Custom Implant Casting With Laminated Wax Templates
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Solution Overview
Problem
Conventional medical implants face issues such as high rejection rates, poor surface finish, increased porosity, and mechanical weakness due to layer-by-layer deposition methods, leading to trauma, pain, and wastage of precious metals, along with inadequate fit and increased risk of dislocation and corrosion.
Innovation Solution
A method involving a wax template assembly with a lamination layer and ceramic slurry coating, followed by sand-raining, de-waxing, and baking to create a mold for casting, which is then filled with metal alloy and heat-treated to form a customized implant with improved mechanical properties and fit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional surgical tools are used to form threads in bone, then the procedure is simple, but the threads have irregular pitch and depth causing stress concentrations
Solution Approach 1:
The system pre-calculates and stores optimal thread formation parameters (pitch, depth, tool path) before the surgical procedure. The controller retrieves these pre-determined parameters during operation, eliminating the need for real-time complex calculations and enabling precise thread formation without increasing operational complexity
Solution Approach 2:
The invention replaces traditional mechanical thread formation methods with a computer-controlled system that uses a motor-driven burr or mill. The controller coordinates the motion of the burr/mill along the implant body, substituting manual mechanical operations with automated mechanical systems that provide precise control over thread pitch and depth
2Adaptability or versatility
If multiple separate tools are used for different surgical steps, then each tool can be optimized for its specific function, but the number of tools and steps increases
Solution Approach 1:
The system employs a single multi-functional tool that can perform multiple surgical operations. The same controller manages thread formation, countersinking, and recess creation by varying the tool path and cutting parameters. This universal tool replaces multiple specialized tools, reducing the number of surgical steps while maintaining functional versatility
Solution Approach 2:
The invention combines multiple surgical functions (thread formation, countersinking, recess creation) into a single integrated process. The controller coordinates these operations sequentially or simultaneously using one tool, merging what were previously separate surgical steps into a unified workflow that reduces complexity
3Stability of the object's composition
If threads are formed after implant placement, then the implant position is stable, but the procedure requires multiple steps increasing surgery time
Solution Approach 1:
The system performs thread formation operations during the implant placement procedure itself, rather than as a separate subsequent step. The controller guides the tool to create threads on the implant body while it is being positioned in the bone, combining stabilization and thread formation into a single integrated action that saves time
Data Source
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AI summary
A method of manufacturing an implant is disclosed. The method includes preparing a wax template assembly based upon anatomical characteristics of an implantation site. Post formation of the template assembly, a lamination layer is provided over the template assembly resulting in a laminated template assembly. The lamination layer is composed of at least one polymer dissolved in one or more solvents. One or more coating layers of a pre-defined coating material are provided over the laminated template assembly to prepare a mold. The mold may then be sand-rained to form a sand coated mold. The sand coated mold may be de-waxed and baked for melting out the template assembly to form a de-waxed mold. A casting material is then poured over the de-waxed mold to form a casted mold which is cooled and solidified to form a casted implant which is further heat treated and finished to form the implant.