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The Sofia Lyme FIA employs immunofluorescence for the rapid differential detection of human IgM and IgG antibodies to Borrelia burgdorferi from serum and plasma specimens from patients suspected of B. burgdorferi infection. This qualitative test is intended for use as an aid in the diagnosis of Lyme disease. A negative result does not preclude infection with B. burgdorferi. All positive results for IgM and/or IgG should be further tested by a corresponding second-tier western blot assay. Test results are to be used in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures.

The Sofia Lyme FIA may be used with Sofia or Sofia 2.

The Sofia Lyme FIA is an immunofluorescence-based, lateral flow assay for detection of IgM and/or IgG antibodies to Borrelia burgdorferi in patient specimens. Reagents for the assay are ready-to-use and provided in the kit.

The assay uses a bidirectional test strip format to detect both IgM and IgG antibodies to B. burgdorferi. One side of the test strip detects IgM antibodies to B. burgdorferi and the other side of the test strip detects IgG antibodies to B. burgdorferi.

To perform the test, a patient serum or plasma specimen is obtained and added to a pre-filled vial containing the lyme running buffer. The diluted sample is then pipetted into the round sample port in the center of the Test Cassette.

The Test Cassette is loaded into Sofia 2 in either the READ NOW Mode or WALK AWAY Mode. In READ NOW Mode, the user allows the cassette to develop on the countertop for 10 minutes. In WALK AWAY Mode, the user immediately after adding the specimen to the cassette is inserted into Sofia 2. Sofia 2 will analyze the test strip at 3, 5, 8, and 10 minutes until both IgM and IgG positive results are received. This feature allows for earlier read times.

Each Sofia Lyme FIA kit will contain one Positive and one Negative Control-each provided in separate dropper bottles. The Positive QC control is formulated with patient Lyme IgM and IgG positive plasma diluted into 1X PBS, and 0.3% Microcide is added to the solution as an antimicrobial. The Negative QC control is formulated with patient negative serum diluted into 1X PBS and 0.3% Microcide is added to the solution as an antimicrobial. External Controls will be tested by adding 2 drops to the test cassette.

Here's an analysis of the provided text to extract the acceptance criteria and study details for the Sofia Lyme FIA device.

Note: The provided document is a 510(k) summary for a medical device. It focuses on demonstrating substantial equivalence to a predicate device, rather than proving that the device meets specific acceptance criteria in the way one might see for a novel AI device with clearly defined performance targets post-development. The performance data section describes the types of studies performed and their general positive outcomes ("good performance," "very good," "comparable performance"), but it does not specify quantitative acceptance criteria or report specific numbers for sensitivity, specificity, or predictive values from a test set against a pre-defined ground truth. The acceptance criteria referred to here are implicitly those required to demonstrate substantial equivalence for regulatory approval, which are less stringent than the "acceptance criteria" usually found in the context of AI/ML model validation against specific quantitative metrics.

Therefore, the answers below are based on the available information, highlighting what is present and noting what is not explicitly stated in this type of regulatory document.

Acceptance Criteria and Device Performance

Based on the nature of a 510(k) submission, the "acceptance criteria" are broad and relate to demonstrating substantial equivalence to a legally marketed predicate device. The performance data presented focuses on analytical and clinical performance attributes that support this claim. Specific quantitative acceptance values are not explicitly listed in the summary, but rather implied by the successful completion of the studies and the conclusion of substantial equivalence.

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)

• Test Set Sample Size: Not explicitly stated in the summary. The "Method Comparison" mentions "prospectively collected specimens from subjects suspected of having Lyme disease," but does not provide a number. "Specificity Study" used "samples obtained from asymptomatic (healthy, normal) populations," also without a specified sample size.
• Data Provenance:
  • Country of Origin: Not specified.
  • Retrospective or Prospective: The "Method Comparison" study explicitly states "prospectively collected specimens." The "Specificity Study" refers to "samples obtained from asymptomatic (healthy, normal) populations," likely indicating prospective collection for that purpose.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

• This device is an in vitro diagnostic (IVD) test, which directly measures biomarkers (antibodies) in patient samples. The concept of "experts" establishing ground truth for individual cases, as in interpreting medical images, does not directly apply here. The performance is evaluated against established methods (the predicate device) or by spiking samples with known concentrations.
• The "ground truth" for evaluating an IVD is typically the true antibody status (positive/negative) determined by reference methods (like Western Blot as mentioned for confirmatory testing) or by known sample characteristics (e.g., healthy controls, defined positive controls). The summary alludes to results being used "in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures," implying clinical diagnosis and confirmatory tests serve as the ultimate clinical ground truth, but this wasn't directly adjudicated by "experts" for the test set in the same way a radiologist would read an X-ray.

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

• Not applicable in the context of this IVD device. Adjudication methods like 2+1 or 3+1 are typically used for subjective assessments (e.g., image interpretation) where human readers establish ground truth. For an IVD, the "ground truth" is derived from a reference laboratory test or clinical definition, not subjective expert consensus on the diagnostic output itself.

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

• No, an MRMC study was not done. This device is not an AI-assisted diagnostic tool that supports human readers in interpretation. It's an automated immunoassay.

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

• This device is inherently "standalone" in its measurement. It's an automated fluorescent immunoassay (FIA) system where the Sofia 2 analyzer performs the reading and provides a result. There isn't a separate "algorithm" being validated outside of the full Sofia Lyme FIA-Sofia 2 system. The performance studies described (analytical, precision, specificity, method comparison, reproducibility) are all evaluating the performance of this system as a whole.

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

• For the Method Comparison study, the ground truth was likely established by the comparative performance against the predicate devices (Vidas Lyme IgG and Vidas Lyme IgM tests), which are themselves established diagnostic tests.
• For the Specificity Study, the ground truth for these samples was "asymptomatic (healthy, normal) populations," implying that the absence of the disease (and thus, antibodies) served as the ground truth.
• For the overall clinical utility, the "Indications for Use" states that the test results are to be used "in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures," and "All positive results for IgM and/or IgG should be further tested by a corresponding second-tier western blot assay." This implies that confirmatory testing (like Western Blot), along with clinical evaluation, contribute to the definitive diagnosis or "ground truth" in clinical practice. The studies themselves don't explicitly detail how definitive ground truth for each case was established beyond comparison with predicate or known healthy status.

8. The sample size for the training set

• This information is not provided because the Sofia Lyme FIA is not an AI/ML device that requires a separate "training set" for model development. It's a chemical immunoassay, and its "development" involves assay optimization and validation rather than model training.

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

• Not applicable, as there is no "training set" in the AI/ML sense for this device.

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