Search Results

The Sofia Influenza A+B FIA employs immunofluorescence to detect influenza B viral nucleoprotein antigens in direct nasal swab, nasopharyngeal swab, and nasopharyngeal aspirate/wash specimens and nasopharyngeal swab and nasopharyngeal aspirate/wash specimens in transport media from symptomatic patients. This qualitative test is intended for use as an aid in the rapid differential diagnosis of acute influenza B viral infections. The test is not intended to detect influenza C antigens. A negative test is recommended these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative results do not preclude influenza virus infections and should not be used as the sole basis for treatment or other patient management decisions. This test is intended for professional and laboratory use.

The Sofia Influenza A+B FIA may be used with Sofia or Sofia 2.

Performance characteristics for influenza A and B were established during February through March 2011 when influenza viruses A/California 7/2009 (2009 H1N1), A/Perth/16/2009 (H3N2), and B/Brisbane/60/2008 (Victoria-Like) were the predominant influenza viruses in circulation according to the Mortality Weekly Report from the CDC entitled "Update: Influenza Activity--United States, 2010-2011 Season, and Composition of the 2011-2012 Influenza Vaccine." Performance characteristics may vary against other emerging influenza viruses.

If infection with a novel influenza virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, samples should be collected with appropriate infection sor novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture samples.

The Sofia Influenza A+B FIA employs immunofluorescence technology that is used with Sofia and Sofia 2 to detect influenza virus nucleoproteins. This test allows for the differential detection of influenza A and influenza B antigens.

The patient sample is placed in the Reagent Tube, during which time the virus particles in the sample are disrupted, exposing internal viral nucleoproteins. After disruption, the sample is dispensed into the Test Cassette sample well. From the sample migrates through a test strip containing various unique chemical environments. If influenza viral antigen is present, they will be trapped in a specific location.

Note: Depending upon the user's choice, the Test 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 and Sofia 2 will scan the test strip and measure the fluorescent signal by processing the results using method-specific algorithms. Sofia and Sofia 2 will display the test results (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 provided text describes the 510(k) premarket notification for the "Sofia® Influenza A+B FIA on Sofia 2" device. Here's an analysis of the acceptance criteria and the study information:

1. Table of Acceptance Criteria and Reported Device Performance:

The document does not explicitly state acceptance criteria in a quantitative, objective manner (e.g., "sensitivity must be >95%"). Instead, the performance studies aim to demonstrate equivalence to the predicate device (Sofia® Influenza A+B FIA on Sofia). Therefore, the "reported device performance" is framed as proving this equivalence.

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

The document mentions a "panel of clinical samples" for the Method Comparison study but does not specify the sample size for this test set nor the specific number of samples used for other studies like LoD, Precision, Early Read, or Reproducibility.

The data provenance is described as:

• "Performance characteristics for influenza A and B were established during February through March 2011"
• Location: Implied to be United States, as it references the "Morbidity and Mortality Weekly Report from the CDC entitled 'Update: Influenza Activity—United States, 2010-2011 Season'".
• Retrospective/Prospective: The collection period (Feb-Mar 2011) and subsequent analysis suggest the data might be retrospective (collected on previously circulating strains and then tested with the devices).

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

The document does not provide information on the number of experts or their qualifications for establishing ground truth for the test set.

4. Adjudication Method for the Test Set:

The document does not explicitly describe an adjudication method (e.g., 2+1, 3+1). It states "viral culture or an FDA-cleared influenza A and B molecular assay" as confirmation methods for negative results, implying these are the primary methods for ground truth, rather than expert adjudication of the Sofia results themselves.

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:

This device is not an AI/CAD-based system designed to assist human readers. It is an in vitro diagnostic (IVD) device that provides automated results (Positive, Negative, Invalid). Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance is not applicable and was not done. The system reports a direct result, not an interpretation for human review.

