Search Results

The GenePOC™ GBS LB assay performed on the revogene™ instrument is a qualitative in vitro diagnostic test designed to detect Group B Streptococus (GBS) DNA from 18-24 hour LIM broth enrichments of vaginal/rectal specimen swabs obtained from pregnant women. The GenePOC GBS LB assay utilizes automated sample processing and real-time polymerase chain reaction (PCR) to detect a cfb gene sequence specific to the Streptococcus agalactiae genome.

The GenePOC GBS LB assay is indicated for the identification of antepartum GBS colonization and does not provide susceptibility results. It is not intended to diagnose or monitor treatment of GBS infection. Culture isolates are needed for performing susceptibility testing as recommended for penicillin-allergic women.

The GenePOC GBS LB assay is a single-use test for the qualitative detection of Group B Streptococcus (GBS) DNA from enriched vaginal/rectal swab specimens using realtime Polymerase Chain Reaction (PCR) technology with fluorogenic detection of the amplified DNA. The GenePOC GBS LB assay utilizes the GBS LB microfluidic cartridge for the simultaneous detection of the target GBS DNA and the internal process control (PrC) DNA (to monitor processing, amplification, and the absence of reaction inhibitors). The GenePOC GBS LB assay is an automated assay performed on the revogene™ including sample processing.

The GenePOC Group B Strep (GBS) LB is composed of a GBS specific disposable microfluidic cartridges, Sample Buffer Tube (SBT) and Disposable Transfer Tool (DTT). These components are used to lyse and dilute the sample, amplify, and detect GBS nucleic acid from vaginal/rectal swabs following LIM broth enrichment. User intervention is required for sample preparation, discharging the LIM broth enriched sample into the SBT, transferring the sample into the cartridge and loading/unloading the cartridge into the revogene instrument. Once the sample is added into the cartridge, the process is then fully automated.

Each GenePOC GBS LB Test kit contains 24 individual pouches, and each pouch has components for 1 test including 1 cartridge, 1 SBT, and 1 DTT. The GBS LB Test is run on the revogene instrument which can process from one up to a maximum of 8 samples simultaneously in the same run. On completion of a run, the results are interpolated by the revogene™ from measured fluorescent signals and embedded calculation algorithms. For the GBS application, two spectral signals are processed: GBS target and Internal Process Control. The output results include positive, negative, indeterminate, and unresolved. On completion of a run, the user removes the used cartridges and disposes of them in normal biological waste. Results may be viewed, printed, transferred, and/or stored by the user.

The provided document describes the GenePOC GBS LB assay, a qualitative in vitro diagnostic test for detecting Group B Streptococcus (GBS) DNA. Here's a breakdown of the acceptance criteria and the study proving the device meets them:

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

The document doesn't explicitly state "acceptance criteria" in a separate table. However, it presents performance metrics that serve as the basis for FDA's substantial equivalence determination. We can infer the "acceptance criteria" from the reported performance results, particularly from the overall clinical performance.

2. Sample size used for the test set and the data provenance:

• Clinical Test Set Sample Size: A total of 771 compliant specimen results were used to determine the clinical performance.
  • 170 GBS positive samples
  • 601 GBS negative samples
• Data Provenance: The data was obtained from a prospective multicenter trial conducted at 4 geographically diverse clinical trial sites, consisting of two Canadian and two US clinical sites.

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

The document describes the ground truth for the clinical study as a "composite reference method consisting of LIM Broth enrichment of the vaginal/rectal swab followed by a subculture on blood agar plate and biochemical identification of GBS." This method is a laboratory-based standard and does not involve a subjective assessment by a human expert (like a radiologist reviewing an image). Therefore, the concept of "number of experts used to establish ground truth" with specific qualifications is not applicable in this context.

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

Since the ground truth is established by a laboratory-based composite reference method (culture and biochemical identification), no human expert adjudication method (like 2+1 or 3+1 for imaging studies) was performed or needed for the ground truth establishment. The results are based on objective laboratory testing.

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 comparative effectiveness study was done. This device is a standalone in vitro diagnostic (IVD) assay designed for direct detection of GBS DNA, not an AI-assisted imaging analysis tool. Therefore, the concept of human readers improving with AI assistance is not applicable.

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

Yes, a standalone performance evaluation was done. The entire performance characterization (analytical and clinical) presented in the document assesses the GenePOC GBS LB assay as a standalone device without human-in-the-loop performance modification. The revogene™ instrument processes the sample and provides the result based on its embedded calculation algorithms. User intervention is limited to sample preparation and loading/unloading.

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

The ground truth used for the clinical study was a laboratory-based composite reference method, specifically:

• LIM Broth enrichment of the vaginal/rectal swab
• Followed by subculture on blood agar plate
• And biochemical identification of GBS

8. The sample size for the training set:

The document does not specify a separate training set size. As this is an in vitro diagnostic device for molecular detection, the "training" aspect is typically related to the development and optimization of the assay itself (e.g., primer design, probe chemistry, algorithmic thresholds) rather than training a machine learning model on a distinct dataset with labeled ground truth in the same way an AI imaging algorithm would be trained. The performance data presented refers to the testing of the developed and finalized assay.

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

Since a distinct "training set" with ground truth (in the AI/ML sense) is not described, the question of how its ground truth was established is not directly applicable. However, the development of the assay itself would have relied on well-characterized GBS strains and clinical samples with known GBS status, likely determined through standard microbiological culture and identification methods (similar to the clinical ground truth). This iterative development-and-testing process leads to the final assay's performance characteristics.

Ask a specific question about this device