Search Results

Ask a specific question about this device

Ask a specific question about this device

Ask a specific question about this device

The Sensititre 18-24 hour MIC or Breakpoint Susceptibility System is an in vitro diagnostic product for clinical susceptibility testing of non-fastidious isolates.

This 510(k) is for amikacin in the dilution range of 0.25-256 µg/mL for testing non-fastidious gram-negative isolates on The Sensititre 18-24 hour MIC or Breakpoint Susceptibility System. Testing is indicated for Acinetobacter spp., Enterobacterales, and Pseudomonas aeruginosa, as recognized by the FDA Susceptibility Test Interpretive Criteria (STIC) webpage.

The Sensititre 18-24 hour MIC or Breakpoint Susceptibility System with Amikacin in the dilution range of 0.25-256 µg/mL demonstrated acceptable performance with the following organisms:

Acinetobacter spp. (Acinetobacter baumannii)

Enterobacterales (Citrobacter freundii, Citrobacter koseri, Enterobacter cloacae complex, Escherichia coli, Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, Providencia stuartii, Serratia marcescens)

Pseudomonas aeruginosa

Not Found

The provided FDA 510(k) clearance letter pertains to The Sensititre 18-24 hour MIC or Breakpoint Susceptibility System with Amikacin. This device is an in vitro diagnostic product for clinical susceptibility testing of non-fastidious isolates, specifically for amikacin in the dilution range of 0.25-256 µg/mL for testing non-fastidious gram-negative isolates on the system. The indications for use specify its application for Acinetobacter spp., Enterobacterales, and Pseudomonas aeruginosa.

Unfortunately, the provided document does not contain the detailed information required to specifically answer your questions about acceptance criteria, study methodology (sample size, data provenance, expert qualifications, adjudication), MRMC studies, standalone performance, or training set details. This clearance letter is a formal notification of substantial equivalence and outlines the intended use and regulatory classifications, but it does not include the full summary of safety and effectiveness data that would typically contain such study specifics.

To get the information you're looking for, you would generally need to refer to the 510(k) Summary document, which is usually part of the full 510(k) submission and is publicly available through the FDA's 510(k) database. This summary typically provides a more detailed overview of the performance studies conducted to support the clearance.

Therefore, I cannot populate the table or answer most of your specific questions based solely on the provided text.

However, I can extract what is implied about acceptable performance:

1. A table of acceptance criteria and the reported device performance

Based only on the statement "The Sensititre 18-24 hour MIC or Breakpoint Susceptibility System with Amikacin in the dilution range of 0.25-256 µg/mL demonstrated acceptable performance with the following organisms," we can infer that the device met the manufacturer's internal acceptance criteria for performance for these organisms, as the FDA has cleared it. Without the 510(k) summary, specific numeric thresholds for performance metrics (e.g., Essential Agreement, Category Agreement) for in vitro diagnostic susceptibility tests are not provided in this letter.

• Acinetobacter spp. (Acinetobacter baumannii)
• Enterobacterales (Citrobacter freundii, Citrobacter koseri, Enterobacter cloacae complex, Escherichia coli, Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, Providencia stuartii, Serratia marcescens)
• Pseudomonas aeruginosa |

The following questions cannot be answered from the provided document:

2. Sample size used for the test set and the data provenance.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts.
4. Adjudication method for the test set.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, and the effect size of how much human readers improve with AI vs without AI assistance. (Note: This device is an in vitro diagnostic for antimicrobial susceptibility testing, not typically an AI-assisted diagnostic read by a human expert in the context of imaging or pathology. An MRMC study is highly unlikely for this type of device.)
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done. (The device itself is the "standalone" test; human interpretation is involved in setting up the test and reading the results, although it's an automated or semi-automated system. Performance is typically measured against a reference method.)
7. The type of ground truth used. (For AST devices, the ground truth is typically a reference method like broth microdilution or agar dilution, performed according to CLSI guidelines.)
8. The sample size for the training set. (While there might be "training" in the sense of model development for an automated reader, a primary training set in the AI/ML sense is not typically discussed for this type of in vitro diagnostic device, which relies on chemical reactions and optical detection.)
9. How the ground truth for the training set was established. (Similar to point 8, this question's premise might not directly apply to this type of device.)

Ask a specific question about this device

QIAstat-Dx Respiratory Panel Plus:

The QIAstat-Dx Respiratory Panel Plus is a multiplexed nucleic acid test intended for use with the QIAstat-Dx system for the simultaneous in vitro qualitative detection and identification of multiple respiratory viral and bacterial nucleic acids in nasopharyngeal swabs (NPS) obtained from individuals with clinical signs and symptoms of respiratory tract infections, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

The following organism types and subtypes are identified using the QIAstat-Dx Respiratory Panel Plus: Adenovirus, Human Coronavirus 229E, Human Coronavirus HKU1, Human Coronavirus NL63, Human Coronavirus OC43, Human Metapneumovirus, Influenza A, Influenza A H1, Influenza A H1N1 pdm09, Influenza A H3, Influenza B, Parainfluenza Virus 1, Parainfluenza Virus 2, Parainfluenza Virus 3, Parainfluenza Virus 4, Respiratory Syncytial Virus, Human Rhinovirus/Enterovirus (not differentiated), SARS-CoV-2, Bordetella pertussis, Chlamydophila pneumoniae, and Mycoplasma pneumoniae.

Nucleic acids from viral and bacterial organisms identified by this test are generally detectable in NPS specimens during the acute phase of infection. Detecting and identifying specific viral and bacterial nucleic acids from individuals presenting with signs and symptoms of a respiratory infection aids in the diagnosis of respiratory infection, if used in conjunction with other clinical, epidemiological and laboratory findings. The results of this test should not be used as the sole basis for diagnosis, treatment or other patient management decisions.

