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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 QStat 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, liver transplantation, and peripartum obstetric 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 analyzer displays the test results (n=5) in three different views: dial display screen, stiffness curves data, and trend screen. The dial display screen is the primary viewing screen and has a dial for each of the five output parameters. Each dial shows the reference range, assay measurement range, parameter abbreviation, and the numerical result for the corresponding parameter. The stiffness curves are a graphical display of shear modulus measurements over time that enable the user to view the development of clot stiffness over time. The trends screen displays results from a patient for up to six time points.

There are two levels of external QStat Controls (QSL1 and QSL2) that are supplied separately (required but not provided materials) for testing on the Quantra System when changing cartridge lots, changing control lots, or after significant changes are made to the Quantra instrument (e.g., software update).

The FDA 510(k) clearance letter for the Quantra QStat Cartridge describes its intended use for evaluating blood coagulation and clot lysis, specifically extending its indication to peripartum obstetric patients. The submission refers to non-clinical and clinical tests to demonstrate the device meets acceptance criteria.

Here's a breakdown of the requested information based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state quantitative acceptance criteria in a table format. However, it describes acceptable performance in relation to interference and clinical agreement.

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size (Clinical Study): 322 subjects
• Data Provenance: Prospective observational study, conducted across seven clinical sites in the US. The study involved parturients (women in labor) aged 18 years or older with concerns for coagulopathy.
• Sample Size (Interference Study): Not explicitly stated with a specific number for the test set, but it mentioned "normal and hypercoagulable whole blood specimens" and that the "number of replicates at each level of a screening study was targeted to provide a 95% confidence interval (2-sided), per CLSI EP07-A2 Guideline."

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

The document does not specify the number or qualifications of experts used to establish ground truth for the clinical test set. Instead, ground truth for some parameters appears to be established by comparison to other legally marketed and established devices (ROTEM delta, TEG 5000) and conventional coagulation testing (aPTT, PT/INR, fibrinogen level, platelet count).

4. Adjudication Method for the Test Set

The document does not describe an adjudication method involving experts for establishing ground truth. The comparison is made against existing, accepted methods and devices.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

There is no mention of a multi-reader multi-case (MRMC) comparative effectiveness study, nor any effect size regarding human reader improvement with or without AI assistance. This device is an in vitro diagnostic (IVD) device that measures coagulation parameters, not an AI-assisted diagnostic imaging or interpretation tool.

6. Standalone (Algorithm Only) Performance Study

Yes, the studies described are standalone performance studies. The clinical and analytical specificity studies evaluate the performance of the QStat Cartridge and Quantra Hemostasis Analyzer directly, not in conjunction with human interpretation for the primary measurement. The comparisons are to other standalone diagnostic methods (ROTEM delta, TEG 5000, conventional coagulation tests).

7. Type of Ground Truth Used

The ground truth used for the clinical performance evaluation was based on:

• Comparison to legally marketed viscoelastic testing devices: ROTEM delta or TEG 5000.
• Comparison to conventional coagulation testing: aPTT, PT/INR, fibrinogen level, platelet count.
• The "concern for coagulopathy" as a trigger for testing suggests clinical suspicion as an initial selection criterion, with the aforementioned tests serving as the gold/reference standard for comparison.

8. Sample Size for the Training Set

The document does not provide information about a separate training set or its sample size. The studies described appear to be focused on performance validation.

9. How the Ground Truth for the Training Set Was Established

As no training set is mentioned, there is no information on how its ground truth was established.

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The Quantra® System is composed of the Quantra Hemostasis Analyzer, QPlus Cartridge, and Quantra Quality Controls Level 1 and 2. The Quantra System is intended for in vitro diagnostic use.

The Quantra Hemostasis Analyzer uses Sonic Estimation of Elasticity via Resonance (SEER) Sonorheometry, an ultrasound-based technology, to measure the shear modulus of whole blood during coagulation. The system is intended to be used by trained professionals at the point-of-care and in clinical laboratories to evaluate the viscoelastic properties of whole blood.

