JP7568257B2 - Catheter for measuring cardiac potential - Google Patents

Description

The present invention relates to a catheter for measuring cardiac potentials.

Atrial fibrillation is particularly observed in elderly patients, in which electricity travels throughout the atria, causing them to become excited at a rate of 400 to 800 beats per minute. Chronic atrial fibrillation can lead to serious medical conditions, including stroke, heart failure, cardiac fatigue, palpitations, palpitations, and chest discomfort. In addition, atrial fibrillation can cause blood flow within the atria to stagnate, forming clots, which can then flow throughout the body and cause embolism, such as cerebral infarction. To treat atrial fibrillation, ablation therapy is used, in which electrical connection sites such as the pulmonary vein orifice, which is the junction between the pulmonary vein and the left atrium, are cauterized to electrically block abnormal excitation from the pulmonary vein from reaching the left atrium.

To diagnose atrial fibrillation, cardiac potential measuring catheters (cardiac catheter-type electrodes) are used, which can electrically stimulate the heart and measure slight changes in the electrical flow (electric potential) of the heart.

Specifically, for example, a multi-electrode ring catheter with a ring part with an electrode at the tip is commercially available (Lasso Catheter manufactured by Biosense Webster). This ring catheter is expensive, costing more than 160,000 yen each, and is disposable.

However, the ring catheters mentioned above have a fixed size of the annular part at the tip. However, the size of the pulmonary veins varies from patient to patient, and the size of each pulmonary vein in the heart also varies. Therefore, it is necessary to use several types of ring catheters with annular parts of different sizes according to the patient or each pulmonary vein during treatment, which results in a problem of high material costs (insurance point burden) for treatment.

The present invention was made in consideration of the above circumstances, and aims to provide a catheter for measuring cardiac potentials that can be used by adjusting the diameter of the annular tip to a size appropriate for the patient and each pulmonary vein.

In order to solve the above problems, the catheter for measuring cardiac potential of the present invention comprises:
Long shaft,
a handle attached to the proximal end of the shaft; and an annular portion having a plurality of ring-shaped electrodes and exposed to the outside from the distal end of the shaft.
Equipped with
By operating the handle, the diameter of the annular portion can be freely enlarged or reduced.

The cardiac potential measuring catheter of the present invention can be used by adjusting the diameter of the annular tip to a size appropriate for the patient and each pulmonary vein, eliminating the need to prepare several different sizes of cardiac potential measuring catheters, thereby reducing the cost of treatment.

1A and 1B are schematic diagrams illustrating an embodiment of the cardiac potential measuring catheter of the present invention. 2A and 2B are enlarged views illustrating deformations of the annular portion of the cardiac potential measuring catheter shown in FIG. 1 . 5A and 5B are enlarged views illustrating another embodiment of the annular portion of the catheter for measuring cardiac potential of the present invention. 5A and 5B are enlarged views illustrating another embodiment of the annular portion of the catheter for measuring cardiac potential of the present invention. 5A and 5B are enlarged views illustrating another embodiment of the annular portion of the catheter for measuring cardiac potential of the present invention. 5A and 5B are enlarged views illustrating another embodiment of the annular portion of the catheter for measuring cardiac potential of the present invention. 5A and 5B are enlarged views illustrating another embodiment of the annular portion of the catheter for measuring cardiac potential of the present invention.

One embodiment of the cardiac potential measuring catheter of the present invention will be described with reference to the drawings. Fig. 1(A) is a schematic diagram illustrating one embodiment of the cardiac potential measuring catheter of the present invention. Fig. 1(B) is an enlarged view showing the state in which the annular portion at the tip of the cardiac potential measuring catheter shown in (A) has been extended. Fig. 2 is an enlarged view illustrating a deformation of the annular portion at the tip of the cardiac potential measuring catheter shown in Fig. 1.

The cardiac potential measuring catheter 1 is an electrode catheter that is inserted into the patient's body (into the cardiac cavity) through a blood vessel and is used for testing and treating atrial fibrillation.

This cardiac potential measuring catheter 1 has a shaft 2 as the catheter body and a handle 3 attached to the base end of the shaft 2.