Negative results in the presence of a respiratory illness may be due to infection with pathogens that are not detected by the test, or due to lower respiratory tract infection that is not detected by a NPS specimen.

Conversely, positive results are indicative of the presence of the identified microorganism, but do not rule out co-infection with other pathogens not detected by the QIAstat-Dx Respiratory Panel Plus. The agent(s) detected by the QIAstat-Dx Respiratory Panel Plus may not be the definite cause of disease.

The use of additional laboratory testing (e.g., bacterial and viral culture, immunofluorescence, and radiography) may be necessary when evaluating a patient with possible respiratory tract infection.

QIAstat-Dx Respiratory Panel Mini:

The QIAstat-Dx Respiratory Panel Mini is a multiplexed nucleic acid test intended for use with the QIAstat-Dx system for the simultaneous in vitro qualitative detection and identification of multiple respiratory viral nucleic acids in nasopharyngeal swabs (NPS) obtained from individuals with clinical signs and symptoms of respiratory tract infections, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

The following viruses are identified using the QIAstat-Dx Respiratory Panel Mini: Influenza A, Influenza B, Respiratory Syncytial Virus, Human Rhinovirus, and SARS-CoV-2.

Nucleic acids from viral organisms identified by this test are generally detectable in NPS specimens during the acute phase of infection. Detecting and identifying specific viral nucleic acids from individuals presenting with signs and symptoms of a respiratory infection aids in the diagnosis of respiratory infection, if used in conjunction with other clinical, epidemiological and laboratory findings. The results of this test should not be used as the sole basis for diagnosis, treatment or other patient management decisions.

Negative results in the presence of a respiratory illness may be due to infection with pathogens that are not detected by the test or due to lower respiratory tract infection that is not detected by a NPS specimen.

Conversely, positive results are indicative of the presence of the identified microorganism, but do not rule out co-infection with other pathogens not detected by the QIAstat-Dx Respiratory Panel Mini. The agent(s) detected by the QIAstat-Dx Respiratory Panel Mini may not be the definite cause of disease.

The use of additional laboratory testing (e.g., bacterial and viral culture, immunofluorescence, and radiography) may be necessary when evaluating a patient with possible respiratory tract infection.

The QIAstat-Dx Respiratory Panel Plus and the QIAstat-Dx Respiratory Panel Mini are multiplexed nucleic acid tests which are designed for use with the QIAstat-Dx system (currently QIAstat-Dx Analyzer 1.0 and QIAstat-Dx Analyzer 2.0). The device modification is to add the QIAstat-Dx Rise as an additional instrument for use with the QIAstat-Dx Respiratory Panel Plus and the QIAstat-Dx Respiratory Panel Mini ("QIAstat-Dx Respiratory Panels"). The QIAstat-Dx Rise is a higher throughput platform, incorporating up to eight QIAstat-Dx Analytical Modules (AM) on a small footprint. The instrument allows queuing up to 18 cartridges, which are scheduled for processing and delivered to the appropriate AM by an integrated robotic handler. The AM used with the QIAstat-Dx Rise is the same AM that can be used with the QIAstat-Dx Analyzer 1.0 or 2.0.

The modified QIAstat-Dx Respiratory Panel Plus and QIAstat-Dx Respiratory Panel Mini are identical to the QIAstat-Dx Respiratory Panel Plus (K233100) and the QIAstat-Dx Respiratory Panel Mini (K242353), respectively, with the exception of the Instructions for Use which were updated to include the assay-specific procedure for the QIAstat-Dx Rise.

The QIAstat-Dx Respiratory Panels are intended to be used with one nasopharyngeal swab (NPS) eluted in Universal Transport Media (UTM), which is not provided with the QIAstat-Dx Respiratory Panels.

All the reagents required for the complete execution of the test are pre-loaded and self-contained in a QIAstat-Dx Respiratory Panel cartridge. The user does not need to manipulate any reagents. During the test, reagents are handled by pneumatically-operated microfluidics without any direct contact with the user or the analyzer actuators.

Within the cartridge, multiple steps are automatically performed in sequence by using pneumatic pressure and a multiport valve to transfer the sample and fluids via the Transfer Chamber (TC) to their intended destinations. Following the introduction of the sample from a disposable transfer pipette, the following assay steps occur automatically and sequentially:

• Resuspension of Internal Control
• Cell lysis using mechanical and/or chemical means
• Membrane-based nucleic acid purification
• Mixing of the purified nucleic acid with lyophilized master mix reagents
• Transfer of defined aliquots of eluate/master mix to different reaction chambers
• Performance of multiplex real-time RT-PCR testing within each reaction chamber

The QIAstat-Dx Respiratory Panel Assay Definition File (ADF) automatically interprets test results and displays a summary on the instrument display screen. The detected analytes are displayed in red. All other tested but not detected analytes are listed in green. The instrument will report if an error occurs during processing, in which case the test will fail and no results will be provided (screen will show "FAIL").

The provided text describes a 510(k) premarket notification for the QIAstat-Dx Respiratory Panel Plus and QIAstat-Dx Respiratory Panel Mini, with a modification to include the QIAstat-Dx Rise instrument. The key takeaway from this document is that the FDA determined the device is substantially equivalent to previously cleared devices. Therefore, the "acceptance criteria" discussed here refer to the demonstration of equivalence to a predicate device, rather than specific performance metrics against a clinical ground truth for a new device.

Here's an analysis based on your questions:

1. A table of acceptance criteria and the reported device performance

Since this is a submission for a modification to an already cleared device, the acceptance criteria are not explicitly stated in terms of clinical performance numbers (e.g., sensitivity, specificity). Instead, the acceptance criteria are focused on demonstrating that adding the new instrument (QIAstat-Dx Rise) does not negatively impact the performance, and that the new system is "substantially equivalent" to the predicate devices.