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

Yes, the studies conducted demonstrate standalone performance of the Sofia 2 device. The device outputs "Positive, Negative, or Invalid" results based on its internal algorithms and fluorescent signal detection, without human interpretation of the signal. The "Method Comparison" study compares the device's performance against the predicate device using clinical samples, effectively evaluating its standalone accuracy.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc):

The ground truth for defining influenza positive/negative status is indicated implicitly by these statements:

• "A negative test is presumptive and it is recommended these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay."
• This suggests that viral culture and/or FDA-cleared molecular assays (which are highly sensitive and specific) were used as the reference standard or "ground truth" to determine the true influenza status of the clinical samples during the performance characteristic studies.

8. The Sample Size for the Training Set:

The document does not specify a sample size for a training set. This type of device (immunofluorescence detection with pre-defined algorithms) typically doesn't involve a "training set" in the machine learning sense. The algorithms are likely developed and validated on internal data during product development, but this information is not provided here. The studies described are primarily for verification and validation against the predicate and established performance characteristics.

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

As mentioned above, a "training set" in the context of machine learning is not applicable here. For the development and initial validation of the device's algorithms, the ground truth would have likely been established using well-characterized samples (e.g., confirmed by viral culture or PCR) to tune the device's sensitivity thresholds for fluorescent signal detection. However, details on this process are not provided in this regulatory submission summary.

Ask a specific question about this device

The Sofia Influenza A +B FIA employs immunofluorescence to detect influenza B viral nucleoprotein antigens in nasal swab, nasopharyngeal swab, and nasopharyngeal aspirate/wash in fresh or transport media specimens from symptomatic patients. This qualitative test is intended for use as an aid in the rapid differential diagnosis of acute influenza A and influenza B viral infections. The test is not intended to detect influenza C antigens. A negative test is presumptive and it is recommended these results be confirmed by virus culture or an FDA-cleared influenza A and B molecular assay. Negative results do not prectude influenza virus infections and should not be used as for treatment or other management decisions. The test is intended for professional and laboratory use.

Performance characteristics for influenza A and B were established during February through March 2011 when influenza viruses A/California 7/2009 (2009 H1N1), A/Perth/16/2009 (H3N2), and B/Brisbane/60/2008 (Victoria-Like) were the predominant influenza viruses in circulation according to the Mortality Weekly Report from the CDC entitled "Update: Influenza Activity-United States, 2010-2011 Season, and Composition of the 2011-2012 Influenza Vaccine". Performance characteristics may vary against other emerging influenza viruses.

If infection with a novel influenza virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.

The Sofia Influenza A+B FIA employs immunofluorescence technology that is used with Sofia to detect influenza virus nucleoproteins. This test allows for the differential detection of influenza A and influenza B antigens.

The Sofia Influenza A+B FIA is a lateral-flow immunoassay that uses monoclonal antibodies that are specific for influenza antigens and have no known cross-reactivity to normal flora or other known respiratory pathogens.

Nasal swab, nasopharyngeal swab, and nasopharyngeal aspirate/wash specimens (both fresh and in VTM) are used for this test. 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 influenza viral antigen is present, they will be trapped in a specific location.

Note: Depending upon the user's choice, the cassette is either placed inside Sofia 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 to be scanned (Read Now Mode).

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

The provided text describes the 510(k) summary for the Sofia® Influenza A+B FIA device. Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided information.

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria in terms of specific performance metrics (e.g., minimum sensitivity or specificity targets). Instead, it presents performance data from a clinical study to demonstrate "substantial equivalence" to a predicate device and suitability for use with viral transport media (VTM).

Therefore, the "acceptance criteria" can be inferred to be a demonstration of substantial equivalence and acceptable performance, particularly when using VTM, compared to the predicate device which only used fresh specimens. The provided text, however, does not include a direct comparison table of the proposed device's performance against the predicate device's performance metrics for all relevant parameters (like sensitivity and specificity). It mainly focuses on the new capability (VTM use) and the overall conclusion of substantial equivalence.

