(105 days)
The IMMAGE® Immunochemistry System Low Concentration Immunoglobulin M (IGMLC) Reagent, when used in conjunction with Beckman Coulter's IMMAGE® Immunochemistry Systems and Cerebrospinal Fluid Protein Calibrator, is intended for the quantitative determination of human immunoglobulin M in serum and cerebrospinal fluid by rate nephelometry.
The IMMAGE® Low Concentration Immunoglobulin M (IGMLC) Reagent and Cerebrospinal Fluid Calibrator are designed for optimal performance on the IMMAGE® Immunochemistry Systems. It is intended for the quantitative determination of immunoglobulin M in serum and cerebrospinal fluid.
Device Acceptance Criteria and Performance Study: Beckman Coulter IMMAGE® Immunochemistry System Low Concentration Immunoglobulin M (IGMLC) Reagent
This response describes the acceptance criteria and the study that proves the Beckman Coulter IMMAGE® Immunochemistry System Low Concentration Immunoglobulin M (IGMLC) Reagent meets these criteria, based on the provided K993547 Summary of Safety & Effectiveness.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document does not explicitly state pre-defined "acceptance criteria" in a typical quantitative format (e.g., "slope must be between X and Y"). Instead, it reports performance data for method comparison and imprecision studies, indicating that these results demonstrate "substantial equivalence" to existing commercial distribution test systems.
Therefore, the "acceptance criteria" are inferred from the reported performance characteristics that were deemed sufficient for demonstrating substantial equivalence. The reported device performance is directly from the provided text.
Inferred Acceptance Criteria based on Predicate Equivalence and Reported Performance:
| Performance Metric | Implied Acceptance Criteria (Demonstrates Substantial Equivalence and Acceptable Performance) | Reported Device Performance (IMMAGE IGMLC) |
|---|---|---|
| Serum Method Comparison | ||
| N | Sufficient sample size for statistical significance | 55 |
| Slope | Close to 1 (indicating proportional agreement with predicate) | 0.977 |
| Intercept | Close to 0 (indicating lack of constant bias with predicate) | 9.12 |
| Mean (IGMLC) | Comparable to predicate mean | 1039 mg/L |
| Mean (Predicate) | Comparable to IGMLC mean | 1054 mg/L |
| Correlation Coefficient | High (indicating strong linear relationship with predicate) | 0.988 |
| CSF Study Results (Qualitative equivalence focus) | ||
| N | Sufficient sample size for statistical significance | 51 (originally 51, then 45 for true positive, 6 for true negative) |
| Sensitivity % | High (indicating ability to correctly identify positive cases) | 100% |
| Specificity % | High (indicating ability to correctly identify negative cases and avoid false positives) | 89.5% (initial) / 100% (after adjustment or for a specific condition) |
| False Positives | Low (ideally 0) | 6 (initial) / 0 (after adjustment or for a specific condition) |
| False Negatives | Low (ideally 0) | 0 |
| Estimated Imprecision (Serum) | ||
| Within-Run % CV | Low (indicating good reproducibility within a single run) | Low: 3.2%, Mid: 1.7%, High: 1.8% |
| Total % CV | Low (indicating good overall reproducibility) | Low: 3.5%, Mid: 2.5%, High: 2.0% |
| Estimated Imprecision (CSF) | ||
| Within-Run % CV | Low (indicating good reproducibility within a single run) | Low: 5.2%, Mid: 2.0%, High: 2.1% |
| Total % CV | Low (indicating good overall reproducibility) | Low: 6.0%, Mid: 4.1%, High: 3.5% |
2. Sample Size Used for the Test Set and Data Provenance
- Serum Study (Method Comparison):
- Sample Size: N = 55
- Data Provenance: Not explicitly stated (e.g., country of origin). It is considered retrospective as it compares the new device's results to a predicate device's results on existing samples.
- CSF Study (Qualitative Evaluation):
- Sample Size: N = 51 (initial reported N for study), with further breakdown for "Test Positive" (51) and "Test Negative" (45+6=51).
- Data Provenance: Not explicitly stated (e.g., country of origin). It is considered retrospective as it evaluates an existing dataset or samples against a reference.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not mention the use of "experts" to establish ground truth in the context of radiologists or similar clinical reviewers.
For this type of in vitro diagnostic device (quantitative determination of immunoglobulin M), "ground truth" is typically established by:
- Serum Study: Comparison to a predicate device/method. The predicate device itself acts as the reference for comparison, implying its established accuracy.
- CSF Study: The reference for "positive" or "negative" status would likely be derived from the predicate method or a clinically accepted reference standard, not from human expert interpretation in the traditional sense. The document refers to "Test Positive" and "Test Negative," which implies a defined reference standard was used to classify samples.
Therefore, the concept of "number of experts" and their "qualifications" as it applies to image interpretation or clinical diagnosis by human experts is not directly applicable here.
4. Adjudication Method for the Test Set
Not applicable. As described in point 3, the ground truth for these types of studies (method comparison, imprecision) is typically based on a predicate device/method or established quantitative benchmarks, not on human adjudication of subjective interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No. An MRMC comparative effectiveness study is not applicable to this type of in vitro diagnostic device (reagent for quantitative measurement). MRMC studies are typically used to assess the effectiveness of diagnostic imaging devices or algorithms that involve human interpretation of images or other complex data.
6. If a Standalone Study (Algorithm Only Without Human-in-the-Loop Performance) was Done
Yes, in essence. The studies described are standalone performance evaluations of the IMMAGE® Immunochemistry System IGMLC Reagent and CSS CAL. The device itself performs the quantitative determination by "rate nephelometry," and the results are reported directly. There is no human "in-the-loop" interpretation step that the device is assisting (e.g., flagging areas on an image for a radiologist). The performance metrics (slope, intercept, correlation, sensitivity, specificity, imprecision) are all measures of the device's inherent analytical performance.
7. The Type of Ground Truth Used
- Serum Method Comparison: The ground truth was established by the predicate device/method (IMMAGE Immunochemistry Systems Immunoglobulin M (IGM) Reagent). The new device's measurements were compared against those obtained from the predicate.
- CSF Study: The ground truth for classifying "positive" or "negative" cases for the CSF study was likely based on a clinical reference standard or the predicate method's results for CSF analysis, if applicable. The details for this specific classification are not explicitly provided beyond the "Test Positive" and "Test Negative" categories.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" or "training data" for this device. For in vitro diagnostic reagents like this, the development process might involve internal optimization and validation studies that could be considered analogous to training, but it's not typically reported in terms of a distinct "training set" like in machine learning applications. The studies reported here are for performance validation rather than model training.
9. How the Ground Truth for the Training Set was Established
As no specific "training set" is mentioned in the provided document, the method for establishing its ground truth is also not described.
§ 866.5510 Immunoglobulins A, G, M, D, and E immunological test system.
(a)
Identification. An immunoglobulins A, G, M, D, and E immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the immunoglobulins A, G, M, D, an E (serum antibodies) in serum. Measurement of these immunoglobulins aids in the diagnosis of abnormal protein metabolism and the body's lack of ability to resist infectious agents.(b)
Classification. Class II (performance standards).