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The RAMP® Influenza A/B Assay is a qualitative immunochromatographic assay used to identify the presence of Influenza A and Influenza B nucleoprotein antigens in nasal wash, nasal aspirate, nasopharyngeal aspirate, and nasopharyngeal swab specimens from symptomatic patients. It is an in vitro diagnostic assay that aids in the rapid differential diagnosis of influenza viral infections in symptomatic patients. A negative test is presumptive and it is recommended these results be confirmed by cell culture. Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other management decisions.

The test performance characteristics for Influenza B were established primarily with retrospective, frozen specimens. Users may wish to further evaluate the sensitivity performance of this test for Influenza B using fresh samples.

The RAMP Influenza A/B Assay is a qualitative immunochromatographic test that utilizes the RAMP 200 instrument for the differential determination of Influenza B in nasal wash/aspirate, nasopharyngeal aspirate, and nasopharyngeal swab samples. A wash/aspirate or swab sample is mixed with Sample buffer and applied into the sample well of the Test Cartidge. The sample migrates along the strip. Fluorescent-dyed latex (test) particles, coated with anti-Influenza A and anti-Influenza B antibodies bind to Influenza A or B antigens, respectively, if present in the sample. As the sample migrates along the strip, Influenza-bound particles are captured at either the Influenza A or the Influenza B detection zone, and additional particles are captured at the internal standard zone.

The instrument then measures the amount of fluorescence emitted by the complexes at the two detection zones (Influenza A and Influenza B) and at the internal standard zone. The instrument calculates a ratio (RAMP Ratio) using the fluorescence reading of each detection zone (A or B) and the internal standard zone. The instrument compares these ratios to pre-defined threshold limits to determine a positive or negative result for Influenza B in the tested sample.

The provided text describes the analytical reactivity study for the RAMP® Influenza A/B Assay, specifically for the K093116 submission, which provides additional analytical reactivity information for the previously cleared K071591 device.

Here's an analysis of the acceptance criteria and the study that proves the device meets them:

1. Table of Acceptance Criteria and Reported Device Performance:

The document focuses on analytical reactivity rather than clinical performance (e.g., sensitivity, specificity in patient samples). The implicit acceptance criterion for analytical reactivity is that the device should consistently detect the target antigen at a certain concentration, and not detect at a lower, non-target concentration.

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

• Test Set Sample Size: For the analytical reactivity study, 5 replicates were tested at each concentration of the Influenza A (Swine NY/02/2009) isolate. This means a total of 25 tests were performed for Influenza A detection (5 concentrations x 5 replicates).
• Data Provenance: The study was conducted using an isolate strain of Influenza A (Swine NY/02/2009) prepared in Copan UTM. This indicates a laboratory-based, analytical study rather than a clinical study with patient samples. The document does not specify a country of origin for the isolate beyond it being "Swine NY/02/2009". It is a prospective study in the sense that the testing was performed specifically for this submission.

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

• Number of Experts: Not applicable. The ground truth for this analytical study was established by the known concentration of the Influenza A isolate (TCID50/mL), which is a quantitative measure determined through laboratory techniques (e.g., cell culture, endpoint dilution assays). It does not involve human expert consensus for qualitative assessment of clinical samples.
• Qualifications of Experts: Not applicable for this type of analytical study.

4. Adjudication Method for the Test Set:

• Adjudication Method: Not applicable. The results are quantitative (TCID50/mL) and instrument-read (RAMP instrument calculates a ratio and determines positive/negative based on predefined thresholds). There is no human adjudication process described.

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:

• MRMC Study: No. This document describes an analytical reactivity study of a diagnostic device (RAMP® Influenza A/B Assay) which is an "immunochromatographic test that utilizes the RAMP 200 instrument". It is not an AI-based device, and therefore, an MRMC comparative effectiveness study involving human readers with/without AI assistance is not relevant or described.

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

• Standalone Performance: Yes, in a way. The RAMP® Influenza A/B Assay with the RAMP 200 instrument determines the result based on measurement of fluorescence and calculation of a ratio against predefined thresholds. This process is automated ("algorithm only") and does not involve real-time human interpretation or human-in-the-loop performance during the test itself. The study confirms the performance of this automated system in detecting the target analyte.

7. The Type of Ground Truth Used:

• Ground Truth: The ground truth for the analytical reactivity study was the known concentration of the viral isolate (Influenza A/Swine NY/02/2009), quantified in Tissue Culture Infectious Dose 50% (TCID50/mL). This is a precise laboratory-derived standard.

8. The Sample Size for the Training Set:

• Training Set Sample Size: Not specified or applicable in the provided text. This document describes a verification study of an already developed device. It is not clear if an explicit "training set" in the context of machine learning was used, as this is primarily a chemical/immunological assay with an automated reader rather than an AI/machine learning algorithm that requires extensive training data. The "pre-defined threshold limits" for the RAMP instrument would have been established during the device's initial development, but the data used for that is not part of this document.

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

• Ground Truth for Training Set: Not specified. As mentioned above, the concept of a "training set" as commonly understood in AI/machine learning isn't explicitly addressed here. The "pre-defined threshold limits" for the RAMP instrument (which guide the positive/negative determination) would have been established during the development of the K071591 device (the predicate). This would likely involve testing characterized positive and negative samples at various concentrations to set appropriate cut-offs, but the details of that process are not included in this submission.

