Electrode catheter

Abstract

An electrode catheter 1 comprises a shaft 2, a plurality of splines, and a distal member 4. The plurality of splines are connected to the distal end side of the shaft 2. The distal member 4 is connected to the distal end sides of each of the plurality of splines. At least two adjacent splines among the plurality of splines have different radiopacity from one another. At least three splines among the plurality of splines may have different radiopacity from one another.

Description

Electrode catheter

[0001] The present disclosure relates to electrode catheters.

[0002] A catheter is a type of medical device inserted into the body for diagnosis or treatment. As an example, an electrode catheter is known that includes a shaft and a basket electrode assembly connected to the tip of the shaft (see, for example, Patent Document 1). Here, the basket electrode assembly includes a plurality of splines.

[0003] Special Publication No. 2016-507349

[0004] During procedures using electrode catheters, doctors and other specialists may use opaque images, such as X-rays, to understand the position and movement of each spline. To improve visibility in opaque images, contrast markers may be attached to each spline. However, there is still room for improvement in the identification of the splines.

[0005] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide an electrode catheter that improves the discernibility of splines in opaque images.

[0006] The electrode catheter of the present disclosure includes a shaft, a plurality of splines, and a tip member. The plurality of splines are connected to a distal end of the shaft. The tip member is connected to each of the distal ends of the plurality of splines. At least two adjacent splines of the plurality of splines have different radiopacities.

[0007] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure.

[0008] The electrode catheter of the present disclosure can improve the discernibility of splines in opaque images.

[0009] 9 is a perspective view schematically showing an example of a deformed state near the tip of the electrode catheter according to the first embodiment. FIG. 1 is a view of the electrode catheter shown in FIG. 1 as viewed from the tip side toward the base end side in the axial direction. FIG. 1 is a view of a portion of the electrode catheter shown in FIG. 1 including a spline as viewed from a direction perpendicular to the axial direction. FIG. 2 is a view of a portion of a modified electrode catheter shown in FIG. 1 including a spline as viewed from a direction perpendicular to the axial direction. FIG. 3 is a view of an example of an opaque image of the electrode catheter shown in FIG. 1 taken from the tip side toward the base end side in the axial direction. FIG. 4 is a view of an example of an opaque image of the electrode catheter shown in FIG. 1 taken from a first direction perpendicular to the axial direction, the portion of the electrode catheter shown in FIG. 1 including a spline as viewed from a second direction perpendicular to the axial direction. FIG. 5 is a view of an example of an opaque image of the electrode catheter according to the second embodiment taken from the tip side toward the base end side in the axial direction. FIG. 6 is a view of an example of an opaque image of the electrode catheter shown in FIG. 9 taken from a first direction, the portion of the electrode catheter including a spline as viewed from a second direction.

[0010] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0011] [First embodiment] Fig. 1 is a perspective view schematically illustrating an example of a deformed state near the tip of an electrode catheter 1 according to a first embodiment of the present disclosure. As shown in Fig. 1, the electrode catheter 1 comprises a shaft 2 to be inserted into a body, a plurality of splines 3a to 3f connected to the tip side of the shaft 2, and a tip member 4 connected to the tip sides of each of the plurality of splines 3a to 3f. Hereinafter, in descriptions common to each of the plurality of splines 3a to 3f, they will also be simply referred to as splines 3.

[0012] Hereinafter, in the electrode catheter 1 and each of the components constituting the electrode catheter 1, the direction along the central axis of the shaft 2 will be referred to as the "axial direction," the radial direction with the central axis of the shaft 2 as the circle center will be referred to as the "radial direction," and the direction around the central axis of the shaft 2 will be referred to as the "circumferential direction." Furthermore, in the electrode catheter 1 and each of the components constituting the electrode catheter 1, of the two sides along the axial direction, the side of the electrode catheter 1 that is inserted into the body will be referred to as the "distal side," and the side that is placed outside the body will be referred to as the "base side."

[0013] The shaft 2 may be a long, cylindrical member. The length of the shaft 2 is, for example, 800 mm to 1800 mm. The outer diameter of the shaft 2 is, for example, 2.0 mm to 5.0 mm. For example, the shaft 2 is made of a known resin such as polyolefin or polyamide.

