(63 days)
The Pacific Hemostasis ThromboScreen® 200 is a photo-optical instrument used for the performance of in-vitro diagnostic coagulation testing of citrated plasma specimens in the clinical laboratory. Coagulation testing capabilities of the device include routine clotting tests such as Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Fibrinogen (Clauss and Derived methods), as well as PT and APTT-based factor assays.
The ThromboScreen® 200 (TS200) is a photo-optical instrument used for the performance of invitro diagnostic clotting procedures in the clinical laboratory. The instrument utilizes photo-optical principles to measure and record the time required for patient plasma specimens to clot. The ThromboScreen® 200 light source is provided by a 470 nm LASER. The incubator block is temperature regulated to 36.5 - 37.5℃ and contains two measuring positions, three reagent and 12 cuvette prewarming positions.
Here's an analysis of the provided text regarding the ThromboScreen® 200, structured to answer your questions:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the comparison to predicate devices (MLA-900C and MLA-1000C). The ThromboScreen® 200 must demonstrate comparable performance in terms of correlation coefficients and precision.
| Test (Reagent, Unit) | Acceptance Criteria (Implied: Comparable to Predicate) | ThromboScreen® 200 Performance (Correlation Coefficient, r) | ThromboScreen® 200 Performance (%CV for within-run precision) | ThromboScreen® 200 Performance (%CV for between-run precision) | Predicate Performance (%CV for within-run precision) | Predicate Performance (%CV for between-run precision) |
|---|---|---|---|---|---|---|
| Prothrombin Time (PT) (Thromboplastin DS, seconds) | High correlation (e.g., >0.90-0.95), comparable precision | 0.98, 0.99 | 1.9, 2.0, 2.8 (Normal); 2.3, 5.7, 3.2 (High) | 1.7% (Normal), 5.9% (Abnormal) | 1.1, 1.5, 1.0 (Normal); 2.8, 2.0, 2.8 (High) | 1.4% (Normal), 8.1% (Abnormal) |
| Prothrombin Time (Thromboplastin DS, INR) | High correlation (e.g., >0.90-0.95), comparable precision | 0.98, 0.99 | Included with PT seconds | Included with PT seconds | Included with PT seconds | Included with PT seconds |
| Activated Partial Thromboplastin Time (APTT-LS reagent, seconds) | High correlation (e.g., >0.90-0.95), comparable precision | 0.98, 0.97 | 5.1, 4.7, 3.3 (Normal); 1.6, 2.3, 2.5 (High) | 3.6% (Normal), 2.8% (Abnormal) | 1.4, 3.3, 0.9 (Normal); 2.9, 2.2, 1.2 (High) | 4.3% (Normal), 7.5% (Abnormal) |
| Clauss Fibrinogen (PH Thrombin reagent, mg/dL) | High correlation (e.g., >0.90-0.95), comparable precision | 0.99, 0.98, 0.98 | 6.7 (Low), 6.8 (Normal), 5.0 (High) | Not specified | 2.0 (Low), 2.1 (Normal), 2.8 (High) | Not specified |
| Derived Fibrinogen (Thromboplastin DS, mg/dL) | High correlation (e.g., >0.90-0.95), comparable precision | 0.99, 0.99 | 5.6 (Low), 2.5 (Normal), 4.1 (High) | Not specified | 2.2 (Low), 3.4 (Normal), 2.1 (High) | Not specified |
| Factor VIII (APTT-LS, % activity) | High correlation (e.g., >0.90-0.95), comparable precision | 0.97 | 9.6 (Low), 10.2 (Normal) | Not specified | 5.3 (Low), 4.7 (Normal) | Not specified |
| Factor V (Thromboplastin DS, % activity) | High correlation (e.g., >0.90-0.95), comparable precision | 0.97 | 2.3 (Low), 2.5 (Normal) | Not specified | 4.0 (Low), 2.0 (Normal) | Not specified |
Summary of Device Performance Meeting Acceptance Criteria:
The study demonstrates high correlation coefficients (ranging from 0.97 to 0.99) for all tested parameters when comparing the TS200 to the predicate devices. The precision data (within-run %CV and between-run %CV) for the TS200 also falls within a similar range or is sometimes better than the predicate devices, supporting the claim of substantial equivalence. For instance, for PT and APTT between-run precision, the TS200 shows comparable or better CVs than the predicate devices in several categories (e.g., PT Normal Plasma, APTT Abnormal Plasma). This suggests the device meets the implied acceptance criteria of performing comparably to legally marketed predicate devices.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Sizes for Correlation Studies (Test Set):
- Prothrombin Time (PT): Site #1 (137 samples), Site #2 (141 samples)
- Activated Partial Thromboplastin Time (APTT): Site #1 (104 samples), Site #2 (121 samples)
- Clauss Fibrinogen: Site #1 (20 samples), Site #2 (20 samples), PH (49 samples)
- Derived Fibrinogen: Site #1 (19 samples), Site #2 (47 samples)
- Factor VIII: PH (49 samples)
- Factor V: PH (45 samples)
- Sample Sizes for Precision Studies (Test Set):
- PT & APTT Between-run: Normal Plasma (n=39 for TS200, n=40 for MLA), Abnormal Plasma (n=38 for TS200 PT, n=40 for MLA PT; n=40 for TS200 APTT, n=40 for MLA APTT).
