Neurostimulator Passive Charge Recovery Using Segmented Electrodes

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Solution Overview

Problem

Existing neurostimulation systems face challenges in efficiently passively recovering charge, particularly with directional leads, leading to charge accumulation and undesired side effects due to higher impedance in segmented electrodes, which complicates therapeutic efficacy over time.

Innovation Solution

A system and method that allows clinicians to selectively use additional electrodes for passive charge recovery, controlled through a user interface or algorithm, to reduce impedance and enhance charge removal from untargeted neural tissue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If segmented electrodes are used for directional leads, then therapeutic precision is improved, but charge recovery speed deteriorates due to higher impedance

Engineering Contradiction:

Improvetherapeutic precisionVSAvoidcharge recovery speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The lead is divided into multiple segmented electrodes around the periphery, allowing selective activation of specific segments to target precise neural pathways while maintaining directional control. Each segment can be independently controlled to deliver stimulation to specific anatomical regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple segmented electrodes are combined to function as passive recovery electrodes simultaneously. During the passive recovery phase, several segments that are not currently delivering stimulation are activated to collectively recover charge, effectively merging their recovery functions to overcome the high impedance of individual segments.

Inventive Principle:

Principle #5Merging (Combining)

2Device complexity

If only activated electrodes are used for passive charge recovery, then device complexity is reduced, but charge accumulation occurs causing side effects

Engineering Contradiction:

Improvedevice complexityVSAvoidcharge accumulation side effects

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

Electrodes are designed to serve multiple functions: they can be activated electrodes during stimulation phases and passive recovery electrodes during recovery phases. This multi-functionality allows the same electrode array to perform both stimulation delivery and charge recovery, eliminating the need for separate electrode sets.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically switches electrode roles between stimulation and recovery phases. Electrodes that are inactive during stimulation become active during passive recovery, and this role assignment changes dynamically based on which electrodes are currently delivering stimulation, optimizing charge recovery at each moment.

Inventive Principle:

Principle #15Dynamics

3Use of energy by moving object

If passive charge recovery is used, then power consumption is reduced, but charge removal speed is insufficient at higher frequencies

Engineering Contradiction:

Improvepower consumptionVSAvoidcharge removal speed

Core Design Contradiction:

Use of energy by moving objectVSSpeed

Solution Approach 1:

Multiple passive recovery electrodes are combined to work simultaneously during the recovery phase. By merging the recovery function across several electrodes, the total charge recovery capacity increases, enabling sufficient charge removal even at higher stimulation frequencies while maintaining passive (low power) operation.

Inventive Principle:

Principle #5Merging (Combining)

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

Enhances passive charge recovery speed, increases therapeutic window, and reduces side effects by distributing charge recovery across a larger electrode surface area, maintaining effective neurostimulation therapy.

Implementation Method 1

delivering neurostimulation pulses of a first polarity to a neural target using at least one stimulation electrode from the plurality of electrodes

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

passively recovering charge using a first number of one or more passive electrodes from the plurality of electrodes

Methodology Applied

Scientific EffectPassive charge recovery: Conduction (electrical)

Data Source

PatentUS20250229092A1Neurostimulation with enhanced passive recovery

Publication Date: 2025.07.17 BOSTON SCI NEUROMODULATION CORP

AI summary

A system may include a neurostimulator and a programmer. The neurostimulator may have a plurality of electrodes, and may be configured to deliver neurostimulation by delivering neurostimulation pulses of a first polarity to a neural target using at least one stimulation electrode from the plurality of electrodes and passively recovering charge using a first number of one or more passive electrodes from the plurality of electrodes. The programmer may have a user interface configured to receive a user input for changing a number of passive electrodes used to passively recover charge from the first number to a second number. The programmer may be configured to control the neurostimulator to passively recover charge using the second number of passive electrodes. Some examples may include fractionalization to control the contribution of each passive electrode used to recover charge. A variable impedance may be used to control a relative charge recovery current.