Electrode for measurement of weak bioelectrical signals

• US 6,622,035 B1
• Filed: 01/21/2000
• Issued: 09/16/2003
• Est. Priority Date: 01/21/2000
• Status: Expired due to Fees

• Current Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Original Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Inventors: Tolvanen-Laakso, Heli, Merilainen, Pekka
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US09/489,556
• Time in Patent Office: 1,334 Days
• Field of Search: 600/372, 600/382-386, 600/391, 600/392, 600/395-397, 607/149, 607/152, 607/153
• US Class Current: 600/391
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/257 using adhesive means, e.g. adhesive pads or tapes
• CPC Class Codes: A61B 5/265 containing silver or silver chloride
• CPC Class Codes: A61B 5/266 containing electrolytes, conductive gels or pastes
• CPC Class Codes: A61B 5/325 Preparing electrode sites, e.g. by abrasion
• CPC Class Codes: A61B 5/685 Microneedles
• CPC Class Codes: A61N 1/04 Electrodes electrosurgical electrodes A61B18/14

Abstract

An electrode for acquiring bioelectrical signals employs an array of spikes that penetrate the viable epidermis layer of the skin of a patient. The spikes may be conductive to provide the bioelectrical signal. Or, the spikes may extend through a conductive layer that provides the bioelectrical signal. The signal obtained from the patient may be amplified using an amplifier and battery circuit present on the electrode body. The electrode may be used with or without conductive paste or gel.

Claims

1. An electrode for obtaining a biopotential signal from the skin of a subject, said electrode comprising:

a carrier having a surface positioned contiguous with the skin of the subject when the electrode is applied to the subject'"'"'s skin;

a plurality of spikes extending from said surface of said carrier for being inserted into and below the surface of the skin of the subject when the electrode is applied to the subject'"'"'s skin, said carrier and spikes presenting electrically conductive surfaces to tissue of the subject'"'"'s skin over essentially the entirety of the elements so as to optimize the extent of the conductive surface area, said spikes having a length of 50 -250 μ

m for extending into the viable epidermis layer of the skin when the electrode is applied to the subject'"'"'s skin, said electrode having between 100 and 10,000 spikes on said carrier surface, the optimized conductive surface area of the carrier and spikes increasing the effective contact area with the subject'"'"'s skin for reducing the biopotential signal impedance; and

a connector for obtaining said biopotential signal and for making the signal available externally of the electrode.

2. The electrode of claim 1 wherein said spikes are arranged in an array and spaced 50 to 250 micrometers apart on said carrier.

3. The electrode of claim 1 wherein the length of the spikes is varied.

4. The electrode of claim 1 wherein spikes are tapered from a base to a tip to facilitate skin penetration.

5. The electrode of claim 4 wherein the spikes have bases adjacent said surface of said carrier and wherein said bases are up to 35 micrometers in width.

6. The electrode of claim 1 wherein the length of the spikes ranges from 100 to 200 μ

m.

7. The electrode of claim 1 wherein the number of spikes is 400-2000 spikes.

8. The electrode of claim 1 further including adhesive for securing the electrode to the skin of the subject.

9. The electrode of claim 8 wherein the adhesive comprises an adhesive tape.

10. The electrode of claim 8 wherein the adhesive is applied to said surface of the carrier.

11. The electrode of claim 10 wherein the adhesive is electrically conductive.

12. The electrode of claim 1 wherein the area of said surface of said carrier ranges from 4 to 25 square millimeters.

13. The electrode of claim 1 further including a conductive layer located on the surface of said spikes and carrier.

14. The electrode of claim 13 further including a conductive medium located between said conductive layer and the skin.

15. The electrode of claim 14 wherein the conductive medium contains antibacterial agents.

16. The electrode of claim 14 further including a retainer for retaining the conductive medium on the conductive layer.

17. The electrode of claim 1 further including an amplifier for boosting the biopotential signal obtained from the subject.

18. The electrode of claim 17 wherein the amplifier is powered by a battery.

19. The electrode of claim 18 wherein said amplifier and battery are incorporated in said carrier.

20. The electrode of claim 18 wherein an open electrical circuit between the amplifier and battery is maintained by placing a removable tape across the battery and the open electrical circuit.