The QPlus Cartridge is a multi-channel cartridge that provides semi-quantitative indications of the coagulation state of a 3.2% citrated venous or arterial whole blood sample. The QPlus Cartridge includes tests to assess coagulation characteristics via the intrinsic pathway, via the extrinsic pathway, and includes tests with a heparin neutralizer. The QPlus Cartridge is indicated for use in cardiovascular or major orthopedic surgeries before, during, and following the procedure.

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 whole blood sample. The QStat Cartridge includes tests to assess coagulation characteristics via the intrinsic pathway, via the extrinsic pathway, and includes a test with tranexamic acid to evaluate clot lysis characteristics. The QStat Cartridge is indicated for use in trauma and liver transplantation procedures.

The Quantra System is indicated for the evaluation of blood coagulation in perioperative patients age 18 years and older to assess possible hypocoagulable and hypercoagulable conditions. Results obtained with the Quantra System should not be the sole basis for patient diagnosis.

The Quantra® System is composed of the Quantra Hemostasis Analyzer, QPlus Cartridge, and Quantra Quality Controls Level 1 and 2. The Quantra Hemostasis Analyzer uses Sonic Estimation of Elasticity via Resonance (SEER) Sonorheometry, an ultrasound-based technology, to measure the shear modulus of whole blood during coagulation. The system is intended to be used by trained professionals at the point-of-care and in clinical laboratories to evaluate the viscoelastic properties of whole blood. The QPlus Cartridge is a multi-channel cartridge that provides semi-quantitative indications of the coagulation state of a 3.2% citrated venous or arterial whole blood sample. The QPlus Cartridge includes tests to assess coagulation characteristics via the intrinsic pathway, via the extrinsic pathway, and includes tests with a heparin neutralizer. 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 whole blood sample. The QStat Cartridge includes tests to assess coagulation characteristics via the intrinsic pathway, via the extrinsic pathway, and includes a test with tranexamic acid to evaluate clot lysis characteristics.

The provided text is a 510(k) summary for a software modification to the Quantra Hemostasis Analyzer. The primary change is extending the QPlus Cartridge maximum assay time for reporting clot stiffness results from 15 minutes to 25 minutes.

Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly present a formal "Acceptance Criteria" table with specific quantitative thresholds. Instead, the "J. CLINICAL AND NON-CLINICAL STUDIES" section describes the studies conducted and their outcomes, which implicitly serve as the demonstration that the device performs acceptably for the modified function.

2. Sample Size Used for the Test Set and Data Provenance:

• Interfering Substance Testing: "similar protocols, acceptance criteria, and sample sizes were utilized" as a previous submission (DEN180017). The exact sample size for this specific study is not explicitly stated in the provided text.
• Precision Testing (Whole Blood Repeatability): The exact sample size is not explicitly stated. It mentions "contrived whole blood requiring an assay time within the extended maximum assay time."
• Clinical Performance Testing: "Clinical samples were collected from adult cardiac surgery patients undergoing treatment in the intensive care unit at a single medical center." The exact number of samples is not explicitly stated. The data provenance is prospective (samples collected for the study) and from a single medical center (country implied to be USA, given FDA submission).

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:

• The document describes a comparative study against a predicate device (ROTEM delta) and evaluations of precision and interference. It does not rely on expert consensus for "ground truth" derived from image interpretation (as would be common for AI/ML in radiology).
• For the clinical performance testing, ground truth is established by the independent measurement from the ROTEM delta, a cleared predicate device.

4. Adjudication Method for the Test Set:

• Since the ground truth is established by comparison to an existing analytical instrument (ROTEM delta) and precision/interference testing, no expert adjudication method (like 2+1 or 3+1 for imaging) is described or relevant for this type of in vitro diagnostic device's performance evaluation.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, What Was the Effect Size of How Much Human Readers Improve with AI vs Without AI Assistance?