The shaft 2 is a long, flexible, and insulating tubular member with a hollow structure. The shaft 2 has a so-called multi-lumen structure in which multiple lumens (pores, through-holes) are formed inside and extend along the longitudinal direction. Various thin wires (such as conducting wires and operating wires) are inserted into each lumen while being electrically insulated from one another. The outer diameter of the shaft 2 can be, for example, in the range of about 1.2 mm to 3.3 mm.

In addition, one or more operating wires (not shown) are inserted inside the shaft 2, and the ends of the operating wires are fixed to the tip side of the shaft 2. The operating wires can be slid back and forth by operating the handle 3. Each operating wire can be used for deflection operations at the tip portion (tip flexible portion 21) of the shaft 2. There are no particular limitations on the material of the operating wires, but examples include superelastic metal materials such as SUS (stainless steel) and Nitinol (nickel titanium).

Although not shown, the shaft 2 may have, for example, an outer portion (shell portion), a wire, an inner portion (core portion), and a resin layer.

The outer part is a tube-shaped member located at the outermost circumference of the shaft 2. This outer part can be made of, for example, a high-hardness nylon elastomer. The nylon elastomer that makes up this outer part can have, for example, different hardness along the longitudinal direction. This allows the shaft 2 to be designed so that its hardness increases stepwise from its tip side to its base end side.

The wires are arranged between the layers of the outer and inner parts to form a braided braid. This braided braid is formed, for example, in a portion of the shaft 2 along the longitudinal direction. Such wires can be made of, for example, stainless steel.

The inner part is a core member located on the inner periphery of the outer part and the wire. This inner part can be made of the same material as the outer part, or, for example, a low-hardness nylon elastomer.

The resin layer is a layer that divides the lumen, and can be made of the same material as the outer part, or, for example, a fluororesin. Examples of this fluororesin include highly insulating materials such as perfluoroalkylvinylether copolymer (PFA) and polytetrafluoroethylene (PTFE).

The handle 3 is attached to the base end of the shaft 2 and has a handle body 31 and a knob 32.

The handle body 31 is the part that the operator holds when using the cardiac potential measuring catheter 1. Inside this handle body 31, the various thin wires (such as conductors and operating wires) mentioned above extend from the inside of the shaft 2 while being electrically insulated from each other.

The knob 32 is a member for performing an operation to deflect the vicinity of the tip of the shaft 2. Specifically, by pushing the knob 32 toward the tip, the operation wire inside the shaft 2 is pulled toward the base end, making it possible to deflect the vicinity of the tip of the shaft 2 (deflection movement operation).

The cardiac potential measuring catheter 1 of the present invention can be used by connecting it to a power supply device (not shown). The power supply device can supply power to the electrodes (tip electrode 6a, ring electrode 6b) of the cardiac potential measuring catheter 1 via conductors.

The cardiac potential measuring catheter 1 of the present invention has a ring portion 5 at the tip side of the catheter.

At the base end, the two tubes 4 cross each other and extend in a direction substantially perpendicular to the extension direction to form a loop. The annular portion 5 opens in a direction opposite to the longitudinal direction of the shaft 2.

The annular portion 5 is made of a flexible tubular structure having a lumen that communicates with one or more lumens in the shaft 2. The annular portion 5 can be made of a biocompatible resin material, as with the shaft 2. The outer diameter of the annular portion 5 is about 1.0 to 2.0 mm, and the loop diameter R is about 2.5 to 30.0 mm.

This annular portion 5 is provided with one tip electrode 6a at the very end and multiple ring-shaped electrodes 6b.

Specifically, multiple ring-shaped electrodes 6b are arranged at predetermined intervals along the longitudinal direction of the shaft 2 from the tip side to the base end side of the shaft 2. Each of the ring-shaped electrodes 6b is fixedly arranged on the outer circumferential surface of the shaft 2. Note that multiple ring-shaped electrodes 6b can be provided on the shaft 2 as well as on the annular portion 5.

The tip electrode 6a and the ring electrode 6b are each electrically connected to the handle 3 via multiple conductors (lead wires) inserted into the lumen of the shaft 2.

The tip electrode 6a and ring electrode 6b can be made of metal materials with good electrical conductivity, such as aluminum (Al), copper (Cu), stainless steel (SUS), gold (Au), platinum (Pt), or various resin materials, but are preferably made of platinum or its alloys.

