Electrical Stimulation Device Voltage Stack Optimization

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Solution Overview

Problem

Medical electrical stimulation devices face inefficiencies in energy consumption due to the need for higher voltage stack settings to achieve desired electrical stimulation amplitudes, leading to wasted energy and reduced battery longevity.

Innovation Solution

The electrical stimulation device determines and stores multiple sets of therapy parameters, including amplitude and pulse width, to deliver effective therapy while using a lower voltage stack setting, maintaining equivalent charge density through adjustments based on strength-duration curves and VOA models, and switching to initial parameters when lead impedance increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If higher voltage stack settings are used to achieve desired electrical stimulation amplitudes, then the electrical stimulation therapy effectiveness is improved, but energy consumption increases and battery longevity decreases

Engineering Contradiction:

Improveelectrical stimulation therapy effectivenessVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by determining alternative therapy parameters (amplitude, pulse width, frequency) that can achieve equivalent charge density and stimulation effectiveness at lower voltage stack settings. The system calculates different parameter combinations based on strength-duration curves and VOA models to reduce voltage while maintaining therapeutic effect, thereby reducing energy consumption and extending battery life.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If higher voltage stack settings are used to achieve desired electrical stimulation amplitudes, then the electrical stimulation therapy effectiveness is improved, but battery longevity decreases

Engineering Contradiction:

Improveelectrical stimulation therapy effectivenessVSAvoidbattery longevity

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system determines alternative parameter sets that reduce the required voltage stack setting while maintaining equivalent charge density and stimulation effectiveness. By calculating different amplitude-pulse width combinations based on strength-duration curves and VOA models, the system extends battery longevity through reduced power consumption while preserving therapeutic effectiveness.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If alternative therapy parameters are used to reduce voltage stack setting, then energy consumption is reduced and battery longevity is prolonged, but the system complexity increases due to multiple parameter sets

Engineering Contradiction:

Improveenergy consumptionVSAvoidsystem complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system performs preliminary calculations of alternative therapy parameters using strength-duration curves and VOA models during device initialization or programming phases. Multiple parameter sets are pre-computed and stored in memory, allowing the device to quickly select optimal parameters without real-time complex calculations, thus reducing operational complexity while maintaining energy efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system incorporates feedback mechanisms to monitor lead impedance and stimulation effectiveness, automatically selecting from pre-computed parameter sets the ones that achieve equivalent charge density at lowest voltage. This feedback-driven selection process manages system complexity by using stored parameter tables rather than real-time optimization calculations.

Inventive Principle:

Principle #23Feedback

4Reliability

If lead impedance increases, then the initial therapy parameters become less effective, but switching to alternative parameters may reduce energy efficiency

Engineering Contradiction:

Improvetherapy effectivenessVSAvoidenergy efficiency

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses feedback from lead impedance monitoring to detect when initial therapy parameters become less effective. When impedance changes are detected, the system switches to alternative pre-computed parameter sets that maintain equivalent charge density at lower voltages, thereby preserving energy efficiency while adapting to changing tissue conditions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP4049720A1Reduced power consumption for electrical stimulation therapy

Publication Date: 2022.08.31 MEDTRONIC INC

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AI summary

Devices, systems, and techniques are described for adjusting therapy parameters defining electrical stimulation therapy. An example system includes a stimulation generator comprising a voltage stack configured to provide a stack voltage based on a multiplier of a battery voltage and processing circuitry. The processing circuitry receives a first set of parameter values that use a first stack voltage of the voltage stack to provide a first electrical stimulation defining a first therapy. The processing circuitry also determines, based on a second stack voltage lower than the first stack voltage, a second set of parameter values that define a second electrical stimulation, the second set of parameters defining a lower amplitude of electrical stimulation. Additionally, the processing circuitry controls the stimulation generator to deliver the second electrical stimulation according to the second set of parameter values using the second stack voltage of the voltage stack.