Optical Pipette Positioning and Volume Verification in Low-Volume Assays
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Solution Overview
Problem
Existing diagnostic instruments face challenges in accurately measuring and verifying the addition of specimen, reagents, and diluents due to improper volume measurements, which can affect the integrity of test results, especially at low volumes.
Innovation Solution
The implementation of an image capture device, such as an on-board digital camera, to capture images and videos of bio-liquid containers and pipette components, processed by an image processor to determine and verify aspiration and dispense volumes, ensuring accurate pipetting operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aspiration pressure readings are recorded and monitored to verify specimen addition, then verification capability is provided, but measurement precision deteriorates at low volumes
Solution Approach 1:
The patent replaces the mechanical/pressure-based verification system with an optical imaging system. Instead of relying on aspiration pressure readings which lack precision at low volumes, the system uses digital images captured by an imaging device to visually measure and verify the volume of specimen, reagent, and diluent additions. This substitution of measurement methodology resolves the contradiction by providing accurate verification independent of pressure-based limitations.
Solution Approach 2:
The patent introduces an imaging device as an intermediary between the aspiration/dispense process and the verification system. The imaging device captures visual evidence of liquid volumes, which then serves as the basis for verification by the processor. This intermediary approach allows for precise measurement of low volumes through image analysis rather than direct pressure sensing.
2Reliability
If existing verification methods are used for liquid reagent and diluent addition, then some verification is achieved, but measurement accuracy deteriorates due to similar limitations
Solution Approach 1:
The patent applies the same optical imaging substitution to reagent and diluent addition verification. Instead of using pressure-based or flow-based verification methods that suffer from accuracy limitations, the system uses imaging to capture and analyze the volume of reagents and diluents added to the reaction container, providing precise verification for all liquid additions.
3Device complexity
If no verification method is used for solid reagent addition, then device complexity is reduced, but measurement precision of all additions deteriorates
Solution Approach 1:
The patent extends the imaging verification system to provide universal verification capability for all types of additions - liquid specimen, liquid reagents, liquid diluents, and solid reagents. The same imaging device and processing algorithm handle all verification needs, providing comprehensive measurement precision across all addition types without requiring separate verification systems for each material type.
Data Source
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AI summary
Methods of determining or verifying proper operation of a diagnostic device are disclosed. The methods include monitoring, with one or more image capture devices, one or more locations to determine proper aspiration, dispense, and/or overall assay component volume fill of one or more bio-liquid containers. Tip immersion depth and location may be also measured and/or verified. Diagnostic devices and apparatus adapted to carry out the method are described, as are other aspects.