[0014] The spline 3 is a member that connects the shaft 2 and the tip member 4. The spline 3 may be a cylindrical member, similar to the shaft 2. The length of the spline 3 when extended linearly is, for example, 20 mm to 50 mm. The outer diameter of the spline 3 is, for example, 0.5 mm to 2.0 mm. The spline 3 is made of a material, similar to the shaft 2, such as a known resin, such as polyolefin or polyamide.

[0015] The splines 3 include at least adjacent splines 3a and 3b. Fig. 1 illustrates an example in which the number of splines 3 is six. Specifically, the example illustrates the splines 3a and 3b, the splines 3b and 3c, the splines 3c and 3d, the splines 3d and 3e, the splines 3e and 3f, and the splines 3f and 3a, each of which is adjacent to the other.

[0016] The spline 3 is connected to the shaft 2. As an example, a portion of the spline 3 including the base end (base end portion) is inserted into the tip side of the shaft 2. The base end portion of the spline 3 and the shaft 2 are joined to each other by a known joining method such as welding or bonding with an adhesive.

[0017] The splines 3 are configured to change shape in response to a deformation operation, which will be described later. Specifically, the shape of each spline 3 changes between a non-deployed or contracted shape in which the splines 3 are not deployed in the radial direction, and a deployed or expanded shape in which the splines 3 are deployed in the radial direction. In the deployed or expanded shape, at least a portion of each spline 3 is separated from each other. Figure 1 shows an example of the deployed shape.

[0018] As shown in FIG. 1 , each spline 3 may have one or more electrodes 5. The electrodes 5 are ring-shaped electrodes for potential measurement or ablation. The electrodes 5 of each spline 3 are arranged spaced apart from one another along the longitudinal direction of the spline 3. In this case, the intervals between adjacent electrodes 5 may be constant or may vary. Furthermore, the number of electrodes 5 of each spline 3 may be the same or may vary.

[0019] The electrodes 5 are made of a metal with good electrical conductivity, such as aluminum (Al), copper (Cu), stainless steel, gold (Au), or platinum (Pt). The length of the electrodes 5 along the splines 3 is, for example, 0.5 mm to 2.0 mm. The outer diameter of the electrodes 5 may be equal to or greater than the outer diameter of the splines 3, and is, for example, 0.5 mm to 2.0 mm. The sizes of the electrodes 5 may be the same or different.

[0020] Conductive wires are individually and electrically connected to the electrodes 5. The conductive wires pass from inside the spline 3 through the shaft 2 and the handle 8 (described later) and are connected to an external power supply device via the handle 8. As an example, the conductive wires connected to the electrodes 5 of the spline 3a pass through a lumen (not shown) of the spline 3a while being electrically insulated from each other. The same applies to the splines 3 other than the spline 3a.

[0021] 1, the tip member 4 may house a portion of the spline 3 including the tip (hereinafter referred to as the "tip portion"). In other words, the tip portion of the spline 3 may be covered with the tip member 4. The tip member 4 is made of a known resin such as nylon, nylon elastomer, polycarbonate, etc., or a known metal such as stainless steel, etc.

[0022] The tip of a long deformation member 14 is fixed to the tip member 4. The deformation member 14 passes through the shaft 2, and the base end of the deformation member 14 is fixed to a slide member 13 (see FIG. 8 ), which will be described later. The deformation member 14 may have a lumen that extends in the axial direction and opens at the tip. A long member such as a guidewire can be housed in the lumen of the deformation member 14, and the long member can protrude from the opening at the tip of the deformation member 14. In this case, the tip member 4 may have an opening that passes through in the axial direction, and the opening may be in communication with the lumen of the deformation member 14.

[0023] Fig. 2 is a view of the electrode catheter 1 as viewed from the distal end toward the proximal end. Fig. 2 can also be said to be a view of the electrode catheter 1 as viewed from the distal end of the distal end member 4 toward the proximal end.

[0024] In this embodiment, the splines 3 are fixed to the shaft 2 and the distal end member 4. The positions at which the splines 3 are fixed are spaced at approximately equal angular intervals. The angular interval is the angle between the lines connecting the positions at which the splines 3 are fixed and the center of the shaft 2 when the electrode catheter 1 is viewed from the distal end toward the proximal end. That is, for the six splines 3, the angular interval between the positions at which adjacent splines 3 are fixed to the distal end member 4 is approximately 60°.

