(31 days)
The ADVIA® Chemistry Cystatin C 2 (CYSC 2) assay is for the in vitro diagnostic use in the quantitative determination of cystatin C in human serum and plasma (lithium heparin, potassium EDTA) on ADVIA Chemistry systems. Measurement of cystatin C aids in the diagnosis and treatment of renal disease.
The ADVIA Cystatin C_2 assay (CYSC_2) is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and plasma by means of particle-enhanced turbidimetry using the ADVIA Chemistry Systems. Used in conjunction with other clinical and laboratory findings, ADVIA Chemistry Cystatin C 2 measurements are used as an aid in the diagnosis and treatment of renal diseases.
The ADVIA Chemistry Cystatin C 2 latex reagent is a suspension of uniform latex particles coated with anti-cystatin-C antibody. When serum or plasma containing cystatin C is mixed with the latex reagent, agglutination takes place resulting in an increase in turbidity. This turbidity is measured at 571 and 805 nm. The cystatin C concentration in serum or plasma is determined from a calibration curve that is generated with the calibrators.
The provided text describes the 510(k) premarket notification for the ADVIA Chemistry Cystatin C 2 Assay (CYSC 2). This is an in vitro diagnostic (IVD) device, not an AI/ML software device. Therefore, many of the requested criteria related to AI/ML device performance (e.g., human-in-the-loop, training set, ground truth experts) are not applicable.
However, I can extract and present the relevant acceptance criteria and study information for this IVD device based on the provided text.
Here's the breakdown of the acceptance criteria and the study proving the device meets them, focusing on the appropriate metrics for an IVD assay:
Acceptance Criteria and Device Performance for ADVIA Chemistry Cystatin C 2 Assay (CYSC 2)
Note: This device is an In Vitro Diagnostic (IVD) assay designed to quantitatively measure Cystatin C in human serum and plasma. Its performance is evaluated through analytical studies, not typically through human-in-the-loop or AI-related metrics. Thus, many of the requested fields (e.g., number of experts, adjudication, MRMC study, standalone AI performance, training set details) are not applicable to this type of device.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Characteristic | Acceptance Criteria (Implicit from Study Design/Results) | Reported Device Performance (ADVIA CYSC_2) |
|---|---|---|
| Method Comparison (vs. Predicate) | High correlation (r ≥ 0.99 for good agreement), slope close to 1, intercept close to 0. | Passing-Bablok Regression: |
| Slope: 1.008 (95% CI: 0.998 to 1.022) | ||
| Intercept: 0.101 mg/L (95% CI: 0.086 to 0.113) | ||
| r-Value: 1.000 | ||
| Weighted Least Square Linear Regression: | ||
| Slope: 1.021 (95% CI: 1.006 to 1.037) | ||
| Intercept: 0.079 mg/L (95% CI: 0.063 to 0.96) | ||
| r-Value: 1.000 | ||
| Repeatability (Intra-assay precision) | Low Coefficient of Variation (%CV) and Standard Deviation (SD) for various concentration levels. | Repeatability (SD / %CV): |
| 0.52 mg/L: 0.01 / 2.0 | ||
| 0.85 mg/L: 0.01 / 1.1 | ||
| 3.91 mg/L: 0.04 / 1.1 | ||
| 1.09 mg/L: 0.01 / 0.9 | ||
| 8.92 mg/L: 0.12 / 1.4 | ||
| Within-Lab Precision (Inter-assay precision) | Low Coefficient of Variation (%CV) and Standard Deviation (SD) for various concentration levels. | Within-Lab Precision (SD / %CV): |
| 0.52 mg/L: 0.02 / 3.7 | ||
| 0.85 mg/L: 0.01 / 1.5 | ||
| 3.91 mg/L: 0.07 / 1.9 | ||
| 1.09 mg/L: 0.01 / 1.2 | ||
| 8.92 mg/L: 0.21 / 2.4 | ||
| Linearity | Deviation from linearity 2.50 mg/L and ≤ 0.25 mg/L for values ≤ 2.50 mg/L. | Samples above 2.5 mg/L deviated no more than 10%. Samples below or equal to 2.5 mg/L demonstrated a bias no greater than 0.03. (Linear fit deviation for entire range: 10%. |
| Bilirubin (conjugated/unconjugated) at 60 mg/dL | ||
| Lipemia (triglycerides) at 1000 mg/dL | ||
| Hemolysis (hemoglobin) at 1000 mg/dL | ||
| Rheumatoid Factor at 1200 IU/mL | ||
| Expected Values (Reference Interval) | Well-defined reference interval for healthy individuals. | 0.64 - 1.23 mg/L (2.5th to 97.5th percentile for healthy individuals) |
| Calibrator Traceability | Traceable to an international reference material. | Traceable to IFCC European Reference Material ERM-DA471/IFCC. |
2. Sample Size and Data Provenance for Test Set
- Sample Size for Method Comparison: 158 frozen human serum samples.
- Data Provenance: Not explicitly stated regarding country of origin or whether samples were prospective/retrospective. The samples were "frozen human serum samples." The predicate device (N Latex Cystatin C) is from Siemens as well, suggesting internal or collaboration data. The healthy samples for expected values were from a "normal range study, performed by Siemens."
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
Not Applicable.
For an IVD assay measuring a quantitative analyte like Cystatin C, the "ground truth" is established by direct measurement using a reference method or by comparing analytical performance to a legally marketed predicate device. This does not involve human expert interpretation of images or other subjective data.
4. Adjudication Method for the Test Set
Not Applicable.
As stated above, this is an IVD assay for quantitative measurement, not an AI/ML device relying on human interpretation and adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not Applicable.
This is an IVD assay, not an AI/ML diagnostic aid for human readers. Its performance is evaluated through analytical studies, not comparative effectiveness of human readers.
6. Standalone (i.e. algorithm only without human-in-the-loop performance) Performance
The listed performance characteristics are the standalone performance of the assay. The device itself (reagents, calibrators, and system) performs the measurement. There is no "human-in-the-loop" once the sample is loaded and the assay run on the instrument, other than for initial setup, quality control, and result interpretation by a clinician.
7. Type of Ground Truth Used
For the method comparison study, the "ground truth" or reference was the N Latex Cystatin C assay (K171072), the predicate device.
For other analytical performance characteristics (precision, linearity, detection capability, interference), the "ground truth" is inherent to the statistical and analytical methods used (e.g., gravimetric dilutions for linearity, certified reference materials for traceability, statistical analysis of replicates for precision/detection limits).
For expected values, the "ground truth" was established by measuring 208 apparently healthy samples (i.e., a healthy population study).
8. Sample Size for the Training Set
Not Applicable.
This is a laboratory diagnostic assay, not a machine learning algorithm that requires a "training set" in the computational sense. The "training" of the assay refers to its development and optimization through extensive laboratory testing and validation, not a data-driven training process.
9. How the Ground Truth for the Training Set was Established
Not Applicable.
There is no "training set" ground truth in the context of an IVD assay as understood for AI/ML devices. The "ground truth" for developing and validating the assay is primarily defined by established metrological principles, analytical chemistry standards, and comparison to recognized reference methods or predicate devices.
§ 862.1225 Creatinine test system.
(a)
Identification. A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.(b)
Classification. Class II.