The "reported device performance" is essentially that the studies "successfully demonstrated the equivalent performance."

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

The document does not specify the sample size for the test set used in the "Equivalence at Low Analyte Concentration," "Carryover," or "Reproducibility" studies. It also does not mention the data provenance (country of origin, retrospective or prospective). These details would typically be found in the actual study reports, which are not included in this FDA clearance letter.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This information is not applicable or provided in this document. For an in vitro diagnostic device like this, ground truth for clinical performance would typically be established by comparing against FDA-cleared or gold standard laboratory methods (e.g., culture, sequencing, or other highly sensitive PCR assays) rather than expert consensus on imaging or clinical findings. Since this submission focuses on establishing equivalence and not initial clinical performance, such details are not expected.

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

This information is not provided and would not typically be part of a 510(k) clearance letter for an IVD device unless specific clinical adjudication was required for complex diagnostic outcomes.

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 is not applicable. The QIAstat-Dx Respiratory Panels are automated in vitro diagnostic devices for detecting nucleic acids. They do not involve human readers' interpretation of images or other data in a way that would necessitate an MRMC study or AI assistance.

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

This is an in vitro diagnostic test. It is inherently a "standalone" system in its operation, as the instrument performs the test and provides a result. There is no mention of a human-in-the-loop component beyond loading the sample and reading the final result from the display screen. The device's "algorithm" (i.e., the assay's detection mechanism and interpretation software) operates without human intervention once the run starts.

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

The document does not explicitly state the "ground truth" used for the analytical studies (Equivalence at Low Analyte Concentration, Carryover, Reproducibility). For such studies, the ground truth would be established by controlled laboratory experiments, where samples with known concentrations of analytes are used, and the assay's results are compared against these known inputs. For initial clinical performance, the ground truth would typically be a highly sensitive and specific reference method, but those studies are for the predicate devices, not this modification.

8. The sample size for the training set

This information is not provided. Training sets are typically associated with machine learning or AI models. While instruments like the QIAstat-Dx have underlying algorithms, they are based on established PCR principles and assay design, not a machine learning training paradigm in the way AI image analysis would be.

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

This information is not provided and is not applicable for this type of IVD device in the context of a 510(k) modification for instrument compatibility.

Ask a specific question about this device

The CareSuperb™ COVID-19/Flu A&B Antigen Combo Home Test is a lateral flow immunochromatographic assay intended for the qualitative detection and differentiation of influenza A and influenza B nucleoprotein antigens and SARS-CoV-2 nucleocapsid antigens directly in anterior nasal swab samples from individuals with signs and symptoms of respiratory tract infection. Symptoms of respiratory infections due to SARS-CoV-2 and influenza can be similar. This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older.

All negative results are presumptive and should be confirmed with an FDA-cleared molecular assay when determined to be appropriate by a healthcare provider. Negative results do not rule out infection with influenza, SARS-CoV-2, or other pathogens.

Individuals who test negative and experience continued or worsening respiratory symptoms, such as fever, cough, and/or shortness of breath, should seek follow up care from their healthcare provider.

Positive results do not rule out co-infection with other respiratory pathogens and therefore do not substitute for a visit to a healthcare provider for appropriate follow-up.

The CareSuperb™ COVID-19/Flu A&B Antigen Combo Home Test is a lateral flow immunoassay intended for the qualitative detection and differentiation of SARS-CoV-2 nucleocapsid antigen, Influenza A nucleoprotein antigen, and Influenza B nucleoprotein antigen from anterior nasal swab specimens.

The CareSuperb™ COVID-19/Flu A&B Antigen Combo Home Test utilizes an adaptor-based lateral flow assay platform integrating a conjugate wick filter to facilitate sample processing. Each test cassette contains a nitrocellulose membrane with immobilized capture antibodies for SARS-CoV-2, Influenza A, Influenza B, and internal control. Following specimen application to the sample port, viral antigens, if present, bind to labeled detection antibodies embedded in the conjugate wick filter. The resulting immune complexes migrate along the test strip and are captured at the respective test lines (C19 for SARS-CoV-2, A for Influenza A, and B for Influenza B), forming visible colored lines. A visible control line (Cont) confirms proper sample migration and test validity. The absence of a control line invalidates the test result.

Each kit includes a single-use test cassette, assay buffer dropper vial, nasal swab, and Quick Reference Instructions (QRI). Test results are visually interpreted 10 minutes after swab removal.

The provided document describes the CareSuperb™ COVID-19/Flu A&B Antigen Combo Home Test, an over-the-counter lateral flow immunoassay for lay users. The study aimed to demonstrate its substantial equivalence to a predicate device and its performance characteristics for qualitative detection and differentiation of SARS-CoV-2, Influenza A, and Influenza B antigens in anterior nasal swab samples.

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

1. Table of Acceptance Criteria and Reported Device Performance

While specific acceptance criteria (i.e., pre-defined thresholds the device must meet for clearance) are not explicitly stated as numbered points in this 510(k) summary, they can be inferred from the reported performance data and common FDA expectations for such devices. The performance data presented serves as the evidence that the device met these implied criteria.

