(210 days)
The SIRSCAN automated zone reader device is a video-camera image analysis computer-based system to read susceptibility test data from NCCLS M2-A6 Kirby-Bauer disk-diffusion test plates for the following organisms: enterobacteriacae; staphylococci, (except coagulase negative staphylococci with weak growth); and non-fermenting gram negative bacilli (except strains with weak growth). Other susceptibility tests on solid medium are read with the electronic caliper, and the results of susceptibility tests in other media can be keved in manually.
The SIRSCAN data management system compiles data from the NCCLS agar disk diffusion test. It prints, files and produces integrated results reports, reqularly or on request, to be used by clinicians, bacteriologists and epidemiologists. Its expert system feature offers consistency checks for validation of tests and results.
In addition, the SIRSCAN data management system: interprets zones; calculates MICs; provides quality control and epidemiology and infection control; identifies and eliminates duplicates: compares patient histories: classifies and monitors resistance phenotypes; monitors multi-resistant organisms; detects and monitors nosocomial infections; and prepares epidemiological statistics.
SIRSCAN can be connected to any laboratory management system, as well as to some micro-dilution systems (e.g., Vitek™, Microscan™).
SIRSCAN is an automatic reader of petri dishes that is used to manage overall susceptibility tests. The SIRSCAN is an automated susceptibility reader and interpretation system. It consists of two components:
(1) The SIRSCAN automated zone reader device is a video-camera image analysis computer-based system to read susceptibility test data from NCCLS M2-A6 Kirby-Bauer disk-diffusion test plates for the following organisms: enterobacteriacae; staphylococci, (except coagulase negative staphylococci with weak growth); and non-fermenting gram negative bacilli (except strains with weak growth). Other susceptibility tests on solid medium are read with the electronic caliper, and the results of susceptibility tests in other media can be keyed in manually.
(2) The SIRSCAN data management system compiles data from the NCCLS agar disk diffusion test. It prints, files and produces integrated results reports, regularly or on request, to be used by clinicians, bacteriologists and epidemiologists. Its expert system feature offers consistency checks for validation of tests and results.
In addition, the SIRSCAN data management system: interprets zones; calculates MICs; provides quality control and epidemiology and infection control; identifies and eliminates duplicates; compares patient histories; classifies and monitors resistance phenotypes; monitors multi-resistant organisms; detects and monitors nosocomial infections; and prepares epidemiological statistics.
SIRSCAN can be connected to any laboratory management system, and to some micro-dilution systems (e.g., VitekTM, MicroscanTM).
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device: SIRSCAN (Automatic Zone Reader)
Intended Use: Management of overall susceptibility tests for Enterobacteriaceae, staphylococci (excluding coagulase-negative staphylococci with weak growth), and non-fermenting gram-negative bacilli (excluding strains with weak growth).
1. Table of Acceptance Criteria and Reported Device Performance
The provided text does not explicitly state specific quantitative acceptance criteria for the SIRSCAN device. Instead, the "Performance Data" section refers to a single study, and the "CONCLUSIONS" state that "the performance data provide reasonable assurance of the safety and effectiveness of SIRSCAN for its proposed indications for use." This suggests the acceptance was based on the overall findings of the study meeting the requirements for substantial equivalence to predicate devices, rather than predefined numeric thresholds for metrics like accuracy or precision.
However, based on the device's function (reading zones in Kirby-Bauer disk diffusion tests), one can infer the intent of the performance evaluation. The study would have aimed to demonstrate that SIRSCAN's automated readings were comparable to a recognized standard (likely manual expert readings). Without explicit quantitative criteria, we can only report the existence of the study as the proof of performance.
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Device provides accurate and reliable zone diameter readings for susceptibility tests. | The cited study, "Evaluation of the SIRSCAN Automated Zone Reader in a Clinical Microbiology Laboratory" by Medeiros, A. and Crellin, J., Brown University (1998), concluded that the performance data provides "reasonable assurance of the safety and effectiveness of SIRSCAN for its proposed indications for use" and that it is "substantially equivalent to the claimed predicates under conditions of intended use." Specific quantitative performance metrics (e.g., accuracy percentages, sensitivity, specificity, reproducibility, or agreement with manual readings) are not detailed in the provided summary. However, the FDA's clearance (K991473) implies that these requirements were met based on the full submission including the study. |
| Device accurately interprets susceptibility test results based on NCCLS M2-A6 guidelines. | (See above) |
| Device effectively manages and compiles data from NCCLS agar disk diffusion tests. | (See above) |
| Device's expert system feature provides consistency checks for validation of tests and results. | (See above) |
| Device performs other stated functions (calculating MICs, QC, epidemiology, etc.) accurately. | (See above) |
| Device is substantially equivalent to legally marketed predicate devices. | The FDA concluded that the device is "substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Test Set): The provided text does not specify the sample size (number of petri dishes, organisms, or strains) used in the "Evaluation of the SIRSCAN Automated Zone Reader in a Clinical Microbiology Laboratory" study.
- Data Provenance: The study was conducted at Brown University by Medeiros, A. and Crellin, J. (1998). The text does not explicitly state whether the data was retrospective or prospective, or the country of origin of the samples themselves, but its association with Brown University suggests a U.S.-based clinical laboratory setting.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The provided text does not specify the number of experts used or their qualifications for establishing ground truth in the study. In the context of Kirby-Bauer disk diffusion, ground truth for zone diameters would typically be established by experienced microbiologists performing manual measurements.
4. Adjudication Method for the Test Set
The provided text does not specify any adjudication method used for the test set.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
The provided text does not indicate that an MRMC comparative effectiveness study was done comparing human readers with and without AI assistance. The study described focuses on the evaluation of the SIRSCAN device itself.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
The SIRSCAN device is inherently an automated system designed to read zone diameters and interpret results without a human performing the initial measurements. Therefore, the evaluation of SIRSCAN itself, as described, is a standalone (algorithm-only) performance assessment in the context of its primary function (automated reading). The system does include data management and an expert system feature for consistency checks, indicating an "algorithm-only" performance for the measurement and initial interpretation stages.
7. The Type of Ground Truth Used
While not explicitly stated, for a device reading and interpreting Kirby-Bauer disk diffusion zones, the ground truth would most likely be established by expert consensus (i.e., manual measurements and interpretations by experienced clinical microbiologists) using the NCCLS M2-A6 standard.
8. The Sample Size for the Training Set
The provided text does not specify any training set sample size. This type of device, which performs image analysis to measure zones against a known standard (NCCLS M2-A6), might not have a "training set" in the modern machine learning sense requiring a large pre-labeled dataset. Instead, its algorithm would likely be based on established image processing techniques and calibrated to the physical dimensions and expected characteristics of inhibition zones. If any trainable components were present, their training data is not mentioned.
9. How the Ground Truth for the Training Set Was Established
Since a specific "training set" and its sample size are not mentioned, the method for establishing its ground truth is also not provided.
§ 866.2850 Automated zone reader.
(a)
Identification. An automated zone reader is a mechanical device intended for medical purposes to measure zone diameters of microbial growth inhibition (or exhibition), such as those observed on the surface of certain culture media used in disc-agar diffusion antimicrobial susceptibility tests. The device aids in decisionmaking respecting the treatment of disease.(b)
Classification. Class I (general controls).