Magnetic External Adjuster for Precise Spinal Distraction

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Solution Overview

Problem

Current treatments for scoliosis, such as fusion surgery and bracing, often result in limited mobility and potential pain, while non-fusion distraction methods like distraction osteogenesis are cumbersome and painful, lacking in controlled and cost-effective solutions for patient use.

Innovation Solution

An external adjustment device featuring permanent magnets and a motor system, allowing for controlled rotation to adjust implanted distraction devices, providing a user-friendly and effective means for scoliosis treatment with minimal pain and improved patient compliance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If fusion surgery is performed to treat scoliosis, then spinal stability is improved, but patient mobility is reduced and pain may occur

Engineering Contradiction:
Improvespinal stabilityVSAvoidpatient mobility
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The distraction device enables dynamic adjustment of spinal length and positioning through motorized actuation, allowing the spine to maintain stability while adapting to movement requirements. The device transitions from static fusion to dynamic adjustable support, resolving the contradiction between stability and mobility.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If non-fusion distraction methods like distraction osteogenesis are used, then patient mobility is preserved, but the treatment becomes cumbersome and painful

Engineering Contradiction:
Improvepatient mobilityVSAvoidtreatment complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces manual mechanical adjustment methods with an automated motorized system controlled by a controller. This substitution eliminates the need for cumbersome manual operations and reduces treatment complexity while preserving patient mobility.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The distraction device incorporates self-adjustment capabilities through automated motors and controllers that can perform adjustments without requiring complex external intervention, making the treatment less cumbersome and more patient-friendly.

Inventive Principle:
Principle #25Self-service

3Device complexity

If manual adjustment methods are used for distraction devices, then device complexity is reduced, but adjustment precision and control are insufficient

Engineering Contradiction:
Improveadjustment mechanism simplicityVSAvoidlengthening control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces manual adjustment mechanisms with motorized actuation systems controlled by controllers that can precisely control the distraction process. This substitution provides accurate lengthening control while maintaining relatively simple device architecture through automated operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The distraction device incorporates feedback mechanisms through controllers that monitor and regulate the adjustment process, ensuring precise control over lengthening parameters. This feedback system enables accurate positioning without requiring complex manual adjustment procedures.

Inventive Principle:
Principle #23Feedback

4Adaptability or versatility

If frequent surgical adjustments are performed for growing rods, then treatment adaptability is improved, but loss of time and increased pain occur

Engineering Contradiction:
Improvetreatment adaptabilityVSAvoidadjustment time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces the need for repeated surgical interventions with motorized adjustment capabilities that can be performed non-invasively. This substitution maintains treatment adaptability for growing patients while eliminating the time loss and pain associated with frequent surgical adjustments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The distraction device enables self-adjustment or easily adjustable configurations that can be modified without requiring surgical intervention. This self-service capability allows treatment adaptation to patient growth while minimizing time loss and procedural pain.

Inventive Principle:
Principle #25Self-service

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 enables precise and controlled lengthening of bones, reducing pain and improving treatment efficacy by allowing patients to perform adjustments easily and safely at home, thereby addressing the limitations of existing scoliosis treatments.

Implementation Method 1

An external adjustment device features permanent magnets and a motor system, allowing for controlled rotation to adjust implanted distraction devices

Methodology Applied
Scientific EffectMagnetic field generation: Magnetic Field

Data Source

PatentEP3386405B1External adjustment device for distraction device
Publication Date: 2023.11.01 NUVASIVE SPECIALIZED ORTHOPEDICS INC
  • EP3386405B1 patent drawingFigure 1
  • EP3386405B1 patent drawingFigure 2
  • EP3386405B1 patent drawingFigure 3

AI summary

An external adjustment device includes at least one permanent magnet configured for rotation about an axis with a first handle extending linearly at a first end of the device and a second handle at a second end of the device, the second handle extending in a direction substantially off axis to the first handle. The external adjustment device further includes a motor mounted inside the first handle and a first button located in the proximity to one of the first handle or the second handle, the first button configured to be operated by the thumb of a hand that grips the one of the first handle or second handle. The first button is configured to actuate the motor causing the at least one permanent magnet to rotate about the axis in a first direction.