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

• Clinical Performance Test Set (Human Samples): N=1644 total participants.
  • Self-collecting: N=1447 (individuals aged 14 or older testing themselves)
  • Lay-user/Tester Collection: N=197 (adults testing individuals aged 2-17 years)
• Data Provenance:
  • Country of Origin: United States ("13 clinical sites across the U.S.").
  • Retrospective/Prospective: The clinical study was prospective, as samples were collected "between November of 2023 and March of 2025" from "symptomatic subjects, suspected of respiratory infection."
• Analytical Performance Test Sets (Contrived/Spiked Samples): Sample sizes vary per study:
  • Precision Study 1: 360 results per panel member (negative, 1x LoD positive, 3x LoD positive).
  • Precision Study 2: 36 sample replicates/lot (for negative and 0.75x LoD positive samples).
  • LoD Confirmation: 20 replicates per LoD concentration.
  • Co-spike LoD: 20 replicates per panel (multiple panels tested).
  • Inclusivity: 5 replicates per strain (for identifying lowest reactive concentration).
  • Competitive Interference: 3 replicates per of 19 sample configurations.
  • Hook Effect: 5 replicates per concentration.
  • WHO Standard LoD: 20 replicates for confirmation.
  • Cross-Reactivity/Microbial Interference: 3 replicates per microorganism (in absence and presence of analytes).
  • Endogenous/Exogenous Substances Interference: 3 replicates per substance (in absence and presence of analytes).
  • Biotin Interference: 3 replicates per biotin concentration.
  • Real-time Stability: 5 replicates per lot at each time point.
  • Transportation Stability: 5 replicates per sample type per lot for each condition.
• Usability Study: 1,795 participants.
• Readability Study: 50 participants.

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

• Clinical Performance (Reference Method - Test Set Ground Truth): The ground truth for the clinical test set was established using FDA-cleared molecular RT-PCR comparator assays for SARS-CoV-2, Influenza A, and Influenza B.

  • This implies that the "experts" were the established and validated molecular diagnostic platforms, rather than human expert readers/adjudicators for visual interpretation.

• Usability/Readability Studies:

  • Usability Study: "Observer agreement with user-interpreted results was 98.7%." This suggests trained observers (likely not "experts" in the sense of clinical specialists, but rather study personnel trained in test interpretation as per IFU) established agreement with user results.
  • Readability Study: The study focused on whether lay users themselves could interpret results after reading the QRI. Ground truth for the mock devices would be pre-determined by the device manufacturer based on their design.

4. Adjudication Method for the Test Set

• Clinical Performance: No human adjudication method (e.g., 2+1, 3+1) is mentioned for the clinical test set. The direct comparison was made against molecular RT-PCR as the gold standard, which serves as the definitive ground truth for the presence or absence of the viruses. This type of diagnostic test typically relies on a definitive laboratory method for ground truth, not human interpretation consensus.
• Usability/Readability Studies: The usability study mentioned "Observer agreement with user-interpreted results," implying direct comparison between user interpretation and a pre-defined correct interpretation or an observer's interpretation. The readability study involved participants interpreting mock devices based on the QRI, with performance measured against the pre-determined correct interpretation of those mock devices.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance

• No AI Component: This device (CareSuperb™ COVID-19/Flu A&B Antigen Combo Home Test) is a lateral flow immunoassay for visual interpretation. It is not an AI-powered diagnostic device, nor does it have a human-in-the-loop AI assistance component. Therefore, an MRMC study related to AI assistance was not applicable and not performed.

6. If a Standalone (i.e., Algorithm Only Without Human-in-the-Loop Performance) Was Done

• Not Applicable: As this is a visually interpreted antigen test, there is no "algorithm only" or standalone algorithm performance to evaluate. The device's performance is intrinsically linked to its chemical reactions and subsequent visual interpretation by the user (or observer in studies).

7. The Type of Ground Truth Used

• Clinical Performance Test Set: FDA-cleared molecular RT-PCR comparator assays (molecular ground truth). This is generally considered a highly reliable and objective ground truth for viral detection.
• Analytical Performance Test Sets: Generally contrived samples with known concentrations of viral analytes or microorganisms against negative pooled swab matrix. This allows for precise control of the 'ground truth' concentration and presence/absence.
• Usability/Readability Studies: For readability, it was pre-defined correct interpretations of "mock test devices." For usability, it was observation of correct procedural steps and comparison of user interpretation to trained observer interpretation.

8. The Sample Size for the Training Set

• Not explicitly stated in terms of a "training set" for the device itself. As a lateral flow immunoassay, this device is developed through biochemical design, antigen-antibody interactions, and manufacturing processes, rather than through machine learning models that require distinct training datasets.
• The document describes the analytical studies (LoD, inclusivity, interference, etc.) which inform the device's technical specifications and ensure it's robust. The clinical study and usability/readability studies are typically considered validation/test sets for the final manufactured device.
• If this were an AI/ML device, a specific training set size would be crucial. For this type of IVD, the "training" analogous to an AI model would be the research, development, and optimization of the assay components (antibodies, membrane, buffer, etc.) using various known positive and negative samples in the lab.

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

• Not applicable in the context of a machine learning training set.
• For the development and optimization of the assay (analogous to training), ground truth would have been established through:
  • Using quantified viral stocks (e.g., TCID₅₀/mL, CEID₅₀/mL, FFU/mL, IU/mL) to precisely spike into negative matrix (PNSM) to create known positive and negative samples at various concentrations.
  • Employing established laboratory reference methods (e.g., molecular assays) to confirm the presence/absence and concentration of analytes in developmental samples.
  • Utilizing characterized clinical samples (if available) with confirmed statuses from gold-standard methods early in development.

Ask a specific question about this device

VITEK 2 AST-Gram Negative Cefazolin is designed for antimicrobial susceptibility testing of Gram-negative bacilli and is intended for use with the VITEK 2 Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents.

VITEK 2 AST-Gram Negative Cefazolin (≤1-≥32 µg/mL) is a quantitative test. Testing is indicated for Enterobacterales (from infections other than uncomplicated UTI) as recognized by the FDA Susceptibility Test Interpretive Criteria (STIC).

