Implantable Lead Reinforcement Member for Electrode Exposure Control
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Solution Overview
Problem
Existing implantable medical leads face challenges in precisely controlling the exposure of electrodes during electrical stimulation therapy, particularly in confined or tortuous tissue environments like the heart, due to limitations in moving insulating members radially and axially, which affects the delivery of therapeutic signals.
Innovation Solution
The implementation of a reinforcement member, such as a braided wire structure, coupled with an insulating member to facilitate axial and radial movement over the lead body, allowing for precise control of electrode exposure and protection against MRI-induced RF fields and mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an insulating member is used to control electrode exposure, then electrode exposure control is improved, but the ability to move the insulating member radially and axially is limited
Solution Approach 1:
The insulating member is designed with dynamic movement capabilities, allowing it to transition between fixed and movable states. The member can be repositioned radially and axially along the lead body to selectively expose electrodes, providing both precise control and operational flexibility.
Solution Approach 2:
The insulating member is divided into multiple segments or sections that can move independently relative to each other. This segmentation allows different portions of the member to be positioned at different locations along the lead body, enabling selective electrode exposure while maintaining overall structural integrity.
2Ease of operation
If the lead is made flexible to navigate tortuous tissue environments, then ease of implantation is improved, but protection against mechanical stress and MRI-induced RF fields is reduced
Solution Approach 1:
The lead incorporates composite construction with multiple layers including flexible polymer insulation and embedded metallic reinforcement elements. This composite structure provides both the flexibility needed for navigation through tortuous tissue paths and the mechanical strength plus RF shielding required for reliable operation.
Solution Approach 2:
Different sections of the lead have different structural properties optimized for their specific functions. The proximal portion has enhanced reinforcement for mechanical strength and RF shielding, while the distal portion with electrodes maintains flexibility for tissue contact, achieving local optimization of both flexibility and protection.
3Reliability
If a reinforcement member is added to protect against mechanical stress and RF fields, then reliability is improved, but device complexity increases
Solution Approach 1:
The reinforcement member is designed to perform multiple functions simultaneously: providing mechanical strength to resist lead crush, offering RF shielding during MRI procedures, and serving as a structural framework for mounting the insulating member and electrodes. This multi-functionality reduces the need for separate components.
Solution Approach 2:
The reinforcement member combines structural support and electromagnetic shielding functions into a single integrated component. The metallic braid or mesh structure provides both mechanical reinforcement and RF interference shielding, merging two protective functions into one element.
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 configuration enables precise control over the delivery of electrical stimulation, enhances electrode exposure management, and provides shielding and protection against MRI-induced fields and mechanical stress, improving therapeutic efficacy and device durability.
Implementation Method 1
the reinforcement member is configured to transfer at least one of a radial or axial force from a proximal portion of the reinforcement member to the insulating member
Implementation Method 2
the reinforcement member may be configured to shield the lead body from RF fields generated during magnetic resonance imaging (MRI)
Data Source
AI summary
An implantable lead including a lead body including an outer surface, a proximal end, a distal end, and at least one electrode; an electrically insulating member that extends axially over a first portion of the outer surface of the lead body between the proximal end and distal end, the electrically insulating member defining at least one aperture that exposes a first portion of the at least one electrode when in a first position over the lead body; and a reinforcement member formed at least partially of a different material than the insulating member and coupled to the insulating member, the reinforcement member extending axially over the outer surface of the lead body between the insulating member and proximal end. The reinforcement member may be configured to transfer at least one of a radial or axial force from a proximal portion of the reinforcement member to the insulating member, wherein the at least one of radial or axial force transferred to the insulating member is sufficient to move the insulating member over the outer surface of the lead body. In some examples, the lead may further include a deployable lobe member configured to anchor the reinforcement member and insulating member adjacent a tissue site within a patient.