(28 days)
IMMULITE® Troponin I is a solid-phase, two-site chemiluminescent enzyme immunometric assay for use with the IMMULITE Automated Analyzer and designed for the quantitative measurement of troponin I in serum, heparinized or EDTA plasma. It is intended for in vitro use as an aid in the diagnosis of acute myocardial infarction (AMI).
IMMULITE® Troponin I is a clinical device for use with the IMMULITE® Automated Immunoassay Analyzer. IMMULITE® Troponin I is a solid-phase, two-site chemiluminescent immunometric assay. The solid phase, a polystyrene bead enclosed within an IMMULITE Test Unit, is coated with a monoclonal antibody specific for troponin I. While the patient sample and alkaline phosphatase-conjugated polyclonal antibody are incubated for 30 minutes at 37 ℃ in the Test Unit with intermittent agitation, troponin I in the sample is bound to form an antibody sandwich complex. Unbound conjugate is then removed by a centrifugal wash, after which substrate is added and the Test Unit is incubated for a further 10 minutes. The chemiluminescent substrate, a phosphate ester of adamantyl dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase to vield an unstable intermediate. The continuous production of this intermediate results in the sustained emission of light, thus improving precision by providing a window for multiple readings. The bound complex – and thus also the photon output, as measured by the luminometer - is proportional to the concentration of troponin I in the sample.
Here's a breakdown of the acceptance criteria and study information for the IMMULITE® Troponin I device, based on the provided text:
Acceptance Criteria and Device Performance
This submission focuses on demonstrating substantial equivalence to a predicate device rather than establishing novel acceptance criteria against a clinical endpoint. The primary "acceptance criteria" presented is the statistical correlation and comparison of results between the new device and the predicate device.
| Acceptance Criteria (Proxy) | Reported Device Performance (IMMULITE® Troponin I vs. Stratus® Cardiac Troponin-I) |
|---|---|
| Correlation Coefficient (r) | 0.91 |
| Linear Regression Slope | 1.00 |
| Linear Regression Intercept | -0.25 ng/mL |
| Mean (IMMULITE) | 15.6 |
| Mean (Kit A - Stratus) | 15.8 |
Explanation of "Acceptance Criteria" for this submission: For in vitro diagnostic devices seeking substantial equivalence, the "acceptance criteria" often revolve around demonstrating analytical performance similar to a legally marketed predicate device. A strong correlation (r-value close to 1), a slope near 1, and an intercept close to 0 in a method comparison study indicate a high degree of agreement between the new device and the predicate. The presented data satisfies these expectations for substantial equivalence.
Study Details
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Sample size used for the test set and the data provenance:
- Sample Size: 97 serum samples.
- Data Provenance: The document does not specify the country of origin of the data or whether it was retrospective or prospective. It only states that the samples had Troponin I concentrations ranging from non-detectable to approximately 180 ng/mL.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This type of in vitro diagnostic device does not typically rely on "experts" to establish ground truth in the same way an imaging or AI diagnosis device would. The "ground truth" for the test set is effectively the measurement obtained from the predicate device (Stratus® Cardiac Troponin-I). The purpose of this study is to show that the new device's measurements correlate well with an already accepted method. No human experts in the sense of clinicians or radiologists were involved in establishing the "ground truth" for the comparative measurements.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable. This was a method comparison study between two analytical instruments. There was no human adjudication of results in the traditional sense, as the comparison was between the quantitative outputs of two assays.
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If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No MRMC comparative effectiveness study was done. This device is an in vitro diagnostic assay, not an AI-assisted diagnostic tool that would involve human readers interpreting output.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, the performance presented is standalone. This study compares the output of the IMMULITE® Troponin I assay (algorithm/device only) against the output of the Stratus® Cardiac Troponin-I assay (itself a standalone device). There is no "human-in-the-loop" component in the performance evaluation described.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The "ground truth" in this context is the measurements provided by the predicate device, the Stratus® Cardiac Troponin-I Fluorometric Enzyme Immunoassay (K951890). This is a common approach for demonstrating substantial equivalence for new in vitro diagnostic assays.
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The sample size for the training set:
- The document does not explicitly mention a "training set" in the context of machine learning or AI algorithms. For an immunoassay, the concept of training generally refers to internal development and calibration processes, which are not typically detailed in 510(k) summaries as a separate "training set" size. The 97 samples mentioned are for method comparison/validation.
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How the ground truth for the training set was established:
- As there's no explicitly defined "training set" in the context of the provided document (which describes an immunoassay, not an AI/ML model), this question is not directly applicable. For an immunoassay, calibration (analogous to "training" in a very broad sense) typically involves using calibrator materials with known concentrations, whose "ground truth" is established through precise manufacturing, standardization, and often traceability to reference methods or materials.
§ 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.