(71 days)
In combination with approved microplate tests (such as the Bartels manufactured, Zymmune™ CD4/CD8 Cell monitoring assay kit) the Zymmune™ Auto-Reader F [with software] is intended for use for in vitro quantification and monitoring of T-cell levels.
The Zymmune™ Auto-Reader F is a microplate reader that measures relative fluorescence signals from samples in a 96-well microplate. The Auto-Reader F is designed to be used with integrated software which collects and reports the measurements made by the microplate reader.
The provided text describes the Zymmune™ Auto-Reader F, a fluorescence microplate reader designed to quantify and monitor T-cell levels. Here's an analysis of its acceptance criteria and the study performed:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state acceptance criteria in a quantitative format. However, the study aims to demonstrate "excellent correlation" between the Zymmune™ Auto-Reader F (with software) and the predicate device (Fluoroskan with manual calculations). The reported device performance is presented as:
| (n=70) | Slope | Intercept | Correlation Coefficient | Acceptance Criteria (Implicit) |
|---|---|---|---|---|
| CD4 T-lymphocyte | 1.018 | 3.6 | 0.994 | Strong correlation (e.g., R > 0.9) and slopes near 1, intercepts near 0 |
| CD8 T-lymphocyte | 1.035 | -3.8 | 0.992 | Strong correlation (e.g., R > 0.9) and slopes near 1, intercepts near 0 |
| CD4/CD8 ratio | 0.982 | 0 | 0.989 | Strong correlation (e.g., R > 0.9) and slopes near 1, intercepts near 0 |
The "Implicit Acceptance Criteria" are inferred from the conclusion stating "Analysis showed excellent correlation" and the high R-values and slopes close to 1 with intercepts close to 0, which are standard indicators of strong agreement in correlation studies.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: 70 clinical samples.
- Data Provenance: The document does not specify the country of origin. It indicates "clinical samples," suggesting they were obtained from patient populations, but does not state whether they were collected retrospectively or prospectively.
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)
This information is not provided in the document. The ground truth for the test set is established by the predicate device (Fluoroskan) with manual calculations using an FDA-reviewed assay kit, not by human experts adjudicating results.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
There was no adjudication method described for the test set in the traditional sense of human experts reviewing cases. The comparison was device-to-device, with the predicate device's output (processed manually) serving as the reference.
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, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study focuses on the performance of a device (Autoreader-F with integrated software) compared to another device (Fluoroskan with manual calculations), not on the improvement of human readers with AI assistance. The Zymmune™ Auto-Reader F integrates software, but the study design is not an MRMC study assessing human performance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance evaluation of the Zymmune™ Auto-Reader F (which includes an integrated software element that utilizes algorithms) was done. The device directly produces CD4 and CD8 T-lymphocyte counts and a CD4/CD8 ratio from the fluorescent signals without human intervention in the calculation process from signal to result. This standalone performance was then compared to the predicate device's results.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The ground truth for this correlation study was established by the predicate device (Flow Laboratories Fluoroskan Reader) combined with manual calculations using the algorithms provided in the FDA-reviewed Zymmune™ CD4/CD8 Cell Monitoring Kit. This can be considered a "reference method" ground truth, where another established and validated method is used as the standard.
8. The sample size for the training set
The document does not specify a separate "training set" size. The 70 clinical samples are described as being used to "validate the performance of the Autoreader-F" which implies it's a test set for performance comparison. It's possible that the algorithms within the integrated software were developed/trained previously, but the document does not provide details on that process or sample size.
9. How the ground truth for the training set was established
As no specific training set is detailed, information on how its ground truth was established is not provided in this document. The integrated software utilizes "algorithms appearing in the Zymmune™ CD4/CD8 Monitoring kit," suggesting these algorithms were previously developed and validated, likely with their own ground truth established during the development of that kit (K933878).
§ 866.4520 Immunofluorometer equipment.
(a)
Identification. Immunofluorometer equipment for clinical use with its electrical power supply is a device used to measure the fluorescence of fluorochrome-labeled antigen-antibody complexes. The concentration of these complexes may be measured by means of reflected light. A beam of light is passed through a solution in which a fluorochrome has been selectively attached to serum protein antibody molecules in suspension. The amount of light emitted by the fluorochrome label is detected by a photodetector, which converts light energy into electrical energy. The amount of electrical energy registers on a readout system such as a digital voltmeter or a recording chart. This electrical readout is called the fluorescence value and is used to measure the concentration of antigen-antibody complexes.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 866.9.