GUIDEWIRE

• US 20110160703A1
• Filed: 12/23/2010
• Published: 06/30/2011
• Est. Priority Date: 12/25/2009
• Status: Active Grant

• Current Assignee: Asahi Intecc Company Limited
• Original Assignee: Asahi Intecc Company Limited
• Inventors: TAKAHASHI, Masayuki, MATSUMOTO, Satoru
• Granted Patent: US 8,608,670 B2
• Time in Patent Office: Days
• US Class Current: 604/528
• CPC Class Codes: A61M 2025/09083 having a coil around a core
• CPC Class Codes: A61M 2025/09133 having specific material compositions or coatings; Materials with specific mechanical behaviours, e.g. stiffness, strength to transmit torque
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 25/09 Guide wires

Abstract

An object of the present invention is to provide a guidewire having high safety and improved flexibility and rotation followability, and capable of directing a catheter with ease. A guidewire of the present invention has an inner coil that surrounds a distal side portion of a core shaft, and an outer coil that surrounds the inner coil and the distal side portion of the core shaft. The core shaft has a second flat part in flattened shape in substantially contact with an inner peripheral surface of the inner coil. With this configuration, the distal side portion of the guidewire is protected by a double coil structure, while having high torsional stiffness. This leads to improvement in safety and rotation followability, while allowing a catheter to be directed with ease.

Claims

1. A guidewire comprising:

a core shaft;

an inner coil that is formed by winding at least one strand, and surrounds a distal side portion of the core shaft;

an outer coil that is formed by winding at least one strand, and surrounds the inner coil and the distal side portion of the core shaft;

a flat part in flattened shape, which is provided in the distal side portion of the core shaft, expands in width toward a distal end of the distal side portion, and is in contact with an inner peripheral surface of the inner coil at least at the distal end of the distal side portion;

a tip joint that joins a front end of the outer coil and a front end of the inner coil to a distal end of the flat part of the core shaft;

an outer rear end joint that joins a rear end of the outer coil to the core shaft; and

an inner rear end joint that joins a rear end of the inner coil to the core shaft on a front side of the outer rear end joint.

2. The guidewire according to claim 1, comprising:

a coil joint that is located between the tip joint and the inner rear end joint, and joins only the outer coil and the inner coil to each other.

3. The guidewire according to claim 1, wherein the flat part has a pair of side surfaces extending substantially in parallel to an axial direction of the core shaft, and slidably in contact with the inner peripheral surface of the inner coil.

4. The guidewire according to claim 1, wherein an average distance between adjacent coils of the strand in the inner coil is shorter than an average distance between adjacent coils of the strand in the outer coil.

5. The guidewire according to claim 2, wherein

the outer coil has an open coiled portion, with coils of the strand spaced from one another, on the front side of the coil joint, and a close coiled portion, with coils of strand substantially in contact with one another, on the rear side of the coil joint.

6. The guidewire according to claim 2, wherein

the outer coil has a radiopaque portion, made up of the strand of a radiopaque material, on a front end side of the outer coil while having a radiotransparent portion, made up of the strand of a radiolucent material, on a rear end side of the outer coil,

the radiopaque portion has an open coiled portion, with coils of strand spaced from one another and wound in an open coiled manner, on a front end side portion of the radiopaque portion while having a close coiled portion, with coils of strand being substantially in contact with one another and wound in a close coiled manner, on a rear end side of the radiopaque portion, and

the coil joint joins the outer coil with the inner coil in the close coiled portion of the radiopaque portion.

7. The guidewire according to claim 6, wherein the radiotransparent portion is wound in a close coiled state where the coils of the strand are in contact with one another.

8. The guidewire according to claim 1, wherein the inner coil is a hollow stranded coil formed by stranding a plurality of strands.