(101 days)
The LITH method is an in vitro diagnostic test for the quantitative measurement of lithium in human serum and plasma on the Dimension Vista® System. 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).
The Drug 4 CAL is an in vitro diagnostic product for the calibration of the LOCI Digoxin (DIGXN) and Lithium (LITH) methods on the Dimension Vista® System.
The LITH method employs a lithium-specific chromoionophore that forms a complex with the Li+ ion in an alkaline solution. The concentration of lithium in the sample is proportional to the increase in absorbance, which is due to the formation of the dye-lithium complex. The reaction is measured using a Bichromatic (510 and 700 mm) endpoint technique.
The Drug 4 Calibrator is a five (5) level, liquid calibrator. It is packaged as a kit of ten vials per level (A, B, C, D and E), 2.5 mL per vial. The product matrix is liquid human serum and contains digoxin and lithium. This product is sold separately from the Flex® reagent cartridge.
Here's a breakdown of the acceptance criteria and study information for the Dimension Vista® Lithium (LITH) Flex® Reagent Cartridge and Dimension Vista® Drug 4 Calibrator, based on the provided text:
Overview:
The submission focuses on demonstrating "substantial equivalence" to predicate devices. This means the new devices (Dimension Vista® Lithium Flex® Reagent Cartridge and Dimension Vista® Drug 4 Calibrator) perform similarly enough to existing, legally marketed devices (Dimension® Lithium Flex® Reagent Cartridge K011033 and Dimension® Drug Calibrator K011035) that they don't raise new questions of safety or effectiveness. The primary study type is comparative testing.
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a substantial equivalence submission, the "acceptance criteria" are implicitly met if the new device performs comparably to the predicate device, as demonstrated through comparative testing. The document states "Comparative testing described in the submission report demonstrates substantial equivalent performance."
Here’s a table summarizing the features compared, which serve as the basis for demonstrating substantial equivalence:
Dimension Vista® Lithium (LITH) Flex® Reagent Cartridge vs. Predicate (K011033)
| Feature | Acceptance Criteria (Predicate: Dimension® Lithium (LI) K011033) | Reported Device Performance (Dimension Vista® Lithium (LITH) K4150) |
|---|---|---|
| Intended Use | Quantitative measurement of lithium in human serum and plasma on Dimension® systems for drug dosage assurance in mental disturbances. | Quantitative measurement of lithium in human serum and plasma on the Dimension Vista® System for drug dosage assurance in mental disturbances. (Identical) |
| Sample Type | Serum and Sodium Heparin Plasma | Serum and Sodium Heparin Plasma |
| Measuring Range | 0.20 - 5.00 mmol/L | 0.20 - 3.00 mmol/L |
| Sample Size | 10 µL | 2 µL |
| Measurement | Bichromatic endpoint (540 and 700 nm) | Bichromatic endpoint (510 and 700 nm) |
Dimension Vista® Drug 4 Calibrator vs. Predicate (K011035)
| Feature | Acceptance Criteria (Predicate: Dimension® Drug Calibrator K011035) | Reported Device Performance (Dimension Vista® DRUG 4 CAL KC460A) |
|---|---|---|
| Intended Use | Calibration of DIG, LI, PHNO, PTN, and THEO methods on Dimension Vista® System. | Calibration of LOCI Digoxin (DIGXN) and Lithium (LITH) methods on the Dimension Vista® System. |
| Matrix | Human serum based | Human serum based |
| Preparation | Liquid: Provided ready to use. | Liquid: Provided ready to use. |
| Target Concentrations | Level 1: ≤ 0.20 mmol/L | |
| Level 2: 0.80 - 1.00 mmol/L | ||
| Level 3: 1.71 - 1.89 mmol/L | ||
| Level 4: 3.42 - 3.78 mmol/L | ||
| Level 5: 5.22 - 5.78 mmol/L | Level 1: ≤ 0.20 mmol/L | |
| Level 2: 0.77 - 1.15 mmol/L | ||
| Level 3: 1.67 - 2.00 mmol/L | ||
| Level 4: 3.35 - 3.85 mmol/L | ||
| Level 5: 5.12 - 5.89 mmol/L | ||
| Storage | Store at 2 to 8 °C. | Store at 2 - 8 °C. |
2. Sample Size Used for the Test Set and Data Provenance
The document states "Comparative testing described in the submission report demonstrates substantial equivalent performance." However, the exact sample sizes for the test set (e.g., number of patient samples, controls) are not specified within the provided text.
The data provenance is also not explicitly stated (e.g., country of origin, retrospective/prospective). As an in vitro diagnostic device, it's highly likely that samples would be human serum and plasma, but the source specifics are missing.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
This information is not applicable and not provided in the context of this device. This is a quantitative chemical assay, not an imaging device or diagnostic interpretation requiring expert human adjudication. The "ground truth" for calibrators and reagent cartridges like these is typically established through analytical methods, reference materials, and specified concentrations, not expert consensus.
4. Adjudication Method for the Test Set
Not applicable and not provided. As explained in point 3, this is a quantitative chemical assay, not a diagnostic interpretation that would involve adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. This type of study is typically for evaluating a diagnostic aid that assists human readers (e.g., AI in radiology). The devices in question are reagents and calibrators for a laboratory instrument, not tools for human interpretation.
6. If a Standalone Performance Study was Done
Yes, in essence, standalone performance was assessed as part of the "comparative testing" mentioned. For an in vitro diagnostic device, demonstrating performance against a predicate device (rather than a human reader) is the standard. The device's performance properties (e.g., precision, measuring range, analytical specificity) would be evaluated when operating on its own as designed, and then these results would be compared to the predicate. The document states "Comparative testing described in the submission report demonstrates substantial equivalent performance," indicating the new device's performance was measured.
7. The Type of Ground Truth Used
The ground truth for these types of devices is based on analytical validation and reference methods.
For the Lithium Flex® Reagent Cartridge: The "ground truth" for lithium concentration in samples would be established by reference methods or validated comparative methods, against which the device's quantitative measurements are compared to assess accuracy, precision, and linearity.
For the Drug 4 Calibrator: The "ground truth" for the calibrator's target concentrations (Levels 1-5) is established by precise formulation and measurement against recognized standards. The matrix itself (human serum) is a specified component.
8. The Sample Size for the Training Set
Not applicable and not provided. These are chemical reagents and calibrators for an IVD assay, not a machine learning or AI algorithm that requires a "training set" in the conventional sense. The development and optimization of such reagents involve experimental design, formulation studies, and analytical verification, rather than machine learning training.
9. How the Ground Truth for the Training Set was Established
Not applicable and not provided. As explained in point 8, there is no "training set" in the context of these 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.