Search Results

The STA R Max 3® and STA Compact Max 3® are fully automatic clinical analyzers designed to be used by professional laboratory personnel and to perform tests on human venous plasmas (in 3.2% trisodium citrate tubes) the results of which aid in the diagnosis of coagulation abnormalities or in monitoring anticoagulant therapy.

The STA R Max 3® and STA Compact Max 3® are fully automatic clinical analyzers designed to be used by professional laboratory personnel and to perform tests on human venous plasmas (in 3.2% trisodium citrate tubes) the results of which aid in the diagnosis of coagulation abnormalities or in monitoring anticoagulant therapy.
The technological characteristics are the same for all STA R Max® Family and STA Compact Max® family analyzers, including STA R Max 30 and STA Compact Max 30, which is based on two measurement principles: Chronometric measurement principle and Photometry measurement principle.
The analyzers use Diagnostica Stago reagents in addition to open adaptation of other available reagents. The instrument performs multiple test methodologies in random access, as selected by the user. These include clotting time or clot-based tests (i.e. chronometric measures) and photometric assays on plasma samples.
Changes include a redesigned PSR module to replace the Hamilton syringes and Valcor pump of the fluidic circuit and the addition of the HIL module for estimating interferences (Hemoglobin, Icterus, Lipemia).

The provided text describes the performance data for laboratory instruments (STA R Max 3® and STA Compact Max 3®) used for in vitro coagulation studies, not for an AI/ML-driven medical device for which the acceptance criteria would typically focus on diagnostic accuracy metrics like sensitivity, specificity, or AUC as evaluated by expert readers.

Therefore, the requested information regarding acceptance criteria and study design elements specific to AI/ML devices (e.g., sample size for test set with provenance, number of experts for ground truth, adjudication methods, MRMC study, standalone performance, training set details) is largely not applicable to the content of this FDA 510(k) summary, as it pertains to traditional in vitro diagnostic instruments and their analytical performance.

The document focuses on:

• Method Comparison: Comparing the new devices' measurements against predicate devices using standard regression analysis (Passing & Bablok, Deming) and correlation coefficients (Spearman's r).
• Precision/Reproducibility: Assessing the variability of measurements within a run, between runs, between days, and between instruments/sites using standard deviation (SD) and coefficient of variation (CV%).
• Interference Testing (HIL): Testing the impact of hemoglobin, icterus, and lipemia on results.

Below is a reinterpretation of the request based on the provided document, focusing on the analytical performance acceptance criteria and study details for these in vitro diagnostic instruments.

Acceptance Criteria and Device Performance for Coagulation Analyzers (STA R Max 3® and STA Compact Max 3®)

The provided document details the analytical performance of the STA R Max 3® and STA Compact Max 3® coagulation analyzers, demonstrating their substantial equivalence to predicate devices (STA R Max® and STA Compact Max®). The acceptance criteria are implicit in the presented method comparison and precision data, aiming to show comparable performance to the legally marketed predicates.

1. Table of Acceptance Criteria and Reported Device Performance

Since this is an in vitro diagnostic (IVD) device (a laboratory instrument) and not an AI/ML-driven diagnostic algorithm, the "acceptance criteria" are defined differently than for radiological AI tools. Here, they relate to statistical comparability (method comparison) and measurement reproducibility (precision). The specific quantitative "acceptance criteria" values (e.g., maximum allowable bias, maximum CV%) are not explicitly stated as discrete numbers in the document's summary tables, but rather are implied by the presentation of regression analysis results (slopes, intercepts, correlation coefficients) and precision statistics (SD, CV%). The expectation is that these values demonstrate strong agreement with the predicate devices and sufficient reproducibility for clinical use.

Performance Data Summary (Representing "Met Acceptance Criteria")

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

• Sample Size:
  • Method Comparison: For each assay and each instrument (STA R Max 3 and STA Compact Max 3), samples were "selected in order to cover the entire measuring range." The exact number of samples (patients) for each method comparison is not explicitly stated as a single number but would be consistent with CLSI EP09c recommendations. For example, the precision data tables indicate 80 replicates per sample per analyzer for single-site precision (e.g., 240 N for "All instruments combined" across 3 analyzers), and 90 N per sample for multi-site precision (across 3 sites) for a total of 270 replicates per sample per parameter across all sites and analyzers.
  • HIL Method Comparison: Not explicitly stated, but samples were "spiked plasma" to create various concentrations across designated indices.
• Data Provenance: The method comparison studies were conducted at "three external sites." Precision studies were conducted at "one external site" (single-site precision) and "three external sites" (multi-site precision). The country of origin is not specified but is implicitly within a region where FDA regulatory standards are applicable.
• Retrospective or Prospective: Not explicitly stated, but given the nature of instrument validation studies, they are typically purpose-generated (prospective) for the study rather than utilizing historical patient data. Spiked plasma for HIL analysis indicates prospective sample preparation.

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

• Not applicable in the context of this IVD device. For an in vitro diagnostic instrument like a coagulation analyzer, "ground truth" is established by the analytical method itself, often by comparison to a well-established reference method or the predicate device that has established analytical accuracy. There are no human "experts" establishing a diagnostic ground truth from images or clinical data in the way an AI/ML diagnostic device would require. The "truth" is the measured concentration or clotting time.

4. Adjudication Method for the Test Set

• Not applicable. As there are no human interpretations or classifications that require adjudication for this type of IVD instrument validation.

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 study pertains to the analytical performance of a laboratory instrument, not an AI-assisted diagnostic tool that aids human readers.

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

• Yes, in the context of an IVD analyzer. The "standalone" performance here refers to the analytical performance of the instrument itself when measuring samples. The entire document describes this "standalone" performance through method comparison and precision studies. The device measures various coagulation parameters directly from plasma samples.

7. The Type of Ground Truth Used

• Analytical Ground Truth: The ground truth for this device's performance is established by:
  • Comparison to a Legally Marketed Predicate Device: The performance of the new devices (STA R Max 3 and STA Compact Max 3) is compared directly to the established performance of their previous versions (STA R Max and STA Compact Max) using patient samples. This is the primary method for demonstrating substantial equivalence.
  • Reference Methods (for HIL): For the HIL interferences, the device's readings were compared against "reference methods, cobas® 8000 modular analyzer (Hemolysis, Icterus, and Lipemia) and spectrophotometer (Lipemia)."
  • Theoretical/Expected Values (for HIL spiking): For HIL, "spiked plasmas were prepared" to provide known concentrations of interfering substances, and the results "matched the index determination for the subject devices and the theoretical index."
  • Repeated Measurements (for Precision): For precision, repeated measurements demonstrating low variability around a mean value for different samples serve as the internal "ground truth" for reproducibility.

8. The Sample Size for the Training Set

• Not applