JP2012034852A - Electrode catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode catheter, in which sharp potential with few noise can be measured by an electrode even though the electrode is excellent in imaging characteristics (visibility by an X-ray image etc.) in use.SOLUTION: The electrode catheter includes a catheter body, a control handle, a catheter tip end part 30 in a double tube structure composed of an inner tube 31 and an outer tube 32, a plurality of metallic rings 41 arranged by being respectively separated in the axial direction in a state interposed between the inner tube 31 and the outer tube 32, and a plurality of lead wires 61. On the tube wall of the outer tube 32 constituting the tip end part 30 of the catheter, opening windows 321 are formed corresponding to positions where the metallic rings 41 are fixed, and electrodes 41A are configured by a part of the outer periphery surface of the exposed metallic rings 41.

Description

  The present invention relates to an electrode catheter in which a plurality of electrodes are mounted on the outer peripheral surface of a catheter tip.

For example, electrode catheters are used as medical instruments for diagnosing or treating cardiac arrhythmias. As such an electrode catheter, one having a distal end portion (catheter distal end portion) that bends in the plane of the catheter has been introduced (see Patent Document 1).
As shown in FIG. 8, the electrode catheter includes a catheter body 110, a control handle 116, a catheter tip 114, a plurality of ring electrodes 140, a tip electrode 138, and a connector 118. In addition, a tension wire and a flexible structure for bending the catheter tip 114 in the plane are disposed inside the electrode catheter.

  9 is a cross-sectional view showing the catheter tip 114 of the electrode catheter shown in FIG. 8, in which 120 is a side hole formed in the tube wall of the catheter tip 114, and 117 is a flexible structure (cross-section). Is a rectangular plate), 130 is a lead wire, 126 and 127 are lumens, and 129 is an injection tube.

  The tip electrode 138 and the ring electrode 140 are each connected to a separate lead wire 130. These lead wires 130 are made of resin-coated metal core wires, and the lead wires 130 connected to the ring-shaped electrode 140 are welded to the inner peripheral surface of the ring-shaped electrode 140 at the respective distal end portions, and the distal end of the catheter. The lumen 126 enters the lumen 126 through the side hole 120 formed in the tube wall of the section 114, extends into the lumen 126, the lumen of the catheter body 110, and the inner hole of the control handle 116, and is connected to the connector 118 at the respective rear end portions. Has been.

  Here, as a method of mounting the ring-shaped electrode 140 to which the lead wire 130 is connected to the catheter tip 114, the lead wire 130 is passed through the side hole 120 formed in the tube wall of the catheter tip 114, and then The coating resin at the distal end portion is peeled to expose the metal core wire, and the metal core wire is welded to the inner peripheral surface of the ring-shaped electrode 138. Next, the ring-shaped electrode 138 is slid on the outer periphery of the catheter distal end portion 114. A method of sliding (sliding) along the axial direction of the catheter tip 114 to a position where it can be fitted and the opening of the side hole 120 can be closed, and is fixed using polyurethane adhesive or the like at that position. (See paragraph 0029 of Patent Document 1).

As an electrode catheter for measuring a potential at a site such as a pulmonary vein of the heart, an electrode catheter having a catheter tip portion formed in a loop shape is known.
Here, the present applicant can measure the potential in almost the entire region of the catheter tip, and has at least one lumen as an electrode catheter that does not damage the inner wall of the blood vessel by the tip of the catheter tip. A main body, a control handle connected to the proximal end side of the catheter main body, a lumen connected to the distal end side of the catheter main body and communicating with at least one lumen of the catheter main body, and formed in a circular loop shape A plurality of ring-shaped electrodes are attached to the outer periphery of the catheter tip, and a spherical tip electrode is attached to the tip of the catheter tip. An electrode catheter having a diameter larger than the outer diameter of the catheter tip has been proposed (see Patent Document 2).

  FIG. 10 is a cross-sectional view showing the catheter tip of the electrode catheter described in Patent Document 2, and FIG. 11 is a partially enlarged cross-sectional view (part F detail view) of FIG.

  10, 230 is a catheter tip, 231 is a ring electrode, 232 is a tip electrode, 234 is a side hole formed in the tube wall of the catheter tip 230, 61 and 62 are lead wires, and 271 is a shape memory characteristic. It is a core wire having. In addition, in FIG. 10, the catheter front-end | tip part 230 which is actually a loop shape is illustrated linearly.

In FIG. 11, 611 denotes a metal core wire constituting the lead wire 61, 612 denotes a coating resin constituting the lead wire 61, W denotes a welded portion, and 251, 252 and 236 each function as an adhesive or sealant. It is a cured resin (resin cured product).
Here, the diameter of the metal core wire 611 constituting the lead wire 61 is, for example, 0.1 mm, and the thickness of the coating resin 612 made of, for example, polyamideimide resin is, for example, 10 μm.

  The lead wire 61 is resistance-welded to the inner peripheral surface of the ring-shaped electrode 231 at the tip portion 61A (a part of the tip portion 61A is a welded portion W). For this welding, the coating resin 612 at the tip portion 61A of the lead wire 61 is peeled off, and the metal core wire 611 is exposed.

As shown in FIG. 10, separate lead wires 61 are connected to the ring-shaped electrodes 231, respectively.
The lead wires 61 connected to the ring-shaped electrode 231 are welded to the inner peripheral surface of the ring-shaped electrode 231 at the metal core wire 611 of each distal end portion 61A, and are formed on the tube wall of the catheter distal end portion 230. Enter the lumen from the side hole 234 and extend to the lumen of the catheter tip 230, the lumen of the catheter body, and the inner hole of the control handle, and at each rear end portion, a connector attached to the proximal side of the control handle It is connected.
Further, a lead wire 62 is connected to the tip electrode 232, and the lead wire 62 extends to the lumen of the catheter distal end portion 230, the lumen of the catheter main body, and the inner hole of the control handle. It is connected to the connector attached to the base end side.

  Here, as a method of attaching the ring-shaped electrode 231 to which the lead wire 61 is connected to the catheter tip portion 230, first, the coating resin 612 at the tip portion 61A of the lead wire 61 is peeled to expose the metal core wire 611, This metal core wire 611 is resistance-welded (spot welded) to the inner peripheral surface of the ring-shaped electrode 231.

Next, a catheter tip 230 having a plurality of side holes 234 corresponding to the position where the ring electrode 231 is fixed is prepared, and each of the ring electrodes 231 is formed on the outer peripheral surface of the catheter tip 230. For example, an adhesive made of a two-component curable epoxy resin is applied to the region to be fixed (the region including the opening of the side hole 234).
A part of this adhesive is spread on the outer peripheral surface of the catheter tip 230 to form an adhesive layer, and the remaining part of the adhesive is filled in the side holes 234 and functions as a sealant.

Next, the rear end of the lead wire 61 connected to the ring-shaped electrode 231 is inserted into the side hole 234 filled with an adhesive, and the lead wire 61 is inserted through the lumen of the catheter distal end portion 230 and the catheter distal end The ring-shaped electrode 231 is slidably fitted to the outer periphery of the portion 230, and the ring-shaped electrode 231 is slid (slided) along the axial direction of the catheter distal end portion 230 to a position where the opening of the side hole 234 can be blocked. The ring-shaped electrode 231 is bonded to the outer peripheral surface of the catheter distal end portion 230 at the position. Then, while the adhesive is not cured, the ring-shaped electrode 231 is caulked, and an ultraviolet curable polyurethane resin is applied to both ends of the ring-shaped electrode 231 and photocured to form a cured resin 236.
On the other hand, the lead wire 61 inserted through the lumen of the catheter distal end portion 230 is passed through the lumen of the catheter body and the inner hole of the control handle, and the rear end portion of the lead wire 61 is connected to the connector.

When using the electrode catheter described in Patent Document 2 manufactured through such a process, the potential data measured by the ring-shaped electrode 231 (outer peripheral surface) is transferred to an electrocardiograph connected to the connector via a cable. Sent.
JP 2006-255401 A (paragraph 0029) Japanese Patent No. 4027411 (Claim 1)

In the electrode catheters described in Patent Documents 1 and 2, in order to measure a sharp potential without noise at a site such as the pulmonary vein of the heart, it is preferable that the ring-shaped electrode is narrow.
However, if the width of the ring electrode is set to be narrow, the welded portion protrudes from the ring electrode when the electrode catheter is manufactured (step of welding the lead wire to the inner peripheral surface of the ring electrode). In addition, the ring-shaped electrode having a narrow width also has a problem in that it has poor contrast when the electrode catheter is used.
For this reason, the width of the ring-shaped electrode cannot be reduced, and a sharp potential cannot be measured with a conventional electrode catheter.

Further, in the electrode catheter described in Patent Document 1, there is a problem that the inner wall of the blood vessel or the heart is damaged by the end portion (edge) of the ring-shaped electrode 140.
In the electrode catheter described in Patent Document 2, although the end portion (edge) of the ring-shaped electrode 231 is covered with the cured resin 236, the coating film of the cured resin 236 cannot be formed thick. The sharp end portion (edge) of the electrode 231 cannot be reliably covered, and the problem of damaging the blood vessel and the inner wall of the heart has not been sufficiently solved.

The present invention has been made based on the above situation.
The first object of the present invention is to prevent a joint portion such as a welded portion from protruding from the metal ring constituting the electrode during manufacture, and to provide a contrast property of the electrode (visual confirmation based on an X-ray image or the like) during use. It is an object of the present invention to provide an electrode catheter that can measure a sharp electric potential with less noise with this electrode, while having excellent properties.
A second object of the present invention is to provide an electrode catheter that does not cause a risk of damaging a blood vessel or an inner wall of the heart by both ends of a metal ring constituting the electrode.

(1) An electrode catheter of the present invention includes a catheter body having at least one lumen;
A control handle connected to the proximal side of the catheter body;
A catheter distal end portion connected to the distal end side of the catheter body, having a double tube structure of an inner tube and an outer tube made of a resin material, and having a lumen communicating with at least one lumen of the catheter body;
A plurality of inner tubes and outer tubes that constitute the catheter distal end are arranged apart from each other in the axial direction, and the inner and outer surfaces of the inner tube and the outer tube are closely fixed to each other. With metal ring,
A plurality of lead wires connected to each of the plurality of metal rings,
In the tube wall of the inner tube constituting the catheter tip, a side hole extending from the outer peripheral surface of the inner tube to the inner peripheral surface is formed corresponding to the fixing position of the plurality of metal rings,
Each of the plurality of lead wires is connected to the metal ring by being joined to the inner peripheral surface of the metal ring at a tip portion thereof, and from the side hole formed in the tube wall of the inner tube, Entering the lumen of the catheter tip, extending to the lumen of the catheter tip, the lumen of the catheter body and the inner bore of the control handle;
In the tube wall of the outer tube constituting the catheter tip portion, in a region covering the outer peripheral surface other than both ends of the metal ring corresponding to the fixing positions of the plurality of metal rings, An opening window is formed over the entire circumference, and the electrode is constituted by a part of the outer peripheral surface of the metal ring exposed by the opening window.

