Shape Memory Intervertebral Implant X-Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current intervertebral implants face challenges in simplified insertion and gentle expansion of intervertebral spaces while ensuring effective fusion, often requiring external forces and complex mechanisms for compression and expansion.
Innovation Solution
A self-expanding intervertebral implant made of shape memory material, such as nickel titanium alloy, that can be compressed for minimally invasive insertion and expands under body heat, featuring a load transmitting part with an X-shape design and keel-like teeth for stabilization, along with an instrument for attachment and detachment without external forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the implant is made rigid to ensure stable fusion, then fusion reliability is improved, but the implant cannot adapt to biomechanical changes and causes excessive stress on surrounding tissues
Solution Approach 1:
The implant transitions from a static rigid structure to a dynamic adaptive structure through shape memory material. The load transmitting part can change its configuration based on thermal stimuli, allowing the implant to adapt its stiffness and geometry to match the biomechanical environment of the intervertebral space, thereby achieving both fusion reliability and biomechanical adaptation.
Solution Approach 2:
The material properties of the implant are changed from fixed to variable through the use of shape memory alloy. By controlling the phase transformation temperature of the material, the implant can change its mechanical parameters (stiffness, strength) in response to body temperature, enabling it to provide stable fusion while adapting to physiological changes.
2Ease of operation
If external compression forces are applied during insertion to maintain compressed condition, then insertion simplicity is improved, but the implant requires complex mechanisms and external forces for compression and expansion
Solution Approach 1:
The implant performs its own compression and expansion functions through the inherent properties of shape memory material. The load transmitting part automatically expands when exposed to body heat without requiring external actuators or complex mechanisms, eliminating the need for external compression forces during insertion while maintaining operational simplicity.
Solution Approach 2:
The patent replaces mechanical compression/expansion mechanisms with a thermal-field-based system. The shape memory material uses thermal energy from the body to drive the phase transformation that causes expansion, substituting complex mechanical actuation systems with a simpler thermal response mechanism.
3Object-affected harmful factors
If the implant is compressed to reduce height for minimally invasive insertion, then insertion invasiveness is reduced, but the implant requires external forces to maintain the compressed condition
Solution Approach 1:
The implant maintains its compressed state during insertion through its own material properties rather than requiring external forces. The shape memory alloy retains the compressed configuration below its transformation temperature, allowing minimally invasive insertion without continuous external compression, and automatically expands when body heat is applied.
4Ease of operation
If the implant expands under body heat to enlarge intervertebral space, then the expansion is gentle and minimally invasive, but the implant requires precise control of transformation temperature
Solution Approach 1:
The transformation temperature of the shape memory material is precisely controlled during manufacturing to match the body temperature range. This parameter optimization allows the implant to remain compressed during insertion and then automatically expand when exposed to body heat, achieving gentle expansion with minimal temperature control requirements.
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 simplified, minimally invasive insertion and gentle expansion of intervertebral spaces, providing stable fusion with reduced rigidity for biomechanical adaptation and improved fusion properties, while minimizing the need for external forces and complex mechanisms.
Implementation Method 1
the implant is made of a material with shape memory properties... the implant can expand under the influence of body heat... a recovery level may be the Af temperature for a nickel titanium alloy that may be preferably between about 20° C. to about 35° C.
Implementation Method 2
a load transmitting part configured to transmit load between the upper wall and the lower wall
Data Source
AI summary
An intervertebral implant includes: a body with an upper wall configured to engage a first vertebral end plate and a lower wall configured to engage a second vertebral end plate, and a load transmitting part configured to transmit load between the upper wall and the lower wall; and the load transmitting part is configured to assume a compressed condition in which a distance between the upper wall and the lower wall defines a first height of the implant and an expanded condition in which the distance between the upper wall and the lower wall defines a second height of the implant that is greater than the first height; and the load transmitting part is attached to the upper wall at at least two first connecting locations and is attached to the lower wall at at least two second connecting locations and has substantially an X-shape in a front view of the implant; and the implant is made of a material that exhibits shape memory properties that permit the implant to remain in the compressed condition without outside forces acting upon it and to change to the expanded condition in response to a temperature being directed to a recovery level.