Metal Flow Channel Geometry for Calibration-Free Insulin Measurement
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Solution Overview
Problem
Existing insulin injection systems lack accuracy in measuring insulin doses due to manufacturing variability in plastic flow channels, requiring individual calibration, and are unable to handle rapid and large flow rate changes during insulin delivery.
Innovation Solution
A metallic cannula-based flow channel with precise dimensions is used, allowing for mass production with reduced variability, and incorporates a TTOF sensor for accurate flow measurement, eliminating the need for individual calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If injection molded plastic flow channels are used, then manufacturing cost is reduced, but manufacturing precision and dimensional consistency deteriorate
Solution Approach 1:
The patent replaces injection molded plastic flow channels with a metal flow channel assembly. The metal channel is formed from a blank by bending and forming operations, providing superior dimensional consistency and precision compared to injection molding. The metal material (such as stainless steel or aluminum) allows for tighter tolerances and more consistent internal dimensions, directly resolving the contradiction between manufacturing cost and manufacturing precision.
Solution Approach 2:
The patent changes the material parameter from plastic to metal, which fundamentally alters the achievable dimensional precision. By selecting appropriate metal materials and forming processes, the flow channel can achieve consistent internal dimensions within tight tolerances, eliminating the need for individual calibration while maintaining manufacturing feasibility.
2Measurement precision
If individual calibration of each flow channel is performed, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent changes the manufacturing process parameters by using metal forming instead of injection molding, which inherently provides better dimensional control. This process change eliminates the need for individual calibration of each flow channel, as the metal forming process can consistently achieve the required precision without requiring calibration adjustments for each unit.
Solution Approach 2:
The metal flow channel design inherently provides the measurement precision needed for accurate flow sensing without requiring external calibration procedures. The consistent dimensional characteristics of the metal-formed channels allow the system to self-calibrate or eliminate calibration requirements entirely, reducing device complexity and manufacturing costs.
3Difficulty of detecting and measuring
If existing TTOF sensors are used, then flow measurement capability is provided, but ability to handle rapid and large flow rate changes deteriorates
Solution Approach 1:
The patent employs a dynamic flow channel design with metal construction that can rapidly respond to changing flow conditions. The metal material and forming process allow for optimized flow paths and dimensions that enable the system to quickly accommodate rapid and large flow rate changes during insulin delivery, improving adaptability while maintaining measurement capability.
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 system provides consistent and accurate insulin dose measurement with reduced manufacturing costs and improved precision, capable of handling rapid flow rate changes and eliminating the need for individual calibration.
Implementation Method 1
Thermal time of flight (TTOF) sensors have been used to detect the time of flight of a heat pulse induced into moving fluid as it travels through a channel of known cross-section over a known distance in order to measure volumetric flow of the fluid.
Implementation Method 2
Thermal time of flight (TTOF) sensors have been used to detect the time of flight of a heat pulse induced into moving fluid
Data Source
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AI summary
An improved flow sensor is provided to enable accurate dose measurements to be made with little or no sensor calibration due to highly accurate flow channel cross section. The flow channel is formed as a metal tube. A sensor window is formed in the side wall of the metal tube, and the flow sensor is mounted in the sensor window. A flow manifold is formed around the metal flow channel.