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The TEG® 6s Hemostasis System consists of the TEG 6s Hemostasis Analyzer and TEG 6s Citrated: K, RT, FF Assay Cartridge. The TEG 6s Hemostasis System is intended for in vitro diagnostic use to provide semi-quantitative indications of the hemostasis state of a venous blood sample. The TEG 6s Hemostasis System records the kinetic changes in a sample of 3.2% citrated whole blood as the sample clots.

The Citrated: K, RT, FF Assay Cartridge contains three independent assays (CK, CRT and CFF) and the system output consists of a table of numerical values for parameters R, LY30, and MA.

The CK assay monitors the hemostasis process via the intrinsic pathway in 3.2% citrated whole blood specimens on the TEG 6s Hemostasis System. Clotting characteristics are described by the functional parameters R (clotting time) and L Y 30 (fibrinolysis after 30 minutes of reaching maximum clot strength).

The CRT assay monitors the hemostasis process via both the intrinsic pathways in 3.2% citrated whole blood specimens on the TEG 6s Hemostasis System. Clotting characteristics are described by the functional parameter MA (maximum clot strength).

The CFF assay monitors hemostasis of 3.2% citrated whole blood specimens in the TEG 6s Hemostasis System after blocking platelet contributions to clot strength. Clotting characteristics are described by the functional parameter MA (maximum clot strength).

Results from the TEG 6s analysis should not be the sole basis for a patient diagnosis, but should be evaluated together with the patient's medical history, the clinical picture and, if necessary, further hemostasis tests. The indication for TEG 65 Hemostasis System use is with adult patients (18 years and older) where an evaluation of their blood hemostasis properties is desired. Hemostasis evaluation with the TEG 6s Hemostasis System using the Citrated: K, RT, FF Assay Cartridge is used to assess clinical conditions in a trauma setting to assess hemorrhage or thrombosis conditions.

For professional use only.

The TEG® 6s Hemostasis System (TEG® Hemostasis analyzer and TEG® 6s Assay Cartridges) is intended for in vitro diagnostic use to provide semi-quantitations of a blood sample's ability to form and maintain a clot. The TEG® 6s Hemostasis System records the kinetic changes in a sample of whole blood as the sample clots, retracts and/or lyses. The system output consists of a table of numerical values resulting from the hemostasis process over time. This information can be used by clinicians to aid in determining if a dysfunction or coagulopathy is present.

To perform a test, a disposable TEG® 6s Assay Cartridge is inserted into the TEG® 6s Hemostasis analyzer. The instrument reads the bar code on the cartridge and identifies the type of cartridge for operator confirmation. Blood (collected in a 3.2% sodium citrate tube) or Quality Control (QC) material is added to the entry port on the cartridge and drawn into the cartridge under the TEG® 6s Hemostasis analyzer control. The amount of the sample drawn into the cartridge is determined by the pre-set volume of the blood chambers in the cartridge. Once in the cartridge, the sample is metered into as many as 4 separate analysis channels, depending upon the assays being performed. Reconstitution of reagents dried within the cartridge is accomplished by moving the sample back and forth through reagent chambers, under the control of microfluidic valves and bellows (pumps) within the cartridge. After each sample has been mixed with reagent, it is delivered to a test cell where it is monitored for viscoelastic changes due to coagulation. Excess sample material is moved under microfluidic control into an enclosed waste chamber within the cartridge.

The TEG® 6s technology is based on a disposable cartridge containing up to 4 independent measurement cells. Each cell consists of a short vertically-oriented injection molded tube (ring). Detection of clotting in the TEG® 6s Hemostasis System is performed optically. A piezoelectric actuator vibrates the measurement cell(s) through a motion profile composed of summed sinusoids at different frequencies. The movement of the measurement cells will induce motion in the sample meniscus, which will be detected by a photodiode. The resulting motion of the meniscus is monitored optically and analyzed by the instrument to calculate the resonant frequency and modulus of elasticity (stiffness) of the sample. By performing a Fast Fourier Transform (FFT) on meniscus motion data, the resonant frequencies can be determined. The analyzer monitors the harmonic motion of a hanging drop of blood in response to external vibration. As the sample transitions from a liquid state to a gel-like state during clotting, the modulus of elasticity (stiffness) and therefore resonant frequency increase. The TEG® 6s Hemostasis analyzer measures these variations in resonant frequency during clotting and lysis.

