(30 days)
In vitro test for the quantitative determination of total bilirubin in human serum and plasma on the cobas c 111 system.
Measurements of the levels of bilirubin and organic compound formed during normal and abnormal destruction of red cells, is used in the diagnosis of liver, hemolytic hematological and metabolic disorders, including hepatitis and gall bladder block.
The Total Bilirubin Special reagent is intended for use on the cobas c 111 analyzer for the quantitative determination of total or direct bilirubin in serum and plasma.
The cobas c 111 analyzer is a partially automated, in-vitro diagnostic analyzer capable of performing clinical chemistry, specific protein and electrolyte tests. Analytes are measured photometrically or turbidimetrically; the analyzer also has an optional ISE module for measuring sodium, potassium and chloride.
The cobas c 111 instrument is a random access analyzer designed to be operated on a bench top in the professional environment using a combination of a photometric analysis unit and an optional ion selective electrodes (ISE).
Here's a breakdown of the acceptance criteria and study information for the Total Bilirubin Special reagent application to the cobas c 111 analyzer, based on the provided text:
Context: This submission is a Special 510(k) for a modification to an existing device. The modification involves applying the already cleared Total Bilirubin Special reagent to a new analyzer, the cobas c 111, which is itself a modification of the COBAS INTEGRA 400 plus. Therefore, the primary focus of the performance data is to demonstrate equivalence of the reagent's performance on the new analyzer compared to its performance on the predicate analyzer.
Acceptance Criteria and Reported Device Performance
The acceptance criteria are implicitly defined by demonstrating equivalence to the predicate device. The performance characteristics of the modified device (on cobas c 111) are compared to the predicate device (on COBAS INTEGRA Total Bilirubin Special, K063543).
| Acceptance Criteria (Implicit: Equivalence to Predicate) | Reported Device Performance (Modified Device: Total Bilirubin Special on cobas c 111) | Predicate Device Performance (COBAS INTEGRA Total Bilirubin Special) |
|---|---|---|
| Precision (Within-run) | 1.79% @ 21.7 µmol/L | 2.44% @ 15.80 µmol/L |
| 0.64% @ 64.2 µmol/L | 1.39% @ 54.00 µmol/L | |
| 2.94% @ 15.2 µmol/L | (Not explicitly within-run for this level) | |
| 0.77% @ 60.0 µmol/L | (Not explicitly within-run for this level) | |
| Precision (Total) | 2.32% @ 21.6 µmol/L | (Not explicitly "Total") |
| 0.71% @ 67.4 µmol/L | (Not explicitly "Total") | |
| 3.10% @ 16.2 µmol/L | (Not explicitly "Total") | |
| 0.79% @ 83.0 µmol/L | (Not explicitly "Total") | |
| Precision (Between day) | (Not explicitly stated for modified device) | 4.13% @ 14.7 µmol/L |
| (Not explicitly stated for modified device) | 2.15% @ 47.20 µmol/L | |
| Measuring Range | 0.1-25.2 mg/dL | 0-25 mg/dL |
| Measuring Range (with postdilution) | 0.1-101 mg/dL | 0-250 mg/dL |
| Lower Detection Limit | 0.1 mg/dL | 0.063 mg/dL |
| Endogenous interferences | Same (as predicate) | Hemolysis: No significant interference up to 1000 mg/dL, Lipemia: No significant interference up to 1400 mg/dL as Intralipid |
| Exogenous interferences | Same (as predicate) | Ascorbic acid at 30 mg/dL causes artificially decreased total bilirubin values |
Note on Acceptance Criteria: For a Special 510(k) like this, the implicit acceptance criterion is that the performance of the modified device is substantially equivalent to the predicate device, meaning it performs as well or better for the critical parameters. The table demonstrates this comparable performance.
Study Information
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Sample sizes used for the test set and the data provenance:
- Test Set Sample Size: The document does not explicitly state the sample size used for the performance evaluation (precision, measuring range, detection limit, interference studies).
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). This is a manufacturer's internal validation, likely conducted in a controlled lab environment.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This being an in-vitro diagnostic (IVD) chemistry analyzer, the "ground truth" for the test set is established by the reference method for total bilirubin (Doumas reference method, as mentioned in the traceability section) and highly controlled laboratory samples (e.g., control materials, spiked samples). There's no mention of human experts interpreting results in the way a radiologist interprets an image.
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Adjudication method for the test set:
- Not applicable in the context of an IVD chemistry analyzer. Results are quantitative outputs from the instrument.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
- No. This is a quantitative in-vitro diagnostic device, not an imaging device that requires human interpretation.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, this is an algorithm-only (analyzer-only) performance study. The analyzer performs the test and provides a quantitative result. There is no human interpretation component in the direct measurement of bilirubin by this device.
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The type of ground truth used:
- Reference Method: The device is standardized against the Doumas reference method for total bilirubin. This is the primary established ground truth for bilirubin measurement.
- Control Materials: Performance is likely evaluated using assayed control materials (e.g., Precinorm U, Precipath U mentioned as quality controls) with known concentration values.
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The sample size for the training set:
- Not applicable as this is not a machine learning/AI algorithm that requires a "training set" in the conventional sense. This is an analytical chemistry device where the "training" would be the initial development and calibration of the reagent and instrument platform.
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How the ground truth for the training set was established:
- Not applicable. The "ground truth" for the development of such an IVD device is based on established clinical chemistry principles and standardization against internationally recognized reference methods (like Doumas). Calibrators are used to establish the measurement curve, and these calibrators are themselves traceable to a reference method.
§ 862.1110 Bilirubin (total or direct) test system.
(a)
Identification. A bilirubin (total or direct) test system is a device intended to measure the levels of bilirubin (total or direct) in plasma or serum. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal distruction of red blood cells, if used in the diagnosis and treatment of liver, hemolytic hematological, and metabolic disorders, including hepatitis and gall bladder block.(b)
Classification. Class II.