Circular Spring Connector Assembly for Corrosion-Resistant Implant Leads

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Solution Overview

Problem

Implantable medical devices face challenges with connectors that require high power due to corrosion in the body's fluid environment and the high cost of platinum iridium alloys, necessitating a durable and affordable connector solution.

Innovation Solution

A circular coil spring assembly using a non-conductive housing with a conductive circular coil spring and attached lead, reducing costs by avoiding expensive machined platinum iridium housings, and incorporating wiper seals for fluid protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional connector design is used, then the device can be assembled, but the connector may disengage or become dislodged during patient activities

Engineering Contradiction:
Improveconnector retentionVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The connector employs a circular spring design where the noose tail configuration creates a curved, looped structure that naturally resists disengagement. The circular geometry allows the spring to flex and conform while maintaining continuous contact with the rod, preventing accidental disconnection during patient movement.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The noose tail spring is configured to engage with and surround the rod, creating a nested arrangement where the spring loop encloses the rod. This nested configuration ensures the connector remains securely attached while allowing the rod to pass through the center of the spring loop.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the connector is made more secure to prevent disengagement, then reliability improves, but the implantation procedure becomes more difficult

Engineering Contradiction:
Improveconnector retentionVSAvoidimplantation difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The spring connector is designed with dynamic properties, allowing it to expand and contract during implantation. The noose tail configuration enables the spring to open wide for easy rod insertion, then automatically contract to secure the rod in place, simplifying the implantation process while ensuring reliable retention.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring is pre-formed into a noose tail configuration with inherent elasticity, so that when the rod is inserted, the spring automatically engages and secures it without requiring additional manipulation or complex assembly steps during surgery.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If a non-circular spring design is used, then manufacturing may be simpler, but the spring may bind or contact the lead body causing issues

Engineering Contradiction:
Improvespring fabricationVSAvoidspring binding
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The circular geometry of the spring ensures uniform distribution of forces and symmetrical clearance around the rod and lead body. This circular configuration prevents the spring from binding or contacting the lead body during connector rotation or movement, eliminating a potential source of malfunction.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The circular spring design serves multiple functions: it provides secure retention of the rod, allows free rotation of the connector, and maintains clearance from the lead body. The universal circular geometry accommodates various orientations and movements without causing binding issues.

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

4Ease of operation

If the spring has high elasticity to allow rotation, then ease of operation improves, but the spring may deform or lose shape

Engineering Contradiction:
Improveconnector rotationVSAvoidspring shape retention
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The circular configuration of the spring provides inherent geometric stability. When the connector rotates, the circular noose tail maintains its shape and orientation relative to the rod, preventing deformation. The symmetrical circular geometry ensures that rotational forces are distributed evenly, preserving the spring's structural integrity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The spring is designed with specific material and dimensional parameters that balance elasticity and shape retention. The noose tail configuration with optimized wire diameter and loop dimensions allows the spring to flex for rotation while maintaining its overall circular geometry and preventing permanent deformation.

Inventive Principle:
Principle #35Parameter changes

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 solution provides a reliable, corrosion-resistant, and cost-effective electrical connection suitable for high-power devices, maintaining functionality over extended periods.

Implementation Method 1

a circular spring having a noose tail configuration... the circular spring allowing rotation of the connector relative to the lead body

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

passing through a center of the circular spring and exiting at the free end of the circular spring... securing the rod in the connector

Methodology Applied
Scientific EffectTension: Tension

Data Source

PatentEP4580743B1Noose tail circular spring connector for implantable medical device
Publication Date: 2026.04.22 TC1 LLC
  • EP4580743B1 patent drawingFigure 1
  • EP4580743B1 patent drawingFigure 2
  • EP4580743B1 patent drawingFigure 3

AI summary

Implantable electrical connectors employ a conductive circular coil spring contact retained with in a non-conductive housing and a conductive lead attached to the conductive circular coil spring contact. An implantable electrical connector assembly includes a male connector and a female connector. The male connector includes an electrical contact mounted to an elongated electrical contact support member. The female electrical connector includes a connector body and a female contact assembly disposed within the connector body. The female contact assembly includes a conductive circular coil spring, a conductive lead, and a non-conductive housing. The conductive lead is connected to the conductive circular coil spring. The conductive circular coil spring is disposed within and retained by the non-conductive housing. The conductive lead extends from within the non-conductive housing to outside of the non-conductive housing.