Transvenous Phrenic Nerve Stimulation Lead with EGM Sensing

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Solution Overview

Problem

Current transvenous phrenic nerve stimulation methods risk inadvertent cardiac stimulation, leading to arrhythmias due to the proximity of electrodes to the heart, which is not effectively minimized by existing techniques.

Innovation Solution

The method involves using a multipolar lead with electrodes positioned along the venous system to selectively stimulate the phrenic nerves while employing EGM sensing and impedance monitoring to ensure safe electrode placement, avoiding cardiac capture by adjusting stimulation parameters and lead positioning based on sensed cardiac signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If transvenous electrodes are positioned in proximity to the phrenic nerve for stimulation, then less invasive implantation is achieved, but the risk of inadvertent cardiac stimulation increases

Engineering Contradiction:

Improveimplantation invasivenessVSAvoidcardiac stimulation risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The venous system is segmented into multiple electrode positioning sites (SVC, IVC, hepatic veins, renal veins), allowing selection of optimal segments that provide phrenic nerve access while maintaining safe distance from the heart. The lead is divided into multiple electrode pairs that can be independently activated based on positioning

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

EGM sensing serves as an intermediary monitoring mechanism that detects cardiac electrical activity in real-time. When cardiac signals are detected, the system automatically adjusts or prevents stimulation, using the sensed cardiac activity as a mediator to prevent harmful cardiac capture while maintaining phrenic nerve stimulation capability

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If electrodes are positioned closer to the phrenic nerve for effective stimulation, then stimulation efficacy is improved, but the risk of cardiac capture increases

Engineering Contradiction:

Improvephrenic nerve stimulation efficacyVSAvoidcardiac capture risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts stimulation parameters (amplitude, pulse width, frequency) and electrode selection based on real-time EGM sensing feedback. Lead positioning can be adjusted during implantation and follow-up based on sensed cardiac activity patterns, optimizing the balance between phrenic nerve capture and cardiac safety

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Stimulation parameters are changed based on detected conditions - when EGM signals indicate proximity to cardiac tissue, the system modifies amplitude, pulse width, or frequency parameters to avoid cardiac capture while maintaining phrenic nerve stimulation. Threshold-based parameter adjustment ensures safe operation

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If lead positioning is adjusted to avoid cardiac tissue, then cardiac stimulation risk is reduced, but phrenic nerve stimulation effectiveness may be compromised

Engineering Contradiction:

Improvecardiac stimulation riskVSAvoidphrenic nerve stimulation effectiveness

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

Multiple electrode pairs along the lead serve universal functionality - they can be used for phrenic nerve stimulation when positioned appropriately, or for cardiac monitoring and pacing when needed. The same lead structure supports multiple functions depending on positioning and activation patterns

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Real-time feedback from EGM sensing informs lead positioning decisions and stimulation parameter selection. The system continuously monitors cardiac electrical activity and uses this feedback to determine optimal electrode activation patterns that achieve phrenic nerve stimulation while avoiding cardiac capture

Inventive Principle:

Principle #23Feedback

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 effectively minimizes the risk of cardiac stimulation during phrenic nerve therapy, ensuring safe and effective respiratory support by accurately positioning electrodes and adjusting stimulation parameters to avoid cardiac capture.

Implementation Method 1

Stimulation of the right and left phrenic nerves to cause contraction of the diaphragm has been proposed for treating respiratory insufficiency

Methodology Applied

Scientific EffectElectrical stimulation: Electrical Impedance Tomography

Implementation Method 2

employing EGM sensing and impedance monitoring to ensure safe electrode placement, avoiding cardiac capture by adjusting stimulation parameters and lead positioning based on sensed cardiac signals

Methodology Applied

Scientific EffectElectrical signal sensing: Electrical Impedance Tomography

Implementation Method 3

employing EGM sensing and impedance monitoring to ensure safe electrode placement

Methodology Applied

Scientific EffectImpedance monitoring: Electrical Impedance Tomography

Data Source

PatentUS8706235B2Transvenous method to induce respiration

Publication Date: 2014.04.22 MEDTRONIC INC

AI summary

A system and method for delivering a nerve stimulation therapy determines whether a cardiac EGM signal can be sensed by a bipolar pair of electrodes selected from a number of electrodes positioned for stimulating a nerve. In response to not being able to sense a cardiac signal using the bipolar pair, stimulation of the nerve using a selected pair of the electrodes is enabled.