Search Results

For VIDAS H. pylori IgG:
VIDAS® H. pylori IgG (HPY) is an automated qualitative test for use on the instruments of the VIDAS family, for the detection of anti-Helicobacter pylori IgG antibodies in human serum or plasma (EDTA) using the ELFA technique (Enzyme Linked Fluorescent Assay). The VIDAS HPY assay is intended as an aid in diagnosis of H. pylori infection in an adult symptomatic population.
This device is an in vitro diagnostic medical device for professional use only.

For VIDAS 3:
The VIDAS 3 system is a complete standalone immunodiagnostic system intended for trained and qualified laboratory technicians (daily routine use) and laboratory administrators (application configuration). This device is an in vitro diagnostic medical device for professional use only.

For VIDAS Lyme IgG II:
The VIDAS Lyme IgG II (LYG) assay is an automated qualitative enzyme immunoassay intended for use on the instruments of the VIDAS family in the presumptive detection of human IgG antibodies to Borrelia burgdorferi in human serum (plain or separation gel) or plasma (sodium heparin). It should be used to test patients with a history and/or symptoms of infection with B. burgdorferi. All VIDAS Lyme IgG II positive specimens should be further tested with a Western Blot IgG assay to obtain supportive evidence of infection with B. burgdorfei. This device is an in vitro diagnostic medical device for professional use only.

For VIDAS RUB IgG:
The VIDAS® RUB IgG (RBG) assay uses Enzyme Linked Fluorescent Assay (ELFA) technology on the instruments of the VIDAS family for the in vitro quantitative measurement of IgG antibodies to rubella virus in human serum. The VIDAS RUB IgG (RBG) assay is intended as an aid in the determination of immune status to rubella. The performance of this device has not been established for screening of cord blood, or for neonatal samples. Likewise, performance characteristics of the assay have not been established for immunocompromised or immunosuppressed individuals.
This device is an in vitro diagnostic medical device for professional use only.

For VIDAS TOXO IgM:
The VIDAS® TOXO IgM (TXM) assay is intended for use on the instruments of the VIDAS family (VITEK ImmunoDiagnostic Assay System) as an automated enzyme-linked fluorescent immunoassay (ELF A) for the presumptive qualitative detection of anti-Toxoplasma gondii IgM antibodies in human serum, as an aid in the diagnosis of acute, recent, or reactivated Toxoplasma gondii infection. This assay must be performed in conjunction with an anti-Toxoplasma gondii lgG antibody assay. VIDAS TOXO IgM (TXM) assay performance has not been established for prenatal screening or newborn testing. This assay has not been cleared by the FDA for blood/plasma donor screening. This device is an in vitro diagnostic medical device for professional use only.

For VIDAS Human Chorionic Gonadotropin:
The VIDAS® HCG (HCG) assay is intended for use on the instruments of the VIDAS family as an automated quantitative enzyme linked fluorescent immunoassay (ELFA) for the determination of human Chorionic Gonadotropin (hCG) concentration in human serum or plasma. The VIDAS HCG (HCG) assay is intended to aid in the early detection of pregnancy.
This device is an in vitro diagnostic medical device for professional use only.

For VIDAS T4:
The VIDAS® T4 (T4) assay is intended for use on the instruments of the VIDAS family as an automated quantitative enzyme-linked fluorescent immunoassay for the determination of human thyroxine (T4) concentration in serum or plasma (heparin). It is intended for use as an aid in the diagnosis and treatment of thyroid disorders. This device is an in vitro diagnostic medical device for professional use only.

For VIDAS Testosterone:
The VIDAS Testosterone (TES) assay is an automated quantitative test for use on the instruments of the VIDAS family for the enzyme immunoassay measure of total testosterone in human serum or plasma (lithium heparin), using the ELFA technique (Enzyme Linked Fluorescent Assay). It is intended as an aid in the diagnosis and management of conditions involving excess or deficiency of this androgen.
This device is an in vitro diagnostic medical device for professional use only.