VITEK 2 AST-Gram Negative Cefazolin (≤1-≥32 µg/mL) has demonstrated acceptable performance with the following organisms:

Enterobacterales (Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri)

The VITEK 2 Gram Negative Susceptibility Card is intended for use with the VITEK 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of clinically significant aerobic Gram- negative bacilli to antimicrobial agents when used as instructed.

The principle of the VITEK® 2 AST cards is based on the microdilution minimum inhibitory concentration (MIC) technique reported by MacLowry and Marsh (1) and Gerlach (2). The VITEK® 2 AST card is essentially a miniaturized, abbreviated and automated version of the doubling dilution technique (3).

Each VITEK® 2 AST card contains 64 wells. A control well which only contains microbiological culture media is resident on all cards. The remaining wells contain premeasured portions of a specific antibiotic combined with culture media. The bacterial or yeast isolate to be tested is diluted to a standardized concentration with 0.45 – 0.5% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK® 2 System automatically fills, seals and places the card into the incubator/reader. The VITEK® 2 Compact has a manual filling, sealing and loading operation. The VITEK® 2 Systems monitor the growth of each well in the card over a defined period of time. At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antibiotic contained on the card.

VITEK® 2 AST-GN Cefazolin has the following concentrations in the card: 1, 2, and 8 (equivalent standard method concentration by efficacy in µg/mL).

The provided text describes the acceptance criteria and a study proving the device meets these criteria for the VITEK 2 AST-Gram Negative Cefazolin antimicrobial susceptibility testing system.

Here's a breakdown of the requested information:

1. Table of Acceptance Criteria and Reported Device Performance

Ask a specific question about this device

The MTS (MIC Test Strip) Sulbactam-Durlobactam 0.004/4-64/4 μg/ml is a quantitative method intended for the in vitro determination of antimicrobial susceptibility of bacteria. MTS consists of specialized paper impregnated with a pre-defined concentration gradient of an antimicrobial agent, which is used to determine the minimum inhibitory concentration (MIC) in μg/ml of antimicrobial agents against bacteria as tested on agar media using overnight incubation and manual reading procedures. MTS Sulbactam- Durlobactam at concentrations of 0.004/4-64/4 μg/ml should be interpreted at 16-20 hours of incubation.

Testing with MTS Sulbactam-Durlobactam at concentrations of 0.004/4-64/4 μg/mL is indicated for Acinetobacter baumannii calcoaceticus complex as recognized by the FDA Susceptibility Test Interpretive Criteria (STIC).

The MTS Sulbactam-Durlobactam 0.004/4-64/4 μg/mL has demonstrated acceptable performance with the following organisms:

Acinetobacter baumannii calcoaceticus complex

MTS Sulbactam-Durlobactam 0.004/4 - 64/4 μg/mL is made of special high-quality paper impregnated with a predefined concentration of gradient sulbactam across 15 two-fold dilutions like those of a conventional MIC method and durlobactam at a fixed concentration of 4 μg/mL. One side of the strip is labeled with the sulbactam-durlobactam code (SUD) and the MIC reading scale in μg/mL. When the MTS is applied onto an inoculated agar surface, the performed exponential gradient of antimicrobial agent diffuses into the agar for over an hour. After 16-20 hours incubation, a symmetrical inhibition ellipse centered along the strip is formed. The MIC is read directly from the scale in terms of μg/mL at the point where the edge of the inhibition ellipse intersects the MIC Test Strip. The MIC Test Strip (MTS) is single use only.

Sulbactam-durlobactam is an intravenous beta-lactam combination antibiotic used to treat hospital-acquired pneumonia and ventilator-associated bacterial pneumonia caused by susceptible isolates of Acinetobacter baumannii-calcoaceticus complex.
MTS is supplied in 3 different packaging options (no additional reagents are included). There is a 10- test box, a 30- test box and a 100-test box.

Here is a description of the acceptance criteria and the study proving the device meets those criteria, based on the provided FDA 510(k) clearance letter for the MTS Sulbactam-Durlobactam device:

Device: MTS Sulbactam-Durlobactam 0.004/4 - 64/4 µg/mL (SUD)
Intended Use: Quantitative method for in vitro determination of antimicrobial susceptibility of Acinetobacter baumannii calcoaceticus complex using MIC Test Strips with manual reading after overnight incubation.

1. Acceptance Criteria and Reported Device Performance

The study evaluated the performance of the MTS Sulbactam-Durlobactam device against a reference broth microdilution MIC method. The primary metrics for performance were Essential Agreement (EA) and Category Agreement (CA), along with an analysis of errors (very major, major, minor). While explicit "acceptance criteria" percentages are not directly stated in the summary, typical FDA criteria for AST systems are implied by the reported results. The guidance document referenced "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems, August 28, 2009" would contain the specific acceptance thresholds. Based on the provided summary, the device performance is reported as follows:

Table of Device Performance

Implied Acceptance Criteria (based on typical FDA AST requirements, generally >90% for EA and CA, and strict limits on major/very major errors):
The reported performance values of 97.3% EA and 92.7% CA, along with very low major errors and zero very major errors, indicate that the device met the acceptance criteria as determined by the FDA. Specifically, the zero very major errors are critical for patient safety, as they avoid situations where a resistant infection might be incorrectly identified as susceptible, leading to inappropriate treatment.

2. Sample Size and Data Provenance

• Test Set Sample Size: 588 isolates for the combined clinical and challenge organism groups.
• Data Provenance:
  • Clinical Testing: Performed at three (3) sites. The precise country of origin is not explicitly stated for the clinical sites, but the submitter (Liofilchem s.r.l.) is based in Italy, and their contact person for the 510(k) is in Westlake, Ohio, USA. The FDA clearance suggests testing was appropriate for the US market.
  • Challenge Isolate Testing: Performed at one site (Laboratory Specialists, Inc., which is the 510(k) preparer's company in Westlake, Ohio).
  • Nature of Data: The data combines retrospective (challenge isolates specifically selected to ensure MIC range coverage, including resistant isolates) and prospective (fresh clinical isolates tested at multiple sites) elements.

