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Bartels Legionella Urinary Antigen ELISA Test is intended as an adjunct to culture for the presumptive diagnosis of past or current Legionnaires' Disease by qualitative detection of Legionella pneumophila Serogroup 1 antigen in human urine.

Bartels Legionella Urinary Antigen ELISA Test is an enzyme-linked immunoassay intended for the qualitative detection of Legionella pneumophila Serogroup 1 antigen in human urine. The kit consists of microelisa stripwells with lid, positive and negative control reagents, conjugate, wash concentrate, colorimetric substrate (2 components) and stop solution. Sufficient materials are provided to perform 96 analyses. The microelisa wells have been pre-coated with purified rabbit antibodies to Legionella pneumophila Serotype 1 (capture antibody). An undiluted urine specimen (100 µL), or positive or negative controls (100 µL each) are each placed in a single microelisa well followed by the addition of 50 uL of Conjugate (horseradish peroxidase-conjugated rabbit antibodies to L. pneumophila). The loaded microelisa plate is then covered with the lid and incubated for 48 to 52 minutes at 34-37°C followed by 4 cycles of wash/aspiration using diluted Wash Solution (manual or automated wash procedure). Colorimetric substrate (tetramethyl benzidine/H2O2 100 µL/well) is then added and incubated for 10 to 12 minutes at 34-37℃ followed by the addition of Stop Solution (1M Phosphoric acid, 100 uL/well). The stopped plate is then read on a microelisa plate reader at 450 nm against an air blank. For a test to be considered valid, the Negative Control must have an optical density (OD) value of less than 0.100 and the Positive Control must be greater than the Positive Cutoff (pco). The pco is equal to 4X the O.D. value of the Negative Control value. Any specimen with an O.D. value ≥ the pco is considered positive. Any specimen with an O.D. value

Here's a breakdown of the acceptance criteria and the study details for the Bartels Legionella Urinary Antigen ELISA Test, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the comparison to the predicate device's performance, as the study aims to establish substantial equivalence.

Note: The acceptance criteria for the Bartels device would be meeting or exceeding these performance characteristics, particularly in comparison to the predicate device, to demonstrate substantial equivalence. The text explicitly states that "Substantial equivalence was established between the Bartels LUA and the predicate device" and that "there is equivalence between reading the results with an automated plate reader and performing a visual interpretation."

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

• Sample Size (Test Set): 274 clinically well-defined urine specimens.
  • 94 urine specimens from patients whose respiratory specimens were culture-positive for Legionella pneumophila Serogroup 1.
  • 150 urine specimens from patients who did not have a diagnosis of Legionella pneumophila.
  • 30 urine specimens from normal healthy volunteers.
• Data Provenance: The study was performed "at a major infectious disease reference laboratory." The country of origin is not specified but is likely the USA given the FDA 510(k) submission. The data is retrospective, as it uses "clinically well-defined urine specimens" which implies they were collected and characterized prior to the study.

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

• The text does not explicitly state the number of experts used to establish the ground truth.
• Qualifications: The ground truth for positive cases was established by "respiratory specimens were culture-positive for Legionella pneumophila Serogroup 1." This indicates that microbiology experts would have performed these cultures, which is a standard diagnostic method. For negative cases, it's based on "patients who did not have a diagnosis of Legionella pneumophila" and "normal healthy volunteers," implying clinical diagnoses and health assessments.

4. Adjudication Method for the Test Set

• The text does not explicitly state an adjudication method. The ground truth appears to be based on established clinical and laboratory diagnostic methods (culture, absence of diagnosis).

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

• No, a typical MRMC study comparing human readers with and without AI assistance was not performed.
• Instead, a comparison was made for the Bartels LUA ELISA Test itself between two interpretation methods:
  • Automated plate reader.
  • Visual interpretation using a provided card.
• Effect Size: The comparison showed that the visual interpretation had slightly different, but still strong, performance characteristics:
  • Automated Reader: Sensitivity 94.7%, Specificity 91.1%, Accuracy 92.3%
  • Visual Interpretation: Sensitivity 92.6%, Specificity 93.9%, Accuracy 93.4%
  • The conclusion states "there is equivalence between reading the results with an automated plate reader and performing a visual interpretation."

