NERVE ELECTRODE

• US 20100145221A1
• Filed: 12/08/2008
• Published: 06/10/2010
• Est. Priority Date: 12/08/2008
• Status: Active Grant

• Current Assignee: Medtronic Xomed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Xomed Incorporated (Medtronic Plc)
• Inventors: Grant, Denise, Brunnett, William C., Pagotto, Carla A., Hacker, David C.
• Granted Patent: US 8,515,520 B2
• Time in Patent Office: Days
• US Class Current: 600/554
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/395 Details of stimulation, e.g. nerve stimulation to elicit EMG response
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0556 Cuff electrodes

Abstract

A nerve monitoring system facilitates monitoring an integrity of a nerve.

Claims

1. An electrode assembly comprising:

a nerve-engaging portion including;

a pair of generally arcuate fingers; and

a base hinge portion from which the respective fingers extend and configured to cause movement of the fingers between a closed position in which the fingers are releasably, slidably engaged in a side-by-side relationship to define a lumen and an open position in which distal ends of the fingers are spaced apart to provide access to the lumen, wherein the base hinge portion supports an electrode contact exposed at a surface of the lumen;

an actuator mechanism including a pair of grip members, both extending outwardly from the base hinge portion and spaced apart from each other such that a releasable pressing action of the grip members relative to each other causes movement of the fingers from the closed position to the open position; and

an electrical lead extending through one of the respective grip members to be in electrical communication with the electrode contact.

2. The electrode assembly of claim 1 wherein the pair of grip members includes a first grip member and a second grip member, the first grip member defining an elongate beam that is substantially longer than the second grip member, and wherein the base hinge portion includes a central bending region that is offset relative to a longitudinal axis of the elongate beam.

3. The electrode assembly of claim 2 wherein the electrical lead extends through the elongate beam.

4. The electrode assembly of claim 3 wherein the electrode contact is sized and shaped to be in alignment with the longitudinal axis of the elongate beam.

5. The electrode assembly of claim 4 wherein the elongate beam and the electrical lead extend in a substantially single direction throughout a length of the beam.

6. The electrode assembly of claim 2 wherein the elongate beam has a length substantially greater than a diameter of the lumen of the nerve-engaging portion.

7. The electrode assembly of claim 6 wherein the elongate beam has a width substantially greater than a side edge of the elongate body.

8. The electrode assembly of claim 1 wherein the respective grip members are spaced apart at an angle between 30 to 110 degrees.

9. The electrode assembly of claim 8 wherein the respective grip members are spaced apart at an angle between 40 to 90 degrees.

10. The electrode assembly of claim 1, wherein with the fingers arranged in their side-by-side relationship, each finger is configured with a radial length sufficient to cause the distal end of each finger to releasably contact a portion of the base hinge portion when the fingers are in the closed position.

11. The electrode assembly of claim 1, wherein in combination with the base hinge portion, a width of each finger independently defines a portion of a length of the lumen.

12. The electrode assembly of claim 1 wherein the respective fingers each include an angled inner edge that forms a generally helical pattern.

13. The electrode assembly of claim 12 wherein each respective finger includes a straight outer edge such that the angled inner edge and the straight edge of each respective finger converges to form a curved tip at the distal end of each respective finger.

14. The electrode assembly of claim 1 and further comprising a system including the cuff electrode and a monitor that comprises:

a stimulation module configured to automatically apply a stimulation signal, via the cuff electrode, to the nerve at periodic intervals;

a response module configured to automatically measure a neurogenic response signal directly from the nerve or indirectly though innervated muscle via the response electrode, wherein the response module includes an identification function configured to identify potential impairment of the nerve by comparing the measured response signals to a baseline response pattern; and

a user interface including a notify function configured to provide automatic notification to the user of the identified potential impairment of the nerve via at least one of a visual or an audible alarm.

15. The electrode assembly of claim 14 wherein the stimulation module is configured to enable user adjustment, via the user interface or via a remote control, a length of the periodic intervals of the stimulation signal to apply one or more different stimulation rates.

