(92 days)
The IMx® Homocysteine assay is a Fluorescence Polarization Immunoassay (FPIA) for the quantitative measurement of total Lhomocysteine in human serum or plasma on the IMx Analyzer. The device can assist in the diagnosis and treatment of patients suspected of having hyperhomocysteinemia and homocystinuria.
IMx Homocysteine is a Fluorescence Polarization Immunoassay for the quantitative measurement of total L-homocysteine in human serum or plasma on the IMx Analyzer.
Here's a breakdown of the acceptance criteria and study information for the IMx Homocysteine assay based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" in a numerical or categorical format. Instead, it demonstrates interchangeability by comparing the IMx Homocysteine assay to a legally marketed predicate device (the University of Bergen Homocysteine HPLC method). The performance is reported in terms of correlation and agreement with this predicate device.
| Performance Metric | Acceptance Criteria (Implied by Predicate Equivalence) | Reported Device Performance (IMx Homocysteine vs. Bergen HPLC Method) |
|---|---|---|
| Correlation Coefficient | Strong correlation (e.g., >0.95) | 0.989 |
| Slope | Close to 1 (e.g., 0.95 - 1.05) | 0.980 |
| Y-intercept | Close to 0 | 0.12 umol/L |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 114 specimens
- Data Provenance: Not explicitly stated (e.g., country of origin). The study is retrospective in the sense that it uses existing specimens to compare a new method to an existing one. However, it doesn't specify if these were newly collected for the study or historical samples.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
This information is not provided in the document. The "ground truth" for this study is the measurement obtained from the predicate device (Bergen HPLC method), not an expert consensus on a clinical condition.
4. Adjudication Method for the Test Set
This information is not applicable/provided. Adjudication methods (like 2+1, 3+1) are typically used when human readers or clinicians are interpreting results, and there's a need to resolve discrepancies. In this case, the reference is a laboratory measurement from another assay.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This study is an analytical performance comparison between two diagnostic assays, not a study involving human readers' performance with and without AI assistance.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, a standalone performance evaluation was done. The IMx Homocysteine assay's performance was directly compared to the Bergen HPLC method without human intervention in the result generation or interpretation for the comparison itself. The assay provides a quantitative measurement.
7. The Type of Ground Truth Used
The ground truth for the comparison study was the measurements obtained from a legally marketed and established predicate device: the University of Bergen Homocysteine HPLC method. This method itself was shown to be equivalent to amino acid analysis for homocysteine detection.
8. The Sample Size for the Training Set
This information is not provided. The document describes a comparison study for substantial equivalence, not the development or training of the IMx Homocysteine assay. Immunoassays like this do not typically have "training sets" in the same way machine learning algorithms do; their calibration and performance are established through analytical validation.
9. How the Ground Truth for the Training Set Was Established
This information is not provided/not applicable for the reasons mentioned above. For an immunoassay, the "ground truth" for calibration would typically be established through highly purified standards of homocysteine with known concentrations.
§ 862.1377 Urinary homocystine (nonquantitative) test system.
(a)
Identification. A urinary homocystine (nonquantitative) test system is a device intended to identify homocystine (an analogue of the amino acid cystine) in urine. The identification of urinary homocystine is used in the diagnosis and treatment of homocystinuria (homosystine in urine), a heritable metabolic disorder which may cause mental retardation.(b)
Classification. Class II.