Search Results

The BD BACTEC Plus Aerobic/F medium is used in a qualitative procedure for the aerobic culture and recovery of microorganisms (bacteria and yeast) from blood. The principal use of this medium is with the BD BACTEC fluorescent series instruments.

The sample to be tested is inoculated into one or more vials which are inserted into the BACTEC fluorescent series instrument for incubation and periodic reading. Each vial contains a chemical sensor which can detect increases in CO2 produced by the growth of microorganisms. The sensor is monitored by the instrument every ten minutes for an increase in its fluorescence, which is proportional to the amount of CO2 present. A positive reading indicates the presumptive presence of viable microorganisms in the vial. Detection is limited to microorganisms that will grow in a particular type of medium.

Resins have been described for the treatment of blood specimens both prior to and after their inoculation into culture media. Resins have been incorporated into BACTEC culture media to enhance recovery of organisms without a need for special processing.

The provided submission describes a device comparison study rather than independent validation against a predefined acceptance criterion. The study aims to demonstrate substantial equivalence of the new device (BD BACTEC Plus Aerobic/F in a plastic bottle) to a predicate device (BD BACTEC Plus Aerobic/F in a glass bottle) in terms of performance. Therefore, the "acceptance criteria" are implicitly defined by the performance of the predicate device.

Here's an analysis based on your requested information:

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

Since specific, quantitative acceptance criteria are not explicitly stated in isolation (i.e., "device must achieve X accuracy"), the acceptance criteria are inferred as demonstrating statistical equivalence or non-inferiority to the predicate device in various performance metrics.

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

• Instrument Time to Detection & Percent Recovery:
  • Test Set Sample Size: 726 paired sets (for TTD), 738 paired sets (for Percent Recovery).
• False Positive Rate:
  • Test Set Sample Size: 240 paired sets (80 bottles from each of 3 lots).
• False Negative Rate:
  • Test Set Sample Size: 82 paired sets.
• BACTEC Instrument Compatibility:
  • Test Set Sample Size: 246 paired sets (new and predicate devices) tested in each of three BACTEC instruments.
• Reproducibility:
  • Test Set Sample Size: Not explicitly stated as a separate number, but implied to be based on the paired sets across different lots for TTD and recovery.
• Antimicrobial Neutralization Capability:
  • Test Set Sample Size: 377 drug-bug combinations per lot (for 3 lots).

Data Provenance: The document does not specify the country of origin of the data or whether it was retrospective or prospective. Given the nature of a 510(k) submission for a medical device, these are typically prospective studies conducted under controlled laboratory conditions, often simulating clinical use. The use of "fresh human blood" indicates a simulated clinical environment for some tests.

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 device is a culture medium for microbial recovery. The "ground truth" for each sample (i.e., presence/absence and identification of microorganisms) would typically be established through laboratory standard techniques such as subculturing and microbial identification (e.g., plating cultures, gram staining, biochemical tests). The document does not mention the use of human experts (like radiologists) for establishing ground truth, as that is not relevant for this type of in-vitro diagnostic device. The ground truth refers to the actual microbial content as determined by standard microbiological methods, rather than human interpretation.

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

Not applicable. The ground truth is established by microbiological methods directly (e.g., isolation and identification of organisms), not by expert adjudication of interpretations.

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

Not applicable. This device is an in-vitro diagnostic culture medium, not an AI-assisted diagnostic tool that involves human readers/interpreters in the diagnostic process. The performance is assessed directly at the instrument and medium level.

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

This refers to the performance of the device itself (the culture medium and its interaction with the BACTEC instrument's detection system), independent of human interpretation. Yes, standalone performance was assessed. The studies described (TTD, Percent Recovery, False Positive/Negative, Instrument Compatibility, Reproducibility, Antimicrobial Neutralization) are all evaluations of the intrinsic performance of the medium and the automated instrument detection system. There is no human interpretation component in the primary detection process that would require a human-in-the-loop study.

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

The ground truth for this device is based on microbiological isolation and identification via laboratory standard methods. This involves:

• For positive samples: Confirmation of microbial growth and identification of the specific organisms present.
• For negative samples: Confirmation of the absence of microbial growth over the incubation period by subculture or other means.
• For false negative cases, like the Leuconostoc example, the "ground truth" that an organism was present but undetected by the device would be established by post-protocol subculture results.

8. The sample size for the training set

The document does not report a "training set" sample size. This is because the studies described are device performance validation studies for a modified culture medium, not machine learning model development. The device itself (the medium and its sensor) is designed to detect CO2 changes, and the "algorithms" mentioned in the device description refer to the instrument's pre-programmed growth and detection algorithms, which would have been developed and validated previously, and are applied consistently across both new and predicate devices.

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

Not applicable, as there is no mention of a "training set" in the context of machine learning for this device. The ground truth for the validation studies was established via standard microbiological techniques as described in point 7.

Ask a specific question about this device