Search Results
Found 1 results
510(k) Data Aggregation
(52 days)
JIF
The Ammonia II assay is an enzymatic in vitro test for the quantitative determination of ammonia in human plasma on Roche/Hitachi cobas c systems.
Ammonia measurements are used in the diagnosis and treatment of severe liver disorders, such as cirrhosis, hepatitis, and Reye's syndrome.
The Ammonia II (NH3L2) assay is an enzymatic in vitro test for the quantitative determination of ammonia in human plasma on Roche/Hitachi cobas c systems. The Ammonia II assay is an enzymatic method, with glutamate dehydrogenase.
This document describes the Ammonia II assay for the quantitative determination of ammonia in human plasma. Here's a breakdown of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are generally qualitative ("All data passed the predetermined acceptance criteria") rather than specific numerical thresholds presented in a consolidated table. However, the reported performance data for each test indicates the values achieved. Based on the provided text, a summary of performance can be extracted:
Ammonia II Assay Performance Summary
| Performance Characteristic | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Precision (Intermediate) | All data passed predetermined acceptance criteria. | AMM-N (67.9 µmol/L): SD 1.61 µmol/L, CV 2.4% |
| AMM-P (243 µmol/L): SD 4.26 µmol/L, CV 1.8% | ||
| Plasma 1 (26.0 µmol/L): SD 1.29 µmol/L, CV 4.9% | ||
| Plasma 2 (57.7 µmol/L): SD 1.72 µmol/L, CV 3.0% | ||
| Plasma 3 (110 µmol/L): SD 1.92 µmol/L, CV 1.7% | ||
| Plasma 4 (480 µmol/L): SD 6.30 µmol/L, CV 1.3% | ||
| Plasma 5 (853 µmol/L): SD 12.4 µmol/L, CV 1.5% | ||
| Limit of Blank (LoB) | ≤ 10 µmol/L | 1.80 µmol/L |
| Limit of Detection (LoD) | ≤ 10 µmol/L | 3.46 µmol/L |
| Limit of Quantitation (LoQ) | ≤ 10 µmol/L | 9.36 µmol/L |
| Linearity | Correlation coefficient (r²) approaching 1.000 for linear fit. | Lot 1: y = 1.003x - 2.19, r² = 0.9999 |
| Lot 2: y = 1.002x - 1.30, r² = 1 | ||
| Lot 3: y = 1.002x - 1.56, r² = 0.9999 | ||
| Endogenous Interference | No significant interference (implicitly, within specified levels). | Hemolysis (114-146 mg/dL): Passed at 36.1-91.8 µmol/L Ammonia |
| Unconjugated Bilirubin (68-69 mg/dL): Passed at 46.4-113 µmol/L Ammonia | ||
| Conjugated Bilirubin (64 mg/dL): Passed at 40.2-89.1 µmol/L Ammonia | ||
| Lipemia (764-771 mg/dL): Passed at 51.5-92.7 µmol/L Ammonia | ||
| Albumin (77.2-77.5 g/L): Passed at 47.2-108 µmol/L Ammonia | ||
| Immunoglobulin (IgG) (71.4-71.7 g/L): Passed at 41.5-83.9 µmol/L Ammonia | ||
| Exogenous Interference (Drugs) | No interference at therapeutic concentrations (except noted). | No interference found for common drug panels with the exceptions of Cefoxitin, Sulfasalazin, and Temozolomid. |
| Matrix Comparison | Correlation (Pearson (r)) approaching 1.000, slope near 1.0, intercept near 0.0. | Lot 1: y = 1.002x – 1.18, r = 1.000 |
| Lot 2: y = 0.987x – 0.77, r = 1.000 | ||
| Lot 3: y = 1.005x – 1.39, r = 1.000 | ||
| Method Comparison (Predicate) | Correlation (r) approaching 1.000, slope near 1.0, intercept near 0.0. | y = 1.001x – 1.90 µmol/L, r = 1.000 |
2. Sample sizes used for the test set and the data provenance
- Precision: Not explicitly stated as a "test set" in the context of diagnostic accuracy but involves replicate measurements of various controls and human plasma samples over 21 days.
- LoB, LoD, LoQ:
- LoB: One analyte-free sample measured with three lots in 10-fold determination in 6 runs (60 measurements per lot).
- LoD: Five samples with low-analyte concentration measured with three lots in two-fold determination in 6 runs (60 measurements per lot).
- LoQ: A low-level sample set (7 human plasma samples) tested in 5 replicates per sample on 5 days.
- Linearity: Not explicitly stated, typically involves a range of spiked samples.
- Endogenous Interferences: Pooled human plasma samples spiked with varying levels of interferent (10 dilution steps per sample), tested in triplicate.
- Exogenous Interferences (Drugs): Two sample pools (low and high NH3L2), each divided into aliquots. Reference aliquot (not spiked) tested n=3. Spiked aliquots tested in triplicate.
- Matrix Comparison: 52-53 tubes of K2 EDTA plasma and 52-53 tubes of K3 EDTA plasma for each of 3 reagent lots (total of ~156-159 tubes per anticoagulant type).
- Method Comparison to Predicate: 112 human plasma samples.
Data Provenance: The document generally refers to "human plasma" samples, suggesting human subjects. The country of origin is not specified but given the submitter is Roche Diagnostics (with registration numbers for Mannheim, Germany, Penzberg, Germany, and the United States), the data could be from multiple regions. The studies are prospective performance evaluations of the device conducted according to CLSI guidelines.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. This device is an in vitro diagnostic (IVD) assay for quantitative measurement. The "ground truth" for the performance characteristics (precision, limits, linearity, interference) is established by analytical methods and reference materials, not by expert interpretation of images or clinical cases.
4. Adjudication method for the test set
Not applicable. This is an IVD assay, and the studies are analytical performance evaluations, not clinical studies involving expert adjudication of diagnostics results or images.
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
Not applicable. This is an IVD assay for quantitative ammonia measurement, not an AI-powered diagnostic imaging device or a decision support system for human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, directly. The studies described (Precision, LoB/LoD/LoQ, Linearity, Interference, Matrix Comparison, Method Comparison) evaluate the analytical performance of the Ammonia II assay itself, without a human-in-the-loop component for result generation. The device (Ammonia II assay on Roche/Hitachi cobas c systems) performs the quantitative determination of ammonia.
7. The type of ground truth used
The ground truth used for these analytical studies is based on:
- Reference materials and spiked samples: For linearity, LoB/LoD/LoQ, and interference studies, known concentrations of analyte or interferents are used to challenge the assay.
- Statistical methods: For precision, calculations of SD and CV reflect the inherent variability.
- Comparative methods: For method comparison, the results are compared against a legally marketed predicate device (Beckman Coulter Ammonia assay) using statistical regression.
- Clinical Laboratory Standards Institute (CLSI) guidelines: These guidelines (EP05-A3, EP17-A2, EP06-A) provide standardized methodologies for establishing analytical performance, which inherently define how "ground truth" is approached for these types of assays.
8. The sample size for the training set
Not applicable. This is not a machine learning or AI device that requires a distinct "training set." The performance studies are analytical evaluations of a chemical assay.
9. How the ground truth for the training set was established
Not applicable, as there is no "training set" in the context of this device.
Ask a specific question about this device
Page 1 of 1