(767 days)
The ROTEM sigma thromboelastometry system is a fully integrated and automated in vitro diagnostic system designed to monitor and analyze a patient's coagulation status by measuring the viscoelastic properties of a 3.2% citrated venous or arterial whole blood sample. The ROTEM sigma system is indicated for use with adult patients 21 years and older where a semi-quantitative evaluation of their blood coagulation properties is desired, in the point of care and laboratory settings. Coagulation evaluations on the ROTEM sigma instrument, together with the ROTEM sigma complete + hep cartridge, are used to assess peri-operative hemorrhage and/or thrombosis in cardiovascular surgery and liver transplantation. The single use, multichannel cartridge ROTEM sigma complete + hep contains the following assays:
INTEM C is a semi-quantitative assay used to monitor coagulation via the intrinsic pathway in citrated whole blood samples.
EXTEM C is a semi-quantitative assay used to monitor coagulation via the extrinsic pathway in citrated whole blood samples.
FIBTEM C is a semi-quantitative assay used to monitor coagulation via the extrinsic pathway in citrated whole blood samples, after blocking platelet contribution to clot firmness.
HEPTEM C is a semi-quantitative assay used to monitor coagulation via the intrinsic pathway in citrated whole blood samples, after inactivating heparin.
Results from the ROTEM sigma should not be the sole basis for a patient diagnosis; ROTEM sigma results should be considered along with a clinical assessment of the patient's condition and other laboratory tests.
For in vitro Diagnostic Use.
For professional use only.
The ROTEM sigma is an in vitro diagnostic (IVD) whole blood hemostasis system intended for use in the evaluation of coagulopathies in Point of Care (POC) or laboratory settings. It uses rotational thromboelastometry to provide semiquantitative information about the coagulation state of a blood sample. The ROTEM sigma system records the kinetic changes in a sample of 3.2% citrated whole blood during clot formation, as well as when the sample clot retracts and/or lyses.
Several parameters are measured and reported for this purpose. The graphical presentation reflects the various physiological results, which describe the interaction between coagulation factors and inhibitors, fibrinogen, platelets, and the fibrinolysis system. Additionally, the effect of certain drugs influencing hemostasis, in particular some anticoagulants (e.g. heparin), can be detected.
The ROTEM sigma technology uses rotational thromboelastometry that is based on a fixed cylindrical cup and an oscillating vertical axis. The axis is supported by a high precision ball bearing and oscillates through an angle of 4.75°. The oscillation of the axis is driven by a motor that is connected to the axis via a spring. For the measurement, the channel's measurement axis engages the plastic pin in the cup of the disposable heated cartridge holding the blood sample. The oscillation is detected optically via a mirror plate at the upper end of the axis, which reflects the light from a diode light source onto a light sensitive sensor. If no clotting takes place, the pin movement is not restricted. As a clot forms and attaches itself between the pin and cup surfaces, the pin movement becomes increasingly restricted. The result is a balance between the spring tension and the tension of the clot. As the clot becomes firmer, the oscillation amplitude of the axis is reduced.
The ROTEM sigma assays are based on the principle of either
- intrinsic coagulation activation with or without the presence of heparin, or
- extrinsic coagulation activation with or without the presence of platelet inhibitors.
Here's an analysis of the provided text to extract information about the acceptance criteria and the study proving the device meets them.
It's important to note that this document is a 510(k) summary for an In Vitro Diagnostic (IVD) device, specifically a Thromboelastometry System (ROTEM sigma). The "acceptance criteria" here refer to performance specifications (e.g., precision, reproducibility, method comparison) for the device's measurements, not typical "acceptance criteria" for an AI/ML model's diagnostic accuracy (like sensitivity/specificity against a ground truth). Similarly, "expert consensus" or "adjudication" in the context of IVDs refers to establishing the accepted values of controls or comparing to a reference method, not to human image interpretation.
Acceptance Criteria and Device Performance for ROTEM sigma Thromboelastometry System
The ROTEM sigma Thromboelastometry System is an in vitro diagnostic device for assessing blood coagulation. Its performance is demonstrated through various analytical studies. The acceptance criteria are implicit in the presentation of the study results, where the variability and agreement with reference methods are shown to be within acceptable ranges for an IVD.
1. Table of Acceptance Criteria and Reported Device Performance
Given that this is an IVD device, the "acceptance criteria" are typically defined by ranges of acceptable precision (CV%), reproducibility (SD/CV%), and correlation with a predicate device (slope, intercept, R-value). The document presents the results of these studies, and the implicit acceptance criteria are met if these results fall within expected performance ranges for such devices.
Summary of Key Performance Parameters (Implicit Acceptance Criteria and Reported Performance)
| Performance Study | Parameter | Acceptance Criteria (Implicit) | Reported Device Performance (Worst Case/Overall) |
|---|---|---|---|
| Precision | %CV (Within-Laboratory) | Should be low, indicating consistent results for identical samples. | Highest %CV observed: |
| (Whole Blood) | INTEM C: CT, A5, A10, A20, MCF | Generally 240 replicates per control type). |
* **Whole Blood (Normal, Contrived Hypocoagulable, Contrived Hypercoagulable):** Run in triplicate, in one (1) day, on five (5) instruments, resulting in 15 replicates per sample type per lot (3 lots => 45 replicates per sample type).
* **Lysis Precision (Normal Whole Blood & Hyperfibrinolysis Blood):** Fifteen (15) replicates per sample type per cartridge lot (3 lots => 45 reps per type).
* **Lot-to-Lot Variability (Normal Donor Whole Blood):** Thirty (30) replicates per cartridge lot (3 lots => 90 replicates).
- Reproducibility (External Clinical Sites):
- Three (3) external clinical sites.
