(140 days)
XN CHECK BF is used for control and calibration verification of Sysmex XN series (XN-10, XN-11, XN-20, XN-21) analyzers. It is not. however, intended for actual calibration of these analyzers. Assayed parameters include:
WBC-BF (10^3/μl), RBC-BF (10^6/ μl), ΜΝ# (10^3/μl), ΜΝ% (%), ΡΜΝ% (%), ΡΜΝ% (%), ΤC-ΒΓ# (10°3/μl)
XN CHECK™ BF is an in-vitro diagnostic product the following: stabilized red blood cell component(s) and stabilized white blood cell component(s) in a preservative medium. The product is packaged in polypropylene plastic vials with a 3 m fill. The vials will be packaged in (4) welled vacuum formed clamshell container with the Instructions for Use / assay sheet. The product storage conditions are at 2 - 8° C.
The provided text describes a 510(k) premarket notification for a medical device called XN CHECK™ BF. This document focuses on the substantial equivalence of the new device to a predicate device, rather than providing a detailed study design with specific acceptance criteria and performance metrics typically found for AI/ML-based medical devices or diagnostic tests.
The XN CHECK™ BF is a hematology quality control mixture for Sysmex XN series analyzers, not an AI-powered diagnostic device. Therefore, many of the questions related to AI/ML device studies (such as sample size for test/training sets, ground truth establishment, expert adjudication, MRMC studies, and standalone performance) are not applicable to this submission.
However, based on the information provided, here's a breakdown of what can be articulated regarding acceptance criteria and the study:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state quantitative acceptance criteria in a table format with specific thresholds (e.g., "accuracy > 90%"). Instead, the "acceptance criteria" are implied by the nature of a quality control product and its intended use, which is to demonstrate stability, reproducibility, and substantial equivalence to a predicate.
| Acceptance Criteria (Implied) | Reported Device Performance and Discussion of Tests |
|---|---|
| Open-Vial Stability | "product performance data for the following studies: Open-Vial Stability... The resultant data set established that XN CHECK BF is safe and effective for its intended use and that the product is stable for the entire product dating." The stated open-vial stability period is 30 days. |
| Closed-Vial Stability | "product performance data for the following studies: Closed-Vial Stability... The resultant data set established that XN CHECK BF is safe and effective for its intended use and that the product is stable for the entire product dating." The stated closed-vial stability period is 84 days. |
| Precision Performance (Reproducibility) | "product performance data for the following studies: ...Precision Performance. The resultant data set established that XN CHECK BF is safe and effective for its intended use and that the product is stable for the entire product dating." "Study results show XN CHECK BF to be consistently reproducible..." |
| Substantial Equivalence to Predicate | Demonstrated through comparison tables (Intended Use, Open Vial Stability, Closed Vial Stability, Reagents, Storage Conditions) which show mostly "Same" or minor "Differences" (addition of analyzer models) that don't alter fundamental performance. "Study results show XN CHECK BF to be ... substantially equivalent to the predicate products." |
| Safety and Effectiveness | "The resultant data set established that XN CHECK BF is safe and effective for its intended use..." and "XN CHECK BF is a safe and effective product, which fulfills its intended use when used 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 in terms of the number of samples or runs for the stability and precision studies. It mentions "product performance data" was collected but does not provide details on the experimental design, number of replicates, or number of lots tested.
- Data Provenance: Not explicitly stated, but the studies were conducted by Streck, Inc., implying internal company data.
- Retrospective or Prospective: Given the nature of stability and precision studies for a quality control material, they would typically be prospective studies designed and executed specifically for this submission, following predefined protocols.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This is not applicable. The device is a hematology quality control mixture, not a diagnostic device requiring expert interpretation for "ground truth." The "ground truth" for a control material would be its manufacturing specifications and the measured values on reference instruments.
4. Adjudication Method for the Test Set
This is not applicable for a quality control product study. Adjudication methods are typically used when subjective interpretations (e.g., image reads) are involved to resolve discrepancies among experts.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC study was not done. This type of study is relevant for diagnostic devices (especially those involving human readers like radiologists) to assess the impact of AI assistance on human performance. The XN CHECK™ BF is a quality control material.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
No, a standalone performance study in the context of an "algorithm only" is not applicable. The device itself is a physical quality control material used with an analyzer, not an algorithm. The "performance" refers to the stability and reproducibility of the control material's measured parameters, not an algorithm's output.
7. The Type of Ground Truth Used
The "ground truth" for a quality control material like XN CHECK™ BF would be the expected target values and ranges for its assayed parameters, established through a rigorous manufacturing and assay process using reference methods and calibrated instruments. This is analogous to a reference standard, not ground truth derived from pathology, expert consensus, or outcomes data used for diagnostic algorithms.
8. The Sample Size for the Training Set
This is not applicable. The XN CHECK™ BF is a manufactured quality control material, not an AI/ML algorithm that requires a "training set."
9. How the Ground Truth for the Training Set Was Established
This is not applicable, as there is no "training set" for this type of device.
§ 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.