Implantable Medical Device Connector With Nested Spring Contacts

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Solution Overview

Problem

Implantable medical devices face challenges in maintaining reliable electrical contact with multiple leads while minimizing size and preventing fluid intrusion, and the manufacturing process is complex and costly due to the need for precise alignment and compression of contact elements and seals.

Innovation Solution

The connector assembly features a cylindrical passage with alternating seal rings and conductive ring contact elements, including garter-type spring contacts and insulative bands, which provide a liquid-tight seal, facilitate easy assembly, and allow for increased contact elements without increasing device size, using external grooves for alignment and compression indicators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of electrical contact elements is increased, then more leads can be provided and electrical stimulation can be delivered to more locations, but the device size would need to be increased

Engineering Contradiction:
Improvenumber of electrical contact elementsVSAvoiddevice size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The connector assembly nests multiple contact elements within a compact cylindrical receptacle, with each contact element and seal element forming a concentric arrangement around a common bore. This nesting allows multiple functional elements to occupy overlapping spatial volumes, increasing the number of contacts without proportionally increasing device size.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention transitions from planar contact arrangements to a three-dimensional cylindrical configuration, stacking contact elements axially within the receptacle. This dimensional change allows more contacts to be packed into a compact volume by utilizing the radial and axial dimensions simultaneously rather than spreading contacts in a single plane.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the spacing between contact elements is decreased, then more contact elements can be accommodated in a given space, but the electrical path between contact elements is shortened which can cause arcing

Engineering Contradiction:
Improvenumber of contact elementsVSAvoidelectrical contact reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

Insulative bands are positioned between adjacent contact elements to serve as intermediary barriers that prevent electrical arcing. These bands maintain electrical isolation even when contact elements are closely spaced, allowing reduced spacing without compromising reliability. The insulative bands act as mediators that enable closer positioning while preserving electrical integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the spacing between contact elements is decreased, then more contact elements can be accommodated, but the width of elastomeric insulating spacers is reduced which can lead to fluid leaking into the IMD

Engineering Contradiction:
Improvenumber of contact elementsVSAvoidfluid intrusion
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The connector assembly uses composite construction with alternating conductive contact elements and insulative seal elements. This composite arrangement provides both electrical isolation and fluid sealing functions. The insulative bands made from materials like PEEK or Delrin provide robust barrier properties that maintain fluid tightness even when overall spacing is reduced, preventing fluid intrusion while accommodating more contacts.

Inventive Principle:
Principle #40Composite materials

4Reliability

If precise alignment and compression of contact elements and seals is required, then reliable electrical contact and fluid sealing can be achieved, but the manufacturing process becomes complex and costly

Engineering Contradiction:
Improveelectrical contact and sealing reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The connector assembly is pre-assembled with contact elements and seal elements in alternating sequence before final installation. This preliminary assembly establishes proper alignment and compression relationships in advance, ensuring reliability while simplifying the final manufacturing integration. The alternating pattern is built-in during assembly, eliminating the need for complex post-assembly adjustments.

Inventive Principle:
Principle #10Preliminary action

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 design ensures reliable electrical contact with multiple leads, prevents fluid intrusion, simplifies manufacturing, and allows for more efficient delivery of electrical stimulation while maintaining a compact device size, enhancing the durability and usability of implantable medical devices.

Implementation Method 1

The electrical contact elements are canted coil springs within circular conductive housings

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2473231B1Connector assemblies for use with implantable medical devices
Publication Date: 2016.10.26 BAL SEAL ENG CO INC
  • EP2473231B1 patent drawingFigure 1~1A
  • EP2473231B1 patent drawingFigure 2~2A
  • EP2473231B1 patent drawingFigure 3~3A

AI summary

Connector assemblies for use to concurrently transmit multiple signals or sources. The connector assemblies are generally formed by coupling a plurality of ring contacts, sealing rings, and spring contact elements together with at least one holding ring to form a connector having a common bore for receiving a lead cable. Contact grooves or spring chambers for positioning the spring contact elements are formed in part by assembling multiple components together. The connector assemblies may be used in a number of industries and applications.