Leaf Spring Contact Assemblies for Implantable Leads

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Solution Overview

Problem

Existing contact assemblies for neurological stimulation systems face challenges in providing a robust and reliable electrical connection while allowing simple, low-force coupling and decoupling, and requiring a compact design to minimize patient discomfort and bulges at the implant site, often resulting in expensive and intricate designs.

Innovation Solution

The use of contact assemblies with housings that incorporate leaf spring portions, which can be shaped in various manners such as arcuate, curved, or angled, to provide a flexible and secure connection with other device components like leads and lead extensions, facilitating secure and easy coupling and decoupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional contact assemblies are used to provide robust electrical connections, then reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidcontact assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The contact assembly is segmented into distinct functional components: a contact member with contact surface, a housing with receiving cavity, and a leaf spring mechanism. This segmentation allows each component to be optimized independently for its specific function while simplifying the overall design and manufacturing process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The leaf spring portion automatically provides contact force and maintains electrical connection without requiring external actuation or complex control mechanisms. The spring's elastic properties enable it to self-adjust to insertion forces and maintain reliable contact throughout the device's operational life.

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional contact assemblies are used to ensure robust connections, then reliability is improved, but insertion and extraction forces increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidinsertion and extraction force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The contact assembly transitions from a static rigid connection to a dynamic spring-based connection. The leaf spring portion can deform elastically during insertion and extraction, absorbing mechanical forces and reducing the peak forces required for coupling and decoupling operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mechanical properties of the contact assembly are changed by introducing a spring mechanism with specific elastic characteristics. This allows the contact force to be maintained at optimal levels for electrical reliability while the spring's compliance reduces insertion and extraction forces through elastic deformation.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If compact contact assemblies are used to minimize patient discomfort, then patient comfort is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecontact assembly volumeVSAvoidmanufacturing simplicity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

Multiple functions are merged into a single integrated housing component: the housing provides structural support, defines the receiving cavity for the contact member, and contains the leaf spring mechanism. This consolidation reduces the number of separate parts and simplifies assembly while maintaining a compact overall size.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing serves multiple purposes simultaneously: it protects internal components, provides a mounting structure for the contact member, contains the leaf spring mechanism, and interfaces with the lead body. This multi-functionality reduces the number of components needed and simplifies the overall device architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 leaf spring-based contact assemblies offer a robust and reliable electrical connection with reduced insertion/extraction forces, enhancing the reliability of neurological stimulation systems while minimizing patient discomfort and the risk of faults, and are designed to be cost-effective and compact.

Implementation Method 1

contact assemblies with housings that incorporate leaf spring portions, which can be shaped in various manners such as arcuate, curved, or angled, to provide a flexible and secure connection

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2776118B1Medical device contact assemblies for use with implantable leads
Publication Date: 2021.09.22 NEVRO CORP
  • EP2776118B1 patent drawingFigure 1
  • EP2776118B1 patent drawingFigure 2~4
  • EP2776118B1 patent drawingFigure 5~6B

AI summary

Medical devices and contact assemblies for electrical connections between medical device components are disclosed herein. A medical device in accordance with a particular embodiment includes a patient implantable element having a receiving cavity and at least one contact assembly positioned in the receiving cavity. The contact assembly can include a housing having an annular shape with an inner surface defining at least in part an opening. The contact assembly can further include a contact disposed at least partially within the opening and having a plurality of leaf spring portions.