Implantable Pulse Generator Header Spring Contact Ring Alignment

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Solution Overview

Problem

Existing implantable pulse generator (IPG) header designs face challenges in maintaining component alignment, electrical isolation, and mechanical retention, leading to high scrap rates and labor-intensive manufacturing processes, with previous methods failing to adequately test assemblies before final completion.

Innovation Solution

The method involves forming a subassembly with spring contact rings, ring seals, and a sleeve, allowing for interim testing and overmolding to secure components in position, using a molding pin and strain relief to ensure electrical isolation and alignment, with novel ring seals and spring contact rings designed to resist deformation and provide robust connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional header manufacturing methods are used, then assembly is completed, but component alignment, spacing, and isolation are difficult to maintain

Engineering Contradiction:
Improvecomponent alignment and spacingVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-assembling the electrical contacts, seals, and strain relief components in a subassembly before final overmolding. This allows alignment and spacing to be established in advance, ensuring manufacturing precision while simplifying the final assembly process. The subassembly is prepared with all components in their correct positions before being integrated into the header housing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the header manufacturing into distinct phases: creating a subassembly with electrical contacts and seals, performing interim testing, and then final overmolding into the header housing. This segmentation allows each component to be manufactured and positioned separately with high precision, then integrated as a unit, resolving the contradiction between manufacturing precision and ease of manufacture.

Inventive Principle:
Principle #1Segmentation

2Reliability

If testing is performed after complete manufacturing, then final product is tested, but entire header must be discarded if issues are found

Engineering Contradiction:
Improveproduct conformanceVSAvoidscrap rate
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent performs interim testing on the subassembly before final overmolding, allowing defects to be detected early when only the subassembly needs to be discarded rather than the entire finished header. This preliminary testing action significantly reduces the scrap rate while maintaining high product conformance standards.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By segmenting the manufacturing process into subassembly production and final header integration, the patent enables testing at the subassembly level. This segmentation allows for targeted disposal of only the defective subassembly rather than the entire header, reducing material loss while ensuring reliability through thorough testing.

Inventive Principle:
Principle #1Segmentation

3Strength

If strong mechanical insertion force is used, then components are securely inserted, but excessive pressure is exerted on inner seal and electrical components

Engineering Contradiction:
Improveretention forceVSAvoidpressure on seal and components
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent employs dynamic elements including spring-loaded electrical contacts and flexible seals that can deflect and accommodate insertion forces. The spring contacts provide resilient engagement that maintains strong retention while absorbing insertion pressure, preventing damage to the seal and electrical components. The dynamic design allows the system to adapt to force variations during assembly.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses flexible seal elements and thin-walled component structures that can deform elastically during insertion to accommodate mechanical forces. These flexible components absorb insertion pressure without transmitting excessive stress to critical electrical components, while still providing secure retention once assembled.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If excessive electrical contact is achieved, then good electrical connection is obtained, but shorts or faults occur which draw off battery power

Engineering Contradiction:
Improveelectrical connection qualityVSAvoidbattery power consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by providing electrical isolation only where needed between adjacent contacts, while maintaining good electrical connection quality at each contact point. The seal elements are positioned specifically at interfaces between electrical contacts to prevent shorts, while the contact surfaces themselves remain highly conductive for reliable signal transmission, thus preventing energy loss without compromising connection quality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces seal elements as intermediary components between adjacent electrical contacts. These seals act as mediators that prevent direct electrical contact between adjacent contacts, eliminating the risk of shorts and battery drain while allowing each contact to maintain its own high-quality electrical connection to the lead electrodes.

Inventive Principle:
Principle #24Intermediary (Mediator)

5Object-affected harmful factors

If insufficient retention forces are used, then less pressure on components is applied, but electrode of the bore loses position or falls out of place

Engineering Contradiction:
Improvepressure on componentsVSAvoidelectrode position stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent uses spring-loaded retention mechanisms that provide dynamic retention forces. The springs maintain constant contact pressure on the electrodes, providing sufficient retention to prevent displacement while allowing the system to absorb shocks and vibrations without transmitting excessive pressure to the components. The dynamic spring mechanism self-adjusts to maintain optimal retention force.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs flexible retaining structures that can deform elastically to accommodate electrode positioning while maintaining retention force. These flexible components provide gentle, distributed pressure that secures electrodes in place without concentrating excessive force on any single point, thus preventing displacement while protecting components from damage.

Inventive Principle:
Principle #30Flexible shells and thin films

6Stress or pressure

If thermoset materials are used for header, then lower molding pressure is required, but molding cycle time increases

Engineering Contradiction:
Improvemolding pressureVSAvoidmolding cycle time
Core Design Contradiction:
Stress or pressureVSLoss of time

Solution Approach 1:

The patent employs composite material construction for the header, combining thermoplastic housing material with metal or other material electrical contacts and seals. This composite approach allows the use of thermoplastic materials that can be molded quickly with lower pressure, while the embedded components provide the necessary structural and electrical properties. The composite structure achieves both low molding pressure and efficient cycle time.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent segments the header into a thermoplastic housing component and separately manufactured electrical contact components. The thermoplastic housing can be quickly molded using efficient thermoplastic processing, while the electrical components are pre-manufactured and then integrated. This segmentation allows optimization of each material type for its specific manufacturing process, achieving both low pressure and fast cycle times.

Inventive Principle:
Principle #1Segmentation

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 approach reduces scrap rates, lowers manufacturing costs, and ensures conformance to performance standards by allowing for pre-overmolding testing and using materials like PEEK and silicone to maintain component alignment and electrical isolation, resulting in a more efficient and cost-effective manufacturing process.

Implementation Method 1

a plurality of spring contact rings, each spring contact ring having a bore

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

each spring contact ring is separated from any adjacent spring contact ring by a ring seal

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 3

Overmolding the subassembly to lock the spring contact rings, ring seals and strain relief of the subassembly in position

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3093927B1Header for implantable pulse generator
Publication Date: 2018.10.17 DONATELLE PLASTICS
  • EP3093927B1 patent drawingFigure 1~4
  • EP3093927B1 patent drawingFigure 5~9
  • EP3093927B1 patent drawingFigure 10~16

AI summary

An implantable pulse generator header comprising a spring contact ring (10) including: a. an outer housing (12) comprising an outer wall (14) and an inner wall (16) surrounding a bore (18) having a longitudinal axis; and b. a spring (24) comprising a base (26) and a plurality of spiral, radial spring fingers (28) extending from the base (26), each spring finger including a flange portion (30) terminating in an electrical contact zone (32), said spring fingers being biased toward a longitudinal axis of the bore (18) and said spring fingers being permitted to flex within the bore (18).