Methods for Reducing Discomfort During Electrostimulation, and Compositions and Apparatus Therefor

• US 20110319975A1
• Filed: 12/30/2009
• Published: 12/29/2011
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: City College of New York
• Original Assignee: City College of New York
• Inventors: Bikson, Marom, Datta, Abhishek, Parra, Lucas, Ho, Johnson, Minhas, Preet, Bansal, Varun, Patel, Jinal, Steingart, Dan, Vega, Jorge
• Granted Patent: US 9,440,063 B2
• Time in Patent Office: Days
• US Class Current: 607/139
• CPC Class Codes: A61N 1/0408 Use-related aspects
• CPC Class Codes: A61N 1/0456 Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• CPC Class Codes: A61N 1/0496 characterised by using specific chemical compositions, e.g. hydrogel compositions, adhesives
• CPC Class Codes: A61N 1/36014 External stimulators, e.g. with patch electrodes external pacemakers A61N1/3625

Abstract

An electrode assembly for neuro-cranial stimulation includes an electrode, a conductive gel, and an adapter including an interior compartment for positioning the electrode relative to the adapter and for receiving and retaining the conductive gel. The conductive gel contacts the electrode along an electrode-gel interface. An orifice at one end of the interior compartment and adjacent to a positioning surface of the adapter for positioning the electrode assembly against a skin surface of a user enables the conductive gel is able to contact the skin surface of the user to define a gel-skin interface, such that a minimum distance between the electrode-gel interface and the gel-skin interface is maintained between 0.25 cm and 1.3 cm. An electrode assembly mounting apparatus is provided for adjustably positioning a plurality of electrode assemblies against target positions on the cranium.

Claims

1. An electrode assembly fir neuro-cranial stimulation comprising:

an electrode;

a conductive gel; and

an adapter including;

an interior compartment for positioning the electrode relative to the adapter and for receiving and retaining the conductive gel, whereby the conductive gel contacts the electrode along an electrode-gel interface, and

an orifice in communication, with the interior compartment and adjacent to a positioning surface of the adapter for positioning the electrode assembly against a skin surface of a user, through which orifice the conductive gel is able to contact the skin surface of the user to define a gel-skin interface,

wherein the positioning surface defined a plane that extends laterally across the orifice and the adapter is further configured so that a minimum distance between the electrode-gel interface and plane during use is between 0,25 cm and 1.3 cm.

2. The electrode assembly of claim 1, wherein an area of the plane within the orifice is between 25 mm² and 95 mm².

3. The electrode assembly of claim 1, wherein a contact area of the electrode-gel interface is between 30 and 1.40 mm².

4. The electrode assembly of claim 1, wherein a ratio of a contact area of the electrode-gel interface and the plane within the orifice is between 0.3 and 5.6.

5. The electrode assembly of claim 1, wherein an area of the plane within the orifice defines a circle or an oval.

6. The electrode assembly of claim 1, wherein one or more surfaces of the electrode define at least one shape selected from the group consisting of rings, thickened rings, discs, pellets, elongated pellets, recessed surfaces, saw-shaped surfaces, concave surfaces, horse shoe-shaped surfaces, helix-shaped surfaces, squares, rectangles, plates, meshes and diaphragms.

7. The electrode assembly of claim 6, wherein the one or more surfaces of the electrode are provided with surface features that increase a surface area of the electrode.

8. The electrode assembly of claim 1, wherein the electrode comprises at least one material selected from the group consisting of metals, alloyed metals, rubber, conductive rubber, Ag/AgCl, Ag, and Au.

9. The electrode assembly of claim 1, wherein the electrode is a ring electrode comprising sintered AgCl.

10. The electrode assembly of claim 9, wherein the sintered AgCl electrode has a porosity of less than 50% with a mean pore size between 1 μ

m and 100 μ

m.

11. The electrode assembly of claim 1, wherein the adapter comprises rigid material.

12. The electrode assembly of claim 11, wherein the adapter comprises a non-conductive plastic material.

13. The electrode assembly of claim 1, further comprising a first sealing member affixed to the positioning surface and extending over the orifice of the adapter, the first sealing member being configured to be peeled off or pierced to enable the conductive gel to contact the skin surface of the user to define the gel-skin interface.

14. The electrode assembly of claim 13, wherein an open end of the interior compartment of the adapter that is distally positioned relative to the orifice comprises a second sealing member, and the first sealing member and the second sealing member are configured to confine the conductive gel within the interior compartment.

15. The electrode assembly of claim 1, wherein the conductive gel has a volume between 0.5 mL and 5 mL.

16. The electrode assembly of claim 1, wherein the conductive gel has a conductivity between 30,000 to 60,000 μ

mho/cm.