A core wire (not shown) having shape memory properties is inserted into the annular portion 5. The core wire remembers the shape of the looped portion (loop shape). A core wire having such shape memory properties is easily deformed (for example, deformed into a straight line) when an external force is applied, but returns to its original shape (loop shape) when the force is removed. Therefore, when this cardiac potential measuring catheter 1 is inserted into the body, the annular portion 5 at the tip can be stretched to pass through a guiding sheath (not shown) that has been inserted previously. After being inserted to a predetermined position in the body, it can return to the shape of the annular portion 5 illustrated in Figures 1 and 2 by coming out from the tip of the guiding sheath (not shown).

A retraction wire (not shown) is also inserted into the annular portion 5. The retraction wire passes through the annular portion 5 and the shaft 2 and is connected to the handle 3.

The distal end of the shaft 2 of the cardiac potential measuring catheter 1 is inserted into the patient's body through a blood vessel, for example, to diagnose atrial fibrillation. At this time, the shape of the shaft 2 near the distal end region inserted into the patient's body deflects in response to the operation of the handle 3 by the operator of the cardiac potential measuring catheter 1.

The cardiac potential measuring catheter 1 is designed to have an adjustable diameter of the annular portion 5. Specifically, as shown in Figs. 2(A) and 2(B), for example, the handle 3 can be operated to retract one of the retraction wires into the shaft 2, thereby expanding the diameter of the annular portion 5. On the other hand, the diameter of the annular portion 5 is designed to be reduced by feeding the tube 4 out of the shaft 2 via the retraction wire. Therefore, during treatment, the annular portion 5 can be adjusted to a size appropriate for the patient or each pulmonary vein, and there is no need to prepare several types of cardiac potential measuring catheters, which reduces the cost of treatment.

Figures 3 (A) and (B) are enlarged views illustrating another embodiment of the annular portion of the cardiac potential measuring catheter of the present invention. Explanations of parts common to the embodiment described using Figures 1 and 2 will be omitted.

As shown in Figures 3(A) and (B), in this embodiment of the cardiac potential measuring catheter 1, the annular portion 5 is provided with a protrusion 51 that protrudes in a direction parallel to the longitudinal direction of the shaft 2. Specifically, the protrusion is provided at a position opposite the intersection of the two tubes 4. The annular portion 5 is provided with the protrusion 5a, improving the operability of advancing and retracting within the guiding sheath (not shown).

In this embodiment of the cardiac potential measuring catheter 1, the handle 3 can be operated to pull the tube 4 of the annular portion 5 into the shaft 2 via the pull-in wire, thereby expanding the diameter of the annular portion 5 (Fig. 3(A)). On the other hand, the diameter of the annular portion 5 can be reduced by pushing the tube 4 out from the shaft 2 (Fig. 3(B)). Therefore, during treatment, the size of the annular portion 5 can be adjusted to suit the patient or each pulmonary vein, and there is no need to prepare several types of cardiac potential measuring catheters 1, reducing the cost of treatment.

Figures 4 (A) and (B) are enlarged views illustrating another embodiment of the annular portion of the cardiac potential measuring catheter of the present invention. Explanations of parts common to the embodiment described using Figures 1 and 2 will be omitted.

As shown in Figures 4(A) and (B), in this embodiment of the cardiac potential measuring catheter 1, a branch portion 7 is provided at the tip of the shaft 2. The branch portion 7 branches into two from the tip of the shaft 2 and is composed of a first branch path 71 and a second branch path 72. The first branch path 71 and the second branch path 72 are bent in a direction perpendicular to the longitudinal direction of the shaft 2 and open in opposite directions. An annular portion 5 extends from the ends of the first branch path 71 and the second branch path 72.

In this embodiment of the cardiac potential measuring catheter 1, for example, the handle 3 can be operated to retract a part of the annular portion 5 into the shaft 2, thereby reducing the diameter of the annular portion 5 (Fig. 4(B)). On the other hand, the diameter of the annular portion 5 can be expanded by feeding the tube 4 out of the shaft 2 via a retraction wire (Fig. 4(A)). Therefore, during treatment, the annular portion 5 can be adjusted to a size appropriate for the patient or each pulmonary vein, and there is no need to prepare several types of cardiac potential measuring catheters, thereby reducing the cost of treatment.