This document describes the TEG® 6s Hemostasis System, an in vitro diagnostic device used to provide semi-quantitative indications of the hemostasis state of a venous blood sample.

Here’s an analysis of the acceptance criteria and the study proving the device meets them:

1. Table of Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state "acceptance criteria" for performance in a pass/fail format with exact numerical thresholds for all evaluated aspects. Instead, it details various performance characteristics and states that the data "supports a substantial equivalence determination." However, based on the performance testing presented, we can infer the implicit acceptance criteria by observing the reported results and the conclusions drawn.

• CK R (minutes): 4.6 - 9.1 (n=157)
• CK LY30 (percent): 0.0 - 2.6 (n=132)
• CRT MA (mm): 52 - 70 (n=152)
• CFF MA (mm): 15 - 32 (n=151) |
  | Analytical Precision: Demonstrated across different coagulation levels (hypo, normal, hyper) and sample types (natural, contrived, patient-derived), using CLSI EP5-A2 guidance with acceptable Standard Deviations (SD) and Coefficients of Variation (%CV). | Three precision studies were conducted. Results (SD and %CV) were reported across reagent lots, operators, instruments, and days for various parameters and sample types (Hypo, Normal, Hyper donors; Contrived samples with Dabigatran/Cytochalasin D/ReoPro, Kaolin/RiaStap; Patient-derived samples with Dabigatran/Warfarin; and low/high/no tPA for LY30). The values are presented in Tables 5, 6, 7, and 8, indicating the device maintains precision across these conditions. (Specific numeric thresholds for "acceptable" are not given, but the presentation implies the results are within acceptable industry limits for such a device). |
  | Interference: Identifies interfering factors and limits for CRT and CFF assays. | For CK assay, no interfering factors were found among: Absence of a Discard Tube, Short Draw, Hemolysis, Hemodilution, Direct Oral Anticoagulants (FXa and direct thrombin inhibitors), Antiplatelet Drug (P2Y12 inhibitor).
  For CRT assay, Hemolysis and Hemodilution above 30% were found to be interfering factors.
  For CFF assay, Hemodilution above 40% was found to be an interfering factor. |
  | Method Comparison (Equivalency to Predicate Device): Slopes of linear regression lines close to 1.0 (with 95% CI containing 1.0), acceptable predictive bias relative to acceptance criteria, and high Pearson linear correlation (>0.9 for identical parameters, 0.86 for CRT MA vs CK MA). | The linear regression slope estimates for all between-device comparisons were close to 1.0, with their respective 95% confidence intervals all containing 1.0 (range 0.99 to 1.06).
  The assessment of predictive bias and its 95% confidence interval relative to the bias acceptance criteria supports equivalency according to CLSI EP09-A3.
  Predicted biases at AMR limits were consistent with reference range limits.
  Pearson linear correlation estimates were above 0.9 for all identical parameters. The correlation for CRT MA (TEG® 6s) and CK MA (TEG® 5000) was 0.86.
  Conclusion: The method comparison data strongly supports the correlation between TEG® 6s and the TEG® 5000. |

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

• Reference Ranges:

  • CK R: 157 samples
  • CK LY30: 132 samples
  • CRT MA: 152 samples
  • CFF MA: 151 samples
  • Provenance: Citrated whole blood from normal donors, representative of normal population distributions (age, gender, race), with no known coagulopathies and not taking any drugs that would potentially affect patient hemostasis. (Implies prospective collection for range establishment).

• Analytical Precision (First Study):

  • Sample Size: Blood from 4 donors (2 Hypo, 1 Normal, 1 Hyper). Run in duplicate for 5 non-consecutive days, across 3 reagent lots, by 2 operators, using 12 analyzers. Each data point in Table 5 represents n=120 replicates.
  • Provenance: Donors with natural coagulation levels (Hypo, Normal, Hyper). (Implies prospective collection from specific donor profiles).

• Analytical Precision (Second Study - Contrived/Patient-Derived):

  • Sample Size:
    • 3 contrived samples (Hypo, Hyper types)
    • 4 patient-derived dabigatran samples
    • 2 patient-derived warfarin samples
    • Each run in duplicate for 5 non-consecutive days, by 3 operators, using up to 12 analyzers. Each data point in Tables 6 and 7 represents N=12 replicates per parameter/sample/patient ID.
  • Provenance: Contrived samples (blood from normal donors spiked with drugs/reagents). Patient-derived samples (blood from clinical patients being treated with therapeutic levels of anticoagulants). (Combination of prospective collection for spiking and retrospective/prospective from clinical patients).