For VIDAS TSH:
The VIDAS® TSH (TSH) assay is intended for use on the instruments of the VIDAS family as an automated quantitative enzyne-linked fluorescent immunoassay (ELFA) for the determination of human thyroid stimulating hormone- (TSH) concentration in human serum or plasma (heparin). It is intended for use as an aid in the diagnosis of thyroid or pituitary disorders.
This device is an in vitro diagnostic medical device for professional use only.

For VIDAS D-Dimer Exclusion II:
VIDAS® D-Dimer Exclusion II™ is an automated quantitative test for use on the instruments of the VIDAS family for the immunoenzymatic determination of fibrin degradation products (FbDP) in human plasma (sodium citrate, CTAD) using the ELFA technique (Enzyme Linked Fluorescent Assay).
VIDAS D-Dimer Exclusion II is indicated for use in conjunction with a clinical pretest probability assessment model to exclude deep vein thrombosis (DVT) and pulmonary embolism (PE) disease in outpatients suspected of DVT or PE. This device is an in vitro diagnostic medical device for professional use only.

The VIDAS® 3 instrument is an automated multiparametric immunoassay system, which uses ELFA (Enzyme Linked Fluorescent Assay) technology. The VIDAS 3 system offers primary tube sampling, automated sample dilution, reagent/sample detection and reagent traceability.
The technology used, which is adaptable to a wide range of assays, combines the EIA method with a final fluorescence reading: this technology is known as ELFA (Enzyme Linked Fluorescent Assay). The enzyme used in the VIDAS product range is alkaline phosphatase, which catalyzes the hydrolysis of the substrate 4-methyl umbelliferyl phosphate (4-MUP) into a fluorescent product 4-methyl umbelliferone (4-MU) the fluorescence of which is measured at 450nm. The immunological methods are either indirect ElA, immunocapture, sandwich or competition, all involving a conjugate using the alkaline phosphatase.

This document describes the performance data for several VIDAS assays when used on the VIDAS 3 instrument, comparing them to their performance on the predicate VIDAS instrument. The tests are primarily for establishing substantial equivalence for the new VIDAS 3 instrument and do not typically include detailed acceptance criteria for the assays themselves, which are already established for the predicate devices. The studies focus on method comparison, precision, linearity, and detection limits.

Here's a breakdown of the requested information based on the provided text, focusing on the VIDAS H. pylori IgG assay as a primary example, and generalizing for others where appropriate:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state acceptance criteria in a quantitative format for method comparison. Instead, it demonstrates "correlation" and "equivalency" between the new device (VIDAS 3) and the predicate device (VIDAS). For precision, specific CV% ranges are reported.

Here's an example for the VIDAS H. pylori IgG assay's method comparison:

Note: For quantitative assays like VIDAS RUB IgG, VIDAS HCG, VIDAS T4, VIDAS Testosterone, VIDAS TSH, and VIDAS D-Dimer Exclusion II, method comparison relies on slope, intercept, and correlation coefficient, implying acceptance criteria for these values (e.g., slope close to 1, intercept close to 0, high correlation coefficient). Precision for these assays also includes CV% for various components.

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

• VIDAS H. pylori IgG:

  • Test Set Size: 250 serum samples (positive, equivocal, and negative).
  • Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). The study compares performance between two instruments, implying samples are run on both.

• VIDAS Lyme IgG II:

  • Test Set Size: 220 serum samples (positive and negative).
  • Data Provenance: Not explicitly stated.

• VIDAS RUB IgG:

  • Test Set Size (Quantitative Method Comparison): 112 serum samples (ranging from 0 to 225 IU/mL).
  • Test Set Size (Qualitative Method Comparison): 220 serum samples (positive, equivocal, and negative).
  • Test Set Size (CDC Reference Panel): 100 specimens (50 pairs of sera).
  • Data Provenance: Not explicitly stated for general samples. The CDC panel implies a curated and standardized set.

