(280 days)
To aid in the detection of platelet dysfunction in citrated human whole blood for use in patients with a suspected disorder of primary hemostasis.
The Dade® PFA-100™ system is an instrument and test reagents in which the process of platelet adhesion and aggregation following a vascular injury is simulated in vitro. Platelet dysfunction detected by the PFA-100 system may be acquired, inherited or induced by platelet inhibiting agents. The PFA-100 system allows for rapid evaluation of platelet function on small samples of anticoagulated whole blood. The single use test cartridge reagents consists of a number of integrated parts including a capillary, a sample reservoir and a biologically active membrane with a central aperture. By application of a constant vacuum, anticoagulated whole blood is aspirated from the sample reservoir through the capillary and the aperture under standardized rheological conditions that expose platelets to high shear stress. The membrane is coated with collagen and one additional agonist. At the beginning of a test, Trigger Solution is dispensed to wet the membrane. Similar to the in vivo mechanism, platelets adhere and aggregate at the aperture thereby gradually diminishing and finally arresting the blood flow. The instrument determines the time from the start of the test until the platelet plug occludes the aperture, and reports that time interval as the Closure Time. Platelet plug formation in the PFA-100 system is dependent on adequate platelet activity and adequate von Willebrand factor status. Therefore, the Closure Time is an indicator of the platelet function in the analyzed whole blood sample.
The Dade PFA-100 Platelet Function Analyzer is intended to aid in the detection of platelet dysfunction in citrated human whole blood for patients with a suspected disorder of primary hemostasis.
1. Table of Acceptance Criteria and Reported Device Performance:
The provided document does not explicitly state pre-defined acceptance criteria. Instead, it compares the performance of the proposed device (PFA-100) to a predicate device (Chrono-log Aggregometer) to demonstrate substantial equivalence. The reported performance of both devices is presented below:
| Metric | Proposed Device (PFA-100) | Predicate Device (Chrono-log Aggregometer) |
|---|---|---|
| Clinical Sensitivity | 96.1% | 97.4% |
| Clinical Specificity | 88.6% | 91.5% |
| Overall Agreement | 90.1% | - |
The study concludes that the Clinical Sensitivity and Specificity of the proposed device are "statistically comparable" to those of the predicate device, indicating that the device meets the implied acceptance of being equivalent to the existing market standard.
2. Sample Size and Data Provenance for the Test Set:
- Sample Size: A total of 328 specimens were tested.
- 176 samples were from subjects with normal platelet function.
- 152 samples were from subjects with platelet dysfunction (von Willebrand disease, aspirin-induced dysfunction, and Glanzmann's thrombasthenia).
- Data Provenance: The document does not explicitly state the country of origin. The study was a clinical study, which typically implies prospective data collection, but it's not explicitly stated if it was fully prospective or included retrospective components. The samples were collected from subjects representing 63% females and 37% males.
3. Number of Experts and Qualifications for Ground Truth:
The document does not specify the number of experts used to establish the ground truth for the test set or their qualifications.
4. Adjudication Method for the Test Set:
The document does not describe any specific adjudication method (e.g., 2+1, 3+1) for the test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No MRMC comparative effectiveness study was explicitly described in the provided text. The study focused on comparing the device's performance to a predicate device, not on the improvement of human readers with AI assistance.
6. Standalone Performance Study:
Yes, a standalone performance study was conducted. The "Clinical Sensitivity" and "Clinical Specificity" values reported for the "Proposed Device PFA-100" represent its standalone performance in detecting platelet dysfunction. The overall agreement with the predicate device also indicates its standalone performance compared to an existing method.
7. Type of Ground Truth Used:
The Platelet Function Status for each sample (used as the ground truth) was based upon "results from a platelet function test panel and clinical history." This suggests a combination of objective clinical laboratory tests and expert clinical judgment.
8. Sample Size for the Training Set:
The document does not mention a separate "training set" or its sample size. The study described appears to be a validation study for the device, comparing its performance to a predicate using the entire collected dataset. This type of device relies on established biological principles and may not involve a machine learning training phase in the traditional sense.
9. How Ground Truth for the Training Set Was Established:
As no separate training set is mentioned, this information is not applicable.
§ 864.5700 Automated platelet aggregation system.
(a)
Identification. An automated platelet aggregation system is a device used to determine changes in platelet shape and platelet aggregation following the addition of an aggregating reagent to a platelet-rich plasma.(b)
Classification. Class II (performance standards).