• No, an MRMC comparative effectiveness study was not done. This device is an in vitro diagnostic (IVD) measurement system, not an AI-assisted diagnostic imaging interpretation tool. Therefore, the concept of "human readers improving with AI assistance" is not applicable here.

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

• The performance studies described (interference, precision, clinical correlation) evaluate the device's performance as a standalone system in generating the measurements (clot time, clot stiffness, etc.). The device itself is an automated system providing quantitative results. Human intervention is primarily in sample collection, loading, and interpreting the output, but the measurement itself is automated by the device's algorithm.

7. The Type of Ground Truth Used:

• Analytical/Instrumental Ground Truth:
  • For Interfering Substance Testing: The ground truth is the known concentration of the interfering substance and the expected effect on coagulation parameters.
  • For Precision Testing: The ground truth is the consistency/repeatability of the device's own measurements across repeated tests, aiming for low variability.
  • For Clinical Performance Testing: The ground truth is derived from the measurements obtained by the ROTEM delta, which is a widely accepted and cleared predicate device for viscoelastic properties of blood. This is a comparative ground truth against an established method.

8. The Sample Size for the Training Set:

• This is a software modification (extended assay time) for an in vitro diagnostic device. The document does not mention any specific training set in the context of machine learning or AI models. The device's underlying technology (SEER Sonorheometry) is based on physical principles, not on learned patterns from a large training dataset in the way a deep learning algorithm would be. The "training" for this type of device would typically involve calibration and validation during development, but not an "AI training set" as commonly understood.

9. How the Ground Truth for the Training Set Was Established:

• As no AI/ML "training set" is described, this question is not applicable in the context of the provided document. The device's measurements are based on established scientific principles and comparison to a predicate device, rather than a machine learning model that requires a ground-truthed training set.

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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 whole blood sample using the Quantra® Hemostasis Analyzer. The QStat Cartridge includes tests to assess coagulation via the intrinsic pathways and includes a test with tranexamic acid to evaluate clot lysis characteristics.

The QStat 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 conditions in trauma and liver transplantation procedures.

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

For prescription use only.

The QStat Cartridge is a single-use, multi-channel (n=4) disposable plastic cartridge used with the Quantra Hemostasis Analyzer to assess a patient's coagulation and clot lysis (possible hypocoagulable and hypercoagulable conditions) in a hospital setting (point of care or laboratory) during trauma and liver transplantation procedures. The QStat Cartridge consists of four independent channels that can be tested simultaneously with Sonic Estimation of Elasticity via Resonance (SEER) Sonorheometry.

Each QStat Cartridge is pre-filled with reagents individually sealed in an airtight pouch. After a QStat Cartridge is removed from its primary packaging, it is inserted into the instrument dock. A venous 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℃, 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.

Each channel of the cartridge contains prefilled lyophilized reagents in the form of beads that enable differential testing without the need for any reagent preparation or pipetting before testing. The assay provides the following information for each patient sample: Clot Time (CT), Clot Stiffness (CS), Fibrinogen Contribution to Clot Stiffness (FCS), Platelet Contribution to Clot Stiffness (PCS) and Clot Stability to Lysis (CSL).

Here's an analysis of the provided text, extracting the requested information about acceptance criteria and the study proving device performance for the QStat® Cartridge:

Acceptance Criteria and Device Performance for QStat® Cartridge

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size Used for the Test Set and Data Provenance

