the proximal side of the distal end portion. an intermediate portion axially overlapped with and fixed to the distal end portion of the distal end member protruding from the imaging lumen of the sheath portion; a proximal end axially overlapping and fixed to the outer surface;
The medical device is a medical device in which the outer shape of the guidewire insertion portion is larger in the order of the position where the tip portion of the guidewire insertion portion is arranged, the position where the intermediate portion is arranged, and the position where the base end portion is arranged . The medical device according to claim 1 , wherein the tip member, the guidewire insertion portion, and the sheath portion are fixed by fusion .

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