3. Experts Used for Ground Truth and Qualifications

This section does not directly apply as the device is an in vitro diagnostic (IVD) for antimicrobial susceptibility testing, not an imaging AI device requiring expert interpretation of images. The "ground truth" for antimicrobial susceptibility is established by a standardized laboratory method (broth microdilution) rather than human expert consensus on subjective data.

4. Adjudication Method for the Test Set

Adjudication methods (like 2+1, 3+1, etc.) are typically used in studies involving human interpretation or subjective assessments. For this AST device, the ground truth is established by a quantitative, objective laboratory method (CLSI broth microdilution guidelines). Therefore, no human adjudication method was employed for establishing the ground truth of the MIC values. Minor discrepancies or errors between the device and the reference method are simply categorized as such (major, minor, very major errors).

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

An MRMC study is not applicable to this type of device. The MTS Sulbactam-Durlobactam is a manual antimicrobial susceptibility test system that determines the MIC directly. It is not an AI-assisted diagnostic imaging system where human readers interpret data with or without AI assistance. The performance is assessed by comparing the device's MIC readings to a gold standard laboratory method, not by comparing human reader performance.

6. Standalone (Algorithm Only) Performance

This concept is applicable, and the study provided details on the standalone performance of the MTS Sulbactam-Durlobactam device. The "performance data" table (Essential Agreement, Category Agreement, and Error Rates) directly refers to the device's ability to accurately determine MIC values and susceptibility categories when compared to the reference method, essentially its "algorithm-only" performance in the context of an IVD. There is no "human-in-the-loop" component for interpretation; the user manually reads the MIC from the strip.

7. Type of Ground Truth Used

The ground truth used for this study was reference broth microdilution MIC method, conducted according to CLSI M7-A11 guidelines. This is a well-established and standardized laboratory method for determining antimicrobial minimum inhibitory concentrations, considered the gold standard for AST.

8. Sample Size for the Training Set

The document does not specify a separate "training set" sample size for the development of the MTS Sulbactam-Durlobactam device. For IVDs like AST systems, the "training" typically refers to the initial development and optimization of the test strip's design, antimicrobial gradient, and manufacturing process to reliably produce specific drug concentrations and diffusion patterns. This is primarily a chemical and engineering development process, not a machine learning training process with a distinct data set. The 588 isolates discussed are for the performance validation (test set) rather than initial model training.

9. How Ground Truth for the Training Set Was Established

As noted above, a distinct "training set" and associated "ground truth establishment" in the machine learning sense are not described for this type of medical device. The "ground truth" for the performance validation was established by the CLSI broth microdilution reference method. For the initial development and optimization phase of such a device, the "ground truth" would implicitly be the accurate and precise measurement of drug concentration gradients and their biological effect on various bacterial strains, guided by established AST principles and drug properties.

Ask a specific question about this device

WELLlife Flu A&B Home Test:
The WELLlife Flu A&B Home Test is a lateral flow immunochromatographic assay intended for the qualitative detection and differentiation of influenza A and influenza B nucleoprotein antigens directly in anterior nasal swab samples from individuals with signs and symptoms of respiratory tract infection. This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing other individuals aged 2 years or older.

All negative results are presumptive and should be confirmed with an FDA-cleared molecular assay when determined to be appropriate by a healthcare provider. Negative results do not rule out infection with influenza or other pathogens. Individuals who test negative and experience continued or worsening respiratory symptoms, such as fever, cough and/or shortness of breath, should seek follow-up care from their healthcare provider.

Positive results do not rule out co-infection with other respiratory pathogens, and therefore do not substitute for a visit to a healthcare provider or appropriate follow-up.

WELLlife Influenza A&B Test:
The WELLlife Influenza A&B Test is a lateral flow immunochromatographic assay intended for the qualitative detection and differentiation of influenza A and influenza B nucleoprotein antigens directly in anterior nasal swab samples from individuals with signs and symptoms of respiratory tract infection. This test is for use by individuals aged 14 years or older testing themselves, or adults testing other individuals aged 2 years or older.

All negative results are presumptive and should be confirmed with an FDA-cleared molecular assay when determined to be appropriate by a healthcare provider. Negative results do not rule out infection with influenza or other pathogens. Individuals who test negative and experience continued or worsening respiratory symptoms, such as fever, cough and/or shortness of breath, should seek follow-up care from their healthcare providers.

Positive results do not rule out co-infection with other respiratory pathogens.

Test results should not be used as the sole basis for treatment or other patient management decisions.

The WELLlife Flu A&B Home Test and WELLlife Influenza A&B Test is a lateral flow immunochromatographic assay intended for the qualitative detection and differentiation of influenza A and influenza B protein antigens. The test has two versions, one for over the counter (OTC) use (WELLlife Flu A&B Home Test) and one for professional use (WELLlife Influenza A&B Test). Both versions of the WELLlife Influenza A&B Test that have an identical general design and are intended for the qualitative detection of protein antigens directly in anterior nasal swab specimens from individuals with respiratory signs and symptoms. Results are for the identification and differentiation of nucleoprotein antigen from influenza A virus, and nucleoprotein antigen from influenza B virus. The test cassette in the test kit is assembled with a test strip in a plastic housing that contains a nitrocellulose membrane with three lines: two test lines (Flu A line, Flu B line) and a control line (C line). The device is for in vitro diagnostic use only.