Inferred "Acceptance Criteria" (Demonstrated Substantial Equivalence and Acceptable Performance with VTM)

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

• Test Set Sample Size: The document does not explicitly state the numerical sample size for the multi-center field clinical study. It only mentions that a "multi-center field clinical study was performed."
• Data Provenance: The study was a "multi-center field clinical study." While the specific countries are not mentioned, it's generally understood that such studies for FDA submissions typically include data from the United States, given the context of the FDA approval. The study collected data "during February through March 2011" making it retrospective in relation to the submission date of October 13, 2015.

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

The document does not provide details on the number or qualifications of experts used to establish the ground truth for the test set.

4. Adjudication Method for the Test Set

The document does not specify the adjudication method used for the test set.

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

An MRMC study was not done. The device, Sofia® Influenza A+B FIA, is an immunofluorescence assay read by an instrument (Sofia Analyzer), not a human visual interpretation. Therefore, the concept of human readers improving with or without AI assistance is not applicable to this device. The results are displayed by the instrument as "Positive, Negative, or Invalid."

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

Yes, a standalone performance evaluation was done. The Sofia® Influenza A+B FIA is an automated system where the Sofia Analyzer scans the test strip and processes the results using "method-specific algorithms." The instrument then displays the results. This represents the algorithm's standalone performance.

7. The Type of Ground Truth Used

The ground truth for the clinical study is not explicitly stated in the provided text. However, for influenza diagnostic tests, the common "gold standards" or ground truths involve:

• Virus culture: This is mentioned in the "Indications for Use" as a recommended confirmation for negative test results ("confirmed by cell culture").
• FDA-cleared influenza A and B molecular assay: Also mentioned in the "Indications for Use" as a confirmation method.

Given the context, it is highly probable that a comparative method such as virus culture or an FDA-cleared molecular assay was used as the ground truth reference for the clinical performance study.

8. The Sample Size for the Training Set

The document does not mention a "training set" in the context of an algorithm or AI development. The device is a lateral-flow immunoassay with an instrument reader. The "method-specific algorithms" within the Sofia Analyzer would be preset and validated, rather than "trained" on a specific dataset in the way a machine learning model is trained. Therefore, there's no explicitly stated training set for an AI/algorithm in this document.

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

As there is no mention of a "training set" for an AI or algorithm in the conventional sense, the establishment of ground truth for such a set is not applicable or described in the provided information.

Ask a specific question about this device

The Sofia Influenza A+B FIA employs immunofluorescence to detect influenza A and influenza B viral nucleoprotein antigens in nasal swab, 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 differential diagnosis of acute influenza A and influenza B viral infections. The test is not intended to detect influenza C antigens. A negative test is presumptive and it is recommended these results be confirmed by virus culture or FDA-cleared influenza A and B molecular assay. Negative results do not preclude influenza virus infections and should not be used as the sole basis for treatment or other management decisions. The test is intended for professional and laboratory use.

Performance characteristics for influenza A and B were established during February through March 2011 when influenza viruses A/California/7/2009 (2009 H1N1), A/Perth/16/2009 (H3N2), and B/Brisbane/60/2008 (Victoria-Like) were the predominant influenza viruses in circulation according to the Morbidity and Mortality Weekly Report from the CDC entitled "Update: Influenza Activity--United States, 2010-2011 Season, and Composition of the 2011-2012 Influenza Vaccine". Performance characteristics may vary against other emerging influenza viruses.

If infection with a novel influenza virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.

The Sofia Influenza A+B FIA employs immunofluorescence technology that is used with the Sofia Analyzer to detect influenza virus nucleoproteins.

The Sofia Influenza A+B FIA is a lateral-flow immunoassay that uses monoclonal antibodies that are specific for influenza antigens and have no known cross-reactivity to normal flora or other known respiratory pathogens.

