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A vitamin B12 test system is a device intended to measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of anemias of gastrointestinal malabsorption.

Competition principle. Total duration of assay: 18 minutes, 37*C. Competition principic. Total adalabating the sample (15 mL) with the •] * incubation (9 immutes). By metreatment 2 (15 mL), bound Vitamin B12 is liberated into the serum.

·2nd incubation (9 minutes): By incubating the pretreated sample with the •2nd incubation (9 innutes): Dy most, and immunocomplex is formed, the ruthenylated" * " intrilisic Tactor (70 this), " = " = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = · 3rd incubation (9 minutes): After addition of of streptaviding of a streptaviding of the still, •3rd incubation (9 mL) and Vitamin B12 labeled with biotin (60 mL), the still-

microparticles (30 mL) and Vitalini Dr.2 recorder become occupied, with the vacant sites of the ruthenylated Intrinst For and B12 biotin complex.
formation of an ruthenylated Intrinsic Factor-Viraming of biotin formation of an rutherrylated markisto i actor-phase via interaction of biotin.
The entire complex becomes bound to the solid phase via interaction of biotin. and streptavidin.

·The reaction mixture is aspirated into the measuring cell where the · I he reaction inixture is aspirated onto the surface of the electrode. microparticles are then removed with Procell. Application of a voltage Unbound substances are then removed was a secure in which is measured
to the electrode then induces chemiluminescent emission which is measured by a photomultiplier (0.4 second read frame).

·Results are determined via a calibration curve which is instrument-· Results are 'delemined ' via- a 'culturation and a master curve provided via the reagent bar code.

**Tris(2,2'-bipyridyl)ruthenium(II) complex (Ru(bpy)**3)

The provided document is a 510(k) Summary for the Boehringer Mannheim Elecsys Vitamin B12 Assay. It describes the device, its intended use, and compares its performance characteristics to a predicate device.

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are not explicitly stated in terms of pass/fail thresholds for the Elecsys Vitamin B12 assay. Instead, the document presents performance characteristics of the Elecsys Vitamin B12 assay and the predicate device (BioRad Quantaphase II B12/Folate Radioassay) for comparison, implying that the Elecsys device's performance should be comparable or superior. The specific performance metrics reported are:

Study Proving Acceptance Criteria:

The study proving the device meets the acceptance criteria is detailed in the "Performance Characteristics" section of the 510(k) Summary. It's a comparative study against a predicate device.

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

• Precision Studies (Within-run and Total):
  • For the Elecsys Vitamin B12 assay, N=60 for each of the three pools/levels tested.
  • For the BioRad Quantaphase II, N=40 for each of the four levels tested.
• Method Comparison:
  • For the comparison of Elecsys to BioRad Quantaphase II B12/Folate Radioassay, the sample size was N=346.
  • For the comparison of the predicate BioRad Quantaphase II to a commercially available radioimmunoassay, the sample size was N=84.

The document does not specify the country of origin of the data or whether it was retrospective or prospective. Given the context of a 510(k) submission for a diagnostic device, such studies are typically prospective clinical performance evaluations.

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

This type of information (number and qualifications of experts) is generally not applicable for the ground truth establishment in analytical performance studies of quantitative in vitro diagnostic (IVD) assays like a Vitamin B12 assay.

For an IVD measuring an analyte concentration:

• The "ground truth" for method comparison and precision is usually an independent, highly accurate reference method or a carefully characterized reference material (e.g., control pools with assigned values).
• For reference ranges, the "ground truth" comes from statistical analysis of a healthy population.
• Interfering substances are tested experimentally by adding known concentrations of potential interferents to samples with known analyte concentrations.

Therefore, expert consensus, as might be used for image classification, is not the mechanism for establishing ground truth in this context.

4. Adjudication Method for the Test Set

Adjudication methods (e.g., 2+1, 3+1) are typically used in studies where human interpretation of data (e.g., medical images) is involved and discrepancies need resolution. For a quantitative in vitro diagnostic assay, the "adjudication method" is not applicable in the same sense. The results are numerical values, and any discrepancies would be resolved through re-testing, statistical analysis protocols, or review of instrument performance, rather than expert adjudication.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size of Human Improvement with AI vs. without AI Assistance

This section is not applicable because the device described, the Elecsys Vitamin B12 Assay, is an automated in vitro diagnostic (IVD) immunoassay. It does not involve human readers interpreting cases or AI assistance in a diagnostic workflow. It generates quantitative results directly.

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

This question is also not truly applicable in the context of this device. The Elecsys Vitamin B12 Assay is a standalone analytical instrument/reagent system designed to automatically measure Vitamin B12 concentrations. Its performance characteristics (precision, linearity, method comparison, interference) represent its "standalone" performance without direct human interpretation of the analytical signal. Human involvement typically comes in operating the instrument, performing calibration, quality control, and interpreting the numerical result in a clinical context, not in interpreting the raw assay signal.

7. The Type of Ground Truth Used

The ground truth used for these studies generally falls into these categories:

• Reference Method / Predicate Device Comparison: For the method comparison study, the results from the BioRad Quantaphase II B12/Folate Radioassay (and another commercially available radioimmunoassay for the predicate) served as the comparative "ground truth" to establish substantial equivalence.
• Known Concentrations: For precision, linearity, and interference studies, samples with accurately known or established concentrations of Vitamin B12 (e.g., control pools, spiked samples, diluted samples) were used to assess the device's accuracy and robustness.
• Clinical Population Data: For the establishment of reference ranges, concentrations measured in a population determined to be healthy or having specific conditions (deficient, indeterminate) would have been used.

8. The Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of device development. For an IVD assay like this, "training" primarily refers to:

• Calibration: The instrument is calibrated using calibrators with known concentrations, which are fundamental to its operation.
• Reagent Development and Optimization: Early development likely involves numerous experiments and samples to optimize reagent formulations and assay parameters.

The N=346 and N=84 for method comparison and N=60 and N=40 for precision studies represent the performance validation or test sets for demonstrating the device's characteristics against a predicate or general standards, not a training set in the machine learning sense. Statistical parameters (like calibration curves) are internal to the instrument, derived from known calibrators and master curves.

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

As "training set" in the machine learning sense is not explicitly described or directly applicable here, the establishment of "ground truth" relates to the calibration of the system and optimization during development, rather than a distinct training phase with a labelled dataset:

• Calibrators: For calibration, the "ground truth" for the calibrator values is established through highly accurate reference methods or certified reference materials, ensuring the accurate assignment of concentration values to the calibrator solutions. These calibrators are then used by the Elecsys instrument to create its internal calibration curve.
• Master Curve: The document mentions "Results are 'delemined' via- a 'culturation and a master curve provided via the reagent bar code." This "master curve" is pre-established by the manufacturer using extensive studies with reference materials and multiple reagent lots, effectively serving as programmatic "ground truth" for the instrument's calculations.

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