Magnetic Implant Adjustment Feedback Through Coupling State Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing external adjustment devices for non-invasively adjustable implants lack feedback mechanisms, making it difficult for users to confirm if adjustments are accurately applied to the implants.

Innovation Solution

An external adjustment device that includes a magnetic element generating a rotating magnetic field, a motor to drive the magnetic element, and a controller to detect the magnetic coupling state with a permanent magnet in the implant, allowing for real-time monitoring of adjustments through rotational speed and acceleration analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If unidirectional adjustment instructions are sent to adjustable implants, then the remote control can issue adjustment commands, but feedback on the actual adjustments achieved is lost

Engineering Contradiction:
Improvefeedback informationVSAvoiddevice structure
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the external adjustment device detects the magnetic coupling state between its magnet and the implant's magnet. The controller monitors whether the magnet is properly coupled to the implant before issuing adjustment commands, ensuring bidirectional communication and confirming that adjustment instructions are successfully transmitted and executed.

Inventive Principle:
Principle #23Feedback

2Reliability

If magnetic coupling detection is added to confirm adjustment accuracy, then user confidence in adjustment success is improved, but the device complexity increases

Engineering Contradiction:
Improveadjustment accuracy confirmationVSAvoiddetection mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical detection mechanisms with a magnetic field-based detection system. The controller detects the magnetic coupling state by monitoring changes in the magnetic field between the external device's magnet and the implant's magnet, eliminating the need for mechanical sensors or complex mechanical feedback structures.

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

Solution Approach 2:

The magnetic field serves as an intermediary between the external adjustment device and the implant. By detecting changes in the magnetic field coupling state, the system can determine whether the magnet is properly attached to the implant without requiring direct mechanical contact or complex sensing mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of information

If real-time monitoring of magnetic coupling state is implemented, then adjustment confirmation is achieved, but energy consumption increases

Engineering Contradiction:
Improveadjustment status informationVSAvoidenergy consumption
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The controller performs magnetic coupling state detection at periodic intervals - specifically, detecting whether the magnet is coupled to the implant before issuing adjustment commands and after adjustments are completed. This periodic detection approach provides necessary feedback information while minimizing energy consumption by avoiding continuous monitoring.

Inventive Principle:
Principle #19Periodic 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

Enables precise and confirmable adjustments to implants by determining the magnetic coupling state and detecting potential stalling conditions, providing users with assurance of successful adjustments.

Implementation Method 1

a magnetic element configured to generate a rotating magnetic field; and a driver configured to drive the magnetic element to generate the rotating magnetic field and configured to rotate a permanent magnet of an adjustable implant

Methodology Applied
Scientific EffectRotating magnetic field: Electromagnetic Induction

Implementation Method 2

the upon a movement of the at least one magnet, the controller is configured to detect a magnetic coupling state of the at least one magnet with the permanent magnet of the adjustable implant

Methodology Applied
Scientific EffectMagnetic coupling: Magnetism

Data Source

PatentEP3920808B1External adjustment device
Publication Date: 2024.06.12 NUVASIVE SPECIALIZED ORTHOPEDICS INC
  • EP3920808B1 patent drawingFigure 1
  • EP3920808B1 patent drawingFigure 2
  • EP3920808B1 patent drawingFigure 3

AI summary

An external adjustment device for non-invasively adjusting an implant, the external adjustment device including a controller in communication with an actuator associated with the adjustable implant and a sensor configured to receive information from or about the adjustable implant. The external adjustment device may further comprise a power source and a display. According to one exemplary embodiment, the external adjustment device comprises a magnetic element configured to generate a rotating magnetic field; and a driver configured to drive the magnetic element to generate the rotating magnetic field and configured to rotate a permanent magnet of an adjustable implant, wherein upon placing the external adjustment device in proximity to an adjustable implant having a permanent magnet the magnetic element is configured to magnetically couple with the permanent magnet, and wherein the external adjustment device is configured to non-invasively determine one or more of a magnetic coupling state and a stalled state of the magnetic element and the permanent magnet disposed within the adjustable implant.