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

• Yes, the performance of the Bartels Legionella Urinary Antigen ELISA Test using an automated plate reader represents a standalone algorithm-only performance. The device provides a quantitative optical density (OD) value, and the cutoff for positive/negative is applied algorithmically (OD value ≥ the pco is considered positive).

7. The Type of Ground Truth Used

• Expert Consensus / Clinical Diagnosis / Pathology:
  • For positive cases: Legionella pneumophila Serogroup 1 culture results from respiratory specimens (considered the "gold standard" as stated in Table 1).
  • For negative cases: Patients "who did not have a diagnosis of Legionella pneumophila" and "normal healthy volunteers." This implies a combined approach of clinical assessment and likely other diagnostic tests (absence of culture results, etc.).

8. The Sample Size for the Training Set

• The text does not mention a separate training set or details on its size. This device is an ELISA test, not a machine learning algorithm in the modern sense. Therefore, it does not typically undergo "training" with a distinct dataset in the way an AI model would. The "design/format" and reagent composition are developed and validated during the product development phase, and the cited clinical study is for performance validation.

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

• As noted above, there isn't a specified "training set" in the context of an AI model. The development of an ELISA test involves extensive research and development to identify appropriate antibodies, optimize concentrations, and establish reaction conditions. The "ground truth" during this development phase would rely on laboratory-derived standards, cultured pathogens, and potentially internal studies with banked clinical samples to refine the assay's components and cutoff values. However, these details are not provided in this 510(k) summary.

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Bartels Clostridium difficile Toxin A Enzyme Immunoassay (EIA) is intended for the qualitative detection of Clostridium difficile Toxin A in human fecal specimens as an aid in the diagnosis of Clostridium difficile -associate diseases.

The Bartels Clostridium difficile Toxin A EIA is a rapid method for the diagnosis of Clostridium difficile toxin A in human fecal samples, to be used as an aid in the detection of Clostridium difficile-associated disease. Microwell strips are coated with mouse IgG to Clostridium difficile toxin A, which selectively captures Clostridium difficile toxin A if present in a stool sample. Irrelevant specimen debris, including non-toxigenic strains of Clostridium difficile, is washed away. Rabbit immunoglobulins to Clostridium difficile toxin A and peroxidase-labeled goat anti-rabbit antibodies are added to the well concurrently in a coincubation step. During incubation, the rabbit anti- Clostridium difficile toxin A binds to captured toxin A. Peroxidase-labeled anti-rabbit antibodies bind to rabbit antitoxin, forming an antitoxin-conjugate complex. Unbound anti-toxin and conjugate are washed away. Solution 3 and Solution 4 are then added and color is produced if the antitoxin-conjugate complex, which possesses the enzyme for the substrate (HRP), is present. This color production is quantified spectrophotometrically and compared to negative and positive controls for determination of the presence of Clostridium difficile toxin A.

The provided document (K990664) is a 510(k) summary for a modification to an existing device, the Bartels Clostridium difficile Toxin A Enzyme Immunoassay (EIA). The document primarily focuses on demonstrating substantial equivalence of the modified device to the previously cleared device (K913229) based on changes to the assay procedure (incubation times, temperature, and addition of a manual wash method), rather than presenting a full de novo study with detailed acceptance criteria and performance reports for the device's initial market clearance.

Therefore, the requested information, specifically detailed acceptance criteria and the comprehensive study that proves the device meets those criteria, is not fully available within this specific 510(k) modification document. This document mainly confirms that the methodological changes did not adversely affect the device's performance compared to the predicate device.

