(50 days)
The Von Willebrand Reagent is intended for the determination of the ristocetin cofactor activity in human plasma.
Von Willebrand Reagent is used for the determination of ristocetin cofactor activity in human plasma. The determination of ristocetin cofactor activity is important in:
- The diagnosis of Von Willebrand's disease.
- The diagnosis of diseases characterized by changes in the ristocetin cofactor.
- Pre-operative screening of haemorrhagic diatheses.
The Von Willebrand Reagent consists of lyophilized platelets and ristocetin.
The provided text describes a 510(k) premarket notification for a medical device called "Von Willebrand Reagent" by Behring Diagnostics. The key information for determining acceptance criteria and the study that proves the device meets them is in the "510(k) SUMMARY OF SAFETY AND EFFECTIVENESS" section (page 2).
Here's a breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" with pass/fail thresholds in a formal table format. However, it reports performance characteristics and compares them to a predicate device, implying these are the metrics used for demonstrating substantial equivalence. Acceptance is based on the substantial equivalence to the predicate device, Helena Laboratories Ristocetin Cofactor Assay.
| Performance Characteristic | Acceptance Criteria (Implied by Comparison) | Reported Device Performance (Von Willebrand Reagent) |
|---|---|---|
| Comparative Analysis | ||
| Correlation Coefficient | High correlation to predicate device | 0.94 (vs. predicate device) |
| Slope | Close to 1 (vs. predicate device) | 0.97 (vs. predicate device) |
| Y-intercept | Close to 0 (vs. predicate device) | -4.4 (vs. predicate device) |
| Precision | ||
| Within-run precision | Acceptable range for diagnostic assay | 6.1% to 16.2% |
| Total precision | Acceptable range for diagnostic assay | 7.6% to 16.9% |
2. Sample Size and Data Provenance for the Test Set
- Sample Size for Test Set: A total of 70 patients (normal and pathological samples).
- Data Provenance: Not explicitly stated, but given the manufacturer (Behring Diagnostics GmbH, Marburg, Germany) and contact information (San Jose, CA, USA), it's likely a prospective study conducted for regulatory submission. The country of origin of the data is not specified.
3. Number of Experts and their Qualifications for Ground Truth
- This information is not provided in the document. The determination of "normal and pathological samples" for Von Willebrand disease is usually based on clinical diagnosis and often confirmed by laboratory tests, but the specific process for establishing ground truth for these specific samples (e.g., number of clinicians, their specialties, and experience) is not detailed.
4. Adjudication Method for the Test Set
- This information is not provided in the document. For laboratory assays like this, ground truth is typically assessed by established diagnostic criteria and reference methods rather than expert adjudication in the same way as, for example, image interpretation.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. This device is an in-vitro diagnostic reagent, not an imaging device or AI-assisted diagnostic tool that would typically involve multiple human readers interpreting results. The comparison is between the new reagent and a predicate reagent.
6. Standalone Performance Study
- Yes, a standalone performance study was done for the Von Willebrand Reagent. The "Comparative Analysis" and "Precision" sections describe the device's performance characteristics in determining ristocetin cofactor activity, independent of human interpretation or assistance beyond standard laboratory procedures.
7. Type of Ground Truth Used
- The ground truth was based on clinical classification of "normal and pathological samples" combined with the results from the predicate device (Helena Laboratories Ristocetin Cofactor Assay), against which the new device's performance was compared using regression analysis.
8. Sample Size for the Training Set
- The document does not mention a separate training set. For in-vitro diagnostic reagents of this type, the development often involves optimization and verification using various samples, but a formally defined "training set" in the context of machine learning is not applicable here. The 70 patients mentioned are for the comparative analysis and likely serve as the primary validation dataset.
9. How the Ground Truth for the Training Set was Established
- As no separate training set is mentioned, this information is not applicable.
§ 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).