[0025] In this embodiment, each spline 3 extends from a position fixed to the distal end member 4 to a position fixed to the shaft 2 so as to rotate around the axis of the shaft 2. That is, each spline 3 extends from the distal end side to the proximal end side so as to twist around the axis of the shaft 2. In the example shown in FIG. 2 , the angular interval between the position where each spline 3 is fixed to the distal end member 4 and the position where each spline 3 is fixed to the shaft 2 is approximately 30°. The multiple splines 3a to 3f include non-linear portions 20 when viewed from the distal end of the distal end member 4 towards the proximal end side. In the example shown in FIG. 2 , each spline 3 includes a non-linear portion 20. The non-linear portions 20 in this embodiment result from the fact that each spline 3 is fixed in a twisted manner so as to rotate around the axis of the shaft 2.

[0026] FIG. 3 is a view of a portion of the electrode catheter 1, including the splines 3, as viewed from the radial direction. As shown in FIG. 3, each spline 3 has a different shape when viewed from the radial direction. In particular, the shapes of two splines 3 that overlap each other when viewed from the radial direction are different from each other. In the example shown in FIG. 3, splines 3a and 3c, which have an overlapping portion 22, have different shapes, and splines 3d and 3f, which also have an overlapping portion 22, have different shapes. These differences in shape are due to the fact that the multiple splines 3a to 3f include the non-linear portion 20 shown in FIG. 2. Furthermore, as described above, each spline 3 extends from the distal end to the proximal end while being twisted so as to rotate around the axis of the shaft 2. Therefore, depending on the direction of twist, it is possible to identify whether each spline 3 is located on the near side or the far side when viewed from a direction intersecting the axial direction.

[0027] Figure 4 is a view of a portion of an electrode catheter 9, which is a modified example of the electrode catheter 1, including the splines 3, viewed from the radial direction. In the electrode catheter 9, each spline 3 extends at the same circumferential position from the position fixed to the distal end member 4 to the position fixed to the shaft 2. Each spline 3 extends from the distal end to the proximal end without twisting around the axis of the shaft 2. In the example shown in Figure 4, the angular interval between the position where each spline 3 is fixed to the distal end member 4 and the position where each spline 3 is fixed to the shaft 2 is approximately 0°. The electrode catheter 9 is similar to the electrode catheter 1 in all other respects.

[0028] 4, the splines 3 of the electrode catheter 9 have similar shapes when viewed in the radial direction. When viewed in the radial direction, the splines 3 of the electrode catheter 9 have a substantially arcuate shape. Unlike the splines 3 of the electrode catheter 1, the splines 3 of the electrode catheter 9 extend from the distal end to the proximal end without twisting around the axis of the shaft 2. Therefore, when viewed in a direction intersecting the axial direction, it is difficult to distinguish whether the splines 3 of the electrode catheter 9 are located on the near side or the far side.

[0029] In this way, in the electrode catheter 1, the non-linear portions 20 cause each spline 3 to have a different shape when viewed from a direction intersecting the axial direction. Also, in the electrode catheter 1, each spline 3 extends from the distal end to the proximal end while being twisted so as to rotate around the axis of the shaft 2, so that it is possible to distinguish whether each spline 3 is located on the near side or the far side when viewed from a direction intersecting the axial direction, depending on the direction of twist. In addition, by combining these features with the different radiopacity of each spline 3 described below, it is easier to further improve the distinguishability of the splines 3.

[0030] During a procedure using the electrode catheter 1, a physician or other doctor may use an opacity image obtained by irradiating the irradiated body with radiation such as X-rays to grasp the position and movement of each spline 3. Here, the opacity image is an image that expresses differences in the radiopacity of the irradiated body relative to the irradiated radiation using shades of gray. In the opacity image, for example, areas of the irradiated body with lower radiopacity are displayed lighter, and areas of the irradiated body with higher radiopacity are displayed darker. It is expected that the opacity image used during a procedure using the electrode catheter 1 will be captured primarily from a direction intersecting the axial direction, as shown in FIGS. 3 and 4 . In this case, it is required to be able to identify each of the multiple splines 3a to 3f, such as which electrode 5 of each spline 3 is in contact with biological tissue and how much each spline 3 has rotated when the electrode catheter 1 is rotated in the circumferential direction. However, if each spline 3 is displayed with the same shade in the opacity image, it would be difficult to identify each spline 3. In an opaque image captured in a direction intersecting the axial direction, it is particularly difficult to distinguish between the splines 3 located on the front side and the splines 3 located on the back side.

