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Automated latex enhanced immunoassay for the quantitative determination of von Willebrand Factor Antigen (VWF:Ag) in human citrated plasma on IL Coagulation Systems.

The VWF:Ag kit is a latex particle enhanced immunoturbidimetric assay to quantify VWF:Ag in plasma. When a plasma containing VWF:Ag is mixed with the Latex Reagent and the Reaction Buffer included in the kit, the coated latex particles agglutinate. The degree of agglutination is directly proportional to the concentration of VWF:Ag in the sample and is determined by measuring the decrease of transmitted light caused by the aggregates.

The provided text describes a Special 510(k) submission for the HemosIL von Willebrand Factor Antigen assay. This submission focuses on a modification to the reagent's open vial stability claim, reducing it from 3 months to 14 days, rather than introducing a new AI/ML device or significant performance changes. Therefore, many of the requested categories related to AI/ML device performance, ground truth, and expert evaluation are not directly applicable.

Here's an analysis based on the provided text, focusing on the relevant sections for acceptance criteria and the study that proves the device meets them:

1. A table of acceptance criteria and the reported device performance

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

• Sample Size: Not specified in the provided text. The text only mentions "testing."
• Data Provenance: Not specified in the provided text.
• Retrospective or Prospective: Not specified.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not applicable. This submission concerns a chemical reagent's stability, not an AI/ML device requiring expert ground truth for interpretation. The "ground truth" here is the chemical performance of the reagent over time.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable. Adjudication methods are relevant for subjective interpretations, typically in diagnostic imaging or similar fields. This study assesses objective chemical stability.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not applicable. This is not an AI/ML device or a diagnostic interpretation study involving human readers.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not applicable. This is not an AI/ML diagnostic algorithm. The study assesses the standalone performance of the reagent's stability.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The "ground truth" for this study is the measured performance characteristics of the HemosIL von Willebrand Factor Antigen reagent (e.g., accuracy, precision, linearity) after being opened and stored for various durations up to 14 days, compared to its performance when fresh or within its original 3-month stability claim. The study aims to demonstrate that the reagent's performance remains acceptable throughout the 14-day open-vial period.

8. The sample size for the training set

Not applicable. There is no "training set" as this is not an AI/ML model being developed. The study is a stability test.

9. How the ground truth for the training set was established

Not applicable. Refer to point 8.

Summary of the Study:

The study described is an open vial stability study for the HemosIL von Willebrand Factor Antigen reagent. The purpose was to provide data to support a change in the labeled open vial stability claim from 3 months to 14 days.

• Study Design: The study was likely a prospective laboratory study where the reagent was opened, stored at 2-8°C, and then tested at various time points (e.g., day 0, day 7, day 14) to assess its performance.
• Methodology: The testing was performed in accordance with the established CLSI EP25-A guideline, which provides guidance for evaluating reagent stability. This guideline would specify how to conduct the study, what performance parameters to measure (e.g., accuracy, precision, linearity), and acceptance criteria.
• Acceptance Criteria for the Study: While not explicitly listed in quantitative terms, the acceptance criteria would dictate the permissible deviation in performance (e.g., % bias, % CV) of the open and stored reagent compared to a freshly opened reagent or a reference measurement, over the 14-day period. The text states "Testing verified all acceptance criteria were met," implying these criteria were predefined and successfully achieved.
• Conclusion: The study demonstrated that the reagent maintained its defined performance specifications for 14 days after opening when stored at 2-8°C, thus supporting the modified insert claim.

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