However, based on the information available and common regulatory practices for 510(k) modifications, I can infer and provide some relevant details:

Missing Information:

• Detailed list of specific acceptance criteria (e.g., sensitivity, specificity thresholds) for the device's initial clearance.
• The comprehensive study report that originally proved the device meets broad acceptance criteria. This document focuses on proving equivalence of a modified procedure.
• Sample size and data provenance for the original clinical studies.
• Number and qualifications of experts for the original ground truth.
• Adjudication method for the original studies.
• Whether an MRMC comparative effectiveness study was done for the original device.
• Effect size of human readers improving with AI vs. without AI assistance (this is an immunoassay, not an AI-based diagnostic).
• Sample size for the original training set (if applicable, for initial development).
• How ground truth for the original training set was established.

Information that can be extracted or inferred from the provided modification document (K990664):

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

Since this is a 510(k) modification for procedural changes, the "acceptance criteria" here refer to demonstrating that the modified procedure performs equivalently to the predicate device whose performance was already established. The document states:

"INTRACEL has made no changes to the manufacturing process or quality control testing procedures for this product. The only changes relate to the incubation and washing conditions employed during performance of the immunoassay. The essential immunoreagents, underlying format and scientific principle remain the same with the improved product."

This implies that the key acceptance criterion for this modification was that the modified assay procedure did not negatively impact the established performance characteristics (sensitivity, specificity, precision, etc.) of the original Bartels C. difficile Toxin A EIA. The document does not list specific numerical performance metrics for the modified device, but rather refers to its equivalence to the predicate.

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

The document does not explicitly state these details for this specific modification. It implies that the changes were validated through internal testing to confirm equivalence. Usually, for procedural changes in a 510(k) modification, manufacturers would perform comparative studies using clinical samples to show that results are consistent between the old and new procedures. However, the details of such a study (sample size, provenance, retrospective/prospective nature) are not provided in this summary.

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

This information is not provided in the document. For an immunoassay like this, the "ground truth" would typically come from a gold standard diagnostic method (e.g., toxigenic culture or a highly validated PCR method) rather than expert consensus on images.

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

Not specified in the document.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

• No, an MRMC comparative effectiveness study was not done. This device is an Enzyme Immunoassay (EIA) for detecting Clostridium difficile Toxin A, not an AI-based diagnostic or imaging device requiring human reader interpretation. Therefore, the concept of "human readers improving with AI vs. without AI assistance" is not applicable here.

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

• Yes, this is a standalone diagnostic test. The Bartels Clostridium difficile Toxin A EIA is an in vitro diagnostic device; its performance is assessed based on its ability to detect the toxin in fecal samples, without human intervention required for its analytical performance beyond running the assay and interpreting the quantitative spectrophotometric result against controls.

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

The document itself does not specify the method for establishing ground truth. However, for a test detecting Clostridium difficile Toxin A, the typical ground truth in clinical validation studies would involve:

• Culture for toxigenic C. difficile strains (cytotoxigenic culture): Considered the gold standard for many years.
• Molecular methods (e.g., PCR for toxin genes): Increasingly used as a gold standard.
• Correlation with clinical outcomes: While not a direct "ground truth" for the presence of toxin, association with clinical disease is crucial for medical devices.

8. The sample size for the training set

This document does not provide details on a "training set" as it relates to machine learning models. For an immunoassay, developmental testing would involve numerous samples, but these are typically not referred to as a "training set" in the context of device regulatory submissions.

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

Not applicable/not specified for an immunoassay in this context.

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The Bartels CINAkit™ CMV Antigenemia Test is intended for use as an aid in the diagnosis of Cytomegalovirus (CMV) infection by the rapid direct qualitative detection of CMV pp65 antigen in human blood leukocytes by indirect immunofluorescence (IF). This product is not intended to be used for testing (i.e. screening) blood or plasma donors.