[0031] Fig. 5 is a diagram showing an example of an opacity image taken of the electrode catheter 1 from the distal end toward the proximal end. Fig. 6 is a diagram showing an example of an opacity image taken of a portion of the electrode catheter 1 including the spline 3 from a first radial direction. Fig. 7 is a diagram showing an example of an opacity image taken of a portion of the electrode catheter 1 including the spline 3 from a second radial direction. The opacity images taken from the radial direction shown in Figs. 6 and 7 are examples of opacity images taken from a direction intersecting the axial direction. In the following diagrams showing opacity images, including Figs. 5 to 7, with regard to the shading of the opacity images, parts with higher radiopacity are indicated by darker hatching, and parts with lower radiopacity are indicated by lighter hatching.

[0032] 5 to 7, in this embodiment, among the multiple splines 3a to 3f, splines 3a, 3e, and 3f have higher radiopacity than the other splines 3, i.e., splines 3b, 3c, and 3d. For example, the radiopacity of each spline 3 can be adjusted by adjusting the content of a highly radiopaque material contained in each spline 3, as will be described in detail below.

[0033] In the electrode catheter 1 of this embodiment, at least two adjacent splines 3 among the multiple splines 3 have different radiopacities. Specifically, adjacent splines 3a and 3b, and adjacent splines 3d and 3e, have different radiopacities. This allows at least two adjacent splines 3 to be displayed with different shading in an opaque image, improving the discernibility of the splines 3 in the opaque image.

[0034] In this embodiment, the multiple splines 3a to 3f include two or more splines 3 that have radiopacity different from the other splines 3, and when viewed from the tip of the distal end member 4 toward the base end, the two or more splines 3 are arranged asymmetrically with respect to the central axis of the shaft 2. Specifically, the other splines 3 are spline 3b, spline 3c, and spline 3d, and the two or more splines 3 are spline 3a, spline 3e, and spline 3f. As shown in Fig. 5, when viewed from the tip of the distal end member 4 toward the base end, the splines 3a, spline 3e, and spline 3f are arranged asymmetrically with respect to the central axis of the shaft 2, i.e., the approximate center position of the distal end member 4 in Fig. 5. In other words, when viewed from the tip of the distal end member 4 toward the base end, the splines 3a, spline 3e, and spline 3f are arranged in positions that are not point-symmetric with respect to the central axis of the shaft 2. In particular, in this embodiment, when viewed from the tip of the tip member 4 toward the base end, the splines 3a, 3e, and 3f are arranged on only one side of a straight line passing through the central axis of the shaft 2, in this case a straight line passing between the splines 3a and 3b and between the splines 3d and 3e.

[0035] As described above, in this embodiment, the multiple splines 3a to 3f include two or more splines 3 that have radiopacity different from the other splines 3, and when viewed from the distal end of the distal end member 4 toward the proximal end, the two or more splines 3 are arranged asymmetrically with respect to the central axis of the shaft 2. This further improves the distinguishability of the splines 3 in an opaque image captured from a direction intersecting the axial direction. Specifically, the distinguishability of the splines 3 is further improved when the electrode catheter 1 is rotated in the circumferential direction. In other words, when the electrode catheter 1 is rotated in the circumferential direction, it is possible to distinguish whether each spline 3 is located on the near side or the far side. In particular, in this embodiment, when viewed from the tip of the tip member 4 toward the base end, the splines 3a, 3e, and 3f are arranged on only one side of a straight line passing through the central axis of the shaft 2.Therefore, as shown in Figures 6 and 7, the splines 3a, 3e, and 3f tend to be concentrated on the front or back side in an opaque image taken from a direction intersecting the axial direction, thereby further improving the distinguishability from other splines 3 when the electrode catheter 1 is rotated circumferentially.

