(140 days)
XN CHECK is used for control and calibration verification of Sysmex XN series (XN-10, XN-11, XN-21) analyzers. It is not, however, intended for actual calibration of these analyzers. Assayed parameters include:
RBC(10^6/uL), HGB(g/dL), HCT(%), MCV(fL), MCH(pg), MCHC(g/dL), PLT(10^3/uL), PLT-F(10^3/uL), RDW-SD(fL), RDW-CV(%), MBC(10^3/uL), NEUT(%), LYMPH (%), MONO(%), EQ(%), BASO(%), IG(%), NEUTH(10^3/uL), LYMPH#(10^3/uL), MONO# (10^3/uL), EO#(10^3/uL), BASO#(10^3/uL), IG#(10^3/μL), IPF(%), IPF# (10^3/μL), RET%, IRF%, RET-HE(pg), NRBC#(10^3/uL), NRBC% (/100 WBC)
XN CHECK™ is an in-vitro diagnostic product that onlowing: stabilized red blood cell component(s), stablized white blood cell component(s), stablized platelet component(s), and stabilized nuclement(s) in a preservative medium. The product is packaged in polypropylene plastic vials with screw caps with a 3 ml fill. The vials will be packaged in (4) welled vacuum formed clamshell ontainer with the Instructions for Use (FU) / assay sheet. Product storage conditions are 2 - 8° C.
Here's an analysis of the provided text regarding the acceptance criteria and study for the XN Check™ device:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state numerical acceptance criteria in a dedicated section. Instead, it discusses the outcomes of the studies. Based on the "Discussion of Tests and Test Results" and "Conclusions Drawn From Tests" sections, the implied acceptance criteria were related to stability and reproducibility, with the reported performance indicating these criteria were met.
Since no specific numerical thresholds are given, the table below reflects what can be inferred:
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Open-Vial Stability: Maintain performance over the stated open-vial period. | Established that XN CHECK is stable for its open-vial period (7 days). |
| Closed-Vial Stability: Maintain performance over the stated closed-vial period. | Established that XN CHECK is stable for its entire product dating (84 days). |
| Precision Performance: Demonstrate consistent and reliable results. | Study results show XN CHECK to be consistently reproducible. |
| Safety and Effectiveness: Be safe and effective for its intended use. | Established that XN CHECK is safe and effective for its intended use. |
| Substantial Equivalence: Performance comparable to the predicate device. | Study results show XN CHECK to be substantially equivalent to the predicate products. |
| Fulfillment of Intended Use: Perform as described in the Indications for Use. | The product fulfills its intended use as instructed in the Instructions for Use. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify the sample size used for the test set for any of the studies (Open-Vial Stability, Closed-Vial Stability, and Precision Performance).
The data provenance is not explicitly stated in terms of country of origin. However, the product is being submitted for FDA approval in the USA, implying studies were conducted to support this market. The studies are described as prospective in nature, as they are performed to "substantiate the product performance claims" for the device being submitted.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The document does not mention the use of experts to establish ground truth for the test set. Given that XN CHECK is a hematology quality control mixture, the "ground truth" would likely be established through predefined assay values and analytical methods, rather than expert interpretation of patient data.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method, as it does not involve expert review or interpretation that would typically require adjudication. The performance evaluation is based on analytical measurements against expected values for the control material.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
A Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted, or at least not described in this document. This type of study is typically performed for diagnostic devices where human readers interpret medical images or data. XN CHECK is a quality control material, not a diagnostic device involving human interpretation.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
A standalone performance study was implicitly done. The studies mentioned (Open-Vial Stability, Closed-Vial Stability, and Precision Performance) relate to the intrinsic performance of the XN CHECK control material itself when analyzed by the Sysmex XN series analyzers. There is no human-in-the-loop component for the function of the control material.
7. Type of Ground Truth Used
The ground truth for this type of device (a quality control mixture) would be the assigned target values and acceptable ranges for each hematology parameter. These values are typically established through rigorous analytical testing and cross-validation against reference methods or previously validated control materials. The document implies these established analytical expectations as the basis for evaluating "reproducibility" and "stability."
8. Sample Size for the Training Set
The document does not specify a training set sample size. For a quality control material, the concept of a "training set" as understood in machine learning (where algorithms learn from data) does not directly apply. The manufacturing and validation process would involve extensive analytical testing during development and manufacturing, but this is not typically referred to as a "training set."
9. How the Ground Truth for the Training Set Was Established
As explained above, a "training set" in the context of machine learning is not applicable here. For the XN CHECK, the "ground truth" (i.e., the expected values and acceptable ranges for performance) would be established by:
- Manufacturing specifications: Parameters are designed to fall within specific ranges.
- Analytical testing: Extensive in-house testing under controlled conditions to determine the mean and standard deviation for each parameter.
- Methodology: Following established laboratory practices and potentially using reference instruments or methods.
- Comparison to predicate: Ensuring the new control material performs comparably to the previously accepted predicate (XN CHECK K120742).
In summary, the provided document focuses on the regulatory submission for a hematology quality control product. As such, the studies described are analytical performance studies (stability, precision) rather than diagnostic efficacy studies and therefore many of the requested elements (like experts, adjudication, MRMC, training sets for algorithms) are not directly relevant or discussed.
§ 864.8625 Hematology quality control mixture.
(a)
Identification. A hematology quality control mixture is a device used to ascertain the accuracy and precision of manual, semiautomated, and automated determinations of cell parameters such as white cell count (WBC), red cell count (RBC), platelet count (PLT), hemoglobin, hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC).(b)
Classification. Class II (special controls). Except when intended for use in blood components, the device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.