21. The electrode of claim 20 wherein the open electrical circuit is closed with a connection means after said tape is removed.

22. The electrode of claim 1 wherein said electrode is of unitary construction and the spikes and the carrier are made from a common material.

23. An electrode for obtaining a biopotential signal from the skin of a subject, said electrode comprising:

a carrier having a surface positioned contiguous with the skin of the subject when the electrode is applied to the subject'"'"'s skin, said carrier being electrically conductive on said surface;

a plurality of spikes, each spike having a base joined to said carrier, said spikes extending from said surface of said carrier for being inserted into and below the surface of the skin of the subject when the electrode is applied to the subject'"'"'s skin, said spikes being electrically non-conductive and having a length of 50-250 μ

m for extending into a viable epidermis layer of the skin when the electrode is applied to the subject'"'"'s skin; and

a connector coupled to said conductive surface for obtaining said biopotential signal and for making the signal available externally of the electrode.

24. The electrode of claim 23 wherein the plurality of spikes comprise 100 to 10,000 spikes.

25. The electrode of claim 23 wherein said plurality of spikes comprise 100 to 10,000 spikes and the area of said surface of the carrier is 4 to 25 square millimeters.

26. The electrode of claim 23 wherein said spikes are arranged in an array and spaced 50 to 250 micrometers apart on said carrier.

27. The electrode of claim 23 wherein the length of the spikes is varied.

28. The electrode according to claim 23 wherein spikes are tapered from a base to a tip to facilitate skin penetration.

29. The electrode of claim 28 wherein the spikes have bases adjacent the surface of the carrier and wherein said bases are up to 35 micrometers in width.

30. The electrode of claim 23 further including a conductive layer located on the surface of said carrier.

31. The electrode of claim 30 further including a conductive medium located between said conductive layer and the skin.

32. The electrode of claim 31 wherein the conductive medium contains antibacterial agents.

33. The electrode of claim 31 further including a retainer for retaining the conductive medium on the conductive layer.

34. The electrode of claim 24 wherein the plurality of spikes comprise 400-2000 spikes.

35. The electrode of claim 23 wherein said carrier is electrically non-conductive.

36. The electrode of claim 23 wherein the area of said surface of the carrier ranges from 4 to 25 square millimeters.

37. The electrode of claim 23 wherein the spikes have a length of 100-200 μ

m.

38. The electrode of claim 23 further including adhesive for securing the electrode to the skin of the subject.

39. The electrode of claim 38 wherein said adhesive is disposed on the carrier for securing the electrode to the skin of the subject.

40. The electrode of claim 39 wherein the adhesive disposed on the carrier is applied to the carrier.

41. The electrode of claim 39 wherein the adhesive is electrically conductive.

42. The electrode of claim 39 wherein the adhesive disposed on the carrier comprises an adhesive tape.

43. The electrode of claim 23 further including an amplifier for boosting the biopotential signal obtained from the subject.

44. The electrode of claim 43 wherein the amplifier is powered by a battery.

45. The electrode of claim 44 wherein said amplifier and battery are incorporated in said carrier.

46. The electrode of claim 44 wherein an open electrical circuit between the amplifier and battery is maintained by placing a removable tape across the battery and the open electrical circuit.

47. The electrode of claim 46 wherein the open electrical circuit is closed with a connection means after said tape is removed.

48. The electrode of claim 23 wherein said electrode is of unitary construction and the spikes and the carrier are made from a common material.

49. An electrode for obtaining a biopotential signal from the skin of a subject, said electrode comprising:

a carrier having a surface positioned contiguous with the skin of the subject when the electrode is applied to the subject'"'"'s skin, said carrier having an area ranging from 4 to 25 square millimeters, said carrier being electrically conductive on said surface;

a plurality of spikes extending from said surface of said carrier for being inserted into and below the surface of the skin of the subject when the electrode is applied to the subject'"'"'s skin, said spikes being electrically non-conductive, said electrode having between 100 and 10,000 spikes on said carrier surface; and

a connector coupled to said conductive surface for obtaining said biopotential signal and for making the signal available externally of the electrode.