• Clinical Performance Study (Method Comparison):
  • Sample Size: 289 adult subjects.
  • Data Provenance: Multi-center prospective observational study conducted at thirteen clinical sites in the US.
  • Sample Types: Involved blood samples from subjects undergoing liver transplant surgery, experiencing major trauma, and 5 normal subjects from whom contrived samples were prepared (6.7% of total samples were contrived by spiking blood from normal volunteers).
• Precision/Reproducibility Studies:
  • Single Site: QSL1 (N=80), QSL2 (N=80) for each parameter.
  • Multi-Site: 60 data points per parameter per sample type (unspiked, tPA spiked to CSL threshold, tPA spiked below CSL threshold) across all sites.
  • Whole Blood Repeatability: Varied per study, but generally involved multiple native and contrived samples (total of 16 sample types) and 12 results obtained from each sample type for variance analysis.
  • Data Provenance: Internal HemoSonics studies and external clinical sites within the US.
• Interference Study: "A total of n=13 native and contrived whole blood samples were evaluated for sample stability". Specific sample sizes for each interferent in screening and dose-response studies are not explicitly stated but are described as "n" or "multiple levels", "one or two levels", etc. The study utilized normal whole blood and hypocoagulable whole blood.
• Reference Range Study:
  • Sample Size: 155 healthy men and women volunteers (≥18 years of age).
  • Data Provenance: Multi-center, prospective, observational study across four (4) external sites in the United States.
• Reader Study:
  • Sample Size: 10 readers.
  • Data Provenance: Conducted with potential users who regularly assess blood coagulation status in critical care settings.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts

The document does not explicitly state the number of experts used to establish a ground truth in the traditional sense (e.g., for image labeling). Instead, the "ground truth" or reference for comparison in the method comparison study was the results from the predicate device, ROTEM Delta Thromboelastometry System, which is itself a commercially available and cleared device for similar measurements.

For the Reader Study, the "ground truth" was the correct interpretation of the QStat results displays as determined by the device's design and intended use, rather than an expert panel judging unknown cases.

4. Adjudication Method for the Test Set

Not applicable in the typical sense of expert adjudication of a test set, as the comparison was primarily against a predicate device (ROTEM delta) or against pre-defined control values and reference ranges.

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 MRMC comparative effectiveness study was performed or described in the provided text for comparing AI assistance to human readers. The Reader Study mentioned (Section P.1) was a usability study to assess interpretation of the device's results displays by potential users, not a comparative effectiveness study of AI impact on reader performance.

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

Yes, the primary performance studies listed under "Analytical Performance" (Precision/Reproducibility, Linearity, Stability, Detection Limit, Analytical Specificity) and "Comparison Studies" (Method Comparison with predicate device, Reference Range) all represent standalone performance of the QStat® Cartridge and Quantra Hemostasis Analyzer system without human intervention in the result generation process itself. The system provides semi-quantitative measurements directly.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

• Method Comparison Study: The predicate device (ROTEM delta) served as the comparative "truth" for evaluating linearity and clinical agreement of the QStat parameters. This is a common approach for establishing substantial equivalence for new diagnostic devices.
• Precision/Reproducibility Studies: Pre-defined control materials (QSL1, QSL2) and contrived samples (spiked with tPA, fibrinogen, DOACs) with expected values/characteristics served as the reference.
• Interference Studies: Pre-determined concentrations of known interferents and their expected effects/non-effects.
• Reference Range Study: Healthy volunteers (n=155) were used to establish normal reference intervals.

8. The Sample Size for the Training Set

The document does not provide details of a specific "training set" size. As this is a diagnostic device that measures viscoelastic properties rather than an AI/ML algorithm that predicts outcomes, the concept of a separate "training set" for model development, distinct from analytical and clinical validation data, is not directly applicable or explicitly detailed in this 510(k) summary. The data presented primarily relates to the analytical and clinical validation of the device.

9. How the Ground Truth for the Training Set was Established

As explained under point 8, the document does not discuss a specific "training set" in the context of an AI/ML model. The QStat Cartridge uses "Sonic Estimation of Elasticity via Resonance (SEER) Sonorheometry" to quantify shear modulus, which is a physics-based measurement, not a machine learning prediction. Therefore, the establishment of "ground truth for the training set" is not relevant for this type of device according to the provided text.

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