Search Results

The Sofia RSV FIA employs immunofluorescence for detection of respiratory syncytial virus (RSV) nucleoprotein antigen in nasopharyngeal swab and nasopharyngeal aspirate/wash specimens taken directly from symptomatic patients. This qualitative test is intended for use as an aid in the rapid diagnosis of acute RSV infections in pediatric patients. Negative results do not preclude RSV infection and should not be used as the sole basis for treatment or for other management decisions. A negative result is presumptive, and it is recommended these results be confirmed by viral culture or an FDA-cleared RSV molecular assay.

The Sofia RSV FIA may be used with the Sofia or Sofia 2.

The Sofia RSV FIA test employs immunofluorescence technology that is used with Sofia for the rapid detection of RSV antigens. The Sofia RSV FIA test involves the disruption of RSV viral antigens. The patient specimen is placed in the Reagent Tube, during which time the virus particles in the specimen are disrupted, exposing internal viral nucleoproteins. After disruption, the specimen is dispensed into the Cassette sample well. From the sample well, the specimen migrates through a test strip containing various unique chemical environments. If RSV viral antigens are present, they will be trapped in a specific location.

Note: Depending upon the user's choice, the cassette is either placed inside of Sofia or Sofia 2 for automatically timed development (Walk Away Mode) or placed on the counter or bench top for a manually timed development and then placed into Sofia 2 to be scanned (Read Now Mode).

Sofia or Sofia 2 will scan the test strip and measure the fluorescent signal by processing the results using method-specific algorithms. Test results will be displayed (Positive, or Invalid) on the screen. The results can also be automatically printed on an integrated printer if this option is selected.

Sofia 2 is a microprocessor-controlled device about the size of a desk top telephone and weighs less than 3 pounds. Sofia 2 uses a fluorescent tag that is illuminated by an Ultraviolet (UV) light source to generate specific results.

The document describes the Sofia RSV FIA device and its performance, but it does not contain a detailed table of acceptance criteria and reported device performance with specific metrics like sensitivity and specificity, nor does it detail the specific clinical study design, sample sizes, and ground truth establishment methods for a clinical evaluation.

However, based on the provided text, here's what can be extracted and inferred:

1. Table of Acceptance Criteria and Reported Device Performance

The submission states that "Numerous studies were undertaken to document the performance characteristics of Sofia 2 and the Sofia RSV assay, as well as to compare the performance between Sofia and Sofia 2." The conclusion is that "These studies demonstrated equivalent performance of the Sofia RSV FIA on the Sofia and Sofia 2 analyzer."
While specific numerical acceptance criteria (e.g., "sensitivity must be >90%") are not explicitly stated within this document, the studies listed (Limit of Detection, Precision, Assay Development Time, Early Read, Method Comparison, Reproducibility) confirm the equivalence of the Sofia RSV FIA on Sofia 2 to the predicate device (Sofia RSV FIA on Sofia). This implies that the acceptance criteria for performance are met if the performance on Sofia 2 is comparable to the already cleared Sofia device.

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

The document mentions "a panel of clinical samples" for the Method Comparison study and "a panel of test samples at various RSV concentrations" for the Reproducibility study. However, the specific sample sizes for these test sets are NOT provided. The data provenance (e.g., country of origin, retrospective or prospective) is also not explicitly stated in this document.

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

This information is not provided in the document. For an in vitro diagnostic device like Sofia RSV FIA, the "ground truth" for clinical samples is typically established by a reference method, such as viral culture or an FDA-cleared molecular assay for RSV, as mentioned in the "Indications for Use" for confirming negative results. Expertise would be in performing and interpreting these reference methods.

4. Adjudication Method for the Test Set

This information is not provided in the document, as it likely pertains to expert review of ambiguous cases, which is not described.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

No, an MRMC comparative effectiveness study involving human readers with and without AI assistance is not described in this document. This device is an in vitro diagnostic (IVD) test, which is a standalone algorithm-based test. The "readers" would be the Sofia/Sofia 2 instruments themselves, not human interpreters of AI output.

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

Yes, the studies described are standalone performance evaluations of the Sofia RSV FIA device (algorithm only), specifically when performed on the Sofia 2 analyzer, and comparing its performance to the Sofia analyzer. The device automatically scans the test strip and processes results using "method-specific algorithms." Humans load the cassette and read the displayed result.

7. The Type of Ground Truth Used

The "Indications for Use" section states: "A negative result is presumptive, and it is recommended these results be confirmed by viral culture or an FDA-cleared RSV molecular assay." This indicates that the ground truth for clinical samples, especially for confirmation, would be established by these reference methods. For laboratory studies like LoD and Reproducibility, the ground truth would be based on known concentrations of RSV.

8. The Sample Size for the Training Set

The document does not mention a training set sample size. For an IVD device like this, the "algorithm" is likely developed and refined during the product development phase (which would involve internal testing and optimization data, akin to a training set), but specific details on that are not provided in this regulatory submission summary for substantial equivalence. The studies described are performance validation studies.

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

Since a training set is not explicitly mentioned, the method for establishing its ground truth is also not provided. If an algorithm was trained, the ground truth would typically be established through highly accurate reference methods (like viral culture or PCR) on a diverse set of samples.

Ask a specific question about this device