(109 days)
The Chempaq XBC Analyzer is an in vitro diagnostic method intended for the quantitative determination of the concentration of white blood cells ("WBC"); granulocytes ("GRN"); lymphocytes ("LYM"); monocytes ("MON"); and total hemoglobin ("HGB") in whole-blood samples (finger stick or venous sample).
The Chempaq XBC Analyzer is indicated for use in: clinical laboratories, and for point-of-care hematology determinations in doctors' offices or by healthcare professionals in hospital settings to identify and classify one or more of the formed elements of blood.
Automated differential cell counter
This document is a 510(k) summary for a modification to the Chempaq XBC Analyzer, a device already on the market. The summary focuses on functional and safety testing to demonstrate that the modifications did not compromise existing white blood cell or hemoglobin measurement functionality and that new functionalities perform as intended. Therefore, this submission does not contain a standalone study or a detailed report of clinical performance against acceptance criteria for the core diagnostic measures (WBC, GRN, LYM, MON, HGB) as it refers to an existing device and modifications.
Based on the provided text, the device is considered substantially equivalent to its predicate, meaning its performance is implied to be similar to the existing (predicate) device. However, specific acceptance criteria and detailed performance data for the diagnostic measurements themselves are not presented in this summary for the modified device.
Here's an analysis based on the information available:
1. A table of acceptance criteria and the reported device performance
The provided text does not contain a table of acceptance criteria or reported device performance for the diagnostic accuracy of WBC, GRN, LYM, MON, or HGB. The document focuses on the functional and safety testing of the modifications to the existing Chempaq XBC Analyzer.
The acceptance criteria mentioned are related to successful operation of:
- Quality Control Cassette (QCC) for PAQ electrical connection and Hemoglobin photometric function.
- Liquid Quality Controls (LQCs) with WBC PAQs.
- Linearity materials with the Analyzer in Linearity mode using WBC PAQs.
- Associated print-out of LQC, QCC, Linearity, and patient ID.
- Detection of mismatches (e.g., wrong PAQ in wrong mode).
- Uncompromised WBC functionality after modifications.
- Software verification and validation.
The "reported device performance" against these specific acceptance criteria is summarized qualitatively: "Results of testing demonstrate that the modifications to the Chempaq XBC Analyzer did not modify white blood cell or hemoglobin measurement functionality, that the added functionality performs as intended, and that potential risks (such as mismatching of PAQ/QCC and test mode) have been mitigated by software changes to detect such mismatches to deliver an error message and prevent reporting of results."
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
The document describes "bench tests" for functional and safety aspects. It does not specify the sample sizes (e.g., number of PAQs, QCCs, or samples tested) for these tests. Data provenance is not mentioned, but given the submitter is Chempaq A/S in Denmark, it's likely the testing was conducted internally by the manufacturer. The tests appear to be prospective, laboratory-based bench testing of the modified device.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This 510(k) summary describes functional and safety testing, not clinical performance for diagnostic accuracy. Therefore, there is no mention of experts establishing ground truth in the context of clinical interpretation or diagnosis. The ground truth for functional tests would be the expected correct behavior of the device (e.g., a printout should occur, an error message should display for incorrect input).
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable, as this is functional and safety testing, not a clinical study requiring adjudication of diagnostic outcomes.
5. 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 device is an automated differential cell counter, not an AI-assisted diagnostic tool that would involve human readers interpreting images or data alongside AI.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This document is a 510(k) for device modifications. It confirms that "Bench performance testing was done to show that all WBC functionality was uncompromised by the modifications." This implies that the device's automated functions (i.e., algorithm only) were tested. However, detailed results of this standalone performance are not provided, as the purpose of the submission is to demonstrate equivalence and safety of the modifications, not to re-establish the primary diagnostic performance. The original Chempaq XBC Analyzer's standalone performance would have been established in a previous 510(k) submission.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the functional and safety testing described, the "ground truth" is the expected behavior and output of the device and its components, determined by engineering specifications and quality control standards (e.g., known values for liquid quality controls, expected printout content, correct error messages).
8. The sample size for the training set
Not applicable. This is a submission for modifications to an existing device, and the testing described is verification and validation of these modifications and their impact on existing functionality. It does not describe the development or training of new algorithms for diagnostic purposes.
9. How the ground truth for the training set was established
Not applicable, as there is no mention of a training set for new algorithms in this submission.
§ 864.5220 Automated differential cell counter.
(a)
Identification. An automated differential cell counter is a device used to identify one or more of the formed elements of the blood. The device may also have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the blood, bone marrow, or other body fluids. These devices may combine an electronic particle counting method, optical method, or a flow cytometric method utilizing monoclonal CD (cluster designation) markers. The device includes accessory CD markers.(b)
Classification. Class II (special controls). The special control for this device is the FDA document entitled “Class II Special Controls Guidance Document: Premarket Notifications for Automated Differential Cell Counters for Immature or Abnormal Blood Cells; Final Guidance for Industry and FDA.”