(274 days)
COULTER® LIN-X Linearity Controls are intended to assess calibration and verify the reportable range of Coulter® Cellular Analysis Systems listed in the TABLE OF EXPECTED RESULTS in conjunction with specific COULTER reagents. Refer to Instructions for Use.
COULTER® LIN-X Linearity Controls are stabilized human blood components whose white blood cells (WBC), red blood cells (RBC), hemoglobin (HGB) and platelets (PLT) concentrations span the instrument's reportable range. Results from repeated measurements for each concentration are compared to the established expected range to assess the instrument's calibration and verify the reportable range.
Here's an analysis of the provided text regarding the COULTER® LIN-X Linearity Control, focusing on acceptance criteria and supporting studies.
Based on the provided K100790 submission for the COULTER® LIN-X Linearity Control, the device is a quality control product, not an AI or diagnostic device that would typically have performance metrics like sensitivity, specificity, or AUC for detecting a condition. Therefore, the acceptance criteria and study designs are geared towards demonstrating the stability and proper assignment of values for a control material, not diagnostic accuracy.
Here's a breakdown of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
For a linearity control, acceptance criteria are generally related to the control material maintaining its specified performance characteristics (e.g., stability, assigned values) over its shelf life and under various conditions. The "performance" is that it "demonstrated acceptable results" within those criteria.
| Acceptance Criteria Category | Reported Device Performance Summary | Specific Study Information from Document |
|---|---|---|
| Open and Closed Vial Stability | Acceptable stability over shelf life. | "Evaluated open and closed vial stability of 3 lots of Level 6 of LIN-X Linearity Control over the shelf life of the product on a DxH™ 300 and DxH™ 300C... LIN-X Linearity Control demonstrated acceptable results." |
| Value Assignment Process | Established process for generating assigned values. | "Value assignment of Level 6 WBC for each lot of LIN-X Linearity Control is determined on validated systems using specific COULTER reagents. Assigned Values are confirmed by multiple analysis of the control product." |
| Range Determination Process | Established WBC expected range for Level 6. | "The expected range for WBC on Level 6 was calculated by a bio-statistician based upon the assigned values and expected ranges of the WBC parameters from Levels 1-5 and 7." |
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
- Test Set Sample Size: For the stability study, it states "3 lots of Level 6". The specific number of individual measurements or vials tested within those lots is not provided. For the value assignment and range determination process, the text refers to "multiple analysis" but does not give a specific number of samples.
- Data Provenance: The document does not explicitly state the country of origin of the data. Given the manufacturer (Beckman Coulter, Inc.) is based in Miami, Florida, USA, and the submission is to the FDA, it is highly probable the studies were conducted in the USA. The studies are prospective in nature, as they involve testing newly manufactured lots and establishing ranges/stability for a new or modified product.
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)
- For the Range Determination Process, "The expected range for WBC on Level 6 was calculated by a bio-statistician". The specific number of biostatisticians or their qualifications (beyond being a "bio-statistician") are not provided.
- For Value Assignment, the text indicates determination "on validated systems" and confirmation by "multiple analysis," implying internal expert processes rather than external expert consensus studies. No specific number or qualification of experts is listed in the typical sense of a clinical diagnostic study.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
This type of adjudication method is not applicable to this device. The device is a linearity control, not a diagnostic tool requiring expert review of findings. The "adjudication" (if one could even call it that) comes from internal laboratory processes and statistical analysis by a biostatistician to establish expected ranges and confirm assigned values.
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
No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic devices (especially those involving image interpretation or complex decision-making, where human performance can be aided by AI). The COULTER® LIN-X Linearity Control is a laboratory quality control product, not a diagnostic or AI-assisted device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
No, a standalone algorithm performance study was not done. This device is a biochemical control, not an algorithm or AI system.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" for a linearity control is its assigned value and established expected range. This is determined through:
- Validated system measurements: Values are determined on "validated systems" using "specific COULTER reagents."
- Multiple analysis: Assigned values are confirmed by "multiple analysis of the control product."
- Statistical calculation: The expected range is calculated by a "bio-statistician" based on assigned values and expected ranges of other levels.
Essentially, the ground truth here is an empirically and statistically established reference value and range for the control material itself, rather than a clinical ground truth like pathology for a patient sample.
8. The sample size for the training set
This concept is not directly applicable. Linearity controls do not use "training sets" in the machine learning sense. The "training" for such a product involves:
- Manufacturing process control: Ensuring consistent quality of the control material.
- Extensive empirical testing: To establish stability and determine precise assigned values and expected ranges. The document mentions "3 lots" for stability, and "multiple analysis" for value assignment, but doesn't quantify this in terms of a "training set" size.
9. How the ground truth for the training set was established
As noted above, there isn't a "training set" in the conventional sense. The "ground truth" (assigned values and expected ranges) for the control is established through:
- Standardized laboratory methods: Using validated instruments and COULTER reagents.
- Repeat measurements: "multiple analysis" confirming assigned values.
- Biostatistical analysis: A biostatistician calculates the expected range based on the empirically determined values and parameters from other known levels of the control. This is a scientific and statistical process for characterizing the properties of the control material itself.
§ 864.8625 Hematology quality control mixture.
(a)
Identification. A hematology quality control mixture is a device used to ascertain the accuracy and precision of manual, semiautomated, and automated determinations of cell parameters such as white cell count (WBC), red cell count (RBC), platelet count (PLT), hemoglobin, hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC).(b)
Classification. Class II (special controls). Except when intended for use in blood components, the device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.