  According to the electrode catheter having such a configuration, each of the plurality of metal rings is disposed between the inner tube and the outer tube, and is disposed on the tube wall of the outer tube corresponding to the fixed position of the plurality of metal rings. Since the opening window is formed, the potential can be measured by an electrode composed of a part of the outer peripheral surface of the metal ring exposed by the opening window. In addition, an opening window is formed in a region covering the outer peripheral surface other than both ends of the metal ring, and the outer peripheral surfaces of both ends of the metal ring are covered with a resin material constituting the outer tube (the metal ring Both ends are sandwiched between the inner and outer tubes and completely sealed).

  That is, the width of the electrode at the catheter tip (the length in the axial direction of the catheter tip) is determined by the width of the opening window (the length in the axial direction of the catheter tip), not the width of the metal ring, Even if the width of the metal ring is widened, by measuring the sharp potential with less noise that could not be achieved with conventional ring electrodes by setting the width of the aperture window sufficiently narrow and the width of the electrode narrow. Can do. In addition, since the entire metal ring including both ends covered with the resin material constituting the outer tube can be visually confirmed in an X-ray image or the like, the contrast of the electrode (visibility by X image or the like) is also excellent. It will be a thing. Furthermore, since the width of the metal ring can be increased, the joint portion such as a welded portion does not protrude from the metal ring in the step of joining the lead wire to the inner peripheral surface of the metal ring.

  In addition, since both end portions (edges) of the metal ring are covered with the resin material constituting the outer tube and the inner tube and are not exposed, the both ends of the metal ring do not damage the inner wall of the blood vessel or the heart.

(2) In the electrode catheter of the present invention, it is preferable that the distal end portion of the catheter is formed in a loop shape.
In a conventional electrode catheter in which a ring-shaped electrode is attached to the outer peripheral surface of the catheter tip portion formed in a loop shape, the outer peripheral surface of the catheter tip portion and the ring-shaped electrode are changed by bending during manufacture and shape change during use. As a result, partial separation occurs between the inner peripheral surface of the tube and a gap (liquid flow path) is easily formed, and blood easily flows into the lumen from the side hole formed at the distal end of the catheter. In such an electrode catheter having a catheter tip formed in a loop shape, the outer peripheral surface of both ends of the metal ring is covered with a resin material that constitutes the outer tube (both ends of the metal ring are covered by the inner tube and the outer tube). It is extremely effective to adopt the structure of sealing.

(3) In the electrode catheter of the above (2), it is preferable that the opening window is formed on a tube wall of the outer tube positioned outside a loop which is a shape of the distal end portion of the catheter.
According to the electrode catheter having such a configuration, the electrode can be present outside the loop. For example, the distal end of the loop-shaped catheter is positioned along the circumferential direction in a blood vessel such as a pulmonary vein. Sometimes, each electrode (exposed portion of the metal ring) attached to the catheter tip can be brought into contact with or close to the inner wall of the blood vessel, and the potential along the circumferential direction of the blood vessel can be reliably measured.

(4) The production method of the present invention is a method for producing the electrode catheter of (1) above,
Connecting each of the plurality of lead wires to each of the plurality of metal rings by resistance welding the lead wires to the inner peripheral surface of the metal ring;
The rear end of the lead wire connected to the metal ring is inserted into a side hole formed in the tube wall of the inner tube corresponding to the position where the metal ring is fixed, and the lead is inserted into the lumen of the inner tube. The metal ring is slid along the axial direction of the inner tube to a position where the metal ring can be slidably fitted to the outer periphery of the inner tube and the opening of the side hole can be blocked. Disposing each of the metal rings on the outer peripheral surface of the inner tube by moving,
The outer tube is fitted to the inner tube in which the metal ring is arranged, and the outer tube covers the outer peripheral surface of the inner tube and the outer peripheral surface of the metal ring, and heat-presses the inner tube to thereby form the inner tube. Forming a catheter tip by fusing a tube and the outer tube, and fixing the metal ring tightly to the inner tube and the outer tube;
By removing the resin covering the outer peripheral surface other than both ends of the metal ring over a part or the entire circumference in the circumferential direction of the outer tube, an opening window corresponding to the fixed position of the metal ring is removed. And forming an electrode by exposing a part of the outer peripheral surface of the metal ring through the opening window.

(5) In the production method of the present invention for producing the electrode catheter of (2) above,
Preferably, the method includes a step of inserting a core wire in which a loop shape is stored into a lumen of the catheter tip after forming an electrode by forming an opening window in the tube wall of the outer tube.

According to the electrode catheter of the present invention, it is possible to measure a sharp electric potential with less noise by this electrode while using the electrode catheter while being excellent in the contrast of the electrode (visibility by an X-ray image or the like). it can. In addition, the lead wire can be easily joined to the inner peripheral surface of the metal ring constituting the electrode at the time of manufacture, and the joint portion of the lead wire does not protrude from the metal ring.
According to the electrode catheter of the present invention, there is no possibility that the inner wall of the blood vessel or the heart is damaged by the end of the metal ring constituting the electrode.