The provided FDA Clearance Letter for the WELLlife Flu A&B Home Test includes details on the device's performance based on non-clinical and clinical studies. Here's a breakdown of the acceptance criteria and the study proving the device meets them, based on the provided text:

Acceptance Criteria and Reported Device Performance

The acceptance criteria for performance are generally implicit in these types of submissions, aiming for high agreement with a comparative method. The reported performance is presented through Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA).

Table 1: Acceptance Criteria and Reported Device Performance (Implicit Criteria)

Study Details

1. A table of acceptance criteria and the reported device performance

• See Table 1 above. The acceptance criteria are inferred from what is typically expected for a diagnostic device of this type seeking FDA clearance (e.g., high sensitivity and specificity, consistent 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:
  • Clinical Study: 680 evaluable subjects (from 766 enrolled) were used for clinical performance evaluation.
  • Non-clinical Studies: Sample sizes vary by study:
    • Lot-to-Lot Precision: 180 results per sample type (3 lots x 3 operators x 2 replicates x 2 runs per day x 5 days).
    • Site-to-Site Reproducibility: 135 replicates per sample type (3 sites x 3 operators x 5 days).
    • LoD: 20 replicates for confirmatory testing.
    • Analytical Reactivity: Triplicates for initial range finding, then triplicates for two-fold dilutions.
    • Cross-Reactivity/Microbial Interference: 3 replicates per organism/virus.
    • Endogenous Interfering Substances: 3 replicates per substance.
    • High Dose Hook Effect: 9 replicates (across 3 lots).
    • Competitive Interference: 9 replicates for each combination.
• Data Provenance:
  • Clinical Study: "A prospective study was performed... between January 2025 and March 2025... at six (6) clinical sites." The country of origin is not explicitly stated, but the FDA clearance implies US-based or FDA-accepted international clinical trials. It's a prospective study.
  • Non-clinical Studies: Performed internally at one site (Lot-to-Lot Precision) or at three external sites (Site-to-Site Reproducibility). These are also prospective experimental studies.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

• The ground truth for the clinical test set was established using an "FDA-cleared molecular comparator method." This is a laboratory-based, highly sensitive, and specific molecular test, which serves as the gold standard for detecting influenza RNA/DNA.
• There is no mention of human experts (e.g., radiologists, pathologists) being used to establish the ground truth for this in vitro diagnostic device. The comparator method itself is the "expert" ground truth.

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

• The document does not describe an adjudication method for conflicting results between the investigational device and the comparator method. Results from the WELLlife Flu A&B Home Test were compared directly to the FDA-cleared molecular comparator method. For an in-vitro diagnostic, typically the molecular comparator is considered the definitive truth.

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 MRMC study was performed. This device is a lateral flow immunochromatographic assay, a rapid antigen test that produces visible lines interpreted directly by the user (either a lay user at home or a professional user). It does not involve "human readers" interpreting complex images or AI assistance in the interpretation of results in the way an imaging AI device would. Therefore, this question is not applicable to the WELLlife Flu A&B Home Test.

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

• This question is primarily relevant for AI/ML-driven software as a medical device (SaMD) where an algorithm provides an output. The WELLlife Flu A&B Home Test is a rapid diagnostic test interpreted visually. Its performance is inherent to the chemical reactions on the test strip, and it's designed for human interpretation (either self-testing or professional use). Therefore, a "standalone algorithm-only" performance study is not applicable in the context of this device's technology. The "device performance" metrics (PPA, NPA) are effectively its standalone performance as interpreted by a human user following instructions.

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

• The ground truth for the clinical study was an FDA-cleared molecular comparator method (e.g., PCR or equivalent), considered the gold standard for influenza detection.

8. The sample size for the training set

• The provided document describes clinical and non-clinical performance evaluation studies. For IVD devices like this one, it's common that the "training set" is not a distinct, formally defined dataset as it would be for a machine learning model. Instead, the device's design, reagent formulation, and manufacturing processes are optimized and validated through iterative development and verification testing (analogue to "training" and "internal validation"). The studies described in this summary are primarily validation studies demonstrating the final product's performance. Therefore, a specific "training set sample size" as one might see for an AI model is not applicable/not explicitly defined in this context.

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

• As mentioned above, for a rapid diagnostic test, there isn't a "training set" in the sense of a machine learning model. Instead, the development process involves:
  • Analytical Validation: Establishing LoD, reactivity, specificity (cross-reactivity, interference) using reference strains, cultured microorganisms, and purified substances with known concentrations and characteristics. This essentially acts as the "ground truth" during the development phase.
  • Design Iteration: The test components (antibodies, membrane, buffer) are optimized to achieve desired sensitivity and specificity against known influenza strains and potential interferents. This iterative process, using well-characterized samples, ensures the device learns (is developed) to correctly identify targets.
  • The FDA-cleared molecular comparator assays serve as the ultimate "ground truth" against which the device's overall clinical performance is measured.

Ask a specific question about this device

The MicroScan Dried Gram-Negative MIC/Combo Panel is used to determine quantitative and qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-negative bacilli. After inoculation, panels are incubated for 16-20 hours at 35°C ± 1°C in a non-CO2 incubator, and read either visually or with MicroScan instrumentation, according to the Package Insert.

This particular submission is for the addition of the antimicrobial cefepime at concentrations of 0.12-64 µg/mL to the test panel. Testing is indicated for Enterobacterales, Pseudomonas aeruginosa and Aeromonas spp., as recognized by the FDA Susceptibility Test Interpretive Criteria (STIC) webpage.

