(21 days)
The TNI method is an in vitro diagnostic test for the quantitative measurement of cardiac troponin I in human serum and plasma on the Dimension® EXL™ integrated chemistry system with LOCI® module. Measurements of cardiac troponin I are used as an aid in the diagnosis of acute myocardial infarction (AMI) and in the risk stratification of patients with acute coronary syndromes with respect to their relative risk of mortality.
The CTNI Sample Diluent is an in vitro diagnostic product for manual dilution of samples with elevated cardiac troponin I results processed on the Dimension Vista® and Dimension® EXL™ integrated chemistry system with LOCI® module.
The Dimension® TNI Flex® reagent cartridge is an in vitro diagnostic device that consists of prepackaged reagents in a plastic eight-well cartridge for use on the Dimension® EXL™ with LM system.
The TNI method is a homogeneous, sandwich chemiluminescent immunoassay based on LOCI® technology. The LOCI® reagents include two synthetic bead reagents and a biotinylated anti-cardiac troponin I monoclonal antibody fragment. The first bead reagent (Sensibeads) is coated with streptavidin and contains photosensitizer dye. The second bead reagent (Chemibeads) is coated with a second anti-cardiac troponin I monoclonal antibody and contains chemiluminescent dye. Sample is incubated with Chemibeads and biotinylated antibody to form bead-cardiac troponin I-biotinylated antibody sandwiches.
Sensibeads are addcd and bind to the biotin to form bead-pair immunocomplexes. Illumination of the complex at 680 nm generates singlet oxygen from Scnsibeads which diffuses into the Chemibeads, triggering a chemiluminescent reaction. The resulting signal is measured at 612 nm and is a direct function of the cardiac troponin I concentration in the sample.
The CTNI Sample Diluent is a liquid, human serum based product with prescrvatives.
Here's an analysis of the provided text, focusing on acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Criteria Category | Acceptance Criteria (Implicit) | Reported Device Performance | Comments |
|---|---|---|---|
| Substantial Equivalence to Predicate Device | Demonstrated through method comparison. Parameters like slope, y-intercept, and correlation coefficient should indicate high agreement. | Method Comparison Statistics: |
- Slope: 1.0325
- Y-intercept: -0.0284 ng/mL
- Correlation Coefficient (r): 0.998
- Sample Size (n): 229 | The reported performance (r = 0.998) shows a very strong linear relationship and excellent agreement between the new device and the predicate device. The slope being close to 1 and the y-intercept close to 0 also confirm this. While explicit acceptance criteria values (e.g., "slope between 0.95 and 1.05") are not stated, the results are overwhelmingly indicative of meeting an implicit acceptance of strong agreement. |
| Intended Use | The device performs its intended function: quantitative measurement of cardiac troponin I in human serum and plasma for diagnosis of AMI and risk stratification. | Stated Intended Use is identical to the predicate device. | No specific performance metrics are provided here, but the claim of substantial equivalence implies the new device also serves this intended use effectively. |
| Sample Type | Accepts human serum and plasma. | The device accepts human serum and plasma, identical to the predicate. | No specific performance metrics here, but adherence to sample type is confirmed. |
| Assay Range | Must have an appropriate and comparable assay range to the predicate. | New device assay range: 0.017-40 ng/mL.
Predicate device assay range: 0.015-40 ng/mL. | The assay ranges are very similar, indicating comparable analytical capability at both the low and high ends. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: 229 human serum and plasma samples.
- Data Provenance: Not explicitly stated regarding country of origin. The study involves "human serum and plasma samples," implying clinical samples. It is a "split sample method comparison study," which means a single set of samples was tested on both the new device and the predicate device. This is a retrospective approach as it uses existing biological samples to compare device performance.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
- Not applicable / Not provided. For this type of study (method comparison for an in vitro diagnostic device measuring a biomarker), "ground truth" isn't typically established by human experts in the same way it would be for image interpretation. Instead, the predicate device's measurement of cardiac troponin I serves as the reference or comparator. The "ground truth" implicitly relies on the established accuracy and reliability of the predicate device itself, which would have undergone its own validation studies.
4. Adjudication Method for the Test Set
- Not applicable / Not provided. Since the study is a direct method comparison between two quantitative assays, there's no "adjudication" in the sense of reconciling divergent expert opinions or labeling. The comparison relies on statistical analysis of quantitative measurements.
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 used for diagnostic imaging devices where human readers interpret medical images, and the AI's impact on their performance is assessed. This document describes an in vitro diagnostic (IVD) device, specifically a blood test for a biomarker, which does not involve human readers interpreting "cases" in the medical imaging sense.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Yes, a standalone performance assessment was effectively done. The "method comparison" study directly assessed the performance of the new device (the algorithm/reagent system) against the predicate device without human interpretation affecting the quantitative output. The results (slope, y-intercept, r-value) directly reflect the standalone analytical performance of the new system.
7. The Type of Ground Truth Used
- The "ground truth" for this study is the measurement obtained from the predicate device, the Dimension Vista® CTNI Flex® reagent cartridge. The study assumes that the predicate device provides accurate and reliable measurements of cardiac troponin I.
8. The Sample Size for the Training Set
- Not provided. This document describes a submission for a medical device (a reagent cartridge) that measures a biomarker. While such devices have analytical characteristics that are "trained" or optimized during their development, this specific 510(k) summary focuses on demonstrating substantial equivalence to an existing predicate device using a method comparison study. It does not detail the internal development or "training" data used to optimize the assay's performance characteristics. This information is typically proprietary and not part of a 510(k) summary focused on equivalence.
9. How the Ground Truth for the Training Set Was Established
- Not provided. Similar to point 8, the methodology for establishing "ground truth" for any internal training or development data is not disclosed in this 510(k) summary. For biochemical assays, this would typically involve a combination of:
- Using reference materials with known concentrations.
- Comparing against highly accurate but perhaps less high-throughput reference methods (e.g., mass spectrometry).
- Spiking studies where known analyte concentrations are added to samples.
- Evaluating linearity and recovery across the analytical range.
§ 862.1215 Creatine phosphokinase/creatine kinase or isoenzymes test system.
(a)
Identification. A creatine phosphokinase/creatine kinase or isoenzymes test system is a device intended to measure the activity of the enzyme creatine phosphokinase or its isoenzymes (a group of enzymes with similar biological activity) in plasma and serum. Measurements of creatine phosphokinase and its isoenzymes are used in the diagnosis and treatment of myocardial infarction and muscle diseases such as progressive, Duchenne-type muscular dystrophy.(b)
Classification. Class II.