Electrical stimulus probe

• US 4,892,105 A
• Filed: 01/11/1988
• Issued: 01/09/1990
• Est. Priority Date: 03/28/1986
• Status: Expired due to Fees

• Current Assignee: Cleveland Clinic Foundation
• Original Assignee: Cleveland Clinic Foundation
• Inventors: Prass, Richard L.
• Primary Examiner(s): Sykes, Angela D.
• Application Number:
  US07/144,642
• Time in Patent Office: 729 Days
• Field of Search: 128/734, 128/741, 128/744, 128/303.1, 128/13, 128/303.18-303.19, 128/639, 128/642, 128/800-801, 128/783-784
• US Class Current: 607/116
• CPC Class Codes: A61B 2505/05 Surgical care
• CPC Class Codes: A61B 5/1106 to assess neuromuscular blockade, e.g. to estimate depth of anaesthesia
• CPC Class Codes: A61B 5/276 Protection against electrode failure
• CPC Class Codes: A61B 5/296 for electromyography [EMG]

Abstract

A hand-held instrument for electrically stimulating tissue of a living body in the presence of body fluid comprising an elongated, relatively fine, electrically conductive wire having a planar conductive surface generally transverse to the axis thereof at one end. Insulation carried flush to the tip of the wire is provided along the peripheral surface of the wire to prevent shunting of electrical stimulus by the body fluid through such surface. A tube encases the insulated wire in a manner such that a portion of the wire is external to the tube and is adjustable relative thereto.

Claims

1. A hand held instrument for electrically stimulating exposed, subcutaneous tissue of a living body comprising:

an elongated, relatively flexible, electrically conductive wire element including a handle end and a tissue engaging end having a planar surface generally transverse to the axis of said wire element, said wire having sufficient rigidity to generally resist bending when in operable contact with said exposed subcutaneous tissue;

a tube encasing said wire element and orienting said wire element along a predetermined path, wherein a predetermined portion of said wire element is external of said tube and is adjustable relative thereto;

handle means disposed on the handle end of said wire element for manipulating said instrument;

means for connecting said wire element to a source of electrical stimulation energy; and

a sheath electrically insulating the peripheral surface along the length of said wire element wherein only said planar surface at the tissue engaging end thereof transmits electrical stimulus to said tissue when said wire element is positioned thereagainst.

2. An instrument as defined in claim 1 wherein said electrically conductive wire element and said tube are detachable from said handle means.

3. An instrument as defined in claim 1 wherein said tube is comprised of thin-walled metal tubing of cylindrical cross-section, and said insulating sheath is disposed between said wire element and said tube.

4. An instrument as defined in claim 1 wherein said instrument is monopolar.

5. A hand-held instrument for electrically stimulating exposed, subcutaneous tissue of a living body comprising:

handle means for manipulating said instrument;

an elongated, relatively flexible, electrically conductive element extending from said handle means having an outer conductive surface extending along the length thereof and a planar conductive surface at the end thereof, said element having sufficient rigidity to generally resist bending when in operable contact with said exposed subcutaneous tissue;

means electrically insulating said outer conductive surface;

means for maintaining said element aligned along a predetermined path, and

means for connecting said element to an electrical stimulation energy, said electrically conductive element and said maintaining means being detachable from said handle means.

6. An instrument as defined in claim 5 wherein,

said electrically conductive element is a solid metal wire,

said maintaining means is a thin-walled tube encasing a portion of said wire, and,

said insulating means is disposed between said tube and said wire.

7. An electrical stimulus probe for electrically stimulating exposed, subcutaneous tissue of a living body, comprising,

an elongated, relatively flexible, electrically conductive wire element having an outer conductive surface and a planar conductive surface at one end thereof, said wire element having sufficient rigidity to resist bending when in operable contact with said exposed subcutaneous tissue.

a sheath electrically insulating said outer conductive surface,

a thin-walled tube encasing said wire element along a major portion thereof, said wire element including a portion external of said tube which is adjustable relative thereto, and

means connecting said wire element to a source of electrical stimulation energy.

8. An electrical probe as defined in claim 7 wherein said connecting means is comprised of handle means attachable/detachable from said probe.

9. An electrical probe as defined in claim 7 wherein said conductive wire element has a diameter of approximately 0.035 inches in diameter.

10. An electrical probe as defined in claim 7 wherein said tube orients said conductive wire element along a predetermined path relative a handle attachable to said probe.

11. An electrical probe as defined in claim 7 wherein said probe has a long needle-like configuration.

12. An electrical stimulus probe for electrically stimulating exposed, subcutaneous tissue of a living body, comprising;

an elongated electrically conductive element having an outer conductive surface and a planar conductive surface at one end thereof,

an axially extending, generally rigid section comprising a major portion of said elongated element,

a relatively flexible section at said one end of said element, said flexible section movable in relation to said rigid section yet having sufficient rigidity to resist movement when in operable contact with said exposed subcutaneous tissue,

a sheath electrically insulating said outer conductive surface of said conductive element wherein only said planar conductive surface is exposed to said subcutaneous tissue, and

means for connecting said wire element to a source of electrical stimulation energy.

13. A probe as defined in claim 12 wherein said rigid section includes tubular means encasing said conductive element.

14. A probe as defined in claim 12 wherein said conductive element has a generally circular cross-section and said flexible section has a diameter smaller than said rigid section.