(36 days)
IMx Free T3 is a microparticle enzyme immunoassay for the quantitative determination of free T3 in human serum or plasma (lithium heparin, sodium heparin, or dipotassium EDTA).
IMx Free T3 is a microparticle enzyme immunoassay for the quantitative determination of free T3 in human serum or plasma (lithium heparin, sodium heparin, or dipotassium EDTA). IMx Free T3 is calibrated with Abbott calibrators. Abbott controls are assayed for the verification of the accuracy and precision of the Abbott IMx Analyzer.
Here's an analysis of the provided text regarding the Abbott IMx Free T3 device, structured to address your specific questions.
It's important to note that the provided 510(k) summary is for a laboratory diagnostic test (immunoassay), not a medical imaging or AI-driven diagnostic device. Therefore, some of your questions, particularly those related to imaging, AI performance, ground truth establishment by experts, and MRMC studies, are not directly applicable or will have "N/A" answers. The evaluation criteria for an immunoassay focus on analytical performance rather than diagnostic accuracy against a "gold standard" pathology or expert consensus in the same way an imaging device would.
Acceptance Criteria and Device Performance Study (K963833 - Abbott IMx Free T3)
This K963833 document describes a 510(k) submission for the Abbott IMx Free T3 immunoassay. The primary method for demonstrating acceptance and substantial equivalence is through correlation with a legally marketed predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria / Performance Metric (Implicit) | Reported Device Performance (IMx Free T3 vs. ACS Free T3) |
|---|---|
| Correlation Coefficient (r) | 0.942 |
| Slope | 1.14 |
| Standard Error of Estimate (SEE) | 0.783 |
| Y-axis Intercept | -0.47 pg/mL |
| Dynamic Range | 1.1 - 30.0 pg/mL (IMx Free T3) |
| Dynamic Range (Predicate Device) | 0.5 - 20.0 pg/mL (ACS Free T3) |
| Intended Use Equivalence | Quantitative determination of free T3 |
| Sample Matrix Equivalence | Human serum or plasma (lithium heparin, sodium heparin, or dipotassium EDTA) for IMx Free T3 vs. Human serum only for ACS Free T3 (Note: This indicates a broader applicability for the new device, not a failure to meet criteria) |
Implicit Acceptance Criteria: The reported correlation metrics (r, slope, SEE, intercept) demonstrate a strong linear relationship between the new device and the predicate device, indicating comparable analytical performance. While specific numeric acceptance thresholds are not explicitly stated in this high-level summary, regulatory bodies typically have internal guidelines or accept industry-standard benchmarks for such correlation studies to demonstrate substantial equivalence. The dynamic range also demonstrates suitable analytical capability.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 767 specimens were used for the correlation analysis.
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. Given the nature of immunoassay development and clinical validation, it is highly probable these were prospective or retrospectively collected clinical samples from a medical facility or laboratory, representing a range of Free T3 concentrations.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- N/A. For this type of immunoassay, the "ground truth" is established by the measurement result from the predicate device (ACS Free T3 Immunoassay). There is no expert panel used to establish a diagnostic ground truth in the way it would be for an imaging study. The predicate device itself serves as the reference for comparison.
4. Adjudication Method for the Test Set
- N/A. No adjudication method is applicable. The comparison is a direct quantitative measurement between two laboratory assays.
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. This is not an AI-driven device, nor does it involve human "readers" interpreting results in the way an imaging study would. It is an automated laboratory immunoassay.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
- N/A (in the context of AI). However, the performance described (correlation analysis) is the "standalone" performance of the IMx Free T3 assay in comparison to the predicate, as it's an automated device. There isn't a "human-in-the-loop" component to the assay's fundamental measurement.
7. The Type of Ground Truth Used
- The "ground truth" for the comparison study was the results obtained from the predicate device, the Ciba Corning Automated Chemiluminescence System (ACS) Free T3 Immunoassay.
8. The Sample Size for the Training Set
- N/A. Immunoassays are not "trained" in the same way machine learning models are. The device is developed through chemical and engineering principles and then validated. There isn't a distinct "training set" of samples in this context. Calibration materials are used to set up the assay, but this is different from a machine learning training set.
9. How the Ground Truth for the Training Set Was Established
- N/A. As mentioned above, there isn't a machine learning "training set" for this type of device. The accuracy of the assay is ensured through the use of Abbott calibrators (for instrument calibration) and Abbott controls (for ongoing verification of accuracy and precision), which are themselves established against highly characterized reference materials or methods.
§ 862.1710 Total triiodothyronine test system.
(a)
Identification. A total triiodothyronine test system is a device intended to measure the hormone triiodothyronine in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases such as hyperthyroidism.(b)
Classification. Class II. This device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.