1 is a perspective view of an electrode catheter according to an embodiment of the present invention. FIG. 2 is a perspective view (part A detail view) showing a catheter tip of the electrode catheter shown in FIG. 1. It is sectional drawing (longitudinal sectional view) which shows typically the internal structure of the electrode catheter shown in FIG. It is sectional drawing (partial expanded sectional view of FIG. 3) which shows the internal structure of the catheter front-end | tip part of the electrode catheter shown in FIG. (1) and (2) are partial enlarged cross-sectional views (part B detailed view and part C detailed view) of FIG. 4, and (3) is a DD cross-sectional view (transverse cross-sectional view) of FIG. . It is sectional drawing for demonstrating the range of the opening window formed in the outer tube | pipe of a catheter front-end | tip part, (1) is a longitudinal cross-sectional view, (2) is a cross-sectional view. It is a perspective view which shows the procedure which produces the catheter front-end | tip part of the electrode catheter shown in FIG. It is a perspective view which shows an example of the conventional electrode catheter. It is sectional drawing which shows the catheter front-end | tip part of the electrode catheter shown in FIG. It is sectional drawing which shows the catheter front-end | tip part in the other example of the conventional electrode catheter. It is a partial expanded sectional view (F section detail drawing) of FIG.

Hereinafter, an electrode catheter according to an embodiment of the present invention will be described.
The electrode catheter 1 shown in FIGS. 1 to 5 includes a catheter main body 10, a control handle 20 connected to the proximal end side of the catheter main body 10, and an inner tube made of a resin material connected to the distal end side of the catheter main body 10. 31 and an outer tube 32 having a double tube structure, and each of the catheter tip 30 formed in a loop shape and the inner tube 31 and the outer tube 32 constituting the catheter tip 30 are each in the tube axis direction. A plurality (9 pieces) of metal rings 41 which are arranged apart from each other and are closely fixed to the outer peripheral surface of the inner tube 31 and the inner peripheral surface of the outer tube 32, and the distal end of the catheter A spherical tip electrode 42 attached to the distal end of the connector 30, a connector 18 attached to the proximal end of the control handle 20, and a plurality of (9) leads for electrically connecting each of the metal ring 41 and the connector 18. line 1 and a lead wire 62 that electrically connects the tip electrode 42 and the connector 18; the tube wall of the inner tube 31 constituting the catheter tip 30 corresponds to the fixing position of the metal ring 41. A plurality (nine) of side holes 34 extending from the outer peripheral surface to the inner peripheral surface of the inner tube 31 are formed, and each of the plurality (nine) of lead wires 61 peels the coating resin 612 at the tip portion 61A. The exposed metal core wire 611 is resistance-welded to the inner peripheral surface of the metal ring 41 so as to be connected to the metal ring 41 and from the side hole 34 formed in the tube wall of the inner tube 31 to the catheter tip 30. , Extends into the lumen of the catheter tip 30, the lumen of the catheter body 10 and the inner bore of the control handle 20, and is connected to the connector 18 at the rear end portion 61B; On the tube wall of the outer tube 32 constituting the distal end portion 30, in the region covering the outer peripheral surface other than both ends of the metal ring 41 corresponding to the fixing position of the metal ring 41, a part of the circumferential direction (catheter A plurality (nine) of opening windows 321 are formed on the outer periphery of the loop that is the shape of the tip 30, and a part of the outer peripheral surface of the metal ring 41 exposed by the opening window 321 (on the outside of the loop). The electrode 41 </ b> A is constituted by a half-circular portion that is positioned.

  The electrode catheter 1 of this embodiment includes a catheter body 10, a control handle 20, a catheter tip 30, a nine metal rings 41 constituting an electrode 41A, a spherical tip electrode 42, a connector 18, and 9 One lead wire 61 and one lead wire 62 are provided. 3 and 4 showing the electrode catheter 1 of the present embodiment, the catheter tip 30 that is actually a loop shape is shown linearly, and in the same figure, the lower side (opening window 321 is formed). Is located outside the loop when the loop shape is formed.

  The catheter body 10 is an elongated tubular structure having one lumen, and includes a first tube 11 and a second tube 12.

  The first tube 11 is required to have certain flexibility (flexibility), incompressibility in the tube axis direction, and torsional rigidity. The rotational torque from the control handle 20 can be transmitted to the catheter tip 30 by the torsional rigidity of the first tube 11.

The first tube 11 is not particularly limited, but a tube made of a resin such as polyurethane, nylon, or polyether block amide “PEBAX (registered trademark)” is braided with a stainless steel wire (blade tube). Can be mentioned.
The length of the first tube 11 is, for example, 50 to 200 cm.

The second tube 12 is a tube that constitutes the distal end portion of the catheter body 10 and has a lumen that communicates with the lumen of the first tube 11, and is provided by a deflection mechanism (a leaf spring disposed in the lumen), which will be described later. Bend.
A non-toxic resin can be used as a constituent material of the second tube 12. The second tube 12 is more flexible than the first tube 11 because it is not braided.
The length of the second tube 12 is, for example, 3 to 10 cm, and more preferably 4 to 7 cm.

  The outer diameter of the catheter body 10 (the first tube 11 and the second tube 12) is preferably 2.6 mm or less, more preferably 2.4 mm or less, and particularly preferably 2.0 to 2.4 mm. Is done.

  The inner diameter of the catheter body 10 is 1 when the outer diameter is 2.3 to 2.4 mm, for example, from the viewpoint of securing the accommodation space such as a wire and a lead wire and ensuring torsional rigidity (thickness). It is preferably about 5 to 1.7 mm.