• VIDAS TOXO IgM:

  • Test Set Size: 198 serum samples.
  • Data Provenance: Not explicitly stated.

• VIDAS Human Chorionic Gonadotropin (hCG):

  • Test Set Size: 113 serum samples.
  • Data Provenance: Not explicitly stated.

• VIDAS T4:

  • Test Set Size: 105 serum samples.
  • Data Provenance: Not explicitly stated.

• VIDAS Testosterone:

  • Test Set Size: 172 serum samples.
  • Data Provenance: Not explicitly stated.

• VIDAS TSH:

  • Test Set Size: 179 serum samples.
  • Data Provenance: Not explicitly stated.

• VIDAS D-Dimer Exclusion II:

  • Test Set Size: 219 plasma samples.
  • Data Provenance: Not explicitly stated.

Across all assays, the studies are described as "Method Comparison" and "Precision" studies, which are typically retrospective analyses of patient samples to compare device performance to an established method.

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

This information is not provided in the document. For in vitro diagnostic devices, ground truth is typically established by comparative methods (e.g., predicate device, reference methods, clinical diagnosis, or other laboratory gold standards) rather than expert consensus on individual cases. The document states that performance was evaluated against the predicate device (e.g., "VIDAS H. pylori IgG assay on the VIDAS 3 to the VIDAS H. pylori IgG assay on the VIDAS"). The "ground truth" for these studies is the result obtained from the predicate VIDAS instrument using its established methodology.

For the VIDAS RUB IgG, a "CDC reference panel" and "CDC low-titer rubella antibody standard" are mentioned, where the reference panel sera were "titered by Hemagglutination Inhibition." This implies that the ground truth for this specific part of the study was established by a recognized reference method (Hemagglutination Inhibition) and certified reference materials from the CDC.

4. Adjudication Method for the Test Set

This information is not explicitly provided. For method comparison studies, typically, discordant results between the new device and the predicate device (or reference method) are investigated. However, the exact adjudication process (e.g., by a third, more definitive test, or expert review of patient clinical history) is not detailed. The phrase "results were evaluated according to CLSI EP12-A2" or CLSI EP9 suggests standard statistical methods for agreement or correlation, which do not necessarily involve expert adjudication of individual discrepancies beyond reporting them.

For quantitative assays where method comparison statistics (slope, intercept, correlation coefficient) are used, "outliers" were removed in some cases (e.g., VIDAS RUB IgG quantitative comparison), implying some form of review or statistical exclusion, but not necessarily expert "adjudication" in the sense of clinical decision-making.

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

No. This document describes performance studies for in vitro diagnostic instruments and assays, not imaging or similar devices that would typically involve human readers interpreting results. Therefore, an MRMC comparative effectiveness study, which assesses improvements in human interpretation with AI assistance, is not applicable and was not performed.

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

The studies described are for the standalone in vitro diagnostic instruments and their associated assays. These are standalone tests, meaning the algorithm (or assay chemistry in this case) processes the sample and provides a result without direct human interpretation of raw data for diagnosis. The "human-in-the-loop" here refers to trained laboratory technicians operating the instrument and interpreting the final quantitative or qualitative results according to established cut-offs/guidelines, rather than interpreting complex images or signals. The purpose of these studies is to confirm that the new instrument (VIDAS 3) produces equivalent results to the predicate instrument (VIDAS) for these assays.

7. The Type of Ground Truth Used

The primary type of "ground truth" used in these studies is the results obtained from the predicate device (VIDAS instrument) for the same assays. The goal is to demonstrate "substantial equivalence" of the new instrument (VIDAS 3) to the predicate.

For the VIDAS RUB IgG assay, a CDC reference panel where samples were "titered by Hemagglutination Inhibition" served as an additional, external reference for ground truth in a specific subset of testing. This is a form of reference method/standardized panel data.