50. The electrode of claim 49 wherein said spikes are arranged in an array and spaced 50 to 250 micrometers apart on said carrier.

51. The electrode of claim 49 wherein the length of the spikes ranges from 50 to 250 micrometers.

52. The electrode of claim 51 wherein the length of the spikes is varied.

53. The electrode of claim 51 wherein the length of the spikes ranges from 100 to 200 μ

m.

54. The electrode of claim 49 wherein the length of the spikes is varied.

55. The electrode according to claim 49 wherein spikes are tapered from a base to a tip to facilitate skin penetration.

56. The electrode of claim 55 wherein the spikes have bases adjacent the surface of the carrier and wherein said bases are up to 35 micrometers in width.

57. The electrode of claim 49 further including a conductive layer located on the surface of said carrier.

58. The electrode of claim 57 further including a conductive medium located between said conductive layer and the skin.

59. The electrode of claim 58 wherein the conductive medium contains antibacterial agents.

60. The electrode of claim 58 further including a retainer for retaining the conductive medium on the conductive layer.

61. The electrode of claim 49 wherein said carrier is formed of an electrically non-conductive material.

62. The electrode of claim 49 wherein said electrode has between 400 and 2000 spikes on said carrier surface.

63. An electrode of claim 49 further including adhesive for securing the electrode to the skin of the subject.

64. The electrode of claim 63 wherein said adhesive is disposed on the carrier for securing the electrode to the skin of the subject.

65. The electrode of claim 64 wherein the adhesive disposed on the carrier comprises an adhesive tape.

66. The electrode of claim 64 wherein the adhesive disposed on the carrier is applied to the carrier.

67. The electrode of claim 64 wherein the adhesive is electrically conductive.

68. The electrode of claim 49 further including an amplifier for boosting the biopotential signal obtained from the subject.

69. The electrode of claim 61 wherein the amplifier is powered by a battery.

70. The electrode of claim 69 wherein said amplifier and battery are incorporated in said carrier.

71. The electrode of claim 69 wherein an open electrical circuit between the amplifier and battery is maintained by placing a removable tape across the battery and the open electrical circuit.

72. The electrode of claim 71 wherein the open electrical circuit is closed with a connection means after said tape is removed.

73. The electrode of claim 49 wherein said electrode is of unitary construction and the spikes and the carrier are made from a common material.

74. A method for obtaining biopotential signals from a subject comprising the steps of:

(a) applying an electrode having an array of spikes to the subject'"'"'s skin, the spikes being electrically non-conductive having a length of 50-250 μ

m for penetrating into the skin to the viable epidermis, the electrode having between 100 and 10,000 spikes mounted on a carrier, the carrier and spikes presenting electrically conductive surfaces to the subject'"'"'s skin, the electrode having an electrical lead;

(b) establishing an electrical signal path from the skin to the conductive surfaces of the electrode; and

(c) obtaining the biopotential signals from the electrical lead.

75. The method of claim 74 further including the step of fastening the electrode to the subject'"'"'s skin.

76. A method for obtaining biopotential signals from a subject comprising the steps of:

(a) applying an electrode having an array of spikes to the subject'"'"'s skin, the spikes having a length of 50-250 μ

m for penetrating into the skin to the viable epidermis, the spikes being electrically non-conductive and mounted on a carrier having a conductive surface positioned contiguous with the subject'"'"'s skin, the electrode having an electrical lead;

(b) establishing an electrical signal path from the skin to the conductive surface to the carrier; and

(c) obtaining the biopotential signals from the electrical lead.

77. The method of claim 76 further including the step of fastening the electrode to the subject'"'"'s skin.

78. A method for obtaining biopotential signals from a subject comprising the steps of:

(a) applying a electrode having an array of spikes to the subject'"'"'s skin so that the spikes penetrate the skin to the viable epidermis, the electrode having between 100 and 10,000 electrically non-conductive spikes extending from an electrically conductive surface of a carrier, the surface having an area of 4 to 25 square millimeters, the electrode having an electrical lead;

(b) establishing an electrical signal path from the skin to the conductive surface of the carrier; and

(c) obtaining the biopotential signals from the electrical lead.

79. The method of claim 78 further including the step of fastening the electrode to the subject'"'"'s skin.