The control handle 20 is connected to the proximal end side of the catheter body 10 (first tube 11). In FIG. 1, 21 is a grip and 22 is a knob.
By rotating the control handle 20, the rotational torque is transmitted to the catheter tip 30 via the catheter body 10.

  Further, by sliding the knob 22, the second tube 12 is bent by a later-described deflection mechanism, and the catheter tip 30 is deflected accordingly.

  Therefore, by operating the control handle 20 to rotate and further deflect the catheter tip 30, the catheter tip 30 can be guided to the target site.

  As shown in FIGS. 4 and 5, the catheter distal end portion 30 is composed of a tube (double tube) composed of an inner tube 31 and an outer tube 32 and is connected to the distal end side of the catheter body 10 (second tube 12). And has a lumen communicating with the lumen of the catheter body 10.

The inner tube 31 constituting the catheter tip 30 is made of a bio-acceptable resin material (thermoplastic resin) such as polyurethane or PEBAX (registered trademark). The inner tube 31 may have a multilayer structure made of different resin materials.
The thickness of the inner tube 31 (the thickness of the tube wall) is, for example, 50 to 250 μm, and is 100 μm if a suitable example is shown.

The outer tube 32 constituting the catheter tip 30 is made of the same or different resin material as the inner tube 31.
The thickness of the outer tube 32 (thickness of the tube wall) is thinner than the thickness of the inner tube 31, for example, 10 to 200 μm, and is 20 μm if a suitable example is shown.

  The catheter tip 30 is a tube having a double tube structure in which an inner tube 31 and an outer tube 32 are heat-sealed. The tube constituting the catheter tip 30 is formed in a substantially circular loop shape. Thereby, the inner peripheral part of the blood vessel can be simultaneously measured in the radial direction. The catheter tip 30 is not a flat circular closed loop, but a spiral loop with the tip electrode 42 as the leading edge (in the present invention, “circular” and “elliptical” Includes those that are helical). Therefore, the inside of the blood vessel can be easily advanced toward the target site.

  Nine metal rings 41 are arranged between the inner tube 31 and the outer tube 32 constituting the catheter distal end portion 30 so as to be separated from each other in the tube axis direction. Nine electrodes 41 </ b> A are formed on the outer peripheral surface of the catheter distal end portion 30 by a part (a half-circular portion located outside the loop).

Each of the nine metal rings 41 has an inner peripheral surface and an outer peripheral surface that are closely fixed to the outer peripheral surface of the inner tube 31 and the inner peripheral surface of the outer tube 32, respectively. Corresponding to the fixing position of the metal ring 41, a side hole 34 extending from the outer peripheral surface to the inner peripheral surface is formed in the tube wall of the inner tube 31.
The metal ring 41 is made of a conductive material such as platinum, gold, iridium, or an alloy thereof, and is preferably made of platinum or a platinum alloy.

  Of course, the number of metal rings 41 (the number of side holes) is not limited to nine. The number of metal rings 41 is preferably 6-20.

  In the electrode catheter 1 of the present embodiment, a spherical tip electrode 42 is attached to the tip of a catheter tip 30 formed in a circular loop shape, whereby almost the entire region of the catheter tip 30, that is, the most A region from the electrode 41A on the base end side (electrode by the metal ring 41) to the tip end on which the tip electrode 42 is attached can be set as a potential measurement region.

As shown in FIG. 3, the electrode catheter 1 of the present embodiment includes a deflection mechanism for deflecting the catheter tip 30.
This deflection mechanism has a pull wire 71 and a leaf spring 72.
The pull wire 71 constituting the deflection mechanism extends to the lumen of the catheter body 10. A proximal end portion 71 </ b> B of the pull wire 71 is fixed inside the control handle 20. The control handle 20 has a piston mechanism (not shown) that moves the proximal end of the catheter body 10 to the distal side relative to the pulling wire 71 by sliding the knob 22 from the state shown in FIG. ) Is provided. On the other hand, the distal end portion 71 </ b> A of the pull wire 71 is fixed to the distal end portion of the leaf spring 72.

  Examples of the constituent material of the pull wire 71 include stainless steel and Ni—Ti alloy. The surface of the pull wire 71 is preferably covered with PTFE “Teflon (registered trademark)” or the like. The diameter of the pull wire 71 is, for example, 0.1 to 0.5 mm.

The base end of the plate spring 72 constituting the deflection mechanism is fixed to the tip of the first coil tube 73.
The first coil tube 73 is configured by winding a wire having a flat or circular cross section into a coil shape, extends to the lumen of the first tube 11, and prevents the first tube 11 from being crushed. Is functioning as

A part of the pulling wire 71 (a range from the tip of the first coil tube 73 to the tip of the leaf spring 72) is surrounded by the second coil tube 74.
The base end of the second coil tube 74 is fixed to the tip of the first coil tube 73, and the tip thereof is slightly based on the tip of the leaf spring 72 (fixed position of the tip 71A of the pull wire 71). It is fixed to the end side.

The inner diameter of the second coil tube 74 is slightly larger than the diameter of the pull wire 71, and the pull wire 71 can move (slide) in the second coil tube 74.
The second coil tube 74 is preferably made of a metal material such as stainless steel, and its outer peripheral surface is preferably covered with a non-conductive member.

