(57 days)
The Urea Nitrogen assay is used for the quantitation of urea nitrogen in human serum, plasma, or urine. Measurements obtained by this device are used in diagnosis and treatment of certain renal and metabolic diseases.
Urea Nitrogen is an in vitro diagnostic assay for the quantitative determination of urea nitrogen in human serum, plasma, or urine. The Urea Nitrogen assay is a clinical chemistry assay in which the urea in the sample is hydrolyzed by urease to ammonia (NH3) and carbon dioxide (CO2). A second reaction, catalyzed by glutamate dehydrogenase (GLDH), converts ammonia and a-ketoglutarate to glutamate and water with the concurrent oxidation of reduced nicotinamide adenine dinucleotide (NADH) to nicotinamide adenine dinucleotide (NAD). Two moles of NADH are oxidized for each mole of urea present. The initial rate of decrease in absorbance at 340/380 nm is proportional to the urea concentration in the sample.
Here's a breakdown of the acceptance criteria and study information based on the provided 510(k) summary for the Urea Nitrogen assay:
1. Table of Acceptance Criteria and Reported Device Performance
The 510(k) summary for the Urea Nitrogen assay focuses on demonstrating "substantial equivalence" to a predicate device rather than defining specific, prescriptive acceptance criteria. Substantial equivalence implies that the performance of the new device is comparable to the predicate such that it can be marketed for the same intended use without raising new questions of safety or effectiveness.
Therefore, the "acceptance criteria" are implied by the performance of the predicate device and the new device's ability to demonstrate similar performance characteristics.
| Performance Characteristic | Acceptance Criteria (Implied by Predicate) | Reported Device Performance (Urea Nitrogen Assay) |
|---|---|---|
| Method Comparison | Acceptable correlation with predicate | Serum: Correlation coefficient = 0.9974, slope = 1.038, Y-intercept = 0.904 mg/dL |
| Urine: Correlation coefficient = 0.9919, slope = 0.983, Y-intercept = 9.993 mg/dL | ||
| Precision | Acceptable precision (comparable to predicate) | Serum: Total %CV = 1.8% (Level 1), 2.0% (Level 2) |
| Urine: Total %CV = 3.8% (Level 1), 3.1% (Level 2) | ||
| Linearity/Assay Range | Acceptable linearity (comparable to predicate) | Serum: up to 234.4 mg/dL |
| Urine: up to 1,991.1 mg/dL | ||
| Limit of Quantitation (Sensitivity) | Acceptable sensitivity (comparable to predicate) | 0.9 mg/dL |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not explicitly stated in the provided text for the method comparison or precision studies.
- Data Provenance: Not specified. It's common for such studies to use human serum, plasma, or urine samples, but the country of origin or whether they were retrospective or prospective is not mentioned.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts
This type of information is generally not applicable to in vitro diagnostic (IVD) assays that measure specific chemical analytes like urea nitrogen. The "ground truth" for these tests isn't established by expert consensus or interpretation of images, but rather by quantitative chemical methods. The comparison is made to a legally marketed predicate device, whose own performance characteristics (including accuracy against reference methods) would have been established previously.
4. Adjudication Method for the Test Set
Not applicable. As described above, this is a quantitative chemical assay, not one that involves human adjudication of diagnostic interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is relevant for imaging devices or AI-assisted diagnostic tools where human interpretation is a critical component, and the goal is to evaluate the impact of technology on reader performance. For a quantitative in vitro diagnostic assay, an MRMC study is not appropriate.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, the performance characteristics described (method comparison, precision, linearity, sensitivity) are for the "algorithm only" or the device in standalone mode, as it's an automated in vitro diagnostic assay. There is no human-in-the-loop component in the direct measurement process of this device.
7. The Type of Ground Truth Used
The "ground truth" for this comparative study is the results obtained from the legally marketed predicate device, the Boehringer Mannheim® Urea Nitrogen assay on the Hitachi® 717 Analyzer. The new Urea Nitrogen assay's performance is compared directly against the results generated by this established predicate device.
8. The Sample Size for the Training Set
Not applicable. This is a traditional in vitro diagnostic assay, not a machine learning or AI-based device that requires a "training set" in the conventional sense. The "training" of the assay refers to its development and optimization by the manufacturer, but not through a data-driven machine learning process.
9. How the Ground Truth for the Training Set was Established
Not applicable, as there is no "training set" in the context of machine learning for this device. The accuracy and performance of the assay would be established internally by the manufacturer during product development using various analytical methods and potentially reference materials, but these are distinct from "ground truth" for a machine learning training set.
§ 862.1770 Urea nitrogen test system.
(a)
Identification. A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of certain renal and metabolic diseases.(b)
Classification. Class II.