Biopotential sensor electrode

• US 6,434,421 B1
• Filed: 03/21/2000
• Issued: 08/13/2002
• Est. Priority Date: 01/31/2000
• Status: Expired due to Term

• Current Assignee: Integrated Biosensing Technologies
• Original Assignee: Integrated Biosensing Technologies
• Inventors: Taheri, Babak A.
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): MARMOR II, CHARLES ALAN
• Application Number:
  US09/532,683
• Time in Patent Office: 875 Days
• Field of Search: 600/547, 600/509, 600/396, 600/395, 600/392, 600/391, 600/372, 607/149, 128/403
• US Class Current: 600/547
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/263 characterised by the electrode materials
• CPC Class Codes: A61B 5/276 Protection against electrode failure
• CPC Class Codes: A61B 5/277 Capacitive electrodes
• CPC Class Codes: A61B 5/304 Switching circuits

Abstract

A method and apparatus for biopotential sensing and stimulation are provided including a sensory component, a biopotential sensor electrode, and a biopotential sensory electrode system. The sensory component includes a first layer of electrically conductive material coupled among a biopotential signal source and a dielectric layer. A second layer of electrically conductive material is coupled among the dielectric layer, resistive elements, a charge balancing current source and sink, and circuits of the associated biopotential electrode. The biopotential sensor electrode includes the sensory component, conditioning components, an interface, and a power source. Stimulation components may also be included to provide stimulation signals to the biopotential signal source. The interface transfers signals to external instrumentation using wireless or wired connections. The power source includes batteries, solar cells, and telemetry power sources. The biopotential sensory electrode system includes electrode arrays and a receiver section that transfers biopotential signals among the biopotential signal source and external instrumentation and equipment. A reference link among the sensor electrodes of an array is provided by a coupling that includes current injection to a surface of the biopotential signal source, or a common wire to all electrodes.

Claims

1. A biopotential sensor electrode for use with external instrumentation to measure a biopotential of a patient, comprising:

at least one sensory component adapted to engage the skin of the patient and sense biopotential signals, the at least one sensory component having a first layer of electrically conductive material coupled to at least one dielectric layer and a second layer of electrically conductive material coupled to the at least one dielectric layer so that the first layer of electrically conductive material is electrically isolated from the second layer of electrically conductive material by the at least one dielectric layer; and

at least one interface coupled to the at least one sensory component and configured to transfer the biopotential signals to the external instrumentation.

2. The biopotential sensor electrode of claim 1, further comprising at least one conditioning component coupled to the at least one interface and the at least one sensory component.

3. The biopotential sensor electrode of claim 2, wherein the second layer of electrically conductive material is coupled to the at least one conditioning component using at least one component selected from a group consisting of high voltage protection circuitry, at least one bond, at least one metal layer, at least one resistive element, charge balancing circuitry, and a feedback amplifier.

4. The biopotential sensor electrode of claim 3, wherein the at least one bond is selected from a group consisting of a permanent metallic bond and at least one mating spring snap connector button, wherein one side of the at least one mating spring snap connector button is disposable.

5. The biopotential sensor electrode of claim 2, wherein the first layer of electrically conductive material is coupled to the at least one dielectric layer through a third layer of electrically conductive material and a first bond, wherein the second layer of electrically conductive material is coupled to the at least one dielectric layer through a fourth layer of electrically conductive material and a second bond.

6. The biopotential sensor electrode of claim 5, wherein the first bond and the second bond are selected from a group consisting of a permanent metallic bond and at least one mating spring snap connector button, wherein one side of the at least one mating spring snap connector button is disposable.

7. The biopotential sensor electrode of claim 2, wherein the second layer of electrically conductive material is coupled to the at least one conditioning component using at least one component selected from a group consisting of charge balancing circuitry and at least one bond.

8. The biopotential sensor electrode of claim 7, wherein the at least one bond is selected from a group consisting of a permanent metallic bond and at least one mating spring snap connector button, wherein one side of the at least one mating spring snap connector button is disposable.

9. The biopotential sensor electrode of claim 2, wherein the at least one conditioning component is coupled to the second layer of electrically conductive material.

10. The biopotential sensor electrode of claim 2, wherein the at least one conditioning component includes at least one component selected from a group consisting of impedance matching circuitry, charge balancing circuitry, amplification and buffering circuitry, programmable gain control circuitry, programmable filter circuitry, feedback control circuitry, and conditioning circuitry.

11. The biopotential sensor electrode of claim 1, further comprising at least one stimulation component coupled among the at least one interface and the at least one sensory component, wherein the at least one stimulation component provides stimulation signals to the skin of the patient.

12. The biopotential sensor electrode of claim 10, wherein the at least one stimulation component comprises at least one component selected from a group consisting of at least one programmable current source, at least one programmable voltage source, at least one programmable generator, at least one current-to-voltage converter, and at least one transresistance amplifier.

13. The biopotential sensor electrode of claim 1, wherein the at least one interface includes a signal transferring component selected from a group consisting of wires, cables, and buses.

14. The biopotential sensor electrode of claim 1, further comprising at least one telemetry component coupled to the at least one sensory component and the at least one interface.