- Four (4) ROTEM sigma instruments per site.
- Three (3) lots of controls (ROTEM sigma ROTROL N and P).
- Run in triplicate, twice a day for five (5) days, resulting in thirty (30) replicates per control per site (90 replicates per control across all sites).
- Interference:
- Various Interferents (Heparins, Acids, Ticagrelor): Eight (8) replicates at three (3) interferent levels for normal and hypocoagulable whole blood samples.
- Lupus Anticoagulant: Eleven (11) donors, each run on three (3) instruments with one (1) replicate per instrument.
- Reference Intervals: One hundred twenty (120) whole blood samples from healthy donors.
- Method Comparison:
- Number of samples for each assay parameter: INTEM C (144-148), EXTEM C (183-187), FIBTEM C (183), HEPTEM C (182).
- Data provenance: Patient samples from the "intended use populations and contrived samples." Conducted at four (4) clinical sites. No specific country of origin is mentioned beyond "internal precision study" and "external clinical sites" (implicitly within the regulatory region/country this submission applies to). The studies are prospective in the sense that they involve planned laboratory testing and data collection.
- Arterial vs. Venous Study: Seventy-four (74) matched venous and arterial citrated whole blood samples. Performed at two (2) external clinical sites.
Data Provenance (Summary):
The studies include data from internal testing and multiple external clinical sites. The samples include healthy donors, patient samples (intended use populations), and contrived samples (e.g., hypocoagulable, hypercoagulable). The studies are analytical performance studies, not clinical outcome studies. These are prospective laboratory studies designed to evaluate technical performance. No specific countries are listed, but the context of an FDA 510(k) submission suggests either U.S. or international data accepted by the FDA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
For an IVD device like the ROTEM sigma, "ground truth" is established by controlled laboratory methods and comparison to existing, cleared predicate devices, rather than human interpretation or expert consensus in the typical sense for image-based AI.
- Precision and Reproducibility: Ground truth is inherent in the preparation of controlled samples (normal, contrived hypocoagulable, contrived hypercoagulable, control materials) with known characteristics. The goal is to demonstrate the device's ability to consistently measure these known or expected characteristics. No external human experts are involved in creating this "ground truth" beyond standard laboratory practices and quality control.
- Method Comparison: The "ground truth" or reference standard for comparison is the predicate device, the ROTEM delta (K083842, K101533). The performance is assessed by correlating the ROTEM sigma's measurements with those of the legally marketed predicate device. This is a comparative study, not one establishing an absolute "ground truth" with human experts.
There is no mention of experts establishing ground truth in the way one would for an AI in medical imaging (e.g., radiologists annotating images).
4. Adjudication Method for the Test Set
For IVD analytical performance studies, traditional "adjudication" (e.g., 2+1, 3+1 for discordant reads) is not applicable. The measurements are quantitative. For method comparison, if there were significant discrepancies between the new device and the predicate, further investigation would occur to understand the cause, but it's not an adjudication process of human interpretation. The consistency across multiple instruments and sites is shown in the reproducibility studies.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No. An MRMC study is typically for evaluating the diagnostic performance of software, often AI, sometimes with and without human assistance (e.g., radiologists reading images). This document describes the analytical performance of an in vitro diagnostic instrument that measures blood coagulation properties. It does not involve human readers interpreting "cases" in a diagnostic context. Therefore, there's no "effect size of how much human readers improve with AI vs without AI assistance" to report here, as AI is not assisting human interpretation in this context; it is the measurement device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
The ROTEM sigma is inherently a "standalone" device in its primary function. It's an automated system that measures coagulation parameters. The performance studies (precision, reproducibility, method comparison) are all "algorithm only" in the sense that they evaluate the device's ability to produce consistent and accurate measurements on its own. Human intervention during operation involves sample loading and system maintenance, but the measurement process itself is automated ("fully integrated and automated").
7. The Type of Ground Truth Used
The "ground truth" in this context refers to established values or reference methods:
- Established Reference Materials/Controls: For precision, reproducibility, and lot-to-lot variability, the "ground truth" is based on the known or expected values of the control materials and the stability of the whole blood samples used.
- Predicate Device (ROTEM delta): For method comparison, the ROTEM delta serves as the reference standard or "ground truth" for evaluating the clinical equivalence of the ROTEM sigma's measurements.
- Healthy Donor Samples: For reference interval establishment, samples from healthy individuals are used to define the typical range of values, which then serve as a clinical "ground truth" for normalcy.
- Contrived Samples: For some studies (precision, method comparison), samples are artificially manipulated (e.g., hypocoagulable, hypercoagulable) to represent different physiological states. The "ground truth" for these is the known manipulation.
There is no "pathology" or "outcomes data" ground truth in the direct sense of a diagnostic accuracy study. The device provides semi-quantitative measurements that aid in diagnosis, but it does not provide a definitive diagnosis itself.
8. The Sample Size for the Training Set
This document describes the validation of a medical device, not the training of an AI/ML model. Therefore, there is no "training set" in the context of machine learning. The device determines coagulation parameters based on a physical principle (rotational thromboelastometry) and built-in algorithms, not from a data-driven training process in the AI sense.
9. How the Ground Truth for the Training Set Was Established
Since there is no "training set" for an AI/ML model, this question is not applicable.
§ 864.5425 Multipurpose system for in vitro coagulation studies.
(a)
Identification. A multipurpose system for in vitro coagulation studies is a device consisting of one automated or semiautomated instrument and its associated reagents and controls. The system is used to perform a series of coagulation studies and coagulation factor assays.(b)
Classification. Class II (special controls). A control intended for use with a multipurpose system for in vitro coagulation studies is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.