Nickel-Titanium Alloy Frame Fatigue Resistance
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Solution Overview
Problem
Current cardiovascular medical devices, such as heart valve repair devices, face challenges in delivering therapeutic functions without interfering with or harming native heart functions, and there is a need for alternative structures and assemblies that enhance durability and performance.
Innovation Solution
The use of a fatigue-resistant nickel-titanium alloy frame, heat-set between 450-550 degrees Celsius, and further processed through pre-strain cycles and heat-setting between 150-350 degrees Celsius, induces specific phases in the alloy to improve durability and shape memory properties, suitable for cardiovascular implants like annuloplasty rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials and structures are used in cardiovascular implants, then manufacturing is simpler and device complexity is lower, but fatigue resistance and durability are insufficient
Solution Approach 1:
The patent applies parameter changes by heat-setting the nickel-titanium alloy frame at elevated temperatures (450-550°C) to achieve specific microstructural phases (R-phase or parent phase) that enhance fatigue resistance. This thermal parameter modification transforms the material properties to improve reliability without fundamentally changing the device structure
Solution Approach 2:
The patent implements preliminary action through pre-strain cycling (10-100 cycles) performed before implantation. This pre-conditioning process stabilizes the frame's shape memory properties and fatigue characteristics in advance, ensuring optimal performance during actual use while simplifying the overall manufacturing workflow
2Duration of action of stationary object
If the frame is heat-set at high temperature (450-550°C) to improve fatigue resistance, then durability increases, but manufacturing complexity and energy consumption increase
Solution Approach 1:
The patent utilizes phase transitions in the nickel-titanium alloy by heat-setting at 450-550°C to transform the microstructure into specific phases (R-phase or parent phase). This phase transition approach achieves enhanced durability through material science principles rather than simply increasing energy input, optimizing the energy-to-performance ratio
3Adaptability or versatility
If pre-strain cycling is applied to enhance shape memory properties, then functional performance improves, but manufacturing time and process complexity increase
Solution Approach 1:
The patent applies partial action by performing a limited number of pre-strain cycles (10-100 cycles) rather than extensive cycling. This partial conditioning is sufficient to stabilize the shape memory properties and fatigue characteristics, achieving the desired adaptability without excessive time investment in the manufacturing process
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
This processing method enhances the fatigue resistance and durability of cardiovascular implants, allowing them to withstand cyclical loading and maintain performance over time, improving their in vivo durability and functionality.
Implementation Method 1
heat setting the device between a temperature of 150-350 degrees Celsius over a time period of at least 24 to 105 hours induces the nickel-titanium alloy to have a R-phase when the frame is at a temperature between 35-39 degrees Celsius
Implementation Method 2
the frame includes a fatigue resistant nickel-titanium alloy that is heat set at a temp in the range of 450-550 degrees Celsius
Implementation Method 3
the frame includes a fatigue resistant nickel-titanium alloy that is heat set at a temp in the range of 450-550 degrees Celsius
Data Source
AI summary
Example medical devices and methods of making example medical devices are disclosed. An example medical device includes a frame configured to be secured to cardiac tissue, wherein the frame includes a fatigue resistant nickel-titanium alloy that is heat set at a temp in the range of 450-550 degrees Celsius.