Nasal swab, nasopharyngeal swab, and nasopharyngeal aspirate/wash specimens are used for this test. 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 influenza viral antigen is present, they will be trapped in a specific location.

• Note: Depending upon the user's choice, the cassette is either placed inside of the Sofia Analyzer for automatically timed development (Walk Away Mode) or placed on the counter or bench top for a manually timed development and then placed into the Sofia Analyzer to be scanned (Read Now Mode).
  The Sofia Analyzer will scan the test strip and measure the fluorescent signal by processing the results using method-specific algorithms. The Sofia Analyzer will display the test results (Positive, Negative, or Invalid) on the screen. The results can also be automatically printed on an integrated printer if this option is selected.

Here's an analysis of the provided text regarding the Sofia® Influenza A+B FIA device:

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size for Test Set and Data Provenance

The provided text describes one analytical study (for H7N9 detection) and refers to previously established performance characteristics for common influenza strains.

• H7N9 Study (Analytical): The sample size for this specific study is not explicitly stated. The study focuses on establishing the Limit of Detection (LoD).
• Previous Performance Characteristics (Clinical): The text mentions that performance characteristics for influenza A and B were established during February through March 2011 when specific influenza viruses were prevalent.
  • Data Provenance: The general context indicates this data would be from the United States, as it references the CDC's Morbidity and Mortality Weekly Report regarding influenza activity in the US.
  • Retrospective or Prospective: The phrasing "performance characteristics were established during February through March 2011" suggests prospective data collection during a specific influenza season. However, no details on how many patient samples were tested are provided in this summary.

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

The provided summary does not explicitly state the number of experts used or their qualifications for establishing ground truth for the test set that determined the original performance characteristics.

For the H7N9 analytical study, the nature of establishing "minimum detectable level" implies laboratory testing rather than expert-based ground truth on clinical samples.

4. Adjudication Method for the Test Set

The document does not describe any adjudication method for establishing the ground truth for the clinical test sets (both for the previously established performance and the H7N9 study).

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

No mention of a Multi-Reader Multi-Case (MRMC) comparative effectiveness study or human reader improvement with/without AI assistance. This device is an immunoassay and an analyzer, not an AI-powered diagnostic imaging tool. Therefore, an MRMC study as typically understood in AI/imaging would not be applicable.

6. Standalone (Algorithm Only) Performance

Yes, the device's performance, as described by the "minimum detectable level" for H7N9 and the "performance characteristics" established for other influenza strains, represents its standalone performance. The Sofia Analyzer processes the results using "method-specific algorithms" and displays "Positive, Negative, or Invalid" results. There is no human-in-the-loop component for interpreting the test outcome itself; the human operates the device and reads its output.

7. Type of Ground Truth Used

• H7N9 Analytical Study: The ground truth for the H7N9 study is based on a known concentration of H7N9 virus (Egg Infective Dose (EID)30/mL), which is a common method for establishing the Limit of Detection for in vitro diagnostic tests.
• Previous Performance Characteristics (Clinical): The intended use statement mentions that for negative results, it is "recommended these results be confirmed by virus culture or FDA-cleared influenza A and B molecular assay." This implies that the ground truth for the clinical performance characteristics (established in 2011) was likely based on confirmation by these more definitive laboratory methods.

8. Sample Size for the Training Set

The document does not provide any information about a "training set" or its sample size. This is an in vitro diagnostic device based on immunofluorescence with specific reagent antibodies and an analyzer using "method-specific algorithms." The development process for such a device would involve extensive analytical validation (e.g., sensitivity, specificity, cross-reactivity) rather than a "training set" in the context of machine learning.

9. How Ground Truth for Training Set Was Established

As no training set is mentioned in the context of machine learning, this question is not applicable based on the provided text. The "method-specific algorithms" in the Sofia Analyzer would have been developed and validated through internal R&D and analytical studies, not typically through a machine learning training process with a dedicated training set and labeled ground truth in the same way an AI imaging algorithm would be.

Ask a specific question about this device