15. The biopotential sensor electrode of claim 13, wherein the at least one telemetry component includes a telemetry receiver and transmitter.

16. The biopotential sensor electrode of claim 14, wherein the at least one interface includes at least one antenna coupled to the at least one telemetry component. platinum, gold, and silver silver-chloride.

17. The biopotential sensor electrode of claim 1, wherein the material of the first layer of electrically conductive material is selected from a group consisting of stainless steel, platinum gold, and silver silver-chloride.

18. The biopotential sensor electrode of claim 1, wherein the at least one dielectric layer is made from at least one material selected from a group consisting of Diamond Like Carbon (DLC) material, tantalum pentoxide, nitride, silicon nitride, oxide, and aluminum dioxide.

19. The biopotential sensor electrode of claim 1, wherein the first layer of electrically conductive material has a surface texture selected from a group consisting of smooth, rough, and bumped.

20. The biopotential sensor electrode of claim 1, further comprising at least one bidirectional multiplexer coupled to the at least one interface to transfer signals to the external instrumentation.

21. The biopotential sensor electrode of claim 1, further comprising a housing selected from a group consisting of a single piece housing, a two-piece housing, and a disposable housing.

22. The biopotential sensor electrode of claim 1, wherein the at least one interface is selected from a group consisting of an analog interface and a digital interface.

23. The biopotential sensor electrode of claim 1, wherein the at least one interface is a digital interface comprising at least one analog-to-digital converter, at least one memory device, at least one input/output interface unit, and at least one state machine.

24. The biopotential sensor electrode of claim 1, further comprising a substrate including at least one electrode array, wherein the at least one electrode array comprises at least one other biopotential sensor electrode.

25. The biopotential sensor electrode of claim 24, further comprising at least one power source shared among the first-named biopotential sensor electrode and the at least one other biopotential sensor electrode.

26. The biopotential sensor electrode of claim 1, further comprising at least one reference link among at least one other biopotential sensor electrode, wherein the at least one reference link allows the biopotential sensor electrode to be synchronized and referenced to a single potential, wherein the at least one reference link is provided by at least one coupling selected from a group consisting of a wired link, a telemetry link, and current injection to the skin surface of the patient.

27. The biopotential sensor electrode of claim 1, further comprising at least one power source coupled to the at least one sensory component and the at least one interface.

28. The biopotential sensor electrode of claim 27, wherein the at least one power source includes a telemetry power component that produces power in response to telemetry signals received from the external instrumentation.

29. The biopotential sensor electrode of claim 27, wherein the at least one power source comprises at least one power source selected from a group consisting of at least one battery and at least one solar cell.

30. A biopotential sensor electrode for use with external instrumentation to measure a biopotential of a patient, comprising at least one sensory component and at least one telemetry component electrically coupled to the at least one sensory component, the at least one sensory component having a stacked structure of first and second layers of electrically conductive material and at least one dielectric layer disposed between the first and second layers of electrically conductive material so as to electrically isolate the first layer of electrically conductive material from the second layer of electrically conductive material, the first layer of electrically conductive material being adapted to engage the skin of the patient and sense biopotential signals and the at least one telemetry component being electrically coupled to the second layer of electrically conductive material to transfer the biopotential signals to the external instrumentation.

31. The biopotential sensor electrode of claim 30 wherein the telemetry component includes a telemetry power source.

32. The biopotential sensor electrode of claim 31 wherein the telemetry power source includes means for remote powering of the electrode.

33. A method for collecting biopotential signals from a patient with external instrumentation and a biopotential sensor electrode having first and second layers of electrically conductive material and at least one dielectric layer disposed between the first and second layers of electrically conductive material, comprising the steps of:

receiving telemetered power signals at the biopotential sensor electrode;

generating power in response to the telemetered power signals;

receiving the biopotential signals from the skin surface of the patient with the biopotential sensor electrode; and

transferring the biopotential signals from the biopotential sensor electrode to the external instrumentation using at least one coupling comprising a wireless link.

34. A biopotential sensor electrode for use with external instrumentation to measure a biopotential of a patient, comprising at least one sensor component and at least one telemetry component electrically coupled to the at least one sensor component, the at least one sensor component having first and second layers of electrically conductive material and at least one dielectric layer disposed between the first and second layers of electrically conductive material, the at least one sensor component being adapted to engage the skin of the patient to sense biopotential signals from the patient and the at least one telemetry component transferring the biopotential signals received from the sensor component to the external instrumentation.

35. A biopotential sensor electrode for use with external instrumentation to measure a biopotential of a patient, comprising at least one sensory component adapted to engage the skin of the patient and measure biopotential signals, the at least one sensory component having first and second layers of electrically conductive material and a dielectric layer disposed between the first and second layers of electrically conductive material, and at least one interface coupled to the at least one sensory component and configured to transfer the biopotential signals to the external instrumentation.

36. The biopotential sensor electrode of claim 35 wherein the at least one interface includes an antenna for permitting wireless communication with the external instrumentation.

37. The biopotential sensor electrode of claim 35 wherein the first layer of electrically conductive material engages the skin of the patient and the second layer of electrically conductive material is electrically coupled to the at least one interface.