Implantable Lead Connector Assembly for High-Density Contact Alignment
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Solution Overview
Problem
Existing connector assemblies for implantable medical devices face challenges in efficiently establishing electrical connections between device electronics and leads, particularly in accommodating multiple leads within a limited space without expanding the device size and ensuring reliable contact deflection and handling integrity.
Innovation Solution
The connector assemblies incorporate a cover assembly and a feedthrough assembly with detachable or permanently attached contact configurations, such as contact ring, leaf spring, and torsion spring contacts, which are designed to align and compress with lead contacts, providing a higher contact density and secure electrical connections through innovative retention mechanisms and materials like nitinol and platinum-iridium alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If stamped compressive leaf contacts are used in known connector assemblies, then electrical connections can be established between device electronics and leads, but the device size must be increased to accommodate multiple leads
Solution Approach 1:
The connector assembly nests multiple electrical contacts within a compact feedthrough assembly structure. The feedthrough pins and compressive leaf contacts are arranged in a nested configuration where contacts are positioned within the feedthrough assembly volume, allowing multiple leads to be connected without proportionally increasing device size. The clamping cover with elastomeric seals receives and organizes multiple leads in a compact arrangement.
Solution Approach 2:
The connector assembly utilizes three-dimensional spatial arrangement of contacts and leads. The feedthrough pins extend through the feedthrough substrate in the vertical dimension, while compressive leaf contacts are arranged in multiple layers and positions. This multi-dimensional contact arrangement allows higher contact density within the available volume, enabling more leads to be accommodated without simply expanding the device footprint.
2Reliability
If compressive leaf contacts are permanently attached to feedthrough pins by laser welding, then reliable electrical connections are established, but manufacturing complexity and precision requirements increase
Solution Approach 1:
The compressive leaf contacts are designed to be self-aligning and self-compressing against the feedthrough pins and lead contacts. The elastic material properties of the leaf contacts provide automatic positioning and compression force, eliminating the need for complex laser welding alignment procedures. The contacts naturally deflect to establish reliable electrical connection upon assembly, reducing manufacturing precision requirements.
Solution Approach 2:
The invention changes the attachment method from permanent laser welding to a combination of mechanical retention and elastic compression. The compressive leaf contacts are retained in a retained position during assembly, then allowed to compress elastically against the contacts. This parameter change from rigid welding to elastic compression simplifies manufacturing while maintaining reliable electrical connection.
3Quantity of substance
If the connector assembly is designed to receive multiple leads, then higher contact density is achieved, but contact deflection and handling integrity become more difficult to ensure
Solution Approach 1:
Each compressive leaf contact is designed with localized elastic properties optimized for its specific position and function. The leaf contacts have varying dimensions, thicknesses, and material compositions tailored to their local requirements for deflection and contact force. This local quality optimization ensures that each contact maintains integrity and proper deflection characteristics even in high-density multi-lead configurations.
Solution Approach 2:
The connector assembly uses composite material structures, particularly the elastomeric seals combining flexible polymer materials with conductive elements. The compressive leaf contacts may use composite or alloy materials that provide both elastic compliance for deflection and sufficient strength for handling integrity. This material composition allows the contacts to be both compliant enough to deflect properly and strong enough to maintain integrity in high-density arrangements.
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
These assemblies enable a higher density of electrical connections, allowing for more leads to be connected without increasing device size, ensuring reliable contact deflection and handling integrity, and providing improved attachability and handling of miniature contacts.
Implementation Method 1
Electrical contacts configured as contact ring assemblies, leaf spring contacts, or torsion spring contacts are permanently attached to the feedthrough contacts
Data Source
AI summary
An implantable medical device includes a cover assembly and a feedthrough assembly that couples with the cover assembly. The cover assembly receives a connector end of a lead having lead contacts, and aligns the lead contacts with pockets or apertures of the cover assembly. The feedthrough assembly may include feedthrough contacts in the form of feedthrough pins at or above a surface of a feedthrough substrate, or conductive vias on the surface of the substrate. Electrical contacts configured as leaf spring contact assemblies, torsion spring contacts, or torsion spring contact assemblies are permanently attached to the feedthrough contacts. When the cover assembly and feedthrough assembly are coupled, contact tabs of the electrical contacts are positioned in the pockets or apertures of the cover assembly. Upon complete seating of the cover assembly and feedthrough assembly, the contact tabs are compressed into contact with the lead contacts.