Skin screw electrodes

• US 9,504,424 B2
• Filed: 02/06/2012
• Issued: 11/29/2016
• Est. Priority Date: 02/04/2008
• Status: Active Grant

• Current Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Inventors: Jia, Wenyan, Sun, Mingui, Sclabassi, Robert Joseph
• Primary Examiner(s): Stoklosa, Joseph
• Assistant Examiner(s): ANTISKAY, BRIAN MICHAEL
• Application Number:
  US14/359,904
• Publication Number:
  US 20150126846A1
• Time in Patent Office: 1,758 Days
• Field of Search: 600372-373, 600382-384, 600/386, 600/390, 600/393
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/251 Means for maintaining electrode contact with the body
• CPC Class Codes: A61B 5/273 Connection of cords, cables or leads to electrodes
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/293 Invasive
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/6839 Anchoring means, e.g. barbs
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61N 1/0452 Specially adapted for transcutaneous muscle stimulation [TMS]
• CPC Class Codes: A61N 1/0456 Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/0464 Specially adapted for promoting tissue growth
• CPC Class Codes: A61N 1/0468 Specially adapted for promoting wound healing
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin

Abstract

Electrodes providing excellent recording and physical stability. Electrodes are disclosed that may include a plurality of small teeth that possess a novel design shape and orientation. The shallow and relatively long teeth run parallel to the rim of the electrode that presses against the patient'"'"'s skin. When the electrode is twisted onto skin, the tiny teeth penetrate the stratum corneum and move nearly horizontally under the stratum corneum, thus anchoring the electrode securely to the skin. The electrodes cause minimal discomfort to the patient since the small teeth do not extend to the pain fibers which are located in deeper layers of the skin. The electrodes may be fabricated in a variety of geometries including cylindrical, disk, and blunt bullet or top shapes. In some instances, the electrodes may be connected to detachable leads having magnetic properties.

Claims

1. An electrode system for attaching an electrode to skin of a patient, comprising:

an electrode having an electrode body comprising an electrode face that is adapted to be pressed against the skin of the patient, wherein said electrode face includes a plurality of teeth that includes teeth located on a rim at a perimeter of said electrode body, wherein each of said plurality of teeth includes a shaft that initially extends from said electrode face, the shaft then turning to run at an orientation that is within about 5°

away from the rim to a depth that is less than a depth of stratum corneum of said patient.

2. The electrode system of claim 1, further comprising a cap that is connected to a distal portion of said electrode body.

3. The electrode system of claim 1, wherein said plurality of teeth includes teeth located across the electrode face.

4. The electrode system of claim 1, wherein the electrode body is a hollow cylinder.

5. The electrode system of claim 1, wherein said electrode body is a cylinder, a blunt bullet, or a disk.

6. The electrode system of claim 2, wherein said cap comprises a magnetic material and is shaped as a cylindrical disk having a hole.

7. The electrode system of claim 6, further comprising a spherical magnetic lead that is adapted to fit snugly into the hole.

8. The electrode system of claim 7, wherein at least one of said teeth, said cap, and said spherical magnetic lead is coated or electroplated with a conductive material.

9. The electrode system of claim 8, further comprising a rubber ring that covers said electrode teeth when said electrode is not attached to said patient.

28. The electrode system of claim 1, wherein the electrode body is bullet-shaped about a central axis and the teeth of the plurality of teeth are distributed on a bullet-shaped surface along the central axis, wherein the sharp ends of the plurality of teeth are aligned so as to face tangentially along the tooth proximal surfaces in directions perpendicular to the central axis so that adjacent teeth are oriented in a substantially common direction.

10. A method of fabricating an electrode comprising the steps of:

applying an etchant-resistant chemical to the surface of a sheet of material in a pattern, said pattern including a plurality of teeth on a rim of said pattern, wherein each of said plurality of teeth includes a shaft that initially extends from said rim and then turns to run at an orientation that is within about 5°

away from the rim to a depth that is less than a depth of stratum corneum of a patient;

etching said sheet of material with an etchant solution;

forming said electrode from said non-etched material, wherein said electrode has an electrode face that is adapted to be pressed against the skin of the patient, wherein said electrode face includes said plurality of teeth.