17. The electrode assembly of claim 1, wherein the conductive gel comprises at least one salt selected from the group consisting of NaCl, KCl and CaCl₂.

18. The electrode assembly of claim 17, wherein a total gel Cl concentration is greater than 150 mM.

19. The electrode assembly of claim 18, wherein the total gel Cl concentration is greater than 200 mM

20. The electrode assembly of claim 1, wherein the conductive gel has a viscosity between 180,000 to 260,000 cPs.

21. The electrode assembly of claim 1, wherein the conductive gel further comprises an additive.

22. The electrode assembly of claim 21, wherein the additive comprises an antioxidant.

23. The electrode assembly of claim 21, wherein the additive comprises an analgesic.

24. The electrode assembly of claim 23, wherein the analgesic is selected from the group consisting of Lidocaine, Benzocaine, and Prilocaine.

25. The electrode assembly of claim 21, wherein the additive comprises a pH buffer.

26. The electrode assembly of claim 21, wherein the additive comprises a penetration enhancer selected from the group consisting of stearic acid, propylene glycol, linoleic acid, ethanol, sodium lauryl sulfate, and oleic acid.

27. The electrode assembly of claim 1, wherein the interior compartment comprises one or more locating tabs for positioning the electrode.

28. The electrode assembly of claim 1, wherein the adapter further comprises a cap member configured for enclosing the electrode in the interior compartment.

29. The electrode assembly of claim 28, wherein the electrode is fixedly provided to the cap member.

30. The electrode assembly of claim 1, wherein the adapter is further configured for positioning a plurality of electrodes within the interior compartment.

31. The electrode assembly of claim 1, wherein the adapter further comprises an accessory piece for holding at least another electrode, the accessory piece being attached to the adapter and in communication with the interior compartment of the adapter whereby the conductive gel flintier extends to contact the other electrode.

32. The electrode assembly of claim 1, wherein the interior compartment comprises one or more fins in proximity to the orifice that extend within the interior compartment.

33. The electrode assembly of claim 32, wherein the one or more fins are configured to position at least a surface of the electrode.

34. The electrode assembly of claim 1, wherein an outer surface of the adapter includes one or more locating features.

35. An apparatus for neuro-cranial stimulation comprising:

one or more electrode assemblies as claimed in claim 1;

one or more bands configured to be secured to the cranium of a user;

two or more apertures provided in one or more apertured elements each configured to be secured to the one or more hands,

wherein a positioning of the one or more electrode assemblies on the cranium of the user is adjustable by one or more of a repositioning of at least one of the one or more bands or by a movement of the one or more electrode assemblies to alternate ones of the two or more apertures.

36. The apparatus of claim 35, wherein the one or more electrode assemblies comprise a minimum of four electrode assemblies and a maximum of five electrode assemblies.

37. The apparatus of claim 35, wherein the apparatus is configured to adjustably position the electrode assemblies within 1 cm of any target position on the cranium of the user.

38. The apparatus of claim 35, wherein the positioning surfaces of the two or more electrode assemblies are capable of being securedly positioned against the skin surface of the user without an adhesive provided to one or more of the positioning surface or the skin surface of the user.

39. The apparatus of claim 35, wherein the one or more apertured elements comprise two or more semicircular plates hingedly joined to form a single circular, articulatable plate.

40. The apparatus of claim 35, wherein the or more apertured elements comprise one or more apertured bands.

41. The apparatus of claim 39, wherein the one or more apertured bands comprise two or more bands having electrode cups for receiving the two or more electrode assemblies, wherein the electrode cups are pivotably mounted at ends of the two or more bands.

42. An apparatus for neuro-cranial stimulation comprising:

one or more electrode assemblies as claimed in claim 1;

a base band configured for encircling a base of the user'"'"'s cranium; and

one or more flexible linear extensions extending upwardly from the base band and including electrode cups at ends of the flexible linear extensions for receiving the two or more electrode assemblies, the two or more flexible linear extensions being movable to adjustably position each of the two or more electrode assemblies against a cranial portion of the skin surface of the user.

43. The apparatus of claim 42, wherein the two or more flexible linear extensions are movable to position each of the two or more electrode assemblies against a cranial portion of the skin surface of the user without applying an adhesive to one or more of the electrode assembly or the cranial portion of the skin surface.