The MicroScan Dried Gram-Negative MIC/Combo Panels with Cefepime (CPE) (0.12-64µg/mL) has demonstrated acceptable performance with the following organisms:

Enterobacterales (Enterobacter spp., Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Citrobacter koseri, (formerly Citrobacter diversus), Citrobacter freundii complex (Citrobacter freudnii, Citrobacter werkmanii and Citrobacter youngae), Klebsiella oxytoca, Morganella morganii, Proteus vulgaris, Providencia stuartii, Providencia rettgeri, Serratia marcescens)

Pseudomonas aeruginosa

Aeromonas spp.

MicroScan Dried Gram-Negative MIC/Combo Panels are designed for use in determining quantitative and qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-negative bacilli.

The principle of MicroScan panels with antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been diluted in broth and dehydrated. Various antimicrobial agents are diluted in broth to concentrations bridging the range of clinical interest. Panels are rehydrated with water after inoculation with a standardized suspension of the organism. After incubation in a non-CO2 incubator for 16-20 hours, the minimum inhibitory concentration (MIC) for the test organism is read by determining the lowest antimicrobial concentration showing inhibition of growth.

The product is single-use and intended for laboratory professional use.

Device Performance Acceptance Criteria and Study Details for MicroScan Dried Gram-Negative MIC/Combo Panels with Cefepime

Based on the provided FDA 510(k) Clearance Letter, the device in question is the MicroScan Dried Gram-Negative MIC/Combo Panels with Cefepime (CPE) (0.12-64 µg/mL), which is an Antimicrobial Susceptibility Test (AST) System. The study described focuses on demonstrating the substantial equivalence of this new configuration (with Cefepime) to a predicate device.

Given the nature of the device (an AST System), the "acceptance criteria" are typically related to the accuracy of determining Minimum Inhibitory Concentration (MIC) and the resulting categorical agreement (Susceptible, Intermediate, Resistant) compared to a reference method. The "study that proves the device meets the acceptance criteria" refers to the performance evaluation conducted for the 510(k) submission.

1. Table of Acceptance Criteria and Reported Device Performance

For AST systems, the key performance metrics are Essential Agreement (EA) and Categorical Agreement (CA) when compared to a CLSI (Clinical and Laboratory Standards Institute) frozen reference panel. The FDA document "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA", dated August 28, 2009, likely outlines the specific acceptance criteria thresholds for EA and CA. While the exact numerical acceptance criteria are not explicitly stated in the provided text, the performance "demonstrated acceptable performance" implies meeting these pre-defined thresholds.

Important Note: The document highlights some instances where the performance was "outside of essential agreement" for Enterobacterales with Prompt inoculation and "below 90%" for Aeromonas spp. with turbidity inoculation and WalkAway read method. These discrepancies are "mitigated with a limitation" in the product labeling, suggesting that while initial performance in those specific conditions did not meet implicit criteria, the overall robust performance with other methods/organisms, coupled with labeling limitations, made the device acceptable for clearance.

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

• Sample Size: The document does not explicitly provide a total number for the test set sample size (e.g., number of isolates tested). It refers to "contemporary and stock Efficacy isolates and stock Challenge strains" used for external evaluations.
• Data Provenance: The document does not specify the country of origin of the data. It mentions "external evaluations," which generally implies testing conducted at clinical sites or contract research organizations. The study appears to be retrospective in the sense that it uses "stock Efficacy isolates and stock Challenge strains" which are pre-existing collections of bacterial isolates. It also mentions "contemporary" isolates, suggesting some recent collection. It implies a laboratory-based performance study rather than a clinical trial with patient outcomes.

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

This type of device (AST System) does not typically rely on human expert interpretation for establishing the "ground truth" of the test set. The ground truth for antimicrobial susceptibility testing is established by a reference method, which for this device is stated as a "CLSI frozen Reference Panel."

Therefore:

• Number of Experts: Not applicable in the context of creating the ground truth for AST.
• Qualifications of Experts: Not applicable.

4. Adjudication Method for the Test Set

As the ground truth is established by a reference method (CLSI frozen Reference Panel), there is no human adjudication method like 2+1 or 3+1 typically used for image-based diagnostics. The device's results are directly compared to the quantitatively or qualitatively determined results from the CLSI reference method.

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

There is no indication that an MRMC comparative effectiveness study was performed. This type of study is not relevant for this device, which is an automated or manually read laboratory diagnostic for antimicrobial susceptibility, not an AI-assisted diagnostic tool that aids human readers in interpretation. The device itself performs the susceptibility test.

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

Yes, the performance data presented is effectively standalone performance of the device (MicroScan Dried Gram-Negative MIC/Combo Panels with Cefepime). The device "read either visually or with MicroScan instrumentation" and its performance (Essential Agreement, Categorical Agreement) is directly compared to the reference standard. The "human-in-the-loop" would be the laboratory professional reading the results, and the study evaluates the accuracy of the device itself in producing those results. Where visual reads are mentioned, it's about the device's ability to produce clear inhibition patterns for visual interpretation, not a human independently interpreting raw data without the device.

7. The Type of Ground Truth Used

The ground truth used was established by a CLSI frozen Reference Panel. This is a recognized and standardized method for determining antimicrobial susceptibility, often involving broth microdilution or agar dilution methods where organisms are tested against known concentrations of antimicrobials. It is a highly controlled and quantitative method to determine the true MIC value against which the device's performance is compared.

8. The Sample Size for the Training Set

The document does not mention a training set or any details about its sample size. This is consistent with the nature of the device. AST systems are generally rule-based or empirically derived systems based on established microbiological principles, rather than machine learning models that require distinct training sets. The development of such panels involves extensive empirical testing during the R&D phase to ensure the correct concentrations and formulations, but this isn't typically referred to as a "training set" in the context of an AI/ML model.

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

As no training set (in the AI/ML sense) is indicated, this point is not applicable.

Ask a specific question about this device