(465 days)
In vitro test for the quantitative determination of lithium in human serum and plasma on Roche/Hitachi cobas c systems. Measurements of lithium are used as an aid in the management of patients taking lithium for the treatment of mental disturbances such as manic-depressive illness (bipolar disorder).
The cassette cobas c501 Lithium contains an in vitro diagnostic reagent system intended for use on Roche/Hitachi cobas c systems for the quantitative determination of lithium in human serum and plasma. The test principle is colorimetric.
The provided text describes a 510(k) submission for the cobas c501 Lithium test system. It outlines the device's intended use, its similarities and differences to a predicate device, and various performance characteristics. However, the document does not contain information typically associated with acceptance criteria or studies proving device performance for AI/ML-driven diagnostics, as none of the requested fields directly apply to this type of medical device.
The device described is an in vitro diagnostic reagent system for the quantitative determination of lithium in human serum and plasma, using a colorimetric test principle. This is a chemical assay, not an AI/ML-driven diagnostic device. Therefore, the concepts of "acceptance criteria" and "study that proves the device meets the acceptance criteria" in the context of AI/ML performance metrics (like sensitivity, specificity, AUC, and human reader improvement) are not applicable to this submission.
The document focuses on demonstrating substantial equivalence to a predicate device (COBAS INTEGRA ISE Direct) by comparing analytical performance characteristics relevant to chemical assays.
Given the nature of the device, I cannot provide the requested information. The document does not describe:
- A table of acceptance criteria and reported device performance in relation to AI/ML metrics. It provides analytical performance characteristics like precision, linearity, and interference.
- Sample size used for the test set and data provenance: While method comparison data is mentioned (e.g., Passing Bablok regression), the specific sample size and data provenance for demonstrating equivalence are not detailed in the provided text.
- Number of experts and qualifications for ground truth: Not applicable for a chemical assay.
- Adjudication method: Not applicable.
- Multi-reader multi-case (MRMC) comparative effectiveness study: Not applicable.
- Standalone (algorithm only) performance: Not applicable.
- Type of ground truth used (expert consensus, pathology, outcomes data): Not applicable in the AI/ML sense. The ground truth for a chemical assay would be reference methods (e.g., Atomic Absorption Spectroscopy as mentioned for traceability).
- Sample size for the training set: Not applicable as it's not an AI/ML model.
- How ground truth for the training set was established: Not applicable.
However, I can extract the analytical performance characteristics that are presented, which serve as evidence of the device's performance for this type of IVD.
Analytical Performance Characteristics of the cobas c501 Lithium (Modified Device)
While the typical "acceptance criteria" for AI/ML are not present, the following analytical performance characteristics are reported for the cobas c501 Lithium system, indicating its performance compared to the predicate and overall suitability:
| Performance Characteristic | Acceptance Criteria (Implicit via predicate comparison or industry standards for IVDs) | Reported Device Performance (cobas c501 Lithium) |
|---|---|---|
| Precision | Demonstrated precision comparable to or better than predicate. | Within run CV: |
| 1.7% @ 0.77 mmol/L | ||
| 1.0% @ 2.38 mmol/L | ||
| 1.9% @ 0.46 mmol/L | ||
| 1.2% @ 1.40 mmol/L | ||
| Total: | ||
| 2.2% @ 0.79 mmol/L | ||
| 1.3% @ 2.42 mmol/L | ||
| 2.3% @ 0.61 mmol/L | ||
| 1.6% @ 1.62 mmol/L | ||
| Endogenous Interferences | No significant interference at specified levels for common interferents. | Hemolysis: No significant interference up to H index of 1000 |
| Icterus: I index of 37 for conjugated and 43 for unconjugated bilirubin | ||
| Lipemia: L index of 2000 | ||
| Exogenous Interferences | No significant interference from common exogenous substances. | NH4Cl: 19.8 umol/L |
| NaCl : 140 mmol/L | ||
| KCl : 4 mmol/ L | ||
| CaCl2: 2.4 mmol/L | ||
| MgCl2: 0.9 mmol/L | ||
| FeCl3: 1.04 mg/L | ||
| Cu (NO3)2: 1.15 mmol/L | ||
| ZnCl2: 1.07 mmol | ||
| (none of these are in the physiological key interference range) | ||
| In very rare cases gammopathy | ||
| Limit of Detection (LOD) | Clinically meaningful detection limit. | 0.05 mmol/L |
| Limit of Blank (LOB) | Defined blank. | 0.03 mmol/L |
| Measuring Range | Clinically relevant measurable range. | 0.05-3.00 mmol/L |
| Extended measuring range: 0.05-6.00 mmol/L |
Study Information (as it pertains to this IVD):
The document mentions "Performance evaluation" was done for several characteristics, but does not provide details on specific study designs, sample sizes, or data provenance beyond what is implicit in standard IVD validation.
- Sample size for test set and data provenance: Not explicitly stated for specific performance studies. The method comparison data includes parameters like Passing Bablok regression (y = 1.037x + 0.004, $\tau$ = 0.940) and Linear regression (y = 1.044x -0.000, r = 0.995) which imply a comparison study with an unspecified number of samples. The data provenance (e.g., country of origin, retrospective/prospective) is not provided.
- Number of experts and qualifications for ground truth: Not applicable for a chemical assay. The ground truth for this device would be established by reference methods.
- Adjudication method: Not applicable.
- Multi-reader multi-case (MRMC) comparative effectiveness study: Not applicable.
- Standalone performance: The performance characteristics listed (precision, interference, limits) represent the standalone analytical performance of the device. This is the equivalent of "algorithm only" performance for a chemical assay.
- Type of ground truth: For analytical performance testing, the ground truth would be established by validated reference methods or materials (e.g., Atomic Absorption Spectroscopy for traceability, or gravimetrically prepared reference materials for calibrators).
- Sample size for the training set: Not applicable, as this is not an AI/ML device.
- How the ground truth for the training set was established: Not applicable.
§ 862.3560 Lithium test system.
(a)
Identification. A lithium test system is a device intended to measure lithium (from the drug lithium carbonate) in serum or plasma. Measurements of lithium are used to assure that the proper drug dosage is administered in the treatment of patients with mental disturbances, such as manic-depressive illness (bipolar disorder).(b)
Classification. Class II.