Neurostimulation Electrode Array Using Channel-Hopping Interleaved Pulse Scheduling
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Solution Overview
Problem
Current prosthetic devices lack effective sensory feedback systems, leading to increased cognitive load and reduced functionality for individuals with upper limb amputations, as they rely heavily on visual cues and attention, and existing non-invasive methods suffer from limited efficacy and discomfort due to localized charge densities.
Innovation Solution
A novel neurostimulation approach using channel-hopping interleaved pulse scheduling (CHIPS) with strategically distributed electrodes delivers sub-threshold current pulses across multiple channels, leveraging spatiotemporal summation to provide comfortable, graded tactile percepts without discomfort or tissue damage, enabling intuitive sensory feedback for prosthetic control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrical stimulation is delivered through a single electrode to activate sensory fibers, then sensation quality and selectivity are improved, but localized charge density increases causing discomfort and tissue damage
Solution Approach 1:
The patent divides the stimulation task across multiple electrodes (at least three electrodes arranged in a triangle around the nerve) rather than using a single electrode. Each electrode delivers sub-threshold pulses sequentially, and their combined effect achieves supra-threshold activation of the target nerve while distributing charge density across multiple contact points, preventing localized tissue damage and discomfort
Solution Approach 2:
The patent combines the effects of multiple sub-threshold stimulation pulses delivered sequentially from different electrodes. The pulses are timed to summate at the target nerve, creating a supra-threshold effect that activates sensory fibers. This merging of sub-threshold effects achieves the desired sensation quality while keeping individual electrode charge densities low
2Device complexity
If non-invasive mechanical or electro-tactile stimulation is used to convey sensory information, then device complexity is reduced, but sensation intuitiveness and efficacy decrease due to percept modality mismatch
Solution Approach 1:
The patent replaces mechanical or electro-tactile stimulation methods with electrical neurostimulation delivered through multiple electrodes. This substitution enables direct activation of sensory fibers in peripheral nerves, evoking somatotopically-matched distally referred sensations that are intuitive and effective, while maintaining relatively simple device architecture
Solution Approach 2:
The patent changes the stimulation parameters by delivering brief, low-amplitude, sub-threshold pulses sequentially from multiple electrodes rather than continuous or single-pulse stimulation. This parameter change enables supra-threshold activation at the target nerve through temporal and spatial summation, achieving intuitive sensations without requiring high charge densities that would cause discomfort
3Measurement precision
If implantable neuromodulation systems are used to activate sensory fibers, then sensation quality and selectivity are improved, but device complexity and invasiveness increase
Solution Approach 1:
The patent applies local quality by strategically positioning electrodes in specific anatomical locations around the target nerve (e.g., triangular arrangement). This localized electrode placement enables selective activation of sensory fibers in the target nerve while avoiding activation of adjacent structures, achieving high sensation quality and selectivity with a non-invasive external device rather than an implantable system
4Reliability
If high charge density is delivered to activate sensory fibers effectively, then sensation quality is improved, but tissue damage and electrode degradation occur
Solution Approach 1:
The patent uses partial action by delivering sub-threshold pulses from each individual electrode that, when applied alone, would not activate the target nerve. However, the sequential combination of these partial effects through temporal and spatial summation achieves the necessary supra-threshold activation for effective sensation, while keeping individual electrode charge densities below damage thresholds
Solution Approach 2:
The patent employs periodic action by delivering stimulation pulses in a sequential, time-interleaved manner from multiple electrodes. Each electrode delivers brief pulses at specific time intervals, creating a periodic stimulation pattern that sums at the target nerve. This periodic delivery enables effective activation while allowing tissue recovery between pulses and distributing charge load over time
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The CHIPS strategy allows for selective activation of sensory fibers with reduced charge density, enhancing tactile perception and reducing cognitive load, enabling users to perform tasks without visual feedback and improving prosthetic control and embodiment.
Implementation Method 1
The systems and methods can leverage the spatiotemporal summation of short, sub-threshold current pulses interleaved across two or more independent stimulation channels
Data Source
AI summary
Systems and methods for delivering targeted neurostimulation therapies to the nervous system of a subject are provided. A set of electrodes can be strategically distributed around a target nerve, and the nerve can be activated though the electrodes using a channel-hopping interleaved pulse scheduling (CHIPS) stimulation strategy. The systems and methods can leverage the spatiotemporal summation of short, sub-threshold current pulses interleaved across two or more independent stimulation channels (hopping from channel to channel) and delivered across electrodes strategically placed in an interfering configuration around the target neural tissue.