(118 days)
A lithium test system is a device intended to measure lithium levels in serum or plasma. Measurements of lithium are used to aid in the management of individuals taking lithium for the treatment of mental disturbances, such as manic-depressive illness (bipolar disorder). For use on Architect and Aeroset analyzers.
The Multigent Lithium test is a spectrophotometric method, which can be readily adapted to automated clinical chemistry analyzers. Lithium present in the sample reacts with a substituted porphyrin compound at an alkaline pH, resulting in a change of absorbance, which is directly proportional to the concentration of lithium in the sample.
Here's a breakdown of the acceptance criteria and study information for the Multigent Lithium device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Metric (Predicate Device: Infinity Lithium Liquid Stable Reagent assay on Hitachi 911 Analyzer) | Achieved Performance (Multigent Lithium) |
|---|---|---|
| Correlation | Correlation coefficient: Not explicitly stated for acceptance, but implied to be high for equivalence. | AEROSET System: 0.999 |
| ARCHITECT c8000 System: 0.999 | ||
| Slope | Slope: Not explicitly stated for acceptance, but implied to be near 1 for equivalence. | AEROSET System: 1.013 |
| ARCHITECT c8000 System: 0.991 | ||
| Y-intercept | Y-intercept: Not explicitly stated for acceptance, but implied to be near 0 for equivalence. | AEROSET System: -0.025 mmol/L |
| ARCHITECT c8000 System: -0.004 mmol/L | ||
| Precision (%CV) | %CV: Not explicitly stated for acceptance, but implied to be functionally acceptable for clinical use. | AEROSET System: Level 1: 4.76%, Level 2: 3.67%, Level 3: 2.96% |
| ARCHITECT c8000 System: Level 1: 2.53%, Level 2: 1.88%, Level 3: 2.02% | ||
| Linearity (Upper Limit) | Linearity: Not explicitly stated for acceptance, but implied to cover the clinical range. | Up to 3.51 mmol/L |
| Limit of Quantitation (Sensitivity) | Sensitivity: Not explicitly stated for acceptance, but implied to be clinically relevant. | 0.10 mmol/L |
Note: The acceptance criteria are implicitly defined by the claim of "similar Performance Characteristics" and "substantially equivalent" to the predicate device. Specific numerical thresholds for acceptance are not provided in this summary.
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size used for the comparative performance studies. It mentions "comparative performance studies were conducted," but details on the number of samples are absent.
- Data Provenance: Not specified. It's unclear if the data was collected retrospectively or prospectively, or the country of origin.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. This device is a diagnostic reagent for measuring lithium levels, which are typically determined by laboratory analysis and not by expert human interpretation of images or other subjective data. The "ground truth" in this context would be the actual concentration of lithium in the samples, as determined by the predicate device (Infinity Lithium Liquid Stable Reagent assay on the Hitachi 911 Analyzer) or a reference method.
4. Adjudication Method for the Test Set
Not applicable. As noted above, this study involves objective chemical measurements, not subjective interpretation requiring adjudication.
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 typically performed for devices that involve human interpretation of diagnostic images (e.g., radiology AI), not for objective chemical assays like this lithium test.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, this study is inherently a standalone performance evaluation of the Multigent Lithium assay. It compares the analytical performance of the new assay directly against a predicate device, without involving human interpretation as an outcome. The device itself performs the measurement.
7. The Type of Ground Truth Used
The ground truth for the device's performance comparison was the results obtained from the predicate device, the Infinity Lithium Liquid Stable Reagent assay on the Hitachi 911 Analyzer.
8. The Sample Size for the Training Set
Not applicable. For a diagnostic reagent intended for chemical measurement, there isn't typically a "training set" in the machine learning sense. The assay is developed based on chemical principles and extensively tested for analytical performance.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there isn't a traditional "training set" with ground truth in this context. The development process would involve optimizing the reagent's formulation and reaction conditions to accurately measure lithium, with performance validated against reference methods and established predicate devices.
§ 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.