The distal end portion 71A of the pull wire 71 is fixed to the distal end portion of the leaf spring 72, and the proximal end portion of the core wire 76 having shape memory characteristics is further fixed to the distal end side thereof. The core wire 76 extends along the lumen of the catheter distal end 30, and the distal end is fixed to the tip electrode 42 as shown in FIG. 3.
The core wire 76 stores the loop shape of the catheter tip 30 and is easily deformed (for example, linearly deformed) by applying force, but returns to the loop shape when the force is removed.
An example of the constituent material of the core wire 76 is a Ni-Ti alloy. The ratio of Ni and Ti in the Ni—Ti alloy is preferably 54:46 to 57:43. Nitinol can be mentioned as a preferred Ni-Ti alloy.

  The deflection mechanism of the catheter tip 30 operates, for example, as follows. That is, when the operator slides the knob 22 of the control handle 20 to the distal end side, the pulling wire 71 and the catheter body 10 are moved relative to each other by a piston mechanism (not shown) in the control handle 20. The leaf spring 72 to which the distal end portion 71A is fixed is bent, and the distal end portion (second tube 12) of the catheter body 10 including the leaf spring 72 is bent. As a result, the catheter distal end portion 30 is deflected. . When the knob 22 is slid toward the proximal end and returned to the original position, the leaf spring 72 becomes linear, and the catheter distal end 30 returns to the original direction. Of course, the deflection mechanism in the electrode catheter of the present invention is not limited to this.

  As shown in FIGS. 3 and 4, the electrode catheter 1 of the present embodiment is attached to each of a plurality (9) of metal rings 41 attached to the catheter distal end portion 30 and the proximal end side of the control handle 20. A plurality of (9) lead wires 61 for electrically connecting the connector 18 are provided. The electrode catheter 1 includes a lead wire 62 that electrically connects the tip electrode 42 and the connector 18.

As shown in FIG. 5, the lead wire 61 for connecting the metal ring 41 and the connector (18) is formed by covering a metal core wire 611 with a resin 612. An example of the coating resin 612 is a polyamideimide resin.
At the tip portion 61A of the lead wire 61, the metal core wire 611 which is exposed by peeling the coating resin 612 is resistance welded (spot welded) to the inner peripheral surface of the metal ring 41.

  As shown in FIGS. 3 and 4, the lead wire 61 connected to each of the metal rings 41 enters the lumen of the catheter tip 30 from the side hole 34 formed in the tube wall of the inner tube 31, and the catheter tip The lumen of the portion 30, the lumen of the catheter body 10 (second tube 12 and first tube 11) and the inner hole of the control handle 20 are attached to the proximal end side of the control handle 20 at the rear end portion 61B. Connected to the connector 18.

  The lead wire 61 is disposed so as to be somewhat movable in the lumen of the catheter body 10 (the second tube 12 and the first tube 11), so that even if the catheter tip 30 is deflected, the lead wire 61 is broken. There is no.

  As shown in FIGS. 4 and 5, the outer wall 32 of the outer tube 32 constituting the catheter tip 30 has a portion in the circumferential direction in the region covering the outer peripheral surface of each metal ring 41 other than both ends (catheter). An opening window 321 (a through-hole extending from the outer peripheral surface of the outer tube 32 to the inner peripheral surface) is formed in a half-circumferential portion located outside the loop, which is the shape of the tip portion 30, and the metal ring exposed by these opening windows 321 An electrode 41 </ b> A is configured by a part of the outer peripheral surface of 41.

According to the electrode catheter 1 having such a configuration, the potential can be measured by the electrode 41 </ b> A configured from a part of the outer peripheral surface of the metal ring 41 exposed by the opening window 321.
In particular, since the electrode 41A is located on the outer periphery of the loop (the lower side in FIGS. 4 and 5), for example, the looped catheter tip 30 is placed in a blood vessel such as a pulmonary vein. When positioned along the direction, each of the electrodes 41A at the catheter tip 30 can be brought into contact with or close to the inner wall of the blood vessel, and the potential along the circumferential direction of the blood vessel can be reliably measured.

  Moreover, the outer peripheral surface of the both ends of the metal ring 41 is covered with a resin constituting the outer tube 32 (both ends of the metal ring 41 are sandwiched and sealed between the inner tube 31 and the outer tube 32). Therefore, blood can be reliably prevented from flowing into the lumen from the side hole 34 formed in the inner pipe 31, and the welded portion W between the inner peripheral surface of the metal ring 41 and the lead wire 61 or the tip of the lead wire 61. Blood does not contact the metal core wire 611 exposed at the portion 61A. That is, by sandwiching both ends of the metal ring 41 with a sheet-like resin material (inner tube and outer tube), excellent sealing properties are obtained, and this sealing property repeatedly deforms the catheter tip 30. It will not be damaged.

  The width of the electrode 41A (the length of the catheter tip 30 in the axial direction) is determined not by the width of the metal ring 41 but by the width of the opening window 321 (the length of the catheter tip 30 in the axial direction). Even when the width of the metal ring 41 is set wide, the width of the electrode 41A can be narrowed by sufficiently narrowing the width of the opening window 321, and a sharp potential with less noise can be measured by this electrode 41A. Can do. In addition, since the entire metal ring 41 including both ends covered with the resin material constituting the outer tube 32 can be visually recognized by an X-ray image or the like, the electrode contrast is excellent (visibility by an X image or the like). It will be. Furthermore, since the width of the metal ring 41 can be increased, the welded portion does not protrude from the metal ring 41 in the process of welding the lead wire 61 to the inner peripheral surface of the metal ring 41.

