Microfluidic Breath Cartridge Capillary Volume Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microfluidic cartridges for breath analysis suffer from poorly controlled sample sizes and temperature issues due to their large size, leading to inaccuracies in results and increased stress on patients, especially those with breathing difficulties.
Innovation Solution
A credit card-sized microfluidic cartridge with a condensation zone and an analysis chamber, featuring a hydrophilic surface for efficient condensation and fluid flow, a capillary structure to control fluid volume, and a laminar structure for flexibility and ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional microfluidic cartridges are used for breath analysis, then the device can collect and analyze breath samples, but the sample size is not well-controlled leading to errors in results
Solution Approach 1:
The cartridge employs passive capillary wicking structures that automatically draw condensed breath sample through the device without requiring external pumps or active control systems. The capillary channels self-regulate the sample volume based on their geometric properties, ensuring consistent and controlled sample delivery to the analysis zone.
Solution Approach 2:
The invention precisely controls the geometric parameters of the capillary channels (width, depth, length) to regulate the volume of breath condensate that can be absorbed and transported. By optimizing these dimensional parameters, the system achieves accurate sample volume control without complex mechanisms.
2Temperature
If conventional microfluidic cartridges are used for breath analysis, then the device can process breath samples, but the large size and mass of components cause temperature control issues due to latent heat capacity
Solution Approach 1:
The cartridge is designed as a disposable single-use device with minimal mass, eliminating the need for complex temperature control systems. The low thermal mass allows rapid thermal equilibrium while the disposable nature ensures each analysis starts with a fresh, thermally stable cartridge, avoiding cumulative heat effects.
Solution Approach 2:
The cartridge is divided into distinct functional zones (condensation zone, transport channels, analysis zone) with optimized volumes. This segmentation allows each zone to be sized appropriately for its function, minimizing overall mass and thermal capacity while maintaining effective temperature control in the analysis region.
3Adaptability or versatility
If larger microfluidic cartridges are used, then more components can be integrated, but the increased mass influences the analysis temperature negatively
Solution Approach 1:
Multiple functions (condensation, sample transport, filtration, and analysis) are integrated into a single compact cartridge structure with minimal intermediate components. The capillary wicking material serves both as transport medium and filtration mechanism, reducing overall component count and mass while maintaining functional versatility.
4Ease of operation
If conventional breath collection methods are used, then breath samples can be collected, but the process causes considerable distress to subjects with breathing difficulties
Solution Approach 1:
The system passively collects breath condensate through condensation on cooled surfaces and automatic capillary wicking, requiring minimal patient effort. The patient simply needs to exhale normally into the device, and the system automatically condenses and transports the sample without requiring forced breathing or prolonged breath-holding.
Solution Approach 2:
Active pumping mechanisms are replaced with passive condensation and capillary wicking phenomena. The phase change of breath moisture and the capillary action in the wicking material automatically drive sample collection and transport, eliminating the need for mechanical forces that would require patient cooperation and effort.
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 cartridge allows for rapid and accurate collection and analysis of exhaled breath condensate with minimal patient distress, achieving precise control over sample volume and temperature, thus improving diagnostic accuracy and efficiency.
Implementation Method 1
a condensation zone to receive exhaled breath
Implementation Method 2
the surface of the condensation zone acting to create a fluid flow path in the peripheral region
Implementation Method 3
a lip to at least partially cover the peripheral region, the lip co-operating with the condensation zone to form a capillary to control fluid flow
Data Source
AI summary
The invention as disclosed herein provides a breath-condensate analysis cartridge suitable for incorporation into an exhalation device. The cartridge comprises a condensation zone to receive exhaled breath, the condensation zone having a peripheral region. An analysis chamber is included in which a condensed breath sample is analysed. The surface of the condensation zone acts. to create a fluid flow path in the peripheral region. A fluid flow path through the peripheral region links the condensation zone to the analysis chamber. A lip at least partially covers the peripheral region, the lip co-operating with the condensation zone to form a capillary to control fluid flow.