(54 days)
The IMMAGE Immunochemistry System Antithrombin III (AT3) Reagent, when used in conjunction with Beckman IMMAGE™ Immunochemistry Systems and Beckman Calibrator 2, is intended for the quantitative determination of human Antithrombin III by rate nephelometry.
The IMMAGE Immunochemistry System AT3 Reagent, in conjunction with Beckman Calibrator 2, is intended for use in the quantitative determination of Antithrombin III concentrations on Beckman's IMMAGE Immunochemistry System.
The provided document describes the IMMAGE™ Immunochemistry System Antithrombin III (AT3) Reagent. The acceptance criteria and supporting study details are summarized below.
1. Table of Acceptance Criteria and Reported Device Performance
The document implicitly uses the performance of the predicate device (Array System Antithrombin III (AT3) Reagent) as the acceptance criteria for the IMMAGE System AT3 Reagent. The key performance metrics evaluated are method comparison (correlation with the predicate), stability, and imprecision.
| Acceptance Criteria Category | Specific Metric | Predicate Performance (Implicit Acceptance) | Reported Device Performance (IMMAGE AT3 Reagent) |
|---|---|---|---|
| Method Comparison | Correlation (r) | High correlation with established methods | 0.996 (vs. Array 360 System AT3 Reagent) |
| Slope | Close to 1.0 | 1.088 | |
| Intercept | Close to 0.0 | -0.10 | |
| Stability | Shelf-life | Established, reliable shelf-life | 24 months shelf-life |
| Open Container Stability | Established, reliable open container stability | 14 day open container stability | |
| Calibration Stability | Established, reliable calibration stability | 14 day calibration stability | |
| Imprecision | Within-Run Imprecision | Low imprecision | "Estimated Imprecision" (details not provided in table, but study was done) |
2. Sample Size for the Test Set and Data Provenance
- Sample Size: N = 136 for the method comparison study.
- Data Provenance: The document does not explicitly state the country of origin. It is a retrospective study as it compares the new device's results to an existing, commercially available predicate device using collected samples. The "plasma" sample type is mentioned.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This device is an in-vitro diagnostic (IVD) for quantitative determination of Antithrombin III. The "ground truth" for such devices is typically established through direct measurement on samples where the analyte concentration is known or determined by a well-established, often reference, method.
- Number of Experts: Not applicable in the context of expert consensus for image review or clinical diagnosis. The ground truth for the method comparison was established by the predicate device (Array 360 System AT3 Reagent), which itself is a laboratory instrument.
- Qualifications of Experts: Not applicable. The "ground truth" here is the measurement from the predicate device.
4. Adjudication Method for the Test Set
The concept of an adjudication method (e.g., 2+1, 3+1) is typically relevant for studies where human interpretation of medical images or clinical data is involved and discrepancies between readers need to be resolved. For an IVD device like the IMMAGE AT3 Reagent, the "adjudication" is essentially the statistical comparison of the new device's output against the predicate device's output. There is no mention of a human adjudication process for resolving discordant results between the IMMAGE system and the Array system; rather, a statistical correlation (regression analysis) is performed.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- Was an MRMC study done? No. This type of study is not applicable for this device. MRMC studies are designed to assess diagnostic performance with and without AI assistance for human readers, typically in image interpretation. The IMMAGE AT3 Reagent is an automated in-vitro diagnostic system that quantifies a biomarker, not an imaging device or an AI assistant for human interpretation.
6. Standalone (i.e. algorithm only without human-in-the-loop performance) Study
- Was a standalone study done? Yes. The performance data presented (method comparison, stability, imprecision) appears to be for the IMMAGE AT3 Reagent operating as a standalone system (algorithm only) without direct human-in-the-loop diagnostic interpretation that would alter its output. The system measures Antithrombin III concentrations, and its accuracy is assessed against a predicate device.
7. Type of Ground Truth Used
- Type of Ground Truth: The ground truth for the performance evaluation (method comparison) was established by the results obtained from a legally marketed predicate device: the Array 360 System AT3 Reagent. This is a form of "reference method" in the context of IVD devices for quantitative analytes.
8. Sample Size for the Training Set
The document does not explicitly mention a "training set" in the context of machine learning or AI algorithm development. This device, being an immunochemistry system, likely relies on established biochemical reaction principles and calibration curves rather than machine learning algorithms trained on large datasets. Therefore:
- Sample Size for Training Set: Not applicable or not specified, as the device doesn't appear to be based on an AI/ML model requiring a training set in the conventional sense. Its performance is validated through analytical studies (method comparison, stability, imprecision).
9. How the Ground Truth for the Training Set Was Established
As noted above, the concept of a "training set" with ground truth in the AI/ML context doesn't appear to apply directly to this device. The system's operation is based on rate nephelometry and calibrated using a specific calibrator (Beckman Calibrator 2). The establishment of the calibrator values would involve a separate, rigorous process, likely traceable to a reference standard, but this is distinct from establishing ground truth for an AI training set.
§ 864.7060 Antithrombin III assay.
(a)
Identification. An antithrombin III assay is a device that is used to determine the plasma level of antithrombin III (a substance which acts with the anticoagulant heparin to prevent coagulation). This determination is used to monitor the administration of heparin in the treatment of thrombosis. The determination may also be used in the diagnosis of thrombophilia (a congenital deficiency of antithrombin III).(b)
Classification. Class II (performance standards).