  Furthermore, since the edges at both ends of the metal ring 41 are covered with the resin material constituting the inner tube 31 and the outer tube 32 and are not exposed, the both ends of the metal ring 41 do not damage the inner wall of the blood vessel or the heart. .

In the electrode catheter 1 of the present embodiment, the width of the metal ring 41 (the axial length indicated by W ₀ in FIG. 6 (1)) is preferably 0.3 to 4 mm, more preferably 0.5. If it shows -1.5mm and a suitable example, it will be 1mm.
When the width (W ₀ ) of the metal ring 41 is too narrow, it is not possible to ensure sufficient contrast of the electrodes (visibility by X image or the like). On the other hand, if the width (W ₀ ) of the metal ring 41 is too wide, the flexibility of the catheter tip 30 may be impaired.

It is preferable that the width of the opening window 321 to determine the width of the electrode 41A (the length in the axial direction indicated by W ₁ in FIG. 6 (1)) is 0.2 to 2 mm, more preferably 0.3 If it shows -1.0mm and a suitable example, it will be 0.5mm.
By setting the width (W ₁ ) of the aperture window 321 to be narrow, an electrode 41A having a narrow width that cannot be realized with a conventional ring electrode while ensuring good contrast (visibility by an X image or the like). The electrode 41A can measure a sharp potential.

The width of both end portions of the (W ₀ -W ₁₎ / 2 the metal ring 41 is determined by is preferably from 0.1 to 1 mm, more preferably Shimese 0.1 to 0.5 mm, a preferable example 0.25 mm.

The ratio of the width of the opening window 321 to the width of the metal ring 41 (W ₁ / W ₀ ) is 0.1 to 0.9, preferably 0.3 to 0.7. .5.
When this ratio (W ₁ / W ₀ ) is less than 0.1, the width of the electrode 41A is too small, making it difficult to measure the potential. On the other hand, when the ratio (W ₁ / W ₀ ) exceeds 0.9, both ends of the metal ring 41 may not be sufficiently sealed with the resin material (the inner tube 31 and the outer tube 32).

As shown in FIGS. 4 and 5, in the electrode catheter 1 of the present embodiment, the opening window 321 that partitions the electrode 41 </ b> A is a part of the circumferential direction in the region covering the outer peripheral surface other than both ends of the metal ring 41 ( Half-circumferential part located outside the loop, formed at an angle θ = 180 ° in FIG. 6 (2), but the formation range of the opening window 321 in the circumferential direction (angle θ in FIG. 6 (2)) is appropriately selected An opening window may be formed on the entire periphery (angle θ = 360 ° in FIG. 6B) in the region covering the outer peripheral surface other than both ends of the metal ring (the region to be covered). .
Moreover, the shape of the opening window 321 is not limited to a rectangle, and various shapes (circular, elliptical, etc.) can be selected.

The electrode catheter 1 according to this embodiment is inserted into a main artery or vein such as a femoral artery, and then advances in a blood vessel toward a target site (for example, a pulmonary vein of the heart).
In the electrode catheter 1, the potential (data) measured by the electrode 41A is sent to an electrocardiograph connected to the connector 18 via a cable.

The electrode catheter 1 of this embodiment can be manufactured as follows.
(1) First, the coating resin 612 at the tip portion 61A (for example, about 0.25 mm from the tip) of the lead wire 61 is peeled to expose the metal core wire 611, and the metal core wire 611 is exposed to the inner peripheral surface of the metal ring 41. Resistance welding (spot welding). In this way, the lead wire 61 is connected to each of the nine metal rings 41.

  (2) On the other hand, a tubular structure (inner tube 31) having nine side holes 34 formed in the tube wall corresponding to the fixing position of the metal ring 41 is prepared, and the metal ring 41 (outer peripheral surface and inner periphery) is prepared. The rear end of the lead wire 61 connected to the metal ring having an adhesive layer formed on the surface is inserted into the side hole 34, the lead wire 61 is inserted through the lumen of the inner tube 31, and the lead wire 61 is connected. The metal ring 41 is slidably fitted to the outer periphery of the inner tube 31, and the metal ring 41 is slid (slid) to a position where the opening of the side hole 34 can be closed. By performing this for nine metal rings 41 (lead wires 61), nine metal rings 41 are arranged on the outer peripheral surface of the inner tube 31, as shown in FIG.

(3) Next, the tubular structure (outer tube 32) is fitted to the inner tube 31 on which the metal ring 41 is disposed, and the outer tube 32 covers the outer circumferential surface of the inner tube 31 and the outer circumferential surface of the metal ring 41. Then, this is heated and pressurized. As a result, the inner tube 31 and the outer tube 32 are fused, and the inner peripheral surface of the metal ring 41 and the outer peripheral surface of the inner tube 31 are in close contact with each other via the adhesive layer. The inner peripheral surface of the tube 31 is in close contact with the adhesive layer. Here, the heating temperature is equal to or higher than the melting point of the resin material constituting the inner tube 31 and the outer tube 32. Further, the pressurizing method is not particularly limited, but a method using a shrinkable tube or the like can be exemplified.
As a result, as shown in FIG. 7B, the nine metal rings 41 are disposed between the inner tube 31 (outer peripheral surface) and the outer tube 32 (inner peripheral surface). A heavy tube (catheter tip 30) is obtained.