BARTELS CINAKIT CMV Antigenemia is an indirect immunofluorescence test that allows detection of Human Cytomegalovirus antigen in leukocytes from peripheral blood. The test uses a monoclonal antibody pool (1C3, AYM-1) which recognizes the 65-68kDa lower matrix structural phosphoprotein (pp) (protein kinase, pp65, present in the nucleus of cells. The antibody pool (blended antibodies) recognizes two epitopes on the protein. Leukocytes are prepared from whole blood by dextran sedimentation and centrifugation; slides are prepared, fixed in formalin and permeabilized on detergent (NP40). Staining is accomplished with primary murine monoclonal antibodies to the pp65 antigen and F(Ab-)2 fluorescein-conjugated anti-mouse immunoglobulin secondary antibody. The slides are read using a fluorescence microscope.

This document describes the Bartels CINAkit CMV Antigenemia test, an immunoassay for the detection of CMV.

Here's a breakdown of the acceptance criteria and study information:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implicitly based on demonstrating substantial equivalence to the predicate device, the BIOTEST CMV BRITE TEST Kit. The performance characteristics of both devices are directly compared.

Note: The reported device performance for Bartels CINAkit CMV Antigenemia is presented in two places:

1. In Table 1, where it lists "Sensitivity: 82.86%, Specificity: 88.67%, Accuracy: 88.06%".
2. In the "Performance Characteristics 2." section, based on the clinical study, where it details "Sensitivity = 29/35 = 83% (95% Confidence interval = 70.4 - 95.3%)" and "Specificity = 266/300 = 89% (95% Confidence interval = 85.1 - 92.3%)". For the purpose of this table, the values from the clinical study are generally considered the primary performance claims. The values in Table 1 might represent initial expectations or a summary, but the detailed clinical study data provides the specific numbers that are directly supported.

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

• Sample Size: 335 clinical specimens.
• Data Provenance: The document does not explicitly state the country of origin. It refers to "clinical specimens" and a "clinical study" but does not specify if it was retrospective or prospective. Given the nature of medical device submissions, it's typically a prospective collection of real-world samples to validate performance, but this is not explicitly stated.

3. Number of Experts Used to Establish the Ground Truth and Qualifications

The ground truth was established by a "culture method," referred to as the "gold standard." This typically implies laboratory testing and interpretation by trained microbiologists or laboratory technicians rather than clinical experts (e.g., radiologists) in the context of imaging. The document does not specify the number of experts or their qualifications for interpreting the culture results.

4. Adjudication Method

Not applicable. The ground truth was established by a "gold standard" culture method, not through adjudication of expert opinions on the test specimens themselves.

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

No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly mentioned or performed. This is a diagnostic kit for laboratory use, not typically a device that involves multiple human readers interpreting images against an AI. The "comparison" mentioned is between the Bartels CINAkit and "Other CMV" (the predicate device) in terms of their performance against a gold standard, not a human-in-the-loop study with AI assistance.

6. Standalone Performance Study

Yes, a standalone performance study was clearly done. The Bartels CINAkit CMV Antigenemia device was evaluated by comparing its results against the "gold standard" culture method on 335 clinical specimens. The reported sensitivity and specificity are for the algorithm (kit) acting alone, without overt human-in-the-loop assistance for interpretation. The interpretation of the immunofluorescence slides by a fluorescence microscope would still involve a human reading the results of the kit-prepared slides.

7. Type of Ground Truth Used

Expert Consensus, Pathology, or Outcomes Data: The type of ground truth used was the culture method, which is explicitly stated as the "gold standard." This implies a microbiology laboratory culture result, which is considered highly reliable for detecting viral presence.

8. Sample Size for the Training Set

The document does not provide information about a separate training set. It describes a single "clinical study" involving 335 specimens for performance evaluation. For immunoassay kits like this, the development process might involve internal validation and optimization, but a distinct "training set" in the context of machine learning is not applicable here.

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

As there is no distinct "training set" described in the context of a machine learning-based device, this question is not applicable. The performance evaluation study used the culture method as the gold standard for its 335 specimens.

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