8. The Sample Size for the Training Set

This information is not explicitly provided in the document. For in vitro diagnostic assays, "training sets" are usually involved in the initial development and optimization of the assay itself (e.g., establishing reagents, parameters, cut-offs). The studies described in this document are focused on the validation and verification of the new instrument's performance with existing, already developed assays, often referred to as "test sets" or "evaluation sets." The assays themselves were presumably developed and "trained" using various sample sets prior to these studies.

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

Since information on a distinct "training set" for the new instrument's validation isn't provided (as the assays were pre-existing), details on its ground truth establishment are also not available in this document. For the development of the original assays, ground truth would have been established through a combination of clinical diagnoses, established reference methods, and correlation with disease status.

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The VIDAS Lyme IgG (LYG) assay is an automated qualitative enzyme immunoassay intended for use on the instruments of the VIDAS family in the presumptive detection of human IgG antibodies to Borrelia burgdorferi in human serum (plain or separation gel) or plasma (sodium heparin or lithium heparin). It should be used to test patients with a history and/or symptoms of infection with B. burgdorferi. All VIDAS Lyme IgG positive specimens should be further tested with a Western Blot IgG assay to obtain supportive evidence of infection with B. burgdorferi.

The VIDAS Lyme IgG assay principle combines a two-step enzyme immunoassay sandwich method with a final fluorescent detection (ELFA). The Solid Phase Receptacle (SPR®) serves as the solid phase as well as the pipetting device for the assay. Reagents for the assay are ready-to-use and predispensed in the sealed reagent strips. All of the assay steps are performed automatically by the instrument. The reaction medium is cycled in and out of the SPR several times.

After a preliminary wash step and a sample dilution step, the sample is cycled in and out of the SPR. Antibodies to B. burgdorferi present in the specimen will bind to the B. burgdorferi antigen coating the interior of the SPR. Unbound sample components are washed away. Anti-human IgG antibodies conjugated with alkaline phosphatase will attach to the immunocomplex bound to the SPR wall. A final wash step removes unbound conjugate.

During the final detection step, the substrate (4-Methyl-umbellifery) phosphate) is cycled in and out of the SPR. The conjugate enzyme catalyzes the hydrolysis of this substrate into a fluorescent product (4-Methyl-umbelliferone) the fluorescence of which is measured at 450 nm. The intensity of the fluorescence is proportional to the quantity of anti-B. burgdorfen IgG antibodies present in the sample. At the end of the assay, results are automatically calculated by the instrument. A test value is generated and a report is printed for each test.

Here's a breakdown of the acceptance criteria and the study details for the VIDAS® Lyme IgG Assay, based on the provided 510(k) summary:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria values for sensitivity, specificity, or agreement rates. Instead, the study reports the performance of the VIDAS Lyme IgG assay and compares it to a predicate device, aiming to demonstrate substantial equivalence rather than meeting specific numerical thresholds set forth as acceptance criteria. However, we can infer performance targets based on the documented results and competitive performance against the predicate.

For the purpose of this exercise, I will present the reported performance, and where applicable, indicate an implicit "acceptance" based on comparison to the predicate device or a recognized standard (like the CDC panel).

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

• Sensitivity Testing: 202 retrospective samples
  • Data Provenance: Not explicitly stated (implied clinical samples from patients meeting case definition).
• Method Comparison (PPA/NPA): 975 fresh or frozen prospectively collected sera
  • Data Provenance: Endemic area of the United States (prospectively collected).
• Analytical Specificity: 100 sera from an endemic population (New York) and 100 sera from a non-endemic population (Texas).
  • Data Provenance: New York (endemic), Texas (non-endemic).
• CDC Reference Panel: 39 serum samples
  • Data Provenance: Obtained from the CDC.
• Cross-Reactivity: Varies for each infection/diagnosis, ranging from 19 to 256 samples.
  • Data Provenance: Not explicitly stated for each group.
• Nonclinical Tests (Precision & Reproducibility): 4 serum samples tested multiple times (80 for precision, 240 for reproducibility) and controls.
  • Data Provenance: Not specified, likely internally prepared or sourced.

