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The QStat Cartridge is a multi-channel cartridge that provides semi-quantitative indications of the coagulation and clot lysis state of a 3.2% citrated venous or arterial whole blood sample using the Quantra Hemostasis Analyzer. The QStat Cartridge includes tests to assess coagulation via the intrinsic and extrinsic pathways and includes a test with tranexamic acid to evaluate clot lysis characteristics.

The OStat Cartridge is intended for in vitro diagnostic use by trained professionals at the point-of-care and in clinical laboratories to evaluate the viscoelastic properties of whole blood by means of the following functional parameters: Clot Time (CT), Clot Stiffness (CS), Fibrinogen Contribution to Clot Stiffness (FCS), Platelet Contribution to Clot Stiffness (PCS), and Clot Stability to Lysis (CSL).

The QStat Cartridge is indicated for the evaluation of blood coagulation and clot lysis in patients age 18 years and older to assess possible hypocoagulable and hypercoagulable conditions in trauma and liver transplantation procedures.

Results obtained with the QStat Cartridge should not be the sole basis for patient diagnosis.

For prescription use only.

The QStat Cartridge is a single-use, multi-channel disposable plastic cartridge used with the Quantra Hemostasis Analyzer for the evaluation of blood coagulation and clot lysis. The measurements are performed in four test channels of the disposable cartridge which enable differential testing with different sets of reagents without the need for any reagent preparation or controlled pipetting. The cartridge utilizes a citrated evacuated blood collection tube filled with a patient whole blood sample The proprietary technology SEER Sonorheometry measures the evolution of shear modulus (i.e., clot stiffness) in all four channels as a function of time. The QStat Cartridge is intended for use in patients 18 years or older by professionals in a hospital setting (point of care or laboratory) to assess possible hypocoagulable and hypercoagulable conditions in trauma and liver transplantation procedures.

Each QStat Cartridge is pre-filled with lyophilized reagent beads individually sealed in an airtight pouch. After a QStat Cartridge is removed from its primary packaging, it is inserted into the instrument dock. A whole blood sample, collected in a 3.2% sodium citrate anticoagulant blood collection tube (minimum volume 2.7 mL), is attached directly to the cartridge and the test is initiated using the touch screen interface on the Quantra Hemostasis Analyzer. The cartridge is the only component of the Quantra System that is in direct contact with blood. The fluidic system within the instrument draws the sample into the cartridge where it is warmed to 37°C, aliquoted, introduced and mixed with the lyophilized reagents, and analyzed. When the test is complete, the cartridge is released from the dock to be disposed of in an appropriate biosafety sharps container.

The provided text is a 510(k) Premarket Notification from the FDA regarding the HemoSonics QStat Cartridge. The purpose of this submission is to expand the approved sample matrices to include arterial whole blood, in addition to the previously cleared venous whole blood.

The document does not detail a study proving the device meets acceptance criteria in the manner of an AI/ML device, as it concerns an in vitro diagnostic (IVD) device for measuring blood viscoelastic properties. Therefore, many of the requested items (e.g., number of experts, adjudication methods, MRMC study, training sets, ground truth establishment for AI/ML) are not applicable or described in this type of submission.

However, based on the information provided, we can infer some aspects relevant to device performance and the expansion of its indications for use.

Here's an analysis based on the provided text, addressing the applicable points and explaining why others are not relevant in this context:

1. A table of acceptance criteria and the reported device performance

The document defines the device's function and indications for use, but it does not provide a table of quantitative acceptance criteria and reported performance metrics for the device itself (e.g., accuracy, precision) in the context of an AI/ML algorithm evaluation. This is a 510(k) submission for a modification to an existing IVD, primarily focused on expanding the sample type. The "acceptance criteria" here refer to demonstrating substantial equivalence for the new claim (arterial blood).

What is reported is the intent to demonstrate equivalency between arterial and venous whole blood samples.

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

The document states: "HemoSonics is submitting this Special 510(k) to demonstrate the equivalency of arterial and venous whole blood samples analyzed on the Quantra Hemostasis Analyzer with the QStat Cartridge in order to expand the sample matrices accepted on this system."

While it explicitly states the intent to perform a study for equivalency, the sample size and data provenance (country, retrospective/prospective) are not provided in this document. This information would typically be detailed in a separate study report submitted as part of the 510(k) supporting data, which is not included in this high-level summary.

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 question is typically relevant for interpretative devices, especially those using AI/ML where human expert interpretation forms the ground truth. For an IVD like the QStat Cartridge, which measures objective viscoelastic properties of blood, the "ground truth" is established by the accuracy and precision of the measurement itself against a reference method or known values, not by expert consensus on image interpretation. Therefore, this concept of "experts" to establish ground truth does not directly apply here.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

Similar to point 3, adjudication methods are used in AI/ML performance studies where multiple human readers might disagree, and a consensus process is needed to establish ground truth. This is not applicable to a laboratory device that performs quantitative measurements.

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, an MRMC study was not done, nor would it be relevant for this type of device. MRMC studies are specific to evaluating the impact of AI assistance on human reader performance in tasks like image interpretation (e.g., radiology for diagnostic accuracy). The QStat Cartridge is an IVD that provides quantitative measurements of blood coagulation; it does not involve human "readers" interpreting cases in the sense of an AI-assisted diagnostic tool.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

This question is also more applicable to AI/ML software. The QStat Cartridge is a physical device that performs measurements. Its performance is evaluated fundamentally in a standalone manner (the device's ability to accurately measure blood properties), but not in the context of an "algorithm only" as understood for AI/ML. The device generates quantitative parameters (Clot Time, Clot Stiffness, etc.). An "algorithm" within the device would process sensor data to yield these parameters, and the evaluation would focus on the accuracy of these output parameters.

7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)

For an IVD like the QStat Cartridge, the "ground truth" for its measurements would be established through:

• Reference Methods: Comparison of the QStat Cartridge's measurements (Clot Time, Clot Stiffness, etc.) against established, validated reference methods for measuring blood viscoelastic properties or related coagulation parameters.
• Known Samples: Testing with samples having known or characterized coagulation properties (e.g., calibrated controls, samples spiked with known substances).
• Clinical Correlation: While not a direct "ground truth" for the measurement itself, the clinical utility of the device's outputs is validated by correlating its results with patient clinical status or outcomes.

The document states the device provides "semi-quantitative indications" and its results "should not be the sole basis for patient diagnosis," indicating its role as a supportive diagnostic tool. The specific ground truth used for the arterial vs. venous equivalency study is not detailed here, but it would involve comparing measurements from paired arterial and venous samples from the same patient.

8. The sample size for the training set

This question is applicable to AI/ML models. Since this is an IVD device measuring physiological parameters, the concept of a "training set" for an AI model as typically distinguished from a "test set" does not apply in the same way. The device's measurement principles are based on established biophysical principles (SEER Sonorheometry), not on training a machine learning algorithm on a dataset. Any internal "algorithms" would be deterministic or model-based, not learned from data in the AI sense.

9. How the ground truth for the training set was established

Not applicable, as explained in point 8.

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