Dual Spring Spinal Stabilizer Fatigue Management

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing spinal stabilization devices lack well-defined connection points for springs, leading to potential weakness and inadequate tension or compression support, and often have separate components that may not securely attach rods to anchors, resulting in instability and limited durability.

Innovation Solution

A dynamic stabilization device featuring a dual spring member with an inner and outer spring, where both springs have equal working lengths and are connected at one end, securely attaching to rods with threaded portions, and anchors with drive receiving surfaces for secure implantation, ensuring stresses remain below the fatigue limit to prevent mechanical failure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If springs are used without well-defined connection points, then the device can be simpler to manufacture, but the connection strength and stability are reduced

Engineering Contradiction:

Improveease of manufactureVSAvoidconnection strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The spring connection system is segmented into distinct functional zones: well-defined connection points at the spring ends for secure attachment to anchors, and a flexible intermediate section with spiral cut grooves for elasticity. This segmentation allows each part to optimize its function while maintaining overall structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the spring have different structural properties. The end regions have well-defined connection points with higher rigidity for secure attachment, while the intermediate regions have spiral cut grooves providing flexibility and elasticity. This local differentiation resolves the contradiction between connection strength and manufacturing simplicity.

Inventive Principle:

Principle #3Local quality

2Device complexity

If separate spring components are used without secure attachment mechanisms, then the device assembly is simpler, but the stability and durability are reduced

Engineering Contradiction:

Improvedevice complexityVSAvoidstability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The spring is integrated with the anchor system through well-defined connection points that are part of the same continuous structure. This merging eliminates the need for separate attachment mechanisms while ensuring stable connection, as the connection points are inherently part of the spring-anchor assembly rather than add-on components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The well-defined connection points are pre-formed as integral parts of the spring structure during manufacturing. This preliminary action ensures that when the spring is installed, the connection points are already prepared for secure attachment to anchors, eliminating the need for additional assembly steps and ensuring immediate stability.

Inventive Principle:

Principle #10Preliminary action

3Force

If springs are allowed to experience high stresses, then the device can handle larger loads, but the risk of mechanical failure increases

Engineering Contradiction:

Improveload capacityVSAvoidmechanical failure risk

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The spring structure incorporates spiral cut grooves that act as stress distribution features, cushioning the concentration of forces at critical points. This beforehand cushioning allows the spring to handle larger loads by distributing stress more evenly throughout the structure, reducing the risk of mechanical failure at weak points.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 device provides enhanced stability and durability by evenly distributing loads between the inner and outer springs, preventing differential loading and ensuring the device operates indefinitely without mechanical failure, effectively addressing the limitations of previous designs.

Implementation Method 1

a dual spring member including an inner spring and an outer spring... evenly distributing loads between the inner and outer springs... ensuring stresses remain below the fatigue limit

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9445845B2Dynamic stabilization systems and devices for a spine

Publication Date: 2016.09.20 JMEA CORP

AI summary

A dynamic stabilization device is disclosed. The device includes a dual spring member comprising an outer spring and an inner spring that have approximately equal working lengths. The dynamic stabilization device is also configured so that the dual spring member does not undergo stresses greater than an effective fatigue limit that is related to a fatigue limit of the spring. Methods for treating a deformity of a spine using a dynamic stabilization device are also disclosed.