(49 days)
The BacT/ALERT SV Culture Bottles are used with the BacT/ALERT Microbial Detection Systems in qualitative procedures for enhanced recovery and detection of aerobic and facultative anaerobic microorganisms (bacteria and fungi) from blood and other normally sterile body fluids.
The BacT/ALERT SV Culture Bottle was developed for the same intended use as the current BacT/Alert Standard Aerobic Culture Bottle, to provide suitable nutritional and environmental conditions for organisms commonly encountered in blood infections and normally sterile body fluids. An inoculated bottle is placed into the BacT/ALERT Microbial Detection Instruments where it is incubated and continuously monitored for the presence of microorganisms that will grow in the BacT/ALERT SV Bottle.
The provided text describes the 510(k) Premarket Notification for the BacT/ALERT SV Culture Bottle. Here's a breakdown of the acceptance criteria and the study that proves the device meets them:
Acceptance Criteria and Device Performance
1. Table of Acceptance Criteria and Reported Device Performance
The core acceptance criterion for the BacT/ALERT SV Culture Bottle was substantial equivalence to its predicate device, the BacT/Alert Standard Aerobic Culture Bottle. This was primarily assessed based on the ability to recover equivalent levels of microorganisms and comparable detection times.
| Acceptance Criteria | Reported Device Performance (BacT/ALERT SV Culture Bottle) |
|---|---|
| Recovery of low levels of microorganisms | Equivalent to the BacT/Alert Standard Aerobic Culture Bottle for 23 tested microorganisms. |
| Detection times | Equivalent to the BacT/Alert Standard Aerobic Culture Bottle. |
| Intended Use | Same as the predicate device: enhanced recovery and detection of aerobic microorganisms (bacteria and fungi) from blood and other normally sterile body fluids. |
| Technological Characteristics | Utilizes the same detection technology (reflectance) as the predicate, with minor changes like sensor type (emulsion vs. disc) but same indicator material. Performance in terms of growth of microorganisms is equivalent. |
It's important to note that the document emphasizes the equivalence to a legally marketed predicate device rather than defining numerical targets for sensitivity, specificity, or time to detection. The acceptance criteria are implicitly met if the new device performs "as well or better than" the predicate.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size:
- 23 organisms were used for the seeded studies.
- For each organism, the study involved a dilution in human blood inoculated into both the BacT/ALERT SV bottle and the BacT/Alert Standard Aerobic bottle. The exact number of samples (bottles) per organism per dilution is not specified, but it implies multiple samples for each of the 23 organisms to assess "recovery of low levels" and "detection times."
- Data Provenance: The organism studies were conducted using "human blood." The country of origin is not specified, but it's likely within the USA, given the FDA submission. The study type was non-clinical testing, specifically seeded studies, meaning known organisms were introduced into samples. This is a form of prospective, controlled laboratory testing.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state the number or qualifications of experts used to establish ground truth. For seeded studies, the "ground truth" is inherently known by the experiment design (i.e., the specific organisms and their concentrations that are deliberately introduced). Therefore, external experts to establish ground truth are typically not required in such studies. Laboratory personnel with expertise in microbiology and instrument operation would have conducted the tests and interpreted the raw detection results.
4. Adjudication Method for the Test Set
Adjudication methods (like 2+1, 3+1) are typically used for interpreting ambiguous results, often with human interpretation (e.g., radiology images). In this context of automated microbial detection using seeded samples, the assessment of "detection" is generally clear-cut based on the instrument's output. Therefore, an explicit adjudication method as described for interpretive tasks is not applicable or mentioned. The "detection times" and "recovery" would be objectively measured by the BacT/ALERT Microbial Detection Systems.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. MRMC studies are relevant for devices that involve human interpretation (e.g., AI-assisted diagnosis in imaging). This device is an automated in vitro diagnostic instrument for microbial detection, where the direct output is from the instrument rather than a human interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
This device is a standalone device in terms of its detection capability. The BacT/ALERT SV Culture Bottle, in conjunction with the BacT/ALERT Microbial Detection Instruments, performs the detection autonomously. Human involvement is in sample preparation, loading, and interpreting the instrument's objective detection signal (e.g., positive or negative for growth, and time to detection). The performance described in the document (recovery and detection times) is the standalone performance of the combined bottle and instrument system.
7. The Type of Ground Truth Used
The ground truth used was known microbial presence and concentration established through seeded studies. Specific organisms were diluted in human blood and intentionally inoculated into the culture bottles, allowing for a direct comparison of the device's ability to detect these known organisms against the predicate device.
8. The Sample Size for the Training Set
The document does not mention a training set because this submission is for a device that relies on a well-established detection technology (reflectance) rather than a novel algorithm requiring extensive data-driven training (like machine learning models). The technology of the new device is stated to be the same as the predicate, with minor physical differences in the sensor. The studies described are validation/verification studies, not training.
9. How the Ground Truth for the Training Set Was Established
As no training set is mentioned or implied, the question of how its ground truth was established is not applicable.
§ 866.2560 Microbial growth monitor.
(a)
Identification. A microbial growth monitor is a device intended for medical purposes that measures the concentration of bacteria suspended in a liquid medium by measuring changes in light scattering properties, optical density, electrical impedance, or by making direct bacterial counts. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I. With the exception of automated blood culturing system devices that are used in testing for bacteria, fungi, and other microorganisms in blood and other normally sterile body fluids, this device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter.