Implantable Pulse Generator Current Architecture for Multi-Electrode Control

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Solution Overview

Problem

Current implantable pulse generators for spinal cord stimulation systems face challenges in efficiently managing stimulation currents across multiple electrodes, requiring complex circuitry and limited resolution in current distribution, which can lead to suboptimal therapy delivery and increased power consumption.

Innovation Solution

The improved pulse generator architecture incorporates a digital-to-analog converter (DAC) circuitry that can operate in multiple modes, allowing independent control of source and sink circuits to manage current distribution across electrodes with higher resolution and flexibility, enabling precise current delivery and optimizing power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex circuitry is used to manage stimulation currents across multiple electrodes, then current distribution control is improved, but device complexity and power consumption increase

Engineering Contradiction:
Improvecurrent distribution controlVSAvoidcircuitry complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the current management function by introducing independent source circuits and sink circuits that can be individually controlled. Each circuit is assigned specific electrodes, allowing precise current distribution control without requiring complex centralized circuitry. This segmentation enables simpler, modular circuit design while maintaining high control precision.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If complex circuitry is used to manage stimulation currents across multiple electrodes, then current distribution control is improved, but power consumption increases

Engineering Contradiction:
Improvecurrent distribution controlVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

By segmenting the current management into independent source and sink circuits with individual control, the system achieves precise current distribution without requiring all circuits to operate at maximum capacity simultaneously. This allows for more efficient power management and reduced overall power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent enables dynamic adjustment of current parameters (amplitude, duration, polarity) through independent control of source and sink circuits. This parameter flexibility allows optimization of power consumption by delivering precise current levels only when and where needed, rather than using fixed high-power settings.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If limited resolution in current distribution is used, then device complexity is reduced, but therapeutic outcome quality deteriorates

Engineering Contradiction:
Improvecircuitry simplicityVSAvoidtherapeutic outcome quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The segmentation into independently controllable source and sink circuits provides fine-grained control over current distribution. This level of control enables high-resolution current delivery to specific electrodes, ensuring optimal therapeutic outcomes while keeping each individual circuit relatively simple in design.

Inventive Principle:
Principle #1Segmentation

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 solution enhances the precision and efficiency of current delivery to spinal cord stimulation electrodes, improving therapeutic outcomes while reducing power consumption and simplifying the device architecture.

Implementation Method 1

digital-to-analog converter (DAC) circuitry that can operate in multiple modes, allowing independent control of source and sink circuits to manage current distribution across electrodes

Methodology Applied
Scientific EffectDigital-to-Analog Conversion:

Data Source

PatentEP3478358B1Use models for a current generation architecture for an implantable medical device
Publication Date: 2021.04.14 BOSTON SCI NEUROMODULATION CORP
  • EP3478358B1 patent drawingFigure 1A~1C
  • EP3478358B1 patent drawingFigure 2A
  • EP3478358B1 patent drawingFigure 2B

AI summary

Current generation circuitry for an Implantable Pulse Generator (IPG) is disclosed. The IPG comprises a plurality of PDACs and NDACs for souring currents to electrode nodes. The PDACs and NDACs can be configured as pairs to each provide stimulation in independent timing channels, or the PDACs can be combined and the NDACs can be combined to provide stimulation in a single timing channel. Further, the PDAC or NDAC can provide a plurality of source branch currents each of the same amplitude to the electrodes via a switch matrix, and pulse definition circuitry can be configured to always connect each of the source branch currents to one of the first one or more electrode nodes via the switch matrix.