(140 days)
XN CAL is used for the calibration and calibration verification of Sysmex XN series (XN-10, XN-11, XN-20, XN-21) analyzers. Assayed parameters include:
WBC (10^3/uL), RBC (10^6/uL), HGB (g/dL), HCT (%), PLT (10^3/ uL), and RET (%)
XN CAL contains the following: stabilized red blood cell component(s), stabilized white blood cell component(s), stabilized platelet component(s), and stabilized nucleated red blood cell component(s) in a preservative medium.
The provided text describes a 510(k) premarket notification for the XN-CAL™ device, a calibrator for cell indices used with Sysmex XN series analyzers. The submission aims to demonstrate substantial equivalence to a legally marketed predicate device.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of formal acceptance criteria with numerical targets. Instead, it discusses the outcomes of various studies to demonstrate the device's performance claims. The key performance claims evaluated are related to stability and precision.
| Acceptance Criteria (Inferred from study types) | Reported Device Performance (Summary from text) |
|---|---|
| Open-Vial Stability: Maintain performance for a specified duration after opening. | XN CAL demonstrated stability for 4 hours (same as predicate device). |
| Closed-Vial Stability: Maintain performance for a specified duration before opening. | XN CAL demonstrated stability for 49 days, an extension from the predicate device's 35 days. The "resultant data set established that XN CAL is safe and effective for its intended use and that the product is stable for the entire product dating." |
| Precision Performance: Maintain consistent and reproducible results. | XN CAL was found to be "consistently reproducible." |
2. Sample Size Used for the Test Set and Data Provenance
The document primarily focuses on the regulatory submission and does not provide specific details regarding the sample sizes or data provenance (e.g., country of origin, retrospective/prospective) for the studies performed. It generally states that "Streck collected product performance data for the following studies: Open-Vial Stability, Closed-Vial Stability, and Precision Performance."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
This information is not provided in the document. For a medical device calibrator, the "ground truth" would likely be established through highly controlled laboratory assays using reference methods, rather than expert interpretation of images or clinical cases.
4. Adjudication Method for the Test Set
This information is not applicable and not provided. Adjudication methods are typically relevant for studies involving human interpretation or diagnosis, which is not the primary function of a calibrator for cell indices.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
An MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic devices that involve human interpretation (e.g., radiologists reading images) and the impact of AI on their performance. The XN-CAL™ is a calibrator, which does not involve human interpretation in the same way.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
A standalone performance study was done. The document describes studies on "Open-Vial Stability, Closed-Vial Stability, and Precision Performance" for the XN CAL device itself. These studies assess the intrinsic performance of the calibrator, independent of human interaction during the calibration process beyond following the instructions for use. The device's performance as a calibrator is evaluated based on its ability to provide stable and precise values for the specified hematological parameters.
7. Type of Ground Truth Used
The ground truth used for evaluating a calibrator like XN-CAL™ would typically be established through:
- Reference materials/methods: Highly accurate and traceable reference materials or established laboratory methods (e.g., manual cell counts, spectrophotometric hemoglobin measurements) would serve as the "true" values against which the calibrator is manufactured and tested.
- Assayed values: The calibrator itself comes with "assayed values," which are the target values for each parameter determined through rigorous testing against reference methods.
The document implicitly refers to this by stating the product performance data "established that XN CAL is safe and effective for its intended use" and "consistently reproducible."
8. Sample Size for the Training Set
The document does not mention a "training set" because XN-CAL™ is a calibrator, not an AI/machine learning algorithm that requires training data. Its performance is based on its chemical and biological formulation and manufacturing consistency.
9. How the Ground Truth for the Training Set Was Established
As explained above, there is no "training set" for this type of device. The "ground truth" for calibrator values would be established through meticulous laboratory analysis using established reference methods, not through a training process in the AI sense.
§ 864.8150 Calibrator for cell indices.
(a)
Identification. A calibrator for cell indices is a device that approximates whole blood or certain blood cells and that is used to set an instrument intended to measure mean cell volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC), or other cell indices. It is a suspension of particles or cells whose size, shape, concentration, and other characteristics have been precisely and accurately determined.(b)
Classification. Class II (special controls). 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.