SYSTEMS AND METHODS FOR PREVENTING NOISE IN AN ELECTRIC WAVEFORM FOR NEURAL STIMULATION, BLOCK, OR SENSING

• US 20150238764A1
• Filed: 05/08/2015
• Published: 08/27/2015
• Est. Priority Date: 05/10/2013
• Status: Abandoned Application

• Current Assignee: Case Western Reserve University
• Original Assignee: Case Western Reserve University
• Inventors: Franke, Manfred
• Application Number:
  US14/707,541
• Publication Number:
  US 20150238764A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0214 Capacitive electrodes
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• CPC Class Codes: A61B 5/7214 using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36142 for improving safety
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

One aspect of the present disclosure relates to a system that can prevent unintended signal components (noise) in an electric waveform that can be used for at least one of neural stimulation, block, and/or sensing. The system can include a signal generator to generate a waveform that includes an intended electric waveform and unintended noise. The system can also include a signal transformer device (e.g., a very long wire) comprising a first coil and a second coil. The first coil can be coupled to the signal generator to receive the waveform and remove the unintended noise from the electric waveform. The second coil can pass the electric waveform to an electrode. The second coil can be coupled to a capacitor that can prevent the waveform from developing noise at an electrode/electrolyte interface between an electrode and a nerve.

Claims

1. A system to prevent noise in an electric waveform used for at least one of neural stimulation, block, and sensing, the system comprising:

a signal generator to generate an electric waveform for at least one of neural stimulation, block, and sensing; and

a signal transformer device, comprising;

a first coil coupled to the signal generator to receive the electric waveform; and

a second coil to pass the electric waveform to an electrode,

wherein the second coil is coupled to a capacitor that prevents the electric waveform from developing noise at an electrode/electrolyte interface between an electrode and a nerve.

2. The system of claim 1, wherein the first coil removes noise from the signal generator from the electric waveform before reaching the electrode that is attached to the second coil.

3. The system of claim 1, wherein the signal transformer device comprises a light-weight core between the first coil and the second coil, and

wherein light-weight core comprises air or a rare earth element.

4. The system of claim 1, wherein the capacitor is coupled to the second coil in parallel,

wherein the capacitor preferentially filters certain frequencies from the electric waveform and passes other frequencies to the electrode.

5. The system of claim 1, wherein the capacitor prevents noise from being established between contacts of the electrode,

wherein the noise comprises a continuous DC-flow.

6. The system of claim 5, wherein the contacts of the electrode each comprise a different electrode material, size, shape, or surface configuration.

7. The system of claim 1, wherein the capacitor has a capacitance of at most 0.1 microfarad.

8. The system of claim 1, wherein the second coil amplifies a voltage or current value of the waveform before passing the waveform to the electrode.

9. A system for neural stimulation, block, or sensing, the system comprising:

a signal generator that generates a waveform having a plurality of components, each of the components having a different resonance frequency, wherein the waveform is fed to a primary transmission lead;

a plurality of electrodes connected to additional components in a secondary transmission lead defining the specific resonance frequency at which the electrode is being operated,

a lead comprising the primary transmission lead and the secondary transmission lead, wherein the lead provides and electrical coupling of the electrodes to the signal generator through means of mechanical attachment and non-faradic electrical coupling that allows the transmission of electric energy preferentially to at least one of a plurality of electrodes based on matched resonance frequency between the signal generator signal and the secondary transmission lead that is directly coupled to the electrode,

wherein each of the electrodes is tuned to a different one of the plurality of components of the waveform based on the resonance frequency.

10. The system of claim 9, wherein the mechanical attachment between the primary transmission lead and the secondary transmission lead facilitates a stable inductive or capacitive coupling of the electric energy from the signal generator to the plurality of leads without a direct faradaic connection between the signal generator and the plurality of electrodes.

11. The system of claim 9, wherein the lead provides mechanical coupling by an insulator that allows permanent or temporary attachment, loosening and reattachment of a secondary transmission lead to various locations on the primary transmission lead.

12. The system of claim 9, wherein the lead selectively transfers electric energy preferentially from the signal generator to at least one of the plurality of electrodes.

13. The system of claim 12, wherein an inductive coupling between the primary and the secondary lead facilitates a voltage multiplication to the at least one of the plurality of electrodes by frequency-selective activation of a secondary lead that features a larger winding ratio than the windings in its electric proximity on the primary lead, the ratio of winding differences facilitating the inductive transformation of the signal voltage arriving at the electrode.

14. A method for avoiding saturation during neural stimulation, block, or sensing, the method comprising:

receiving, by a first coil of a signal transformer device, an electrical waveform from a signal generator device, wherein the first coil prevents saturation of the electrical waveform at an output of the signal generator device; and

passing, by a second coil of the signal transformer device, the electrical waveform to at least one of a plurality of electrodes, wherein the second coil is coupled to a capacitor that prevents saturation of the waveform at the at least one of the plurality of electrodes.

15. The method of claim 14, further comprising ensuring that the electrical waveform that reaches the plurality of electrodes is not contaminated by DC components, thereby preventing a change in pH in proximity to the plurality of electrodes and preserving health of the neural tissue in proximity to the electrodes.

16. The method of claim 14, wherein the signal generator intentionally generates a monophasic or charge-unbalanced biphasic electrical waveform, which requires less energy to generate than a charge-balanced biphasic electrical waveform.

17. The method of claim 16, wherein the signal transformer device transforms the monophasic electrical waveform or the charge-unbalanced electrical waveform into a charge-balanced biphasic waveform.

18. The method of claim 14, wherein at least one of the first coil and the second coil is coupled to a fixed or adjustable component to adjust a tuning frequency of an electromagnetic coupling within the signal transformer device,

wherein the component comprises at least one of a resistor, a capacitor, and an inductor.

19. The method of claim 14, wherein the first coil is coupled to a capacitor, and

further comprising:

measuring a value of a DC offset on the capacitor; and

using feedback logic to eliminate the DC offset.

20. A method comprising:

selectively activating one or more electrodes for neural stimulation or block by having a primary component of a lead directly coupled to a signal generator and a multitude of secondary components of the leads coupled to electrodes, wherein each of the secondary components operates at a specific resonance frequency; and

transferring electric energy from the signal generator to one or more electrodes at specific ratios resulting from a matching of the generator'"'"'s signal frequency components and the resonance frequency of the secondary leads.

21. The method of claim 20, further comprising filtering a preferential signal transfer of intended vs. unintended signal components from the signal generator to one or more electrodes.