Universally functional biomedical electrode

• US 6,356,779 B1
• Filed: 06/04/1999
• Issued: 03/12/2002
• Est. Priority Date: 06/04/1999
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Carim, Hatim M., Katzenmaier, Kevin R., Netherly, Samuel G.
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US09/326,778
• Time in Patent Office: 1,012 Days
• Field of Search: 600/391, 600/392, 606/32, 607/149, 607/152, 607/129, 607/142
• US Class Current: 600/391
• CPC Class Codes: A61N 1/0408 Use-related aspects
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/0496 characterised by using specific chemical compositions, e.g. hydrogel compositions, adhesives

Abstract

A universally functional biomedical electrode is disclosed, where the electrode has a resistive element that reduces edge effect by a redistribution of current within the electrode and in mammalian tissue contacting the electrode. In one embodiment, the electrode has at its perimeter in one layer the resistive element that provides a cross-sectional area to reduce edge effect regardless of the type of biomedical instrumentation connected thereto. With the construction of other layers suitable for multifunctional electrode usage, this electrode can serve as a single item in inventory at health facilities.

Claims

1. A universally functional biomedical electrode, comprising:

an electrode element;

a conductive adhesive material in contact with the electrode element;

a highly resistive material, wherein the highly resistive material reduces edge effect by limiting the conduction through the conductive adhesive material by modifying z-axis impedance of the conductive adhesive material as a gradient from the center toward the periphery.

2. The electrode of claim 1, wherein the electrode redistributes current employing the equation:

3. The electrode of claim 1, wherein the limiting of conduction is provided by a screen embedded at a periphery of the conductive adhesive material in the electrode.

4. The electrode of claim 3, wherein the screen has pores in a pattern selected from the group consisting of a regularly repeated pattern, an irregularly repeated pattern, and an essentially random pattern of holes.

5. The electrode of claim 4, wherein the pores have a diameter ranging from about 0.03 mm to about 1.27 mm;

wherein the pores are spaced apart such that a percentage of surface area of pores in the screen ranges from about 1% to about 30%; and

wherein the thickness of the screen ranges from about 0.020 mm to about 1.000 mm.

6. The electrode of claim 5, wherein the pattern of pores provides a gradual or stepwise transition from a higher screening of z-axis electrical conduction at an edge of the electrode to a lower or absence of screening of z-axis electrical conduction at a center of the electrode.

7. The electrode of claim 5, wherein the screen comprises a small number of holes with a complex or convoluted border geometry selected from the group consisting of sunbursts with very long and thin points and radial spokes extending from a central hub.

8. The electrode of claim 4, wherein the pattern of pores provides a gradual or stepwise transition from a higher screening of z-axis electrical conduction at an edge of the electrode to a lower or absence of screening of z-axis electrical conduction at a center of the electrode.

9. A method of using an electrode, comprising the steps of:

(a) adhering at least one electrode of claim 1 to mammalian tissue of a patient; and

(b) performing at least one biomedical function using the at least one electrode, wherein the at least one biomedical function is selected from the group consisting of monitoring, defibrillation, pacing, electrosurgical dispersing, impedance measuring, and combinations thereof.

10. The method of claim 9, wherein at least two biomedical functions are concurrently performed.

11. The method of claim 9, wherein at least two biomedical electrodes are used in a pair for the at least one biomedical function.

12. The method of claim 11, wherein the at least two biomedical electrodes are a pair having differing compositions or constructions, and wherein the pair of electrodes are configured such that one electrode has negative polarity and one other electrode has positive polarity.

13. A biomedical electrode, comprising:

at least one electronic conductor in contact with an ionically conductive material that interfaces mammalian tissue for exchanging electromagnetic energy, the ionically conductive material containing;

(a) at least one highly resistive material, having an impedance that is substantially higher than that of the ionically conductive material;

(b) at least one of the said highly resistive material(s) being substantially coplanar with a major surface of the conductor; and

(c) the highly resistive material having a geometry, shape and apertures selected to alter the current density profile reaching an interface between the electrode and mammalian tissue.

14. The electrode of claim 13, wherein the highly resistive material resides in the ionically conductive adhesive between the electronic conductor and the mammalian tissue.

15. A universally functional biomedical electrode, comprising:

an electrode element, the electrode element comprising;

a conductive adhesive material in contact with the electrode element;

a screen embedded at a periphery of the conductive adhesive material, the screen comprising pores in a pattern selected from the group consisting of a regularly repeated pattern, an irregularly repeated pattern, and an essentially random pattern of holes, wherein the pores have a diameter ranging from about 0.03 mm to about 1.27 mm, wherein the pores are spaced apart such that a percentage of surface area of pores in the screen ranges from about 1% to about 30%, wherein the thickness of the screen ranges from about 0.020 mm to about 1.000 mm, wherein the screen reduces edge effect by a redistribution of current within the electrode and in mammalian tissue contacting the electrode by limiting the conduction through the conductive adhesive material, and wherein the screen limits conduction through the conductive adhesive material by modifying z-axis impedance of the conductive adhesive material as a gradient from the center toward the periphery.

16. The electrode of claim 15, wherein the pattern of pores provides a gradual or stepwise transition from a higher screen of z-axis electrical conduction at an edge of the electrode to a lower or absence of screening of z-axis electrical conduction at a center of the electrode.

17. The electrode of claim 15, wherein the screen comprises a small number of holes with a complex or convoluted border geometry selected from the group consisting of sunbursts with very long and thin points and radical spokes extending from a central hub.