[0036] In this embodiment, among the multiple splines 3a to 3f, the two or more splines 3 having radiopacity different from that of the other splines 3 include at least two adjacent splines 3. Specifically, of the two or more splines 3a, 3e, and 3f having radiopacity different from that of the other splines 3, spline 3a and spline 3f are adjacent to each other, and spline 3e and spline 3f are adjacent to each other. As a result, in an opaque image captured from a direction intersecting the axial direction, two adjacent splines 3 tend to be concentrated and positioned on the near side or the far side, thereby further improving the distinguishability from other splines 3 when the electrode catheter 1 is rotated in the circumferential direction.

[0037] In this embodiment, at least three of the multiple splines 3 may have different radiopacities. In this case, two or more of the "two or more splines 3 having radiopacity different from that of the other splines 3" may have different radiopacities, and all of the "other splines 3" may have the same radiopacity. Specifically, two of the splines 3a, 3e, and 3f may have the same radiopacity, and the remaining spline 3 may have a different radiopacity. Furthermore, the splines 3b, 3c, and 3d may have the same radiopacity. This causes the at least three splines 3 to be displayed with different shading in the opaque image, thereby further improving the distinguishability of the splines 3 in the opaque image.

[0038] Incidentally, the radiopacity of each spline 3 can be varied by adjusting the content of a highly radiopaque material (hereinafter also referred to as the "first material") contained in each spline 3. Specifically, the content of the first material contained in splines 3a, 3e, and 3f is higher than the content of the first material contained in splines 3b, 3c, and 3d. Examples of the first material include tungsten, barium, platinum, and gold. Among the multiple splines 3a to 3f, there may be a spline 3 that does not contain the first material.

[0039] As described above, the radiopacity of each spline 3 can be varied by adjusting the content of the first material contained in each spline 3. However, if the content of the first material varies, physical properties other than radiopacity may also vary. In particular, if the hardness of each spline 3 varies, this may affect operability.

[0040] Therefore, the difference in hardness between the splines 3 may be reduced by adjusting the content of the second material in addition to the first material for each spline 3. The radiopacity of the second material is lower than that of the first material. Examples of the second material include talc, silica, and polyether block amide.

[0041] As described above, the "at least two adjacent splines 3" having different radiopacities may contain a first material and a second material. Here, it is sufficient that the "at least two adjacent splines 3" as a whole contain the first material and the second material. There may be splines 3 that do not contain the first material, or there may be splines 3 that do not contain the second material. The radiopacity of the first material is higher than the radiopacity of the second material. Among the "at least two adjacent splines 3," the content of the first material in one spline 3 is higher than the content of the first material in the other spline 3. The content of the second material in the one spline 3 is different from the content of the second material in the other spline 3. Either the one spline 3 or the other spline 3 may not contain the second material. The content of the second material can be detected by element or functional group using infrared spectroscopy (IR) or the like.

[0042] Fig. 8 is a diagram showing a schematic diagram of an example of the overall structure of the electrode catheter 1. As shown in Fig. 8, the electrode catheter 1 may include a handle 8 connected to the proximal end side of the shaft 2.

[0043] The slide member 13 is a part that accepts a deformation operation, such as a sliding operation, by the operator when deforming the shape of the spline 3 between the undeployed shape or contracted shape and the expanded shape or expanded shape. The slide member 13 is slidable along the central axis of the shaft 2 in the handle body 11, and depending on the position of the slide member 13, the shape of the spline 3 can be deformed to the undeployed shape or contracted shape, the expanded shape or expanded shape, or any intermediate shape between the undeployed shape and the expanded shape.

[0044] [Second Embodiment] Fig. 9 is a diagram showing an example of an opaque image of an electrode catheter 1A according to a second embodiment of the present disclosure, imaged from the distal end toward the proximal end. Fig. 10 is a diagram showing an example of an opaque image of a portion of the electrode catheter 1A, including the splines 3Aa to 3Af, imaged from a first radial direction. Fig. 11 is a diagram showing an example of an opaque image of a portion of the electrode catheter 1A, including the splines 3Aa to 3Af, imaged from a second radial direction. The electrode catheter 1A according to this embodiment differs from the electrode catheter 1 according to the first embodiment in the radiopacity of some of its components, but is otherwise common. Regarding the electrode catheter 1A according to this embodiment, descriptions of matters common to the electrode catheter 1 according to the first embodiment will be omitted as appropriate. Hereinafter, descriptions of the splines 3Aa to 3Af that are common to each other will be simply referred to as spline 3A.

