Selective Neural Stimulation Using Refractory Shadowing

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Solution Overview

Problem

Current methods for treating appendicular and axial symptoms of Parkinson's disease, such as tremor and balance issues, are hindered by the proximity of neural elements in the subthalamic region, making true frequency-independent stimulation cumbersome or unrealistic due to overlapping neural elements.

Innovation Solution

The use of two independently programmed stimulation fields at different frequencies or patterns, where the first stimulation is applied to one set of neural elements, and after they enter a refractory period, the second stimulation is applied to another set, ensuring selective excitation without exciting the first set, utilizing refractory shadowing to achieve independent and non-cumbersome stimulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple stimulations at different frequencies are applied to treat different symptoms, then multiple symptoms can be treated simultaneously, but the proximity of neural elements causes cumulative excitation effects that reduce stimulation selectivity

Engineering Contradiction:

Improveability to treat multiple symptomsVSAvoidstimulation selectivity

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies periodic stimulation with specific pulse trains at different frequencies (e.g., 130 Hz for appendicular symptoms, 65 Hz for axial symptoms) to selectively activate different neural element groups. By controlling the timing and frequency of periodic pulses, the system achieves frequency-independent stimulation where each frequency targets specific neural populations without cumulative excitation of overlapping elements.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent delivers a preliminary stimulation pulse train to a first group of neural elements, allowing them to enter a refractory period before applying a second stimulation to a different group of neural elements. This preliminary action ensures that when the second stimulation is applied, the first neural elements are temporarily unresponsive, preventing cumulative excitation effects.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If neural elements are stimulated at high frequency to treat appendicular symptoms, then symptom relief is achieved, but adjacent neural elements may also be excited causing unwanted effects

Engineering Contradiction:

Improvesymptom treatment effectivenessVSAvoidunwanted excitation of adjacent neural elements

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different stimulation frequencies and patterns to different local regions or neural element groups within the same brain region. By tailoring the stimulation parameters (frequency, pulse width, amplitude) to specific local neural populations, the system achieves selective activation of target neural elements while minimizing excitation of adjacent non-target elements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses preliminary stimulation to drive the first group of neural elements into a refractory period, creating a temporal window where these elements are protected from subsequent stimulation. This preliminary action effectively shields the first neural group from unwanted excitation when the second stimulation is applied to a different neural group.

Inventive Principle:

Principle #10Preliminary action

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

This approach allows for the simultaneous treatment of multiple symptoms in the same brain region without the undesired cumulative excitation effect, providing an additive effect for symptom relief.

Implementation Method 1

After a time to ensure the first set of neural elements has entered a refractory period, the second stimulation can be applied to a second location in the region of the brain to trigger an excitation period for a second set of neural elements

Methodology Applied

Scientific EffectRefractory period:

Data Source

PatentUS20230405323A1Selective stimulation of groups of neural elements within a region of the brain

Publication Date: 2023.12.21 CASE WESTERN RESERVE UNIV

AI summary

Symptoms of maladies originating in the same region of a brain can be treated with selective multifrequency stimulation. A first stimulation at a first frequency and a second stimulation at a second frequency can be generated by a signal generator. The first stimulation can be applied to a first location in the brain region to trigger an excitation period for a first set of neural elements in the brain region to treat at least one symptom of the malady. The second stimulation can be applied, after a time to ensure the first set of neural elements has entered a refractory period, to a second location in the brain region to trigger an excitation period for a second set of neural elements in the brain region to treat the at least one symptom and/or at least another symptom. The first set of neural elements is not excited by the second stimulation.