Implantable Lead Shield for Directed Cardiac Electric Fields
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable medical leads often require higher energy levels to capture and defibrillate the heart due to electrical fields being directed away from the heart, stimulating extracardiac tissue and increasing the risk of pain or other sensations, especially in patients with prior sternotomies where adhesions complicate lead placement.
Innovation Solution
The use of a separately implantable shield configured to impede the electric field from the medical lead, directing it away from the heart and reducing the likelihood of stimulating extracardiac tissue, allowing for lower energy levels to capture the heart and extending the ICD's service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If higher energy levels are used for pacing and defibrillation, then capture reliability is improved, but stimulation of extracardiac tissue increases causing pain and discomfort
Solution Approach 1:
The patent introduces an electrical shield as an intermediary component positioned between the pace electrode and extracardiac tissues. This shield mediates the electrical field by blocking its direct interaction with extracardiac structures, thereby enabling effective cardiac capture at lower energy levels without stimulating painful extracardiac tissues.
Solution Approach 2:
The shield is selectively positioned over specific portions of the pace electrode, creating localized modification of the electrical field. This local quality approach allows the electrical field to be directed toward the heart while blocking extracardiac stimulation in specific anatomical regions, balancing capture effectiveness with pain reduction.
2Reliability
If higher energy levels are used for defibrillation, then defibrillation effectiveness is improved, but patient perception of therapy increases
Solution Approach 1:
The electrical shield serves as a mediator that allows defibrillation therapy to be delivered effectively to the heart while preventing the electrical field from directly stimulating extracardiac tissues that would be perceived by the patient. This enables lower energy defibrillation without compromising effectiveness or increasing patient discomfort.
3Ease of manufacture
If conventional extravascular lead placement is used, then ease of implantation is improved, but electrical field directionality is poor leading to energy waste
Solution Approach 1:
The shield acts as an intermediary that improves energy efficiency by directing the electrical field generated by the pace electrode toward the heart. This directional control reduces energy waste from field dispersion and enables effective therapy delivery using lower energy levels, while maintaining the simplicity of extravascular lead placement.
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
The shield reduces the likelihood of stimulating extracardiac tissue, decreases patient perception of pacing therapy, and lowers energy consumption, thereby extending the ICD's service life.
Implementation Method 1
a pace electrode configured to deliver a pacing pulse that generates an electric field proximate to the pace electrode
Implementation Method 2
The shield is configured to impede an electric field of the electrical therapy in a direction from at least one of the first defibrillation electrode, the second defibrillation electrode, or the pace electrode away from a heart of the patient
Data Source
AI summary
An example medical device system includes an implantable medical lead including a first defibrillation electrode and a second defibrillation electrode, the first and second defibrillation electrodes configured to deliver antitachyarrhythmia shocks, and a pace electrode disposed between the first defibrillation electrode and the second defibrillation electrode, the pace electrode configured to deliver a pacing pulse that generates an electric field proximate to the pace electrode. The medical device system includes a shield configured to be implanted in a patient separately from the implantable medical lead and disposed anterior at least one of the electrodes, wherein the shield is configured to impede an electric field of the electrical therapy in a direction from at least one of the first defibrillation electrode, the second defibrillation electrode, or the pace electrode away from a heart of the patient.