- Within-run: Not explicitly stated as a number of independent samples for each CV, but rather performed on "Low," "Normal," and "High" control levels. Usually, precision studies involve a certain number of replicates over a set number of days.
- Data Provenance: The data was collected from "in-house" (Pacific Hemostasis, PH) and "two external testing laboratories." The document states that "Specimens were evaluated from apparently healthy individuals and from patients with different pathological conditions." The country of origin is not explicitly stated, but given the submission to the FDA (USA), it's highly probable the data originated in the USA. The study is prospective in the sense that fresh clinical samples were collected and tested on both the new device and predicate devices for comparison.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This type of device (manual coagulation instrument) does not typically involve human expert interpretation for establishing ground truth in the same way an image analysis device would. The "ground truth" for the test set is established by the results obtained from the legally marketed predicate devices (MLA-900C and MLA-1000C), which are considered the reference standard for these in-vitro diagnostic assays. Therefore, no human experts for "ground truth interpretation" are detailed or required in this context. The experts involved are likely laboratory personnel who performed the tests on both instruments, ensuring proper methodology.
4. Adjudication Method for the Test Set
Not applicable. The study is a method comparison study where the new device's results are directly compared to those of predicate devices. There is no ambiguous output from the device that would require adjudication by experts.
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 is an in-vitro diagnostic instrument for coagulation testing, not a medical imaging device or a device involving human "readers" or AI assistance in interpretation.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the study primarily evaluates the standalone performance of the ThromboScreen® 200 instrument itself (algorithm only, if one considers the photo-optical clot detection as an "algorithm") against predicate instruments. The instrument provides a direct numerical readout (clotting time, concentration, etc.), and the study assesses its accuracy and precision in generating these results independently. Human intervention is limited to sample preparation and loading, which is standard for manual/semi-automated lab instruments.
7. The Type of Ground Truth Used
The ground truth is established by the results obtained from the legally marketed predicate devices (MLA-900C and MLA-1000C). These predicate devices are considered reliable and accurate for measuring coagulation parameters. The study assumes that if the ThromboScreen® 200 produces results highly correlated and comparable in precision to these established methods, then its measurements are also accurate.
8. The Sample Size for the Training Set
There is no mention of a "training set" in the context of this device and study. The ThromboScreen® 200 is an instrument that measures a physical property (clotting time) using photo-optical principles. It does not appear to involve machine learning or algorithms that require a separate training phase with labeled data in the way an AI-powered diagnostic might. The device's operational parameters (e.g., 470 nm laser, 37°C incubator) are fixed by its design and engineering, not trained on a data set.
9. How the Ground Truth for the Training Set was Established
Not applicable, as there is no specific "training set" described for this type of device.
§ 864.5400 Coagulation instrument.
(a)
Identification. A coagulation instrument is an automated or semiautomated device used to determine the onset of clot formation for in vitro coagulation studies.(b)
Classification. Class II (special controls). A fibrometer or coagulation timer intended for use with a coagulation instrument is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.