16. A nerve electrode assembly comprising:

an electrical lead;

an elongate body housing the electrical lead with the electrical lead extending at least proximally from a proximal end of the elongate body, the elongate body including;

a recess defined in a first side of the elongate body and including a mouth facing away from the promixal end of the elongate body; and

a distal contact portion including an electrode contact in communication with the electrical lead, wherein the distal contact portion is located distally relative to the mouth of the recess and forms a generally arcuate shape; and

a resilient arm including a distal portion and a generally semicircular proximal portion extending from the distal contact portion of the elongate body, the arm having a length sufficient to cause the distal portion to extend proximally beyond the distal contact portion of the elongate body and into the recess upon removable, slidable insertion of the distal portion of the arm into the recess, wherein a combination of the proximal portion of the arm and the distal contact portion of the elongate body define a lumen.

17. The nerve electrode claim 16 wherein the recess extends generally parallel to the first side of the elongate body, wherein the mouth of the recess is oriented in substantially the same direction as a generally concave surface of the distal contact portion of the elongate body, and wherein the recess defines a slot extending proximally from the mouth toward the proximal end of the elongate body.

18. The nerve electrode of claim 16 wherein elongate body includes a second side generally opposite the first side with the first side and the second side defining a general wedge shape having a narrow portion adjacent the proximal end of the elongate body and a wider portion adjacent the distal contact portion of the elongate body.

19. The nerve electrode of claim 16 wherein the distal portion of the arm has a length at least two times longer than an arc length of the proximal portion of the arm.

20. An electrode assembly comprising:

an electrical lead; and

a generally Y-shaped body including an elongate stem and a distal nerve-engaging portion, wherein the stem houses the electrical lead and includes a proximal end from which the electrical lead proximally extends, and wherein the distal nerve-engaging portion includes;

a pair of spaced apart, generally wedge-shaped fingers extending distally from the stem and defining a recessed base portion between the respective fingers; and

an electrode contact positioned at the recessed base portion and in electrical communication with the electrical lead.

21. The electrode assembly of claim 20 wherein each respective wedge-shaped finger defines a tip corresponding to a narrow portion of the wedge shape and includes a generally non-uniform thickness that increases from the tip toward the stem.

22. The assembly of claim 20, wherein an angle of about 60 degrees to about 120 degrees is formed between a longitudinal axis of each of the respective fingers.

23. The electrode assembly of claim 20 wherein each respective finger forms an inner side and an outer side, and the outer sides of the pair of fingers form a reflex angle relative to each other, the inner sides of the pair of finger form at least one of a generally obtuse angle or an acute angle relative to each other such that the generally Y-shaped body has a shape generally corresponding to a concave quadrilateral.

24. A method of monitoring a nerve, the method comprising:

introducing a nerve electrode through a wall of a sheath and advancing the electrode through an interior of the sheath;

maneuvering the nerve electrode within the sheath to a cause a recess-shaped contact portion of the nerve electrode to releasably engage a target nerve located within the sheath and to releasably anchor the nerve electrode relative to the target nerve, wherein the maneuvering action further comprises;

interposing a trunk of the nerve electrode between a first structure and a second structure within the sheath;

interposing a first portion of the contact portion between the target nerve and the first structure within the sheath; and

interposing a second portion of the contact portion between the target nerve and the second structure within the sheath; and

applying a stimulation signal to the target nerve via an electrical lead that extends through a trunk of the nerve electrode and that is in electrical communication with an electrode contact of recess contact portion.

25. The method of claim 24, comprising:

further anchoring engagement of the contact portion relative to the target nerve via fastening the trunk of the nerve electrode relative to the sheath.

26. The method of claim 25, comprising:

arranging the nerve electrode as a Y-shaped member via;

providing the trunk as an elongate element; and

providing a first finger and a second finger extending from the trunk to form the recess-shaped contact portion, wherein the first finger forms the first portion of the contact portion and the second finger forms the second portion of the contact portion.