Optical Liquid Level Detection for Contamination-Free Reagent Containers
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Solution Overview
Problem
Existing methods for determining liquid levels in containers, such as those used in automated analytical instruments, are inaccurate, time-consuming, and can lead to liquid contamination.
Innovation Solution
A system and method using an image capture apparatus and controller to determine liquid levels in containers without physical contact, employing image processing techniques to analyze digital images of the containers and calculate liquid levels based on gradient values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual visual inspection is used to determine liquid level, then the method is simple to implement, but it is inaccurate and time-consuming
Solution Approach 1:
The patent replaces manual visual inspection with an automated optical sensing system. An image sensor captures images of the liquid level, and image processing algorithms automatically determine the liquid level position. This substitution eliminates human involvement in the measurement process, providing both higher accuracy and faster detection without time loss.
2Extent of automation
If electro-capacitive or pressure methods with probes are used, then liquid level can be determined automatically, but the liquid in the container becomes contaminated
Solution Approach 1:
The patent introduces light as an intermediary medium to transfer information about the liquid level without physical contact. The optical sensor detects light reflections or transmissions that indicate the liquid level position, allowing automated measurement while keeping the probe (light) outside the liquid, thus preventing contamination.
Solution Approach 2:
The patent replaces mechanical probes that physically contact the liquid with an optical sensing system. The image sensor and light source remain external to the liquid, using optical fields instead of mechanical contact to determine liquid level, thereby achieving automation without contamination.
3Productivity
If manual inspection is used, then no additional equipment is needed, but the process is time-consuming and inaccurate
Solution Approach 1:
The patent employs an image sensor that can serve multiple functions: capturing liquid level information, providing visual documentation, and potentially monitoring other container characteristics. This multi-functionality justifies the added device complexity by delivering superior productivity and additional capabilities beyond simple liquid level detection.
Data Source
AI summary
Disclosed herein are a system and method for determining a liquid level in a container based on data extracted from a digital image of the container. An image capture apparatus captures an image of a container used to store liquid reagents used by analytical instruments to test patient samples. A controller receives the captured image and extracts an analysis region based on a container type and applies a gradient filter to the analysis region. A location of a minimum gradient value (i.e., a row index) is determined based on the air-to-liquid boundary of the liquid in the extracted analysis region. A volume module calculates the liquid level in the analysis region by dividing the row index by a length of a gradient column vector and compares the determined liquid level to a threshold analysis region fraction for the container type to determine whether to output an alert.