Figures 5 (A) and (B) are enlarged views illustrating another embodiment of the annular portion of the cardiac potential measuring catheter of the present invention. Explanations of parts common to the embodiment described using Figures 1 and 2 will be omitted.

As shown in Fig. 5 (A) and (B), in this embodiment of the cardiac potential measuring catheter 1, a branch portion 7 is provided at the tip of the shaft 2. The branch portion 7 branches into two from the tip of the shaft 2, and is roughly T-shaped with a first branch path 71 and a second branch path 72 that bend in a direction perpendicular to the longitudinal direction of the shaft 2. The first branch path 71 and the second branch path 72 are arranged on the same straight line, and open in opposite directions. An annular portion 5 extends from the ends of the first branch path 71 and the second branch path 72.

In this embodiment of the cardiac potential measuring catheter 1, for example, the handle 3 can be operated to retract a portion of the annular portion 5 into the shaft 2, thereby reducing the diameter of the annular portion 5 (FIG. 5(B)). On the other hand, the diameter of the annular portion 5 can be expanded by feeding the tube 4 out of the shaft 2 via a retraction wire (FIG. 5(A)). Therefore, during treatment, the annular portion 5 can be adjusted to a size appropriate for the patient or each pulmonary vein, eliminating the need to prepare several types of cardiac potential measuring catheters, thereby reducing the cost of treatment.

Figures 6 (A) and (B) are enlarged views illustrating another embodiment of the annular portion of the cardiac potential measuring catheter of the present invention. Explanations of parts common to the embodiment described using Figures 1 and 2 will be omitted.

As shown in Figures 6(A) and 6(B), in this embodiment of the cardiac potential measuring catheter 1, the tip of the shaft 2 is inclined to provide a bent portion 8. The end of the bent portion 8 opens in a direction perpendicular to the longitudinal direction of the shaft 2, and the annular portion 5 extends from this end. The tip 5A of the annular portion 5 is fixed to the outer surface near the base end of the bent portion 8 located opposite the end 8A of the bent portion 8.

In this embodiment of the cardiac potential measuring catheter 1, for example, the handle 3 can be operated to retract a portion of the annular portion 5 into the shaft 2 (FIG. 6B). The tip 5A of the annular portion 5 is fixed to the bent portion 8, so that the diameter of the annular portion 5 is designed to be reduced by retracting a portion of the annular portion 5 into the shaft 2 (FIG. 6A). On the other hand, the diameter of the annular portion 5 is designed to be expanded by sending the tube 4 out of the shaft 2 via the retraction wire. Therefore, during treatment, the annular portion 5 can be adjusted to a size appropriate for the patient or each pulmonary vein, and there is no need to prepare several types of cardiac potential measuring catheters, which reduces the cost of treatment.

Figures 7 (A) and (B) are enlarged views illustrating another embodiment of the annular portion of the cardiac potential measuring catheter of the present invention.

As shown in Figures 7(A) and (B), in this embodiment of the cardiac potential measuring catheter 1, a branch portion 7 is provided at the tip of the shaft 2. The branch portion 7 has a first branch path 71 and a second branch path 72, and is divided into two at the tip of the shaft 2. The first branch path 71 has a first bent portion 81 that bends in one direction perpendicular to the longitudinal direction of the shaft 2, and the second branch path 72 has a second bent portion 82 that bends in the opposite direction to the first bent portion 81.

The first electrode portion 51 extends from the end of the first bent portion 81, curved in a semicircular arc, and has a tip 51A fixed near the base end of the second branch path 72. The second electrode portion 52 extends from the end of the second bent portion 82, curved in a semicircular arc, and has a tip 52A fixed near the base end of the first branch path 81. The semicircular first electrode portion 51 and second electrode portion 52 form a substantially annular ring portion 5.

