Turbidity Light Scattering for Sample Adequacy Control
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Solution Overview
Problem
Current methods for determining sample adequacy in clinical diagnostics, particularly for HPV testing, often result in inaccurate or unrepresentative test results due to inadequate sample acquisition and contamination, leading to unnecessary testing and potential misrepresentation of patient health status.
Innovation Solution
A Sample Adequacy Control Measurement System (SAM) using turbidity light scattering techniques to non-destructively assess sample cellularity, allowing for the determination of sample adequacy before testing, thereby preventing the processing of inadequate samples and ensuring representative test results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light scattering techniques are used to measure sample adequacy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical cell counting methods with optical light scattering techniques. The system uses a light source and detector to measure turbidity and determine sample adequacy, eliminating the need for manual microscopy and cell counting while achieving higher precision and automation.
Solution Approach 2:
The patent introduces turbidity measurement as an intermediary parameter to assess sample adequacy. Rather than directly counting cells, the system measures light scattering properties of the sample, which correlate with cell density, providing an indirect but accurate method for determining adequacy.
2Loss of time
If sample adequacy is determined before testing, then loss of time is reduced by avoiding unnecessary testing, but measurement precision requirements increase
Solution Approach 1:
The patent performs sample adequacy assessment before conducting the main diagnostic testing. By measuring turbidity and determining cell density in advance, the system identifies inadequate samples that should not proceed to costly and time-consuming HPV testing, thereby saving time and resources.
Solution Approach 2:
The patent establishes specific turbidity thresholds and cell density criteria to objectively determine sample adequacy. By defining quantitative parameters for adequacy assessment, the system achieves high measurement precision that enables reliable pre-screening decisions.
3Ease of operation
If traditional sampling methods are used, then ease of operation is maintained, but reliability of test results deteriorates due to inadequate samples
Solution Approach 1:
The patent implements a feedback mechanism where turbidity measurement results immediately inform whether a sample is adequate for testing. This feedback loop allows operators to identify and reject inadequate samples before they compromise test reliability, while maintaining simple sampling procedures.
Solution Approach 2:
The patent replaces subjective visual assessment of sample adequacy with objective optical measurement. The light scattering technique provides quantifiable data on cell density, eliminating operator variability and ensuring consistent reliability judgments without complicating the sampling process.
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 effectively determines sample adequacy, reducing the likelihood of false negative results, saving resources by halting unnecessary testing and providing confidence in test outcomes, while ensuring that only representative samples are analyzed.
Implementation Method 1
A sample is illuminated by a light source and a detector situated to detect light scattered from particles in the sample is provided.
Implementation Method 2
measuring the turbidity of the sample
Data Source
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AI summary
Cervical cancer screening using HPV testing can yields a high negative predictive value of approximately 99.5% for prediction of cervical lesions of CIN3 or greater. However, sample adequacy can affect the number of at-risk women that may go undetected due to the inadequacy of the tested sample. We have approached this challenge of increasing sample assurance of the negative results by estimating the cell count in known fluid volumes using light scattering techniques, in particular turbidity. These methods may be used as a fast, convenient, and economical method for measuring sample adequacy for other uses as well. Particular examples using these methods in conjunction with the HC2 HPV test are provided herein.