[0045] As shown in Figures 9 to 11, in this embodiment, of the multiple splines 3Aa to 3Af, splines 3Aa and 3Ae have higher radiopacity than the other splines 3A, namely, splines 3Ab, 3Ac, 3Ad, and 3Af.

[0046] As with the electrode catheter 1 of the first embodiment, in the electrode catheter 1A of this embodiment, of the multiple splines 3A, at least two adjacent splines 3A have different radiopacities. Specifically, adjacent splines 3Aa and 3Ab, adjacent splines 3Ad and 3Ae, adjacent splines 3Ae and 3Af, and adjacent splines 3Af and 3Aa have different radiopacities. This provides the same effects as in the first embodiment.

[0047] As in the first embodiment, in this embodiment, the multiple splines 3Aa to 3Af include two or more splines 3A that have radiopacity different from that of the other splines 3A, and when viewed from the distal end of the distal end member 4 toward the proximal end, the two or more splines 3A are arranged asymmetrically with respect to the central axis of the shaft 2. Specifically, the two or more splines 3A that have radiopacity different from that of the other splines 3A are splines 3Aa and 3Ae. In particular, in this embodiment, when viewed from the distal end of the distal end member 4 toward the proximal end, the splines 3Aa and 3Ae are arranged on only one side of a straight line passing through the central axis of the shaft 2, in this case, a line passing between splines 3Aa and 3Ab and a line passing between splines 3Ad and 3Ae. The effects obtained thereby are similar to those of the first embodiment.

[0048] Unlike the first embodiment, in this embodiment, some splines 3A of two or more splines 3 having radiopacity different from that of the other splines 3A are arranged between the other splines 3. Specifically, of two splines 3Aa and 3Ae having radiopacity different from that of the other splines 3A, spline 3Aa is arranged between the other splines 3Af and 3Ab. Similarly, spline 3Ae is arranged between the other splines 3Ad and 3Af. This means that adjacent splines 3A have radiopacity different from each other in at least two locations, thereby further improving the distinguishability of splines 3A in an opaque image.

[0049] As in the first embodiment, in this embodiment, at least three splines 3A among the plurality of splines 3 may have different radiopacities. Specifically, the splines 3Aa and 3Ae may have different radiopacities, and the other splines 3A may have the same radiopacity. The effect achieved thereby is the same as in the first embodiment.

[0050] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changes, additions, and deletions of components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with a design modification combines the effects of the combined embodiments and modifications. Any combination of components included in each embodiment is also effective as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched objects.

[0051] For example, although the examples in each embodiment have shown an example in which the number of splines 3 or splines 3A is six, the number of splines 3 or splines 3A may be three or more. Furthermore, although the examples in each embodiment have shown an example in which each spline 3 or spline 3A is fixed to the shaft 2 at a position rotated in the circumferential direction from the position at which it is fixed to the tip member 4, each spline 3 or spline 3A may be fixed to the shaft 2 at the same position in the circumferential direction from the position at which it is fixed to the tip member 4. Even in this case, if the spline 3 or spline 3A includes a non-linear portion 20, the spline 3 or spline 3A can have a different shape when viewed from a direction intersecting the axial direction. Furthermore, the spline 3 or spline 3A does not necessarily have to include the non-linear portion 20.

[0052] The embodiments may be specified by the following items.

[0053] [Item 1] An electrode catheter (1) comprising: a shaft (2); a plurality of splines (3) connected to the distal end of the shaft (2); and a distal end member (4) connected to the distal end of each of the plurality of splines (3), wherein at least two adjacent splines (3) of the plurality of splines (3) have different radiopacities.

[0054] According to the electrode catheter (1) relating to the first item, at least two adjacent splines (3) are displayed with different shades in the opaque image, thereby improving the distinguishability of the splines (3) in the opaque image.