In this embodiment of the cardiac potential measuring catheter 1, for example, the handle 3 can be operated to retract a part of the first electrode portion 51 and the second electrode portion 52 into the shaft 2 (FIG. 7(B)). The tip of the first electrode portion 51 is fixed to a part of the second branch 72, and the tip of the second electrode portion 52 is fixed to a part of the first branch 71. Therefore, the semicircular arc-shaped first electrode portion 51 and the second electrode portion 52 are each reduced in size by retracting a part of the first electrode portion 51 and the second electrode portion 52 into the shaft 2, and the diameter of the annular portion 5 is reduced overall. On the other hand, the diameter of the annular portion 5 is designed to be expanded by sending the tube 4 out of the shaft 2 via the retraction wire (FIG. 7(A)). Therefore, the annular portion 5 can be adjusted to a size according to the patient or the size according to each pulmonary vein during treatment, and there is no need to prepare several types of cardiac potential measuring catheters, which reduces the cost of treatment.

In this way, the cardiac potential measuring catheter 1 of the present invention comprises a long shaft 2, a handle 3 attached to the base end of the shaft 2, and a number of ring-shaped electrodes, and comprises an annular portion 5 exposed to the outside from the tip of the shaft 2, and the diameter of the annular portion 5 can be freely enlarged or reduced by manipulating the handle 3.

The cardiac potential measuring catheter of the present invention is not limited to the above embodiments.

REFERENCE SIGNS LIST 1 Catheter for measuring cardiac potential 2 Shaft 3 Handle 4 Tube 5 Annular portion 5a Projection portion 6a Tip electrode 6b Ring-shaped electrode 7 Branch portion 71 First branch path 72 Second branch path 8 Bending portion 91 First electrode portion 92 Second electrode portion

Claims (4)

Long shaft,
a handle attached to the proximal end of the shaft; and an annular portion having a plurality of ring-shaped electrodes and exposed to the outside from the distal end of the shaft.
Equipped with
The annular portion has a base end side, and two tubes cross each other, extend in a direction substantially perpendicular to the extension direction, form a loop, and open in a direction opposite to the longitudinal direction of the shaft,
The annular portion is provided with a protrusion protruding in a direction parallel to a longitudinal direction of the shaft at a position opposite to an intersection point where the two tubes intersect ,
A catheter for measuring cardiac potential, characterized in that the diameter of the annular portion can be freely enlarged or reduced by operating the handle. Long shaft,
a handle attached to the proximal end of the shaft; and an annular portion having a plurality of ring-shaped electrodes and exposed to the outside from the distal end of the shaft.
Equipped with
The annular portion is open in a longitudinal direction of the shaft,
A branched portion having a first branched passage and a second branched passage is provided at a tip of the shaft,
The first branch passage and the second branch passage are bent in a direction perpendicular to a longitudinal direction of the shaft and open in opposite directions to each other,
the annular portion extends from an end of the first branch path and an end of the second branch path,
A catheter for measuring cardiac potential, characterized in that the diameter of the annular portion can be freely enlarged or reduced by operating the handle. Long shaft,
a handle attached to the proximal end of the shaft; and an annular portion having a plurality of ring-shaped electrodes and exposed to the outside from the distal end of the shaft.
Equipped with
The annular portion is open in a longitudinal direction of the shaft,
a bending portion is provided at a tip of the shaft, an end of the bending portion is open toward a direction perpendicular to a longitudinal direction of the shaft, the annular portion extends from the end of the bending portion, and a tip of the annular portion is fixed to the bending portion,
A catheter for measuring cardiac potential, characterized in that the diameter of the annular portion can be freely enlarged or reduced by operating the handle. Long shaft,
a handle attached to the proximal end of the shaft; and an annular portion having a plurality of ring-shaped electrodes and exposed to the outside from the distal end of the shaft.
Equipped with
The annular portion is open in a longitudinal direction of the shaft,
A branched portion having a first branched passage and a second branched passage is provided at a tip of the shaft,
The first branch path has a first bent portion that is bent in one direction perpendicular to a longitudinal direction of the shaft, and the second branch path has a second bent portion that is bent in a direction opposite to the first bent portion,
a first electrode portion extends from an end of the first bent portion , and a tip of the first electrode portion is fixed to a part of the second branch path; a second electrode portion extends from an end of the second bent portion , and a tip of the second electrode portion is fixed to the first branch path;
The first electrode portion and the second electrode portion form the annular portion,
A catheter for measuring cardiac potential, characterized in that the diameter of the annular portion can be freely enlarged or reduced by operating the handle.

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