(83 days)
The A . T 10 Series is also a leukocyte differential counter. Both instruments are For In Vitro Diagnostic Use in clinical laboratories.
The COULTER® A. T Series Analyzers have the same intended use as the predicate device.
The product is a hematology Automated Cell Counter and Automated Differential Cell Counter which like the predicate device, COULTER® COUNTER® S-PLUS IV and LYSE S PLUS D, uses the Coulter method of impedance measurement for particle counting and sizing. Blood cells passing through a small opening simultaneously with an electric current cause an impedance change in the orifice. This electrical pulse can be sized and counted. While the number of pulses indicates the particle count, the size of the electrical pulse is proportional to cell volume.
Under the controlled condition of lysis, a chemical reaction demonstrates one distinct population of leukocytes: lymphocytes. Mature normal lymphocytes and variant atypical lymphocytes are the WBC cells, and tend to occupy the size range from 35 to 90 fL.
The COULTER® ACT Series Analyzers are quantitative, automated hematology analyzers.
Here's an analysis of the provided 510(k) summary regarding the COULTER® AC-T Series Analyzer, framed around your requested points:
COULTER® AC-T Series Analyzer Study Analysis
Based on the provided 510(k) summary, the following information can be extracted regarding acceptance criteria and the study conducted:
1. Acceptance Criteria and Reported Device Performance
The summary states that "Testing met all acceptance criteria" for precision, accuracy, and carryover. However, specific numerical acceptance criteria or detailed performance results (e.g., specific coefficients of variation for precision, correlation coefficients for accuracy limits for carryover) are not provided in this summary. To fully address this point, one would need to consult the full 510(k) submission document.
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Precision | Met all acceptance criteria |
| Accuracy | Met all acceptance criteria |
| Carryover | Met all acceptance criteria |
2. Sample Size Used for the Test Set and Data Provenance
The provided summary does not specify the sample size used for the test set. It also does not specify the data provenance (e.g., country of origin, retrospective or prospective). This information would typically be detailed in the full study report.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The summary does not provide information on the number of experts used to establish ground truth, nor their qualifications. Given the device is an automated cell counter, the "ground truth" for parameters like WBC, RBC, Hgb, etc., would typically be established by reference methods or predicate devices, not visual expert review. For the differential counts (LY # and LY %), a manual differential performed by a qualified medical technologist or pathologist would serve as the ground truth.
4. Adjudication Method for the Test Set
The summary does not specify any adjudication method. For automated cell counters, adjudication in the sense of reconciling differing expert opinions is generally not applicable for basic CBC parameters. For differential counts, if multiple manual differentials were performed for ground truth, an adjudication method might be used, but this is not mentioned.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
There is no indication of a Multi-Reader Multi-Case (MRMC) comparative effectiveness study being conducted. This type of study is more common for imaging devices where human interpretation is a primary component. The COULTER® AC-T Series Analyzer is an automated instrument, and while its results would be compared to a reference method, it's not a human-in-the-loop diagnostic aid in the way an MRMC study evaluates.
6. Standalone Performance Study
Yes, a standalone performance study was clearly done. The entire submission focuses on the performance of the COULTER® AC-T Series Analyzer itself in determining parameters like WBC, RBC, Hgb, Hct, MCH, MCH, Plt, LY #, and LY %. The testing for precision, accuracy, and carryover directly assesses the algorithm's (and instrument's) performance without human intervention in the result generation.
7. Type of Ground Truth Used
Based on the nature of the device (automated hematology analyzer) and the parameters measured, the ground truth would most likely be established using:
- Reference Methods: For parameters like hemoglobin, established spectrophotometric methods would be used.
- Predicate Device Comparison: The summary explicitly states substantial equivalence to the COULTER® COUNTER® S-PLUS IV and LYSE S PLUS D (K823355), implying that results from the predicate device (or a similar reference analyzer) would be used as a gold standard for accuracy testing.
- Manual Differentials: For the leukocyte differential counts (LY # and LY %), the ground truth would be established by expert microscopic review of blood smears by qualified medical technologists or pathologists.
The summary does not explicitly state the type of ground truth, but these are the standard practices for this type of device.
8. Sample Size for the Training Set
The summary does not provide information on the sample size for the training set. Automated hematology analyzers typically do not undergo "training" in the machine learning sense that current AI algorithms do. Instead, their internal algorithms are developed and refined through extensive R&D and calibration procedures, often using a large, diverse set of samples. If this device utilized classical parameter-based algorithms, there wouldn't be a distinct "training set" in the modern AI context.
9. How the Ground Truth for the Training Set Was Established
As mentioned above, the concept of a "training set" and "ground truth for a training set" as typically understood in recent AI/ML contexts does not directly apply to this 1996 device in the same way. The internal algorithms for counting and sizing are based on the established Coulter principle and refined through engineering and calibration rather than iterative machine learning. If any "calibration" or developmental samples were used, their "ground truth" would have been established through highly controlled reference methods or predicate device comparisons.
§ 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.”