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

The document does not specify the number or qualifications of experts used to establish ground truth for the clinical samples.

• For the Sensitivity Testing, samples were from "patients meeting a case definition of LD and confirmed positive for B. burgdorferi infection." This implies clinical diagnosis and/or confirmatory testing (which often involves expert interpretation), but direct expert counting or qualifications are not provided.
• For the Method Comparison, samples were "submitted for routine Lyme disease testing." Ground truth was established by comparison with a predicate device and then confirmed with a commercially available Lyme IgG Western Blot method, following CDC recommendations for two-tier testing. This indicates a multi-methodological approach to ground truth, but not direct expert consensus on each case.
• For the CDC Reference Panel, the samples are described as a "masked, characterized serum panel." This implies the CDC (as an expert body) established the clinical status, but the specific process (e.g., number of experts, qualifications) is not detailed.
• For Cross-Reactivity, samples were "negative with the test being evaluated and positive for the potentially interfering disease." This indicates known positivity for other infections, likely established by standard diagnostic methods.

4. Adjudication Method for the Test Set

• Clinical Sensitivity/Method Comparison: The primary adjudication method for positive cases appears to be second-tier testing with a Western Blot IgG assay, in accordance with CDC recommendations. The document states: "All VIDAS Lyme IgG positive specimens should be further tested with a Western Blot IgG assay to obtain supportive evidence of infection with B. burgdorferi" and "the VIDAS Lyme IgG positive results and the predicate Lyme IgG positive and equivocal results were confirmed using a commercially available Lyme IgG Western Blot method." This suggests a hierarchical adjudication process where initial positives are subjected to a confirmatory test.
• For the initial comparison between VIDAS and the predicate (prior to Western Blot), "equivocal results [from the predicate] were considered as positive for the evaluation."

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

No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not conducted. This device is an automated in vitro diagnostic assay, not an AI-assisted diagnostic tool that interprets images or signals requiring human reader input or comparison.

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

Yes, the studies presented are standalone performance evaluations of the VIDAS Lyme IgG assay. As an automated enzyme immunoassay, its performance is assessed independently, without human interaction in the analytical process itself, beyond sample loading and results interpretation. The assay generates a quantitative result which is then interpreted qualitatively (positive/negative) by the instrument.

7. The Type of Ground Truth Used

The ground truth used in the studies varies by context:

• Clinical Sensitivity: "Patients meeting a case definition of LD and confirmed positive for B. burgdorferi infection" - implies a combination of clinical diagnosis and potentially laboratory confirmation (though specific methods for confirmation aren't exhaustively detailed for this set).
• Method Comparison: Western Blot IgG results served as the confirmatory ground truth for positive and equivocal first-tier results, following CDC recommendations. The initial comparison was against a predicate EIA (Platelia™ Lyme IgG).
• Analytical Specificity: Clinical categorization as "apparently healthy subjects from an endemic population" or "non-endemic population with no known history of Lyme disease" for negative cases, and diagnosed "infection or diagnosis" for cross-reactivity panels.
• CDC Reference Panel: The CDC provided a "masked, characterized serum panel," indicating ground truth established by the CDC, likely based on clinical status and expert characterization.

8. The Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of device development or algorithm training. This is expected for an in vitro diagnostic assay of this type, where performance is derived from biochemical reactions rather than machine learning algorithms trained on data. The studies described are validation and verification studies for the manufactured product.

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

Since no explicit training set is mentioned as part of the assay's development or a machine learning approach, the concept of establishing ground truth for a training set is not applicable here. The assay's "training" in a broad sense would be in its initial design, optimization, and calibration based on known positive and negative samples, but these are not described in the same way as a machine learning training dataset.

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