Alginate Hydrogel Foam for Tissue-Equivalent Lung Phantom
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tissue-equivalent materials for simulating human lung tissue in radiation therapy lack the necessary mechanical and radiological properties, particularly in terms of Young's Modulus, which is several orders of magnitude higher than that of human lungs.
Innovation Solution
Development of alginate hydrogels with controlled density, elasticity, and radiological properties similar to human lung tissue, achieved by varying the concentration of sodium alginate and the Ca2+:—COOH molar ratio, resulting in materials with mechanical and radiological tissue-equivalent properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyurethane foam-based materials are used to achieve desired radiological properties, then radiological properties are improved, but Young's Modulus becomes several orders of magnitude larger than human lung tissue
Solution Approach 1:
The patent uses composite materials by combining alginate hydrogel with porous foam structures. The alginate provides tissue-equivalent mechanical properties (Young's Modulus of 1-13 kPa matching lung tissue), while the porous structure tuned to specific densities provides radiological equivalence. This composite approach resolves the contradiction by decoupling mechanical and radiological property optimization.
Solution Approach 2:
The patent employs porous alginate hydrogel materials with controlled porosity and density. The porous structure allows tuning of radiological properties (density, electron density, effective atomic number) to match lung tissue, while the alginate base material maintains appropriate mechanical compliance. The porosity is controlled to achieve radiological equivalence without compromising mechanical properties.
2Quantity of substance
If materials with density close to water are used to match human organ density, then density is improved, but mechanical strength and structural stability deteriorate
Solution Approach 1:
The patent applies local quality by creating heterogeneous porous structures within the hydrogel. Different regions have different pore sizes and densities optimized for specific functions: some regions provide structural support while others are optimized for radiological equivalence. The local porosity distribution allows the material to achieve overall density matching lung tissue (0.26-1.06 g/cm³) while maintaining adequate mechanical strength through strategically placed structural elements.
Solution Approach 2:
The patent uses preliminary crosslinking of the alginate hydrogel network before final porosity introduction. This preliminary structural establishment provides a strong base framework that can subsequently accommodate porous structures without compromising overall mechanical integrity. The pre-formed gel network ensures structural stability is established before density optimization through porosity control.
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
The alginate hydrogels demonstrate mechanical properties such as Young's Modulus within the desired range for human lungs, and radiological properties that closely match those of human lung tissue, enhancing their suitability for use in radiation therapy simulations.
Implementation Method 1
Alginate is a natural polysaccharide that can undergo ionic crosslinking with divalent cations
Implementation Method 2
The mixture was then sealed and allowed to gel for approximately 24 hours at room temperature to form homogeneous hydrogels
Data Source
AI summary
Disclosed is a hydrogel and hydrogel-based foam, which are made of a naturally-derived material, alginate hydrogel in combination with CaCO3, glucono delta-lactone (GDL), and sodium lauryl ether sulfate, as well as methods for making alginate hydrogel and alginate hydrogel foam, which have radiological and mechanical properties equivalent to those of human lung. The material is environment-friendly, and the hydrogel properties can be readily adjusted by changing the alginate concentration, Ca2+ ratio, and solution volume in the container. The hydrogel and hydrogel foam disclosed here have potential to be used for making tissue-equivalent phantoms of various human organs, in particular human lung, for radiotherapy dosimetry, and other applications such as bioimplants, artificial biological tissues, soft robotics, and optics.