(154 days)
The STA® - Liatest® Free PS kits are intended for use with analyzers of the STA® line suitable with these reagents for the antigenic assay of free Protein S in plasma by the immuno-turbidimetric method.
The STA® - Liatest® Free PS test kit is comprised of a suspension of latex microparticles coated with two (2) different mouse monoclonal anti-human free protein S antibodies stabilized with bovine albumin. Also in the test kit is an HEPES buffer. Testing is carried out in citrated human plasma via the immunoturbidimetric method utilizing external calibrator plasmas for the STA® - Liatest Free PS (the predicate device is pre-calibrated, not utilizing external calibrator plasmas).
Here's an analysis of the provided text regarding the STA® - Liatest® Free PS device, focusing on acceptance criteria and study information.
It's important to note that the provided documents are a 510(k) Summary and an FDA clearance letter. These typically focus on demonstrating substantial equivalence to a predicate device rather than detailing specific de novo clinical study results, acceptance criteria, and performance for this specific device modification as if it were a new device. The provided text does not include detailed acceptance criteria or a dedicated study proving performance against such criteria in the way a clinical trial might for a novel device. Instead, it highlights the device's technological characteristics and argues for substantial equivalence to a previously cleared predicate device.
Therefore, the answers below are derived from the information available and will reflect the nature of a 510(k) submission, which often relies on comparison to a predicate rather than extensive new performance studies for minor modifications.
1. Table of Acceptance Criteria and Reported Device Performance
The documents do not present specific, quantitative acceptance criteria (e.g., minimum sensitivity, specificity, accuracy targets) for the modified STA® - Liatest® Free PS device, nor do they report detailed performance results against such criteria. The primary "performance" being assessed here is its equivalence to the predicate device.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not explicitly stated as quantitative targets for the modified device. The submission focuses on demonstrating substantial equivalence to the predicate device (STA® - Liatest® Free Protein S, K010963) rather than proving performance against new, specific numerical thresholds. | Substantial Equivalence: The modified device (STA® - Liatest® Free PS) is deemed substantially equivalent to the predicate device in terms of indication/intended use, formulation/materials, technology, and safety. The primary difference (use of external calibrator vs. pre-calibrated) is accounted for in the procedure. |
| Technological characteristics matching predicate or being adequately addressed. | The modified device maintains the immuno-turbidimetric method using latex microparticles coated with anti-human free protein S antibodies. The change is in the calibration method. |
| Safety and Effectiveness (implied via equivalence). | The submission concludes "yielding no new questions in safety, effectiveness, or technology" compared to the predicate device. |
2. Sample Size Used for the Test Set and Data Provenance
The documents do not mention a specific "test set" and sample size for performance evaluation in the context of a new clinical study for this modified device. The determination of substantial equivalence relies on comparing the modified device's characteristics to those of the predicate device.
- Sample Size for Test Set: Not specified.
- Data Provenance: Not specified, as a new study with a specific data set for the modified device's performance is not detailed.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided. Given that this is a 510(k) for a modification (calibration method) to an in-vitro diagnostic device, and not a de novo submission requiring extensive new clinical validation of diagnostic accuracy, expert consensus for ground truth on a new test set would not typically be a primary focus. The focus is on ensuring the calibration change does not negatively impact the performance established by the predicate.
4. Adjudication Method for the Test Set
Not applicable, as no new test set requiring expert adjudication for ground truth is described in the provided text.
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
Not applicable. This device is an in-vitro diagnostic (IVD) kit for measuring Protein S in plasma using an automated analyzer (STA® line). It is not an AI-assisted diagnostic tool that involves human readers interpreting images or results, nor is it a device that would undergo an MRMC study.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
This refers to an IVD device's standalone performance, which is inherent in its operation. The device is a "kit" that works with analyzers of the STA® line. Its performance would be based on its ability to accurately measure free Protein S. While the document asserts substantial equivalence, it doesn't detail a standalone performance study with specific metrics (e.g., precision, accuracy, linearity) for this specific modification's impact. Such studies would typically be part of the product development and validation for the modified device, but their results are summarized as "no new questions in safety, effectiveness, or technology" rather than presented in detail in the 510(k) summary.
7. The Type of Ground Truth Used
For an IVD device like this, "ground truth" typically refers to:
- Accurate analyte concentrations: Established through reference methods, certified calibrators, or internal validation processes.
- Clinical outcomes: Correlating measurements with patient disease status (e.g., deficiency vs. normal).
The document implies that the ground truth for establishing the performance of the predicate device (which the modified device is compared to) would have involved such methods. For the modified device, the "ground truth" for demonstrating equivalence would revolve around showing that the new calibration method yields results consistent with the predicate device and accurately reflects the concentration of Free Protein S. The mention of "external calibrator plasmas" for the modified device suggests that its calibration curve is established against known concentrations using these calibrators.
8. The Sample Size for the Training Set
The concept of a "training set" is primarily relevant for machine learning or AI-driven devices. This IVD kit does not involve a machine learning algorithm that is "trained" on a dataset in the conventional sense. Its "training" involves the use of calibrators to establish a standard curve for quantitative measurement, but this is a different paradigm from AI training. Therefore, a "training set sample size" as commonly understood in AI/ML is not applicable.
9. How the Ground Truth for the Training Set Was Established
As explained above, there is no "training set" in the AI/ML sense. For the calibration process, the "ground truth" is established by the Diagnostica Stago's STA® - Free PS Calibrator which are presumably plasmas with known, verified concentrations of free Protein S. The process of how those calibrator values were established (e.g., against a recognized reference method or material) is not detailed in these documents but would be part of the manufacturer's quality system and product development.
§ 864.7290 Factor deficiency test.
(a)
Identification. A factor deficiency test is a device used to diagnose specific coagulation defects, to monitor certain types of therapy, to detect coagulation inhibitors, and to detect a carrier state (a person carrying both a recessive gene for a coagulation factor deficiency such as hemophilia and the corresponding normal gene).(b)
Classification. Class II (performance standards).