Substernal ICD Lead Layout for Defibrillation and Pacing Comfort

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Solution Overview

Problem

Subcutaneous ICD systems require high energy for defibrillation, leading to larger size, increased cost, and reduced patient comfort, while lacking anti-tachycardia pacing capabilities without extreme discomfort.

Innovation Solution

An implantable substernal ICD system with a lead positioned within the anterior mediastinum, delivering electrical stimulation therapy via electrodes without entering the vasculature or attaching to the heart, capable of defibrillation, cardioversion, and pacing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If subcutaneous ICD systems are used to avoid lead wires within the heart, then surgical risks are reduced, but energy requirements increase to around 80 Joules

Engineering Contradiction:

Improvesurgical safetyVSAvoiddefibrillation energy

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces an intermediary substance (conductive gel or saline) between the subcutaneous electrodes and the heart to improve electrical coupling. This mediator reduces the impedance and energy requirements for defibrillation by facilitating more efficient current transmission through the chest wall and into the heart, thereby resolving the contradiction between surgical safety and energy consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If subcutaneous ICD systems deliver high energy shocks, then defibrillation effectiveness is achieved, but device size increases due to larger batteries and capacitors

Engineering Contradiction:

Improvedefibrillation effectivenessVSAvoiddevice size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the electrical parameters of the system by introducing conductive media that reduce impedance and improve current distribution. This allows for more efficient energy transfer, enabling the use of smaller batteries and capacitors while maintaining defibrillation effectiveness, thus resolving the contradiction between reliability and device size.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If subcutaneous ICD systems are designed with smaller components, then patient comfort and system longevity improve, but energy output for defibrillation is reduced

Engineering Contradiction:

Improveenergy efficiencyVSAvoiddefibrillation capability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The conductive gel or saline acts as an intermediary that amplifies the efficiency of energy transmission. By improving the electrical coupling between electrodes and heart tissue, smaller energy outputs can achieve the same defibrillation effect, resolving the contradiction between energy efficiency and defibrillation capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If conventional subcutaneous ICD systems are used, then defibrillation is possible, but anti-tachycardia pacing cannot be delivered without extreme patient discomfort

Engineering Contradiction:

Improvedefibrillation functionVSAvoidpacing comfort

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by using conductive media specifically at the electrode-heart interface to improve current distribution and reduce current density at any single point. This allows for lower intensity pacing stimuli that are effective yet comfortable for the patient, resolving the contradiction between defibrillation reliability and pacing comfort.

Inventive Principle:

Principle #3Local quality

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

Reduces energy requirements for defibrillation, decreases device size, enhances patient comfort, and provides effective anti-tachycardia pacing, improving system longevity and reducing discomfort.

Implementation Method 1

The ICD is configured to deliver electrical stimulation to a heart of the patient using the one or more electrodes

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS12472370B2Implantable cardioverter-defibrillator (ICD) system including substernal lead

Publication Date: 2025.11.18 MEDTRONIC INC

AI summary

Substernal implantable cardioveter-defibrillator (ICD) systems and methods for providing substernal electrical stimulation therapy to treat malignant tachyarrhythmia, e.g., ventricular tachycardia (VT) and ventricular fibrillation (VF) are described. In one example, an implantable cardioveter-defibrillator (ICD) system includes an ICD implanted in a patient and an implantable medical electrical lead. The lead includes an elongated lead body having a proximal end and a distal portion, a connector at the proximal end of the lead body configured to couple to the ICD, and one or more electrodes along the distal portion of the elongated lead body. The distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the ICD is configured to deliver electrical stimulation to a heart of the patient using the one or more electrodes.