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The AFP method is an in vitro diagnostic test for the quantitative measurement of alphafetoprotein in human serum and lithium heparinized plasma on the Dimension Vista® System. Measurements of alpha-fetoprotein are used as an aid in managing nonseminomatous testicular cancer when used in conjunction with physical examination, histology/pathology, and other clinical evaluation procedures.

The Dimension Vista® AFP method is a homogeneous, sandwich chemiluminescent immunoassay based on LOCI® technology. The LOCI® reagents include two synthetic bead reagents and a biotinylated anti-AFP monoclonal antibody fragment. The first bead reagent (Chemibeads) is coated with an anti-AFP monoclonal antibody and contains chemiluminescent dye. The second bead reagent (Sensibeads) is coated with streptavidin and contains a photosensitizer dye. Sample is incubated with biotinylated antibody and Chemibeads to form bead-AFP-biotinylated antibody sandwiches. Sensibeads are added and bind to the biotin to form bead-pair immunocomplexes. Illumination of the complex at 680 nm generates singlet oxygen from Sensibeads which diffuses into the Chemibeads, triggering a chemiluminescent reaction. The resulting signal is measured at 612 mm and is a direct function of the AFP concentration in the sample.

Here's a breakdown of the acceptance criteria and study details for the Siemens Healthcare Diagnostics Inc. Dimension Vista® AFP Flex® reagent cartridge, based on the provided 510(k) summary:

1. Table of Acceptance Criteria and Reported Device Performance:

The primary objective of this submission is to add lithium heparinized plasma as an approved sample type. Therefore, the "acceptance criteria" are implied by the comparison to the existing, approved serum sample type. The study demonstrates analytical and clinical agreement between serum and lithium heparinized plasma samples.

2. Sample Size Used for the Test Set and Data Provenance:

• Sample Size for Test Set: 70
• Data Provenance: The document states "human serum versus lithium heparinized plasma samples," implying human-derived samples. There is no information regarding the country of origin of the data or whether it was retrospective or prospective.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:

This submission does not involve clinical experts establishing a ground truth for diagnostic accuracy in the traditional sense (e.g., radiologists interpreting images). Instead, it's a comparative analytical study assessing the equivalence of different sample types for the same assay. The ground truth for AFP levels would be the measurement obtained from the predicate device using serum samples. Therefore, this section is not directly applicable.

4. Adjudication Method for the Test Set:

Not applicable. This was an analytical comparison study between two sample types using instrument measurements, not a diagnostic interpretation study requiring adjudication.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size:

No, an MRMC comparative effectiveness study was not done. This is an in vitro diagnostic device for quantitative measurement, not an imaging or interpretation device that would typically involve human readers.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:

Yes, a standalone performance assessment was conducted in the sense that the device (Dimension Vista® AFP Flex® reagent cartridge) was used to measure AFP levels in both serum and lithium heparin plasma samples. The reported performance refers to the analytical agreement of these measurements, without human intervention in the result generation itself.

7. The Type of Ground Truth Used:

The "ground truth" in this context is the analytical measurement obtained from the predicate Dimension Vista® AFP method using serum samples. The study aims to demonstrate that lithium heparin plasma samples provide equivalent measurements to these established serum values.

8. The Sample Size for the Training Set:

The document does not explicitly mention a "training set" in the context of an algorithm or machine learning model. This is an update to a reagent cartridge for an established immunoassay. The method itself (LOCI® technology) is a well-defined chemical reaction, not a machine learning algorithm that requires a separate training set for model development.

9. How the Ground Truth for the Training Set Was Established:

Not applicable, as explained in point 8.

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