Optical Stopper Position Detection in Translucent Medicament Containers
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Solution Overview
Problem
Existing medicament container systems lack an accurate and reliable method for determining the longitudinal position of the stopper, which is crucial for precise dosing and monitoring the remaining quantity of the medicament.
Innovation Solution
An arrangement using at least one light source and one photo-sensitive sensor, either laterally arranged next to the medicament container or circularly around its head, to detect the light/dark boundary caused by the opaque stopper, with a processor unit determining the stopper's position and calculating the remaining medicament quantity based on the light source characteristics and positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If no optical detection system is used, then the medicament container maintains simple design and manufacturing, but the longitudinal position of the stopper cannot be accurately determined
Solution Approach 1:
The patent introduces an optical intermediary system consisting of a light source and photo-sensitive sensor that mediates between the stopper position and the detection mechanism. The light source emits light through the translucent container wall, and the sensor detects light attenuation caused by the opaque stopper, converting physical position into measurable optical signal without requiring direct contact or complex mechanical sensors on the stopper itself.
Solution Approach 2:
The patent replaces potential mechanical position sensing mechanisms with an optical detection system. Instead of using mechanical encoders, potentiometers, or contact-based sensors that would add complexity to the moving stopper assembly, the invention uses non-contact optical fields to detect stopper position through light attenuation, thereby substituting mechanical sensing with optical sensing.
2Measurement precision
If the container wall is made opaque for better visibility, then the stopper position can be easily observed, but light cannot penetrate through to enable optical detection
Solution Approach 1:
The patent applies local quality by differentiating the optical properties of different container components. The container wall is designed with translucent properties specifically in the regions where optical detection is needed, allowing light penetration for sensor detection. The stopper itself maintains opaque properties for visibility and sealing function. This localized differentiation of optical characteristics enables both optical detection and visual observation without compromise.
Solution Approach 2:
The patent utilizes optical property differences (analogous to color changes) between the translucent container wall and the opaque stopper. The stopper's opacity creates a distinct optical contrast against the translucent background, enabling the photo-sensitive sensor to detect the stopper's position through light attenuation. This optical contrast principle allows the sensor to distinguish the stopper from the container wall based on their different light transmission characteristics.
3Measurement precision
If additional sensors and light sources are added to the container, then stopper position can be detected, but the container design requires modifications
Solution Approach 1:
The patent applies universality by designing the optical detection components to serve multiple functions. The light source not only enables stopper position detection but can also illuminate the medicament for visual inspection. The photo-sensitive sensor detects stopper position and can potentially monitor light transmission changes indicating medicament level or container integrity. This multi-functionality reduces the need for separate dedicated components, simplifying manufacturing.
Solution Approach 2:
The patent implements self-service through the optical system's ability to use the container's own structural features (translucent wall, opaque stopper) as integral parts of the detection mechanism. The container wall serves both as protective housing and as an optical medium for light transmission. The stopper's inherent opacity serves both sealing/visibility functions and as the detection target for light attenuation measurement, eliminating the need for separate detection markers or indicators.
4Loss of information
If the stopper is made opaque for visibility, then the remaining medicament quantity can be monitored, but the inner surface quality treatment (siliconization) may be compromised
Solution Approach 1:
The patent transitions the visibility function from a two-dimensional surface coating problem to a three-dimensional optical property solution. Instead of attempting to make the stopper surface visually distinctive through surface coatings or markings that could interfere with siliconization, the invention uses the stopper's bulk opaque material property to create visual contrast. The opacity is an inherent bulk property rather than a surface treatment, allowing the stopper to maintain its standard siliconized surface for low friction while providing optical contrast for position detection and medicament quantity monitoring.
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
Enables high-accuracy determination of the stopper's longitudinal position and calculation of the remaining medicament quantity, facilitating automatic dosing and improving dosing precision in devices like insulin pens without requiring design modifications to the primary packaging or medicament container.
Implementation Method 1
at least one light source and at least one photo-sensitive sensor, wherein the light source is arranged to emit light into the medicament container and the sensor is arranged to detect the transmitted light
Data Source
Figure 1~4
Figure 5~7
Figure 8a~9b
AI summary
The invention refers to an arrangement and a method for determining a longitudinal position of a stopper (4) for sealing a compartment (5) of a translucent medicament container (1) for a liquid medicament (M). The arrangement comprises a circular light source (8) and a photo sensitive sensor (7), wherein either the light source (8) or the sensor (7) is laterally arrangeable next to the medicament container (1) extending over at least part of the length of the medicament container (1), and wherein the respective other of the light source (8) and the sensor (7) is arrangeable in a circular manner around a head of the medicament container (1). The light source is arranged to emit light into the medicament container. The light is scattered by the medicament or medicament container (1) and detected by the sensor (7). The sensor (7) is connected to a processor unit for detecting the position of the stopper (4).