(4) Next, the resin (the constituent resin of the outer tube 32) covering the outer peripheral surface excluding both ends of the metal ring 41 is removed over a part of the outer tube 32 in the circumferential direction (half-circumferential portion). Thus, the opening window 321 is formed.
Examples of the method for forming the opening window 321 include a laser cutting (drilling) machining method and a mechanical cutting (drilling) machining method. Of these, a cutting method using a laser is preferable.
As a result, as shown in FIGS. 7C and 7D, a part of the outer peripheral surface of the metal ring 41 (a half peripheral portion of the outer peripheral surface excluding both ends) is exposed by the opening window 321, and this is exposed to the electrode 41A. It can be.

(5) Next, a core wire (not shown) in which the loop shape is stored is inserted into the lumen of the catheter distal end portion 30 including the inner tube 31 and the outer tube 32. At this time, adjustment is made so that the opening window 321 is positioned outside the loop.
Next, the lead wire connected to the tip electrode 42 is inserted into the lumen from the distal end opening of the catheter tip portion 30, and the tip electrode 42 is attached to the catheter tip portion 30.

(6) Next, each of the lead wire 61 and the lead wire 62 inserted through the lumen of the catheter distal end portion 30 (inner tube 31) is passed through the lumen of the catheter body and the inner hole of the control handle. The end portion is connected to the connector 18.
Thereby, as shown in FIG.7 (e), the catheter front-end | tip part 30 which is formed in a loop shape and the electrode 41A is arrange | positioned on the outer side (half circumference part) of the said loop can be comprised.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to these, A various change is possible.
For example, the catheter tip portion does not need to be formed in a loop shape, and may be a straight shape or a gently curved shape (for example, a shape as shown in FIG. 8).

DESCRIPTION OF SYMBOLS 1 Electrode catheter 10 Catheter main body 11 1st tube 12 2nd tube 18 Connector 20 Control handle 21 Grip 22 Knob 30 Catheter tip 31 Inner tube 32 Outer tube 321 Opening window 34 Side hole 41 Metal ring 41A Electrode 42 Tip electrode 61 Lead wire 611 Metal core wire 612 Coating resin 61A Lead wire tip 61B Lead wire trailing edge 62 Lead wire 71 Pull wire 72 Leaf spring 73 First coil tube 74 Second coil tube 76 Core wire W Spot weld

Claims (5)

A catheter body having at least one lumen;
A control handle connected to the proximal side of the catheter body;
A catheter distal end portion connected to the distal end side of the catheter body, having a double tube structure of an inner tube and an outer tube made of a resin material, and having a lumen communicating with at least one lumen of the catheter body;
A plurality of inner tubes and outer tubes that constitute the catheter distal end are arranged apart from each other in the axial direction, and the inner and outer surfaces of the inner tube and the outer tube are closely fixed to each other. With metal ring,
A plurality of lead wires connected to each of the plurality of metal rings,
In the tube wall of the inner tube constituting the catheter tip, a side hole extending from the outer peripheral surface of the inner tube to the inner peripheral surface is formed corresponding to the fixing position of the plurality of metal rings,
Each of the plurality of lead wires is connected to the metal ring by being joined to the inner peripheral surface of the metal ring at a tip portion thereof, and from the side hole formed in the tube wall of the inner tube, Entering the lumen of the catheter tip, extending to the lumen of the catheter tip, the lumen of the catheter body and the inner bore of the control handle;
In the tube wall of the outer tube constituting the catheter tip portion, in a region covering the outer peripheral surface other than both ends of the metal ring corresponding to the fixing positions of the plurality of metal rings, An electrode catheter characterized in that an open window is formed over the entire circumference, and an electrode is constituted by a part of the outer peripheral surface of the metal ring exposed by the open window.   The electrode catheter according to claim 1, wherein the distal end portion of the catheter is formed in a loop shape.   The electrode catheter according to claim 2, wherein the opening window is formed in a tube wall of the outer tube located outside a loop having a shape of the catheter tip. A method for manufacturing the electrode catheter according to claim 1, comprising:
Connecting each of the plurality of lead wires to each of the plurality of metal rings by resistance welding the lead wires to the inner peripheral surface of the metal ring;
The rear end of the lead wire connected to the metal ring is inserted into a side hole formed in the tube wall of the inner tube corresponding to the position where the metal ring is fixed, and the lead is inserted into the lumen of the inner tube. The metal ring is slid along the axial direction of the inner tube to a position where the metal ring can be slidably fitted to the outer periphery of the inner tube and the opening of the side hole can be blocked. Disposing each of the metal rings on the outer peripheral surface of the inner tube by moving,
The outer tube is fitted to the inner tube in which the metal ring is arranged, and the outer tube covers the outer peripheral surface of the inner tube and the outer peripheral surface of the metal ring, and heat-presses the inner tube to thereby form the inner tube. Forming a catheter tip by fusing a tube and the outer tube, and fixing the metal ring tightly to the inner tube and the outer tube;
By removing the resin covering the outer peripheral surface other than both ends of the metal ring over a part or the entire circumference in the circumferential direction of the outer tube, an opening window corresponding to the fixed position of the metal ring is removed. And forming an electrode by exposing a part of the outer peripheral surface of the metal ring through the opening window and forming an electrode. A method for producing the electrode catheter according to claim 2, comprising:
5. The method according to claim 4, further comprising inserting a core wire in which a loop shape is stored into a lumen of the catheter tip after forming an electrode by forming an opening window in a tube wall of the outer tube. Manufacturing method of electrode catheter.

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