(46 days)
for the quantitative determination of digitoxin in human serum or plasma (sodium heparin and potassium oxalate).
automated fluorescence polarization immunoassays (FPIA).
Given the provided text, the device is an in-vitro diagnostic (IVD) assay, specifically the Abbott AxSYM® Digitoxin assay, and the "acceptance criteria" and "study" refer to the validation performed for its substantial equivalence determination.
Here's a breakdown of the information requested, based only on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance (AxSYM Digitoxin vs. TDx/TDxFLx Digitoxin) |
|---|---|---|
| Slope | Close to 1.0 | 0.96 |
| Y-intercept | Close to 0.0 | 0.58 |
| Correlation Coefficient | Close to 1.0 | 0.97 |
| Std. Error of the Y estimate | Low | 1.87 |
Note: The acceptance criteria are "implied" because the text doesn't explicitly state numerical thresholds but rather presents the results as evidence of substantial equivalence, indicating these values were considered acceptable.
2. Sample size used for the test set and the data provenance
- Sample Size: 517 (This refers to the number of samples used in the "Correlation studies").
- Data Provenance: Not specified in the provided text (e.g., country of origin, retrospective or prospective).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This section is not applicable to this type of IVD study based on the provided text.
- The "ground truth" for an IVD correlation study like this isn't established by human experts interpreting images or clinical cases. Instead, it's typically established by a reference method (in this case, the predicate device, TDx/TDxFLx Digitoxin assay) or gravimetric purity for calibrators/controls.
4. Adjudication method for the test set
This section is not applicable to this type of IVD study based on the provided text.
- Adjudication methods (like 2+1 or 3+1) are common in studies involving human interpretation of data (e.g., imaging studies where multiple readers interpret a scan). For a quantitative IVD assay correlation, "adjudication" in this sense is not performed. The comparison is objective, based on numerical results from two different automated 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
This section is not applicable to this type of study.
- This is an IVD assay, not an AI-assisted diagnostic tool for human readers. Therefore, an MRMC study and AI assistance metrics are irrelevant.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Yes, a standalone performance was done.
- The "Abbott AxSYM® Digitoxin assay" is an automated fluorescence polarization immunoassay (FPIA) system. Its performance is measured independently of human interpretation of individual assay results, and it directly outputs quantitative digitoxin levels.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The "ground truth" for the correlation study reported (comparing AxSYM to TDx/TDxFLx) is the predicate device's measurements (TDx/TDxFLx Digitoxin assay).
- For the calibrators and controls used by the AxSYM Digitoxin assay, the ground truth is established by gravimetric preparation using purified material obtained from commercial sources.
8. The sample size for the training set
The text does not explicitly mention a separate "training set" for the AxSYM Digitoxin assay.
- For IVD assays, particularly those developed before the widespread use of machine learning, the "training" analogous to ML models involves optimizing reagents, calibration curves, and analytical parameters. This is typically done through iterative development and testing, not a distinct "training set" in the machine learning sense. The 517 samples mentioned are for the correlation study between the new and predicate devices.
9. How the ground truth for the training set was established
As there's no explicitly defined "training set" in the machine learning sense for this IVD, this question is not directly applicable.
- However, for the key components of the assay (calibrators and controls), the ground truth (their assigned values) is established through gravimetric preparation using purified material and subsequent verification using protocols involving multiple instrument testing.
§ 862.3300 Digitoxin test system.
(a)
Identification. A digitoxin test system is a device intended to measure digitoxin, a cardiovascular drug, in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of digitoxin overdose and in monitoring levels of digitoxin to ensure appropriate therapy.(b)
Classification. Class II.