(96 days)
Quantitative determination of rheumatoid factors (RF) in human serum. lithium heparin and EDTA plasma on the BN™ II and BN ProSpec® Systems as an aid in the diagnosis of rheumatoid arthritis.
Polystyrene particles coated with an immunocomplex consisting of human immunoqlobulin and antihuman IgG from sheep are aggregated when mixed with samples containing RF. These aggregates scatter a beam of light passed through the sample. The intensity of the scattered light is proportional to the concentration of the respective protein in the sample. The result is evaluated by comparison with a standard of known concentration.
Here's a breakdown of the acceptance criteria and study details based on the provided text:
Acceptance Criteria and Device Performance
The provided 510(k) summary focuses on demonstrating substantial equivalence to a predicate device, rather than explicit pre-defined clinical acceptance criteria often seen with novel devices. The primary performance metric presented for equivalence is strong correlation with the predicate device.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Strong linear correlation with the predicate device (N Latex RF) for all tested concentrations. | Correlation Coefficient: 0.98 (for N Latex RF Kit vs. predicate) |
| Strong linear correlation with the predicate device (N Latex RF) for concentrations ≤ 100 IU/mL (closer to clinical cutoff). | Correlation Coefficient: 0.87 (for N Latex RF Kit vs. predicate, ≤ 100 IU/mL) |
| Slope close to 1.0 for all tested concentrations. | Slope: 1.098 (for N Latex RF Kit vs. predicate) |
| Intercept close to 0 for all tested concentrations. | Intercept: -12.94 (for N Latex RF Kit vs. predicate) |
| Slope close to 1.0 for concentrations ≤ 100 IU/mL. | Slope: 0.992 (for N Latex RF Kit vs. predicate, ≤ 100 IU/mL) |
| Intercept close to 0 for concentrations ≤ 100 IU/mL. | Intercept: -6.81 (for N Latex RF Kit vs. predicate, ≤ 100 IU/mL) |
Note: The acceptance criteria are "implied" because the document states the goal is to demonstrate substantial equivalence, and the reported performance metrics are key indicators used to support that claim. Specific numerical thresholds for "strong correlation" or "close to" are not explicitly defined as pass/fail criteria within this summary.
Study Information
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Sample size used for the test set and the data provenance:
- Sample Size: 90 serum samples were evaluated, with 43 of these samples specifically evaluated for concentrations ≤ 100 IU/mL.
- Data Provenance: Not explicitly stated regarding country of origin or specific demographics. The study is retrospective in the sense that it uses existing samples to compare performance with the predicate device.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. This study compares the performance of a new device against an existing, legally marketed predicate device (N Latex RF – K942328). The "ground truth" for the test set is established by the measurements from the predicate device itself. No human experts were involved in establishing an independent ground truth for the test set.
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Adjudication method for the test set: Not applicable. As the study compares against a predicate device's measurements, there is no need for expert adjudication.
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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: Not applicable. This is an in vitro diagnostic (IVD) device for quantitative determination of rheumatoid factors, not an imaging device or an AI-assisted diagnostic tool that involves human reader performance.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done: Yes. The performance study evaluates the N Latex RF Kit as a standalone assay (algorithm only) without any human-in-the-loop component influencing the measurement results. The device quantifies RF levels directly.
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The type of ground truth used: The "ground truth" for this substantial equivalence study is the measurements obtained from the legally marketed predicate device (N Latex RF). The new device's measurements are compared against these predicate measurements.
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The sample size for the training set: Not applicable. This device is a reagent kit for an immunoassay, not a machine learning or AI model that requires a "training set" in the conventional sense. The device's calibration would be part of its manufacturing and quality control process, but not a "training set" like that for an AI algorithm.
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How the ground truth for the training set was established: Not applicable. See point 7.
§ 866.5775 Rheumatoid factor immunological test system.
(a)
Identification. A rheumatoid factor immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the rheumatoid factor (antibodies to immunoglobulins) in serum, other body fluids, and tissues. Measurement of rheumatoid factor may aid in the diagnosis of rheumatoid arthritis.(b)
Classification. Class II (performance standards).