• Analytical Precision (Third Study - CK LY30):

  • Sample Size: 3 sample types (no tPA, low tPA, high tPA). 12 replicates per sample type, by 3 operators, using 3 reagent lots for 5 days. Each data point in Table 8 represents N=58 to N=60 replicates.
  • Provenance: Normal donors (for no tPA) and normal donor blood spiked to create low/high tPA samples. (Implies prospective collection for spiking).

• Method Comparison:

  • Sample Size:
    • CFF MA: 450 samples
    • CK R: 405 samples
    • CK LY30: 86 samples
    • CRT MA vs. CK MA: 336 samples
  • Provenance: Conducted at 12 US clinical sites, enrolling adult patients (18+ years) who met full or limited trauma team criteria of the American College of Surgeons or similar institutional guidelines. (This indicates prospective, multi-center, real-world clinical data collection).

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

For this device, the "ground truth" is typically established by the inherent physical properties of the blood samples (clotting characteristics) and comparison to an established predicate device (TEG® 5000), not by human expert interpretation of results in the traditional sense of image analysis or diagnostic decision-making.

• Reference Ranges: Established using samples from "normal donors" with "no known coagulopathies." The determination of "normal" is likely based on standard medical criteria, possibly verified by physicians or lab personnel, but not explicitly stated as "expert consensus" in the document.
• Precision Studies: Ground truth is the measured value of the parameters (R, MA, LY30) from the samples themselves, along with their known characteristics (e.g., "hypo," "hyper," spiked with certain drugs). This is measured intrinsically by the device itself, not by external human experts.
• Method Comparison: The predicate device, TEG® 5000, serves as the "ground truth" or reference for comparison. The study assesses how closely the TEG® 6s results correlate with the TEG® 5000, rather than comparing to a diagnostic expert's opinion. Clinical experts (physicians) would ultimately interpret both TEG® 5000 and TEG® 6s results to make patient diagnoses, but they are not directly establishing the "ground truth" for the device's functional performance in this context.

Therefore, the document does not mention human experts establishing ground truth for the test sets in the way AI/ML studies often describe.

4. Adjudication Method for the Test Set

Not applicable in the conventional sense. The studies described are performance evaluations of an in vitro diagnostic device, involving quantitative measurements. There is no mention of an adjudication process (e.g., 2+1, 3+1 consensus) because the "ground truth" for the performance tests (precision, method comparison) is based on instrumental measurements and comparison to a predicate, not subjective human interpretations that would require adjudication.

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 MRMC comparative effectiveness study was done. This device is an in vitro diagnostic tool that provides numerical parameters describing blood hemostasis. It is not an AI-assisted diagnostic imaging device or a tool designed to directly improve human reader performance for tasks like lesion detection in images. The output is a graphical tracing and a table of numerical values for R, LY30, and MA, which clinicians then interpret.

6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done

The performance studies described are standalone (algorithm/device only) in nature. The TEG® 6s Hemostasis System automatically measures and outputs parameters without human-in-the-loop diagnostic assistance within the measurement process itself. The interpretation of these results for patient diagnosis is then performed by a professional. The studies evaluate the device's ability to accurately and precisely perform these measurements.

7. The Type of Ground Truth Used

The types of "ground truth" used are:

• Defined Reference Ranges: Established from "normal donors" (i.e., empirically derived from a healthy population).
• Known Sample Characteristics: For precision and interference studies, samples were classified as Hypo, Normal, Hyper, or specifically manipulated (spiked with drugs/reagents like Dabigatran, Warfarin, Kaolin, RiaStap, tPA) to represent known coagulation states.
• Predicate Device Measurements: For method comparison, the measured values from the legally marketed Thrombelastograph® Coagulation Analyzer (TEG®) – 5000 served as the reference for determining substantial equivalence.

8. The Sample Size for the Training Set

The document does not specify a separate "training set" in the context of machine learning. The TEG® 6s Hemostasis System is described as a measurement device based on physical principles (resonant frequency, modulus of elasticity) rather than a machine learning algorithm that is "trained" on data. Therefore, the concept of a separate training set, as typically defined in AI/ML, is not applicable or discussed here. The reference ranges and performance characteristics are established via analytical studies on various sample types.

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

As explained in point 8, there is no explicit "training set" in the AI/ML sense. The device's operational characteristics and parameter calculations are based on established biophysical principles of coagulation, not on machine learning from a labeled training dataset.

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