(68 days)
The XW-100 Automated Hematology Analyzer (XW-100) is a quantitative automated hematology analyzer intended for in vitro diagnostic use to classify and enumerate the following parameters for venous whole blood anticoagulated with K2/K3 EDTA: WBC, RBC, HGB, HCT, MCV, PLT, LYM%, Other WBC%, NEUT%, LYM#, Other WBC#, and NEUT#. It is not for use in diagnosing or monitoring patients with primary or secondary chronic hematologic diseases/ disorders, oncology patients, critically ill patients, or children under the age of 2.
The XW-100 Automated Hematology Analyzer is an electrical resistance type blood cell counter. This technology may be variously referred to as direct current (DC) or impedance. The analyzer uses a human whole blood specimen and produces results for 12 hematology parameters, including the basic complete blood count (CBC), 3 part white blood cell (WBC) differential, and MCV. The analyzer uses DC with hydrodynamic focusing for all parameters except hemoglobin, which is measured photometrically. The patient sample is aspirated, measured, diluted with diluent (and Lyse for WBC measurement), then fed into a transducer chamber by means of a hydrodynamic focusing nozzle. The transducer chamber has a minute hole, or aperture. Electrodes are mounted on both sides of the aperture chamber, through which flows the DC. Blood cells suspended in the diluted sample are injected through the aperture by the hydrodynamic focusing nozzle. The hydrodynamic focusing nozzle is positioned in front of the aperture and in line with the aperture's center. This method improves cell counting accuracy because all blood cells are separated from each other and can only pass through the aperture in 1 direction, 1 at a time. When a cell passes through the aperture, it causes a change in the DC resistance that is directly proportional to its size. These resistance changes are captured as electric pulses. The various blood cell counts are calculated by counting the pulses that occur in each cell size category. The analyzer then determines blood cell volume and identifies rare and pathological cells by creating and analyzing histograms of the various cell populations using their respective pulse heights. Hemoglobin is measured photometrically using a noncyanide methodology, which reduces the presence of hazardous materials in the analyzer waste stream. The quality controls that are used with the XW-100 CLIA Waived Automated Hematology Analyzer comprise XW QC CHECK, which contains stabilized red blood cell component(s), stabilized WBC component(s), and stabilized platelet component(s) in a preserving medium. XW QC CHECK components are packaged in glass vials with screw caps containing 2 mL. The vials are packaged in a welled vacuum- formed clamshell container. XW QC CHECK is stored at room temperature (15°C-25°C).
1. Table of Acceptance Criteria and Reported Device Performance:
The document refers to clinical performance data in K143577 and clinical field data and flex studies in CW170004. Without access to these referenced documents, a specific table of acceptance criteria and reported device performance cannot be generated. However, the summary states that "The performance data demonstrated substantial equivalence to the predicate device." This implies that the device met the performance requirements that allowed it to be deemed substantially equivalent to the predicate.
2. Sample Size Used for the Test Set and Data Provenance:
The available document does not explicitly state the sample size used for the test set or the data provenance (e.g., country of origin, retrospective/prospective) for the clinical performance data (K143577) or the clinical field data and flex studies (CW170004).
3. Number of Experts Used to Establish Ground Truth and Qualifications:
This information is not provided in the given document.
4. Adjudication Method for the Test Set:
This information is not provided in the given document.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
A Multi-Reader Multi-Case (MRMC) comparative effectiveness study is not mentioned or described in the provided text. The device described, the XW-100 Automated Hematology Analyzer, is an automated diagnostic device, not one typically involving human readers for interpretation in the same way as, for example, an imaging diagnostic AI.
6. Standalone (Algorithm Only) Performance Study:
The information presented describes the automated hematology analyzer as a standalone device. Its performance data (referenced in K143577 and CW170004) would pertain to its direct measurements and classifications without direct human-in-the-loop intervention during the analysis process, as it is an "Automated Hematology Analyzer."
7. Type of Ground Truth Used:
While not explicitly stated for the referenced studies, for automated hematology analyzers, the common ground truth for evaluating performance would generally involve:
- Reference Methods: Comparison to established, highly accurate reference methods (e.g., manual microscopy and differential counts performed by highly experienced laboratory technologists) for cell enumeration and classification.
- Clinical Outcomes/Pathology: For certain parameters, correlation with patient pathology reports or clinical outcomes might also be used as a broader validation.
8. Sample Size for the Training Set:
The document does not provide information regarding a specific training set size. Automated hematology analyzers like the XW-100 are typically developed and calibrated using extensive internal datasets, but the details of these are not included here.
9. How Ground Truth for the Training Set Was Established:
This information is not provided in the given document. For such devices, the ground truth for training data would typically be established through well-defined laboratory protocols, including manual differential counts by expert morphologists and correlation with other established diagnostic techniques.
§ 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.”