(17 days)
The MYO method for the Dimension® RxL with the heterogeneous immunoassay module is a device used to quantitatively measure myoglobin in human serum and plasma as an aid in the rapid diagnosis of acute myocardial infarction.
The MYO method for the Dimension® RxL system with the heterogeneous immunoassay module is a one-step enzyme immunoassay based on the "sandwich" principle. Sample is incubated with chromium dioxide particles (CrO-) coated with monoclonal antibodies specific for myoglobin and conjugate reagent (ß-galactosidase labeled monoclonal antibodies specific for myoglobin). A particle/MYO/coniugate sandwich forms during the incubation period. Unbound conjugate and analyte are removed by magnetic separation and washing. The sandwich bound ß-galactosidase is combined with the chromogenic substrate chlorophenol redß-d-galactopyranoside (CPRG) and catalyzes the hydrolysis of CPRG to the chromophore, chlorophenol red (CPR). The concentration of MYO present in the patient sample is directly proportional to the rate of color change measured at 577nm due to formation of CPR.
This submission describes the Myoglobin Flex™ reagent cartridge for the Dimension® RxL system, intended for quantitative measurement of myoglobin in human serum and plasma to aid in the rapid diagnosis of acute myocardial infarction. The study performed is a split sample comparison against a predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implicit) | Reported Device Performance (vs. Predicate) |
|---|---|
| Good correlation coefficient | 0.992 |
| Slope close to 1.0 | 1.04 |
| Intercept close to 0 | -4.15 ng/mL |
Note: The document does not explicitly state pre-defined acceptance criteria. The "Conclusion" section implies that the reported performance metrics (correlation, slope, intercept) were considered sufficient to demonstrate substantial equivalence to the predicate device.
2. Sample Size and Data Provenance
- Sample Size for Test Set: 204 clinical patient samples.
- Data Provenance: Not explicitly stated, but the samples are described as "clinical patient samples," suggesting they were collected from human subjects. The country of origin and whether the data was retrospective or prospective are not provided.
3. Number of Experts and Qualifications for Ground Truth
The study does not involve expert readers to establish ground truth in the traditional sense of image interpretation. It's a quantitative immunoassay comparison. The "ground truth" for the test set is established by the measurements obtained from the predicate device, the Stratus® Myoglobin assay. Therefore, the concept of expert consensus or qualifications of experts for ground truth is not applicable here.
4. Adjudication Method for the Test Set
Not applicable. This is a quantitative assay comparison, not a study involving human interpretation that would require adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not applicable. This study does not involve human readers interpreting cases, and therefore, no MRMC study was performed. The comparison is between two automated assay systems.
6. Standalone Performance Study
Yes, in a way, the study demonstrates the standalone performance of the Myoglobin Flex™ reagent cartridge relative to the predicate device. The performance metrics (correlation, slope, intercept) directly reflect how the new device performs on its own when measuring myoglobin in patient samples, as compared to an already established method. There is no human-in-the-loop component for these quantitative measurements.
7. Type of Ground Truth Used
The "ground truth" for the comparison study was effectively the measurements obtained from the predicate device, the Stratus® Myoglobin Fluorometric Enzyme Immunoassay. The new device's performance was evaluated by how closely its results aligned with those from the predicate device on the same samples.
8. Sample Size for the Training Set
The document does not mention a "training set" in the context of an algorithm or machine learning model. This is an immunoassay, and its development would typically involve reagent formulation, optimization, and validation, rather than machine learning training.
9. How Ground Truth for the Training Set Was Established
Not applicable, as there is no mention of a training set or ground truth establishment relevant to an algorithm development in this context. The "training" of such a device primarily involves optimizing its chemical and enzymatic reactions and calibration, not a data-driven model.
§ 866.5680 Myoglobin immunological test system.
(a)
Identification. A myoglobin immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the myoglobin (an oxygen storage protein found in muscle) in serum and other body fluids. Measurement of myoglobin aids in the rapid diagnosis of heart or renal disease.(b)
Classification. Class II (performance standards).