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The RAMP® Influenza A/B Assay is a qualitative immunochromatographic assay used to identify the presence of Influenza A and Influenza B nucleoprotein antigens in nasal wash, nasal aspirate, nasopharyngeal aspirate, and nasopharyngeal swab specimens from symptomatic patients. It is an in vitro diagnostic assay that aids in the rapid differential diagnosis of influenza viral infections in symptomatic patients. A negative test is presumptive and it is recommended these results be confirmed by cell culture. Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other management decisions.

The test performance characteristics for Influenza B were established primarily with retrospective, frozen specimens. Users may wish to further evaluate the sensitivity performance of this test for Influenza B using fresh samples.

The RAMP Influenza A/B Assay is a qualitative immunochromatographic test that utilizes the RAMP 200 for the differential determination of Influenza B in nasal wash, nasal aspirate, nasopharyngeal aspirate, and nasopharyngeal swab samples. A wash/aspirate or swab sample is added to the Sample Buffer. The Sample Buffer is optimized to improve binding of the anti-influenza antibodies to the nucleoprotein antigens and reduce non-specific binding and fluorescent signal background. This sample is then mixed using the Assay Tip containing fluorescent-dyed particles conjugated to specific antibodies and applied into the sample well of the Test Cartridge. The sample migrates along the strip. Fluorescent-dyed particles coated with anti-Influenza A and anti-Influenza B antibodies bind to Influenza A or B antigens, respectively, if present in the sample. As the sample migrates along the strip, Influenza-bound particles are captured at either the Influenza A or the Influenza B detection zone, and excess fluorescent- dyed particles are captured at the internal standard zone.

The instrument then measures the amount of fluorescence emitted by the complexes at the two detection zones (Influenza A and Influenza B) and at the internal standard zone. The instrument calculates a ratio (RAMP Ratio) using the fluorescence reading of each detection zone (A or B) and the internal standard zone. The instrument compares these ratios to pre-defined threshold limits to determine a positive or negative result for Influenza B in the tested sample.

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

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state pre-defined acceptance criteria in a dedicated section with target values. However, based on the performance study results, we can infer the observed performance metrics. The primary method of comparison is against cell culture.

2. Sample Size and Data Provenance:

• Test Set (Clinical Performance):

  • Prospective Study: 844 fresh specimens (nasal wash/aspirate, nasopharyngeal aspirate, or nasopharyngeal swab samples). This study was conducted in North America during the 2006-2007 influenza season.
  • Retrospective Study: 75 retrospective frozen clinical nasopharyngeal swab samples and 130 retrospective frozen clinical wash/aspirate samples. These were compared to original cell culture results performed on fresh specimens.

• Training Set: The document does not explicitly mention a training set size or methodology for the device's algorithm. The studies described are for analytical (device characteristics) and clinical performance evaluation, not for training a machine learning model. This is a traditional IVD.

3. Number of Experts and Qualifications for Ground Truth (Test Set):

• The ground truth for the clinical performance studies was established using cell culture. The document does not specify the number or qualifications of experts involved in performing or interpreting the cell culture results. It states that "cell culture testing was performed using fresh specimens" and implies these are standard laboratory procedures.

4. Adjudication Method (Test Set):

• The document describes comparison studies where the RAMP® Influenza A/B Assay results were compared directly against cell culture results. The term "adjudication method" typically applies to resolving discrepancies between multiple readers or between a new device and a reference standard where a third, independent assessment is needed. In this case, cell culture acts as the definitive gold standard, and direct comparison is made. There is no mention of a separate adjudication process beyond the cell culture determination.

5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study:

• No, a multi-reader multi-case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance was not done. This device is an in-vitro diagnostic (IVD) assay that produces a direct result, not an AI-assisted diagnostic imaging tool that improves human reader performance. The "readers" here are the laboratory personnel performing the assay.

6. Standalone Performance Study:

• Yes, a standalone performance study was done for the device. The "Clinical Performance" section directly compares the RAMP® Influenza A/B Assay (algorithm only, as it generates the result) against the cell culture gold standard. The sensitivity and specificity results presented in the tables are indicative of the algorithm's standalone performance.

7. Type of Ground Truth Used:

• For the clinical performance studies, the ground truth was viral cell culture. This is explicitly stated: "The performance of the RAMP Influenza A/B Assay was compared to cell culture."

8. Sample Size for the Training Set:

• As mentioned in point 2, the document does not describe the training of a machine learning algorithm. Therefore, there is no explicit training set size provided for this device in the context of AI/ML. The analytical studies describe the development and validation of the assay's operational parameters rather than training a model.

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

• Not applicable, as there is no mention of an AI/ML training set in the document. For the development of the assay (which could be considered analogous to "training" in a traditional IVD context), the process involves determining optimal reagent concentrations, binding efficiencies, and establishing cut-off values. This is based on internal analytical studies (like LoD, precision, reactivity) using characterized viral strains and clinical samples, rather than a separate ground truth establishment for a training set in the AI sense.

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