Systems and methods for preventing noise in an electric waveform for neural stimulation, block, or sensing
Inventors
Assignees
Case Western Reserve University
Publication Number
US-12274882-B2
Publication Date
2025-04-15
Expiration Date
2034-05-12
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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.
Core Innovation
The invention relates to systems and methods for preventing unintended signal components, referred to as noise, in an electric waveform used for neural stimulation, nerve block, and/or neural sensing. Specifically, the system utilizes a signal generator to produce an electric waveform that may contain both the intended signal and unwanted noise. A signal transformer device comprising a first and second coil is positioned between the signal generator and the electrode. The first coil receives the waveform and removes unintended noise components before the signal is sent onward.
A capacitor is coupled to the second coil of the signal transformer and is strategically located between this coil and the electrode. This component is configured to prevent additional noise from developing at the electrode/electrolyte interface, a region known to be prone to potential differences and pH changes that can damage nerve tissue. The overall filter system involves passive electric circuit components, including inductors and capacitors, optimized for compact size and weight.
The problem addressed by this invention is that high-frequency waveforms, such as kilohertz frequency alternating current (KHFAC) used for nerve block, are susceptible to contamination by low-frequency noise or DC offsets, which can lead to persistent nerve conductivity reduction or tissue damage. Traditional approaches like using capacitors or shunting resistors are not practical or feasible at these frequencies, as they do not adequately discharge DC imbalances. The disclosed system ensures that the waveform reaching neural tissue is free from harmful DC contamination and unintended noise, thereby protecting both the neural tissue and the associated devices.
Claims Coverage
There are two independent claims, each introducing a main inventive feature: (1) a method for removing signal noise before electrical waveform delivery, and (2) a filter system configured to remove signal noise before delivery to an electrode.
Method for removing signal noise before electric waveform delivery
This method involves: - Receiving, by a first inductive coil within a filter system, a signal consisting of an electrical waveform and signal noise generated by a signal generator. - Removing the signal noise via the filter system, which includes the first inductive coil electromagnetically coupled to a second inductive coil with a lightweight core separating them, and a capacitor coupled in parallel to the second inductive coil and to the electrode. - Delivering the electric waveform to the electrode for neural stimulation or nerve block, where the capacitor prevents additional noise from developing at the electrode/electrolyte interface.
Filter system for removing signal noise before electrode delivery
This system comprises: - A first inductive coil to receive an electrical signal that includes both waveform and signal noise. - A second inductive coil electromagnetically coupled to the first, configured for signal transfer and noise removal. - A lightweight core separating the inductive coils. - A capacitor coupled in parallel to the second inductive coil and also to at least one electrode, and located between the second inductive coil and the electrode, to prevent additional noise from developing at the electrode/electrolyte interface.
The inventive features focus on a specific arrangement of inductive coils, a lightweight core, and a capacitor—to remove signal noise before neural stimulation or nerve block, while preventing noise development at the electrode/electrolyte interface.
Stated Advantages
Prevents contamination of electric waveforms with unintended signal components such as DC noise, thereby protecting nerve tissue from electrochemical damage.
Removes noise automatically without the limitations of conventional capacitors or shunting resistors, even for high-frequency waveforms such as KHFAC.
Maintains the health of neural tissue and electrode integrity by preventing pH changes and electrochemical reactions at the electrode/electrolyte interface.
Provides a compact and lightweight filter system using entirely passive components for improved practicality in neural applications.
Documented Applications
Neural stimulation using electric waveforms with reduced noise for improved safety and efficacy.
Nerve conduction block applications, including temporary nerve block using KHFAC waveforms with minimized DC contamination.
Neural sensing applications, including acquisition of neural or muscular signals such as electroneurogram (ENG), electromyogram (EMG), or electrooculogram (EOG), with filtered signals free of DC potential differences.
Use in neural prosthesis devices for motor, sensory, or cognitive function restoration, as well as electrode arrays, spiral electrodes, cuff electrodes, and other electrical interfaces for nerves.
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