46. The method of claim 43, further comprising the steps of:

connecting the one or more electrode assemblies to a power source; and

generating a predetermined current through the one or more or more electrode assemblies for a predetermined time period,

44. A method for performing neuro-cranial stimulation, the method comprising the steps of:

selecting one or more electrode assemblies each comprising;

an electrode for receiving electrical energy from a regulated current source,

a conductive gel, and

an adapter including;

an interior compartment for positioning the electrode relative to the adapter and for receiving and retaining the conductive gel, whereby the conductive gel contacts the electrode along an electrode-gel interface, and

an orifice in communication with the interior compartment and adjacent to a positioning surface of the adapter; and

positioning the positioning surface of each electrode assembly against a cranial portion of the skin surface of the user, whereby the conductive gel material contacts the skin surface of the cranium along a gel-skin interface at the orifice, such that a minimum distance between the electrode-gel interface and the gel-skin interface is between 0.25 cm and 1.3 cm.

45. The method of claim 44, wherein in the positioning step each electrode assembly is positioned against the cranial portion of the skin surface of the user without applying an adhesive to one or more of the electrode assembly or the cranial portion of the skin surface.

47. The method of claim 44 Wherein a cross-sectional area of the orifice of each electrode assembly is between 25 mm² and 95 mm² and a current density at the liquid/gel-skin interface of the electrode assembly is between 0.1 mA per cm² and 10 mA per cm².

48. The method of claim 44, further comprising the step of pre-treating the skin surface of the cranium prior to the positioning step.

49. The method of claim 48, wherein the pre-treating step further comprises the step of applying a chemical to one or more of the conductive gel or the skin surface.

50. The method of claim 49, wherein the chemical comprises one or more of an antioxidant, an analgesic or a rubefacient.

51. The method of claim 48, wherein the pre-treating step further comprises the step of applying a pre-treatment waveform to the skin surface.

52. The method of claim 51, wherein the pre-treatment waveform comprises one of:

a DC current between 0.1 to 1 mA, applied for 0.1 to 60 minutes, or

an AC current between 0.1 to 1 mA, having a frequency between 0.01 to 500 kHz and applied for 0.1 to 60 minutes.

53. The method of claim 52, wherein the pretreatment waveform comprises the AC current having frequency of 0.01 to 500 kHz, a pulse width of 0.1 us to 100 seconds, and an inter-pulse interval 0.1 us to 100 seconds.

54. The method of claim 51, wherein the pre-treatment waveform comprises at least one of:

electrical noise selected from the group consisting of white noise, Gaussian noise, noise, thermal noise, and short noise.

55. The method of claim 51, wherein the electrical pre-treatment waveform comprises a current ramped with a slope of between 1 mA per minute to 1 mA per ms.

56. The method of claim 55, wherein the electrical pre-treatment waveform comprises Gaussian waveform with a standard deviation of between 0 to 10000.

57. The method of claim 44, further comprising the step of monitoring an electrode resistance for at least one of the one or more electrode assemblies.

58. The method of claim 44, wherein the at least one or more electrode assemblies comprise at least two or more electrode assemblies, and the method further comprises the step of monitoring a voltage applied across at least two of the at least two or more electrode assemblies.

59. The method of claim 44, further comprising the step of monitoring a pH of the conductive gel.

60. An electrode assembly for neuro-cranial stimulation comprising:

an electrode;

a conductive liquid or gel; and

an insulator,

wherein;

the conductive liquid or gel contacts the electrode along an electrode-liquid/gel interface and reaches an exterior surface of the electrode assembly for contacting the skin surface of a user at a liquid/gel-skin interface, and

the insulator is configured to position the electrode so that a minimum distance between the electrode-liquid/gel interface and the exterior surface of the electrode assembly for contacting the skin surface is no less than 0.25 cm.

61. A method for performing neuro-cranial stimulation, the method comprising the steps of:

selecting two or more electrode assemblies each comprising;

an electrode;

a conductive liquid or gel; and

an insulator,

wherein the conductive liquid or gel contacts the electrode along an electrode-liquid/gel interface and reaches an exterior surface of the electrode assembly for contacting the skin surface of a user at a liquid/gel-skin interface;

positioning the positioning surface of each electrode assembly against a cranial portion of the skin surface of the user, whereby the conductive gel material contacts the skin surface of the cranium along a liquid/gel-skin interface at the orifice, such that a minimum distance between the electrode-liquid/gel interface and the liquid/gel-skin interface is between 0.25 cm and 1.3 cm;

connecting the two or more electrode assemblies in anode/cathode pairs; and

generating a predetermined current through each anode/cathode pair for a predetermined, time period,

wherein a cross-sectional area of the orifice is between 25 mm² and 95 mm² and a current density at the liquid/gel-skin interface is between 0.1 mA per cm² and 10 mA per cm².