(245 days)
The GloCyte Automated Cell Counter System is intended for use by trained healthcare professionals in clinical laboratories to provide quantitation of fluorescence labeled total nucleated cells and erythrocytes in cerebrospinal fluid collected from adult and pediatric patients.
The GloCyte Low and High Level Controls are assayed hematology controls designed to monitor the performance of the GloCyte Automated Cell Counter System. Assayed parameters include total nucleated cells and erythrocytes.
The GloCyte® Automated Cell Counter System is an automated cell counter that concentrates and enumerates total nucleated cells (TNCs) and red blood cells (RBCs) using fluorescent microscopy and digital image analysis principles. The test method uses one of two reagents to stain TNCs (propidium iodide with detergent) or RBCs (fluorochrome labeled anti- human RBC antibody in buffer with stabilizers), and a digital imaging system to count the cells. The image is captured by a digital CCD camera, and the fluorescent stained cells are counted via digital image processing.
The GloCyte® Automated Cell Counter System includes the Instrument, Computer (hardware & software), Vacuum Station, Sample Preparation Tray, Barcode Reader, Pipettes (10 and 30 µL), Test Cartridge, TNC and RBC Reagents, Low and High Level Controls.
Here's an analysis of the provided text regarding the GloCyte® Automated Cell Counter System, focusing on acceptance criteria and supporting studies:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state acceptance criteria in a dedicated table. However, it implicitly defines successful performance by stating that "Results were shown to meet acceptance criteria" for accuracy and "The results of the repeatability study met acceptance criteria." The reproducibility study also "met acceptance criteria." Based on the reported data, the implicit acceptance criteria would relate to achieving results within the stated ranges, slopes, intercepts, and CVs.
| Test Category | Acceptance Criteria (Implicit from "met acceptance criteria") | Reported Device Performance |
|---|---|---|
| Accuracy (Hemocytometer vs. GloCyte) | TNC: Slope ~1, Intercept ~0. Bias: none or within acceptable limits. | TNC Pediatric (N=129): Range 0-7,672; Slope 0.963 (0.909, 1.000); Intercept 0.037 (0.000, 0.182); Bias: none. |
| TNC Adult (N=223): Range 0-9,900; Slope 1.000 (1.000, 1.003); Intercept 0.000 (-0.003, 0.000); Bias: none. | ||
| RBC: Slope ~1, Intercept ~0. Bias: none or within acceptable limits. | RBC Pediatric (N=196): Range 0-817,500; Slope 0.910 (0.885, 0.935); Intercept 0.000 (-0.045, 0.058); Bias: -9% (proportional). | |
| RBC Adult (N=267): Range 0-901,250; Slope 1.000 (0.986, 1.007); Intercept 0.000 (0.000, 0.015); Bias: none. | ||
| Repeatability (%CV) | Within acceptable CV limits (not explicitly defined numerically, but met by observed values). | TNC (N=26): Range 4-10,313 cells/uL; %CV Results 2.5-18.0. |
| RBC (N=29): Range 5-727,800 cells/uL; %CV Results 2.7-16.3. | ||
| Precision/Reproducibility (%CV) | Within acceptable CV limits for Within-Run, Between-Run, Between-Day, Between-Site, Between-Operator, and Total. | TNC Low (N=480): Mean 10.6; Within-Run 10.1, Between-Run 0.0, Between-Day 1.6, Between-Site 3.9, Between-Operator 2.4, Total 11.2. |
| TNC High (N=480): Mean 122.9; Within-Run 5.9, Between-Run 0.0, Between-Day 0.0, Between-Site 3.1, Between-Operator 1.5, Total 6.9. | ||
| RBC Low (N=480): Mean 11.3; Within-Run 9.2, Between-Run 0.0, Between-Day 1.9, Between-Site 3.8, Between-Operator 2.7, Total 10.5. | ||
| RBC High (N=480): Mean 130.0; Within-Run 5.3, Between-Run 0.0, Between-Day 0.7, Between-Site 1.7, Between-Operator 1.0, Total 5.7. | ||
| Linearity | A linear relationship between measured and expected values. | TNC: 0-7,438 cells/µL. |
| RBC: 0-615,644 cells/µL. | ||
| Reportable Range | LoQ combined with linear range. | TNC: 3-6,500 cells/µL. |
| RBC: 2-615,644 cells/µL. | ||
| Interfering Substances | No interference observed at specified concentrations. | Reported in Table 5-8, detailing highest concentrations with no observed interference for various substances (Bilirubin, Hemoglobin, Protein, Lactate, various bacteria, Candida albicans, Platelets, Monocytes). Note: Hemolytic Hemoglobin, RBC fragments, and Nucleated RBCs were noted as potential interferents for certain assays. |
| Quality Control Stability | Stability claim of 7 months for controls stored at 2-8°C. | Data supports a preliminary stability claim of 7 months based on testing at Month 7. |
2. Sample Size Used for the Test Set and Data Provenance
- Accuracy Study (Hemocytometer vs. GloCyte):
- TNC Pediatric: 129 samples
- TNC Adult: 223 samples
- RBC Pediatric: 196 samples
- RBC Adult: 267 samples
- Data Provenance: "clinical sites and in-house using clinical and contrived CSF specimens." This indicates a mix of prospective (clinical) and possibly retrospective (clinical) or laboratory-prepared (contrived) data. The country of origin is not specified but implicitly US, given the FDA submission.
- Repeatability Study:
- TNC: 26 samples
- RBC: 29 samples
- Data Provenance: "three clinical sites and in-house using clinical and manipulated CSF specimens as well as GloCyte® Low and High Level Controls." Similar to accuracy, a mix of data types and locations.
- Precision/Reproducibility Study:
- Each TNC and RBC level (Low/High) had 480 measurements (likely 2 operators * 2 measurements/day * 20 days * 3 sites).
- Data Provenance: "three clinical sites," using GloCyte® Low and High Level Controls.
- Linearity Study:
- Used "Contrived RBC and TNC CSF samples, created by dilution of human blood cells into blank CSF." Tested on three GloCyte® Automated Cell Counter Systems.
- Determination of LoB, LoD, LoQ:
- No specific sample size mentioned, but studies were conducted "according to CLSI EP17-A2."
- Interfering Substances:
- No specific sample size mentioned for each interferent, but "Interference testing was conducted."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number or qualifications of experts used to establish ground truth for the test sets. For the accuracy study comparing GloCyte to Hemocytometer, the Hemocytometer results would serve as the comparative method. However, who performed the hemocytometer counts and their qualifications are not detailed.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method (e.g., 2+1, 3+1) for establishing the ground truth or resolving discrepancies in the test set.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not done. The device is an automated cell counter, which aims to replace or assist manual counting, but the study described focuses on the device's analytical performance against established methods, not human reader performance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
Yes, the studies described are standalone performance evaluations of the GloCyte® Automated Cell Counter System. The device is designed to be an automated system, and the reported accuracy, repeatability, precision, linearity, and reportable range studies all reflect the algorithm and instrument's performance without direct human intervention in the cell counting process for the test results.
7. The Type of Ground Truth Used
- For the accuracy study, the ground truth for TNC and RBC counts was established by comparison against Hemocytometer counts ("Hemocytometer vs. GloCyte TNC and RBC counts").
- For repeatability, precision/reproducibility, linearity, LoB, LoD, LoQ, and interfering substances, the ground truth was implicitly the expected value or reference method result derived from standard laboratory practices and controlled preparations, rather than expert consensus on individual cases or pathology reports. For example, linearity uses "true concentrations of the analyte" and "expected values."
8. The Sample Size for the Training Set
The document does not mention the sample size for a "training set." The GloCyte® Automated Cell Counter System uses digital image analysis principles to count cells. While such systems are often developed using training data, this submission focuses on the validation or performance testing datasets. It does not provide details about model development or the data used to "train" its algorithms.
9. How the Ground Truth for the Training Set Was Established
Since no training set is discussed or implied in the provided text, the method for establishing its ground truth is also not elaborated upon.
§ 864.5200 Automated cell counter.
(a)
Identification. An automated cell counter is a fully-automated or semi-automated device used to count red blood cells, white blood cells, or blood platelets using a sample of the patient's peripheral blood (blood circulating in one of the body's extremities, such as the arm). These devices may also measure hemoglobin or hematocrit and may also calculate or measure one or more of the red cell indices (the erythrocyte mean corpuscular volume, the mean corpuscular hemoglobin, or the mean corpuscular hemoglobin concentration). These devices may use either an electronic particle counting method or an optical counting method.(b)
Classification. Class II (performance standards).