11. The method of claim 10, wherein said forming step includes rolling said sheet of material into a cylinder.

12. The method of claim 11, further comprising a step of fusing said sheet into said cylinder after said forming step.

13. The method of claim 12, wherein said fusing is achieved using adhesive, soldering, epoxy, or sintering.

14. The method of claim 10, further comprising a step of coating said sheet of material with a layer of sintering agent prior to said etching step.

15. The method of claim 10, wherein said fusing is achieved using sintering, and further comprising a step of heat-treating said electrode to achieve said sintering after said forming step.

16. The method of claim 11, wherein said cylinder defines a body of said electrode.

17. The method of claim 10, wherein said forming step comprises rolling said sheet of material into a coil to form a body of said electrode having an electrode face.

18. The method of claim 17, wherein said plurality of said teeth is located on said electrode face.

19. The method of claim 18, wherein said body of said electrode is a cylinder, a blunt bullet, or a disk.

20. The method of claim 17, further comprising a step of fusing said sheet into said coil after said forming step.

21. The method of claim 20, wherein said fusing is achieved using adhesive, soldering, epoxy, or sintering.

22. The method of claim 21, further comprising a step of coating said sheet of material with a layer of sintering agent prior to said etching step.

23. The method of claim 21, wherein said fusing is achieved using sintering, and further comprising a step of heat-treating said electrode to achieve said sintering after said forming step.

24. An electrode for attachment to skin of a patient, comprising:

an electrode body having a proximal surface and a distal surface;

a plurality of teeth situated at the proximal surface of the electrode body, the plurality of teeth including teeth situated on a rim at a perimeter of the electrode body, wherein each of said plurality of teeth is situated at a corresponding indentation of the proximal surface of the electrode body, and is defined by a proximal tooth surface that extends from the proximal surface of the electrode body at the associated indentation along an arc having a terminal portion that is at an orientation that is within about 5°

away from the proximal surface of the electrode body, and is further defined by a distal tooth surface that extends opposite the proximal tooth surface from the electrode body at the associated indentation to the terminal portion of the proximal tooth surface so that the proximal tooth surface and the distal tooth surface form a sharp end.

25. The electrode of claim 24, wherein the terminal portions of the proximal tooth surfaces of each of the plurality of teeth are oriented at an angle of between 4 degrees and 5 degrees from an unindented portion of the proximal surface of the electrode body.

26. The electrode of claim 24, wherein the electrode body is cylindrical, and the proximal surface of the electrode body is a circular annulus.

27. The electrode of claim 26, wherein the sharp ends of the plurality of teeth are aligned such that adjacent teeth are oriented in a substantially common direction.

29. A method of fabricating an electrode comprising the steps of:

applying an etchant-resistant chemical to the surface of a sheet of material in a pattern, the pattern defining a plurality of teeth situated at a proximal surface of an electrode body of the electrode, the plurality of teeth including teeth situated on a rim at a perimeter of the electrode body, each of said plurality of teeth is situated at a corresponding indentation of the proximal surface of the electrode body, and is defined by a proximal tooth surface that extends from the proximal surface of the electrode body at the associated indentation along an arc having a terminal portion that is at an orientation that is within about 5°

away from the proximal surface of the electrode body, and a distal tooth surface that extends opposite the proximal tooth surface from the electrode body at the associated indentation to the terminal portion of the proximal tooth surface, so that the proximal tooth surface and the distal tooth surface form a sharp end;

etching said sheet of material with an etchant solution; and

forming said electrode from said non-etched material, wherein said electrode has an electrode face that is adapted to be pressed against the skin of the patient, wherein said electrode face includes said plurality of teeth.