[0055] [Item 2] The electrode catheter (1) according to Item 1, wherein at least three of the plurality of splines (3) have different radiopacities.

[0056] According to the electrode catheter (1) relating to the second item, at least three splines (3) are displayed in different shades in the opaque image, thereby further improving the distinguishability of the splines (3) in the opaque image.

[0057] [Item 3] The electrode catheter (1) described in item 1 or 2, wherein the plurality of splines (3) includes two or more splines (3) having radiopacity different from that of the other splines (3), and when viewed from the distal end of the distal end member (4) toward the proximal end, the two or more splines (3) are arranged asymmetrically with respect to the central axis of the shaft (2).

[0058] According to the electrode catheter (1) relating to the third item, in an opaque image taken from a direction intersecting the axial direction, the two or more splines (3) tend to be concentrated and arranged on the semicircular side in the circumferential direction, thereby further improving the distinguishability from other splines (3).

[0059] [Item 4] The electrode catheter (1) according to item 3, wherein the two or more splines (3) include at least two adjacent splines (3).

[0060] According to the electrode catheter (1) relating to the fourth item, in an opaque image taken from a direction intersecting the axial direction, adjacent splines (3) tend to be concentrated and arranged on the semicircular side in the circumferential direction, thereby further improving the distinguishability from other splines (3).

[0061] [Item 5] The electrode catheter (1) according to item 3 or 4, wherein some of the two or more splines (3) are arranged between other splines (3).

[0062] According to the electrode catheter (1) relating to the fifth item, adjacent splines (3) have different radiopacity at at least two locations, thereby further improving the distinguishability of the splines (3) in the radiopaque image.

[0063] [Item 6] The electrode catheter (1) according to any one of Items 1 to 5, wherein the plurality of splines (3) include a non-linear portion when viewed from the distal end of the distal end member (4) toward the proximal end.

[0064] According to the electrode catheter (1) relating to the sixth item, the non-linear portions tend to make the multiple splines (3) have different shapes when viewed from a direction intersecting the axial direction, which makes it easier to further improve the identifiability of the splines (3).

[0065] [Item 7] An electrode catheter (1) described in any one of items 1 to 6, wherein at least two adjacent splines (3) comprise a first material and a second material, the radiopacity of the first material is higher than the radiopacity of the second material, the content of the first material in one of the at least two adjacent splines (3) is higher than the content of the first material in the other of the at least two adjacent splines (3), and the content of the second material in one of the splines is different from the content of the second material in the other of the at least two adjacent splines (3).

[0066] According to the electrode catheter (1) relating to the seventh item, when the radiopacity is varied by adjusting the content of the first material in each spline (3), the content of the second material can also be adjusted to reduce the difference in other physical properties such as hardness.

[0067] The present disclosure may be utilized in electrode catheters.

[0068] 1, 1A...electrode catheter, 2...shaft, 3...spline, 4...tip member, 5...electrode, 20...non-linear portion

Claims

1. An electrode catheter comprising: a shaft; a plurality of splines connected to a distal end of the shaft; and a distal end member connected to the distal end of each of the plurality of splines, wherein at least two adjacent splines among the plurality of splines have different radiopacities.

2. The electrode catheter of claim 1, wherein at least three of said plurality of splines have different radiopacities.

3. The electrode catheter according to claim 1, wherein the plurality of splines include two or more splines having a radiopacity different from that of other splines, and when viewed from the distal end of the distal member toward the proximal end, the two or more splines are arranged asymmetrically with respect to the central axis of the shaft.

4. The electrode catheter of claim 3, wherein the two or more splines include at least two adjacent splines.

5. The electrode catheter according to claim 3, wherein some of the two or more splines are disposed between the other splines.

6. The electrode catheter according to claim 1, wherein the plurality of splines include a non-linear portion when viewed from the distal end of the distal member toward the proximal end.

7. An electrode catheter according to any one of claims 1 to 6, wherein the at least two adjacent splines comprise a first material and a second material, the radiopacity of the first material is greater than the radiopacity of the second material, the content of the first material in one of the at least two adjacent splines is greater than the content of the first material in the other of the at least two adjacent splines, and the content of the second material in one of the splines is different from the content of the second material in the other of the at least two adjacent splines.

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