Implantable electrode lead and implantable medical instrument using the implantable electrode lead

• US 6,950,710 B2
• Filed: 03/06/2001
• Issued: 09/27/2005
• Est. Priority Date: 03/06/2000
• Status: Expired due to Term

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Tsuboi, Fuminori, Ishizuka, Yoshizo, Shirakawa, Katsuhiro
• Primary Examiner(s): Bockelman, Mark
• Application Number:
  US09/937,062
• Publication Number:
  US 20030088302A1
• Time in Patent Office: 1,666 Days
• Field of Search: 607/116, 607/122, 607/119, 607/63, 607/27, 607/28, 439/909, 600/377, 600/547
• 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 having at least one connecting terminal 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 at least one electrode to said at least one connecting terminal,

said lead body comprising a helical parallel coil of a plurality of conductive wires respectively having different properties and insulated from each other, wherein said helical parallel coil is made by rolling the plurality of conductive wires in parallel with the same diameter so that the plurality of conductive wires are next to each other, and

said plurality of conductive wires electrically connecting said at least one electrode to said at least one connecting terminal in parallel so as to form a parallel circuit.

2. The implantable electrode lead according to claim 1, wherein said different properties include different electrical resistances and different mechanical properties.

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

4. The implantable electrode lead according to claim 3, wherein said composite conductive 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 3, wherein said composite conductive 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.

6. The implantable electrode lead according to claim 3, wherein said first and second single layers of said composite conductive wire contain silver and a cobalt alloy, respectively.

7. The implantable electrode lead according to claim 1, wherein said plurality of conductive wires are made of different materials.

8. The implantable electrode lead according to claim 1, wherein among said plurality of conductive wires, a first conductive wire has an electrical resistivity of not more than 5 μ

Ω

·

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

Ω

·

cm.

9. An implantable medical instrument using an implantable electrode lead having at least one electrode to be implanted in a predetermined portion of a living body and a lead body to electrically connect said at least one electrode to at least one connecting terminal of said instrument,

said lead body comprising a helical parallel coil of a plurality of conductive wires respectively having different properties and insulated from each other, wherein said helical parallel coil is made by rolling the plurality of conductive wires in parallel with the same diameter so that the plurality of conductive wires are next to each other,

said plurality of conductive wires electrically connecting said at least one electrode to said at least one connecting terminal in parallel so as to form a parallel circuit, and

said implantable medical instrument has informing means for determining that at least one of said plurality of conductive wires is damaged based on conductivity between said at least one electrode and said at least one connecting terminal, and for informing of the damage.

10. The implantable medical instrument according to claim 9, further having measuring means for measuring a motion state or posture of the living body where said electrode is implanted.

11. The implantable medical instrument according to claim 10, wherein 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.

12. The implantable medical instrument according to claim 10, 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.

13. The implantable medical instrument according to claim 9, wherein said informing means measures a parameter that changes on the basis of a change in total electrical resistance of said plurality of conductive wires, compares the parameter with a preset reference parameter, and informs that at least one of said plurality of conductive wires is fractured when the parameter that changes is smaller than the reference parameter.

14. The implantable medical instrument according to claim 13, wherein the parameter includes either one of current, frequency, and time.

15. The implantable medical instrument according to claim 9, wherein said different properties include different electrical resistances and different mechanical properties.