Magnetic Adjustable Implant Feedback for Non-Invasive Distraction Control
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Solution Overview
Problem
Current treatments for scoliosis, such as braces and fusion surgeries, are ineffective or invasive, and existing distraction devices for bone lengthening are cumbersome and prone to complications, while early onset scoliosis and knee osteoarthritis require more effective and less invasive solutions.
Innovation Solution
A system with an adjustable implant using wireless magnetic adjustment, controlled by an external device with Hall effect sensors and motors, allows for precise non-invasive adjustment of spinal curvature or bone lengthening without the need for repeated surgeries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If fusion surgery is performed to treat scoliosis, then spinal curvature is corrected, but spinal flexibility is reduced and invasive surgery is required
Solution Approach 1:
The implant includes an adjustable distraction device with a lead screw mechanism that can be dynamically adjusted after implantation. The magnet coupled to the lead screw allows non-invasive modification of the distraction force applied to the spine, enabling the system to adapt as the child grows and spinal curvature changes, thereby maintaining both correction effectiveness and spinal flexibility.
2Adaptability or versatility
If adjustable implants are used for growing children, then repeated surgeries are needed to adjust for growth, but this increases infection risk and surgical trauma
Solution Approach 1:
The implant replaces the need for repeated surgical adjustments with a non-invasive magnetic adjustment system. A magnet coupled to the lead screw can be rotated externally through the skin using a magnetic field generator, allowing the distraction device to be adjusted for growth without any surgical incisions or risk of infection.
3Shape
If fixed distraction force is applied, then initial curvature correction is achieved, but the device cannot adapt to ongoing spinal growth
Solution Approach 1:
The distraction device incorporates a lead screw mechanism with a magnet that can be remotely adjusted. This allows the distraction force to be dynamically modified after implantation to accommodate ongoing spinal growth in children, maintaining proper spinal alignment throughout development without requiring additional surgeries.
4Ease of operation
If non-invasive adjustment is implemented, then surgical interventions are reduced, but precise control of distraction force becomes more difficult
Solution Approach 1:
The system incorporates sensors that provide feedback on the position of the magnet and the degree of distraction applied. This feedback mechanism allows the magnetic field generator to precisely control the rotation of the lead screw and thereby accurately regulate the distraction force, ensuring precise control despite the non-invasive nature of the adjustment.
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
Provides a less invasive and more effective method for managing scoliosis and osteoarthritis by allowing controlled adjustment of spinal curvature or bone lengthening, reducing the need for surgeries and minimizing complications.
Implementation Method 1
The permanent magnet is configured for rotation in response to an externally applied moving magnetic field
Implementation Method 2
The lead screw is threadingly engaged with a female thread, disposed within the second portion, such that the rotation of the permanent magnet causes the rotation of the lead screw, which adjusts the dimension
Implementation Method 3
controlled by an external device with Hall effect sensors and motors
Data Source
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AI summary
An adjustable implant (300, 330, 358, 386, 400, 420, 444, 462, 1000) for wireless adjustment of a dimension within a body, comprises a first portion (301, 334, 360, 396, 404, 422, 458, 472), configured for coupling to a first location in the body; a second portion (302, 336, 364, 398, 406, 424, 450, 464), configured for coupling to a second location in the body; and a magnetic drive configured to adjust a relative distance between the first portion and the second portion. The magnetic drive includes at least one driven magnet (304, 340, 366, 381, 402, 432, 454, 478, 1010) configured to revolve about an axis in response to a magnetic field imposed by a driver magnet (510, 511; 606, 608; 706, 708; 1106, 1108) outside of the body. The adjustable implant is configured to transmit a signal indicative of the responsiveness of the driven magnet to the driver magnet. A change in the responsiveness is indicative of a change in a force applied between the body and the first and second portions.