(35 days)
The COULTER® AC-T diff™ analyzer is a quantitative, automated hematology analyzer and leukocyte differential counter For In Vitro Diagnostic Use in clinical laboratories.
The product is a hematology Automated Differential Cell Counter which like the predicate devices, COULTER A C T Series Analyzer and 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 three distinct populations of leukocytes: lymphocytes, mononuclear cells and granulocytes. The percentage of leukocytes that fall into each of the three categories is derived from the WBC histogram: the LY area is approximately from 35 fL to 90 fL, the MO area is approximately from 90 fL to 160 fL and the GR area is approximately from 160 fL. The COULTER® AC T diff™ Analyzer is a quantitative, automated hematology analyzer and leukocyte differential counter For In Vitro Diagnostic Use in clinical laboratories. The COULTER® AC T diff analyzer has the same intended use as the predicate devices. Both the A.T diff and the predicate devices utilize the Coulter principle for cell counting and sizing in combination with automatic diluting and mixing for sample processing and a beam photometer for hemoglobinometry. The same reagent system, consisting of isotonic diluent, lytic reagent, and cleaning agent, is used on the AS.T diff analyzers and the predicate devices. The ACT diff analyzers and the predicate devices have the ability to print and transmit results if the instrument has been setup to do so. The COULTER AC T diff Analyzer is the same device as the COULTER AS T Series Analyzers except for the modifications required for the measurement of a three-part leukocyte differential, RDW, and MPV, automated calibration and quality control evaluation, patient storage and selectable print profiles.
The provided text describes the COULTER® AC·T diff™ Analyzer, a hematology automated differential cell counter. However, it does not include a detailed study proving the device meets specific acceptance criteria.
The submission states: "Testing described in Section 2 of this submission focuses on attributes of precision and accuracy for the additional parameters (i. e. WBC differential, RDW and MPV). Testing met all acceptance criteria." However, "Section 2" and the actual test results or acceptance criteria themselves are not provided in the input text.
Therefore, the following information is based on the available text, with limitations noted for what is not present.
Acceptance Criteria and Device Performance Study Details (Based on Available Information):
Limitations: The provided document is a 510(k) summary (K973634) and an FDA clearance letter. It does not contain the detailed study report, specific acceptance criteria values, or reported performance metrics. It only states that "Testing met all acceptance criteria" for precision and accuracy of WBC differential, RDW, and MPV.
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Table of Acceptance Criteria and Reported Device Performance:
Note: The specific acceptance criteria values and reported performance metrics are not provided in the given text. The text only states that testing met these criteria for the parameters listed below.
Parameter Acceptance Criteria Reported Device Performance WBC Differential (Lymphocytes, Monocytes, Granulocytes) (Specific criteria for precision and accuracy not provided in this document) "Testing met all acceptance criteria" for precision and accuracy. Red Cell Distribution Width (RDW) (Specific criteria for precision and accuracy not provided in this document) "Testing met all acceptance criteria" for precision and accuracy. Mean Platelet Volume (MPV) (Specific criteria for precision and accuracy not provided in this document) "Testing met all acceptance criteria" for precision and accuracy.
Further Study Details (Based on Available Information):
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Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not specified in the provided text.
- Data Provenance: Not specified (e.g., country of origin, retrospective or prospective).
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not provided as the ground truth determination method is not detailed. For a differential cell counter, this would typically involve trained laboratory technologists performing manual differential counts, potentially reviewed by pathologists.
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Adjudication method for the test set:
- Not specified.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done, and 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 hematology analyzer, not an AI-assisted diagnostic tool for human readers in the context of image interpretation. It performs automated cell counting and differentiation.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, implicitly. Automated hematology analyzers operate in a standalone manner to count and differentiate cells. The "testing" mentioned for precision and accuracy likely refers to the performance of the device's algorithms and internal measurement systems without human intervention during the measurement process. Human intervention would occur in sample preparation, loading, and result review.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Not explicitly stated, but for hematology analyzers, the reference method for confirming accuracy of automated differential counts is typically manual microscopic differential count performed by trained technologists, which can be considered a form of "expert consensus" or "gold standard" in hematology.
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The sample size for the training set:
- Not applicable / Not specified. Automated hematology analyzers from this era (1997) typically rely on pre-programmed algorithms based on physical principles (impedance) and defined cell size ranges, rather than machine learning models that require explicit training sets in the modern sense. The "training" would involve extensive engineering, calibration, and validation against known samples to establish the correct parameters for cell differentiation.
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How the ground truth for the training set was established:
- Not applicable / Not specified. As explained above, the device likely relies on established physical principles and pre-defined parameters rather than a machine learning training set with ground truth labels. If any "calibration" or parameter optimization was done against known samples, the ground truth would have been established through a reference method like manual differential counts.
§ 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.”