Living body insertion electrode lead, and living body insertion medical instrument using the same

• US 20030088302A1
• Filed: 01/29/2002
• Published: 05/08/2003
• Est. Priority Date: 03/06/2000
• Status: Active Grant

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Shirakawa, Katsuhiro, Tsuboi, Fuminori, Ishizuka, Yoshizo
• Granted Patent: US 6,950,710 B2
• Time in Patent Office: Days
• US Class Current: 607/122
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371

Abstract

An electrode lead, which is used as an implantable electrode lead and a symptom of disconnection of which can be found and detected at an early stage before complete disconnection. Also, an implantable medical instrument which uses this electrode lead safely is provided. More specifically, in an implantable electrode lead obtained by connecting conductor wires 23 and 27 with large electrical resistances and conductor wires 20 and 26 with small electrical resistances parallel to each other, when one of the low-strength conductor wires 20 and 26 is disconnected, a change in electrical resistance of the implantable electrode lead can be detected and informed. Hence, a symptom before total disconnection of the implantable electrode lead can be detected.

Claims

1. An implantable electrode lead having a distal end provided with at least one electrode to be implanted in a predetermined portion of a living body in order to perform at least one of transmission of an electrical stimulation pulse to a living body and sensing of an electrical signal from the living body, a proximal end provided with connecting means to be connected to an implantable medical instrument, and a lead body provided between said distal end and said proximal end and adapted to electrically connect said electrode and said connecting means to each other, characterized in that

said lead body includes a plurality of wires with different mechanical properties and insulated from each other,

said plurality of wires being electrically connected to said at least one electrode to be parallel to each other.

2. The implantable electrode lead according to claim 1, characterized in that said plurality of wires are wires with different electrical resistances.

3. The implantable electrode lead according to claim 1 or 2, characterized in that each of said plurality of wires is a wire with a single layer made of at least one metal material, or a composite wire with a plurality of different single layers made of at least one metal material.

4. The implantable electrode lead according to claim 3, characterized in that said composite wire with said plurality of different single layers has a clad structure obtained by covering a first single layer with a second single layer among said plurality of types of single layers.

5. The implantable electrode lead according to claim 1 or 2, characterized in that said plurality of wires are made of have different materials.

6. The implantable electrode lead according to any one of claims 1 to 5, characterized in that among said plurality of wires, a first wire has an electrical resistivity of not more than 5 μ

Ω

·

cm and a second wire has an electrical resistivity of not less than 5 μ

Ω

cm.

7. The implantable electrode lead according to claim 3 or 4, characterized in that said composite wire has a first single layer made of a metal material or alloy material with an electrical resistivity of not more than 5 μ

Ω

·

cm and a second single layer made of a metal material or alloy material with an electrical resistivity of not less than 5 μ

Ω

·

cm.

8. The implantable electrode lead according to any one of claims 3, 4, and 7, characterized in that said first and second single layers of said composite wire contain silver and a cobalt alloy, respectively.

9. The implantable electrode lead according to any one of claims 1 to 8, characterized in that said lead body comprises a helical parallel coil of said plurality of wires insulated from each other.

10. An implantable medical instrument using an implantable electrode lead having an electrode to be implanted in a predetermined portion and a lead body to be electrically connected to said electrode, characterized in that

said lead body includes a plurality of wires with different mechanical properties and insulated from each other,

said plurality of wires being electrically connected to said at least one electrode to-be parallel to each other, and

said implantable medical instrument has informing means for discriminating and determining that at least one of said different wires is fractured.

11. The implantable medical instrument according to claim 10, characterized by further having measuring means for measuring a motion state or posture of the living body where said electrode is implanted.

12. The implantable medical instrument according to claim 10, characterized in that said informing means measures a parameter that changes on the basis of a change in total electrical resistance of said plurality of wires, compares the parameter with a preset reference parameter, and informs that at least one of said plurality of wires is fractured when the parameter that changes is smaller than the reference parameter.

13. The implantable medical instrument according to claim 12, characterized in that the parameter includes either one of current, frequency, and time.

14. The implantable medical instrument according to claim 11, characterized in that said measuring means further has acceleration sensor means for measuring an acceleration, and measures the motion state or posture of the living body on the basis of a measurement result of said acceleration sensor means.

15. The implantable medical instrument according to claim 11 or 14, characterized in that said implantable medical instrument further has storage means, and when a measurement result obtained by said measuring means satisfies a predetermined condition, the measurement result is recorded in said storage means.

16. The implantable medical instrument according to any one of claims 10 to 15, characterized in that said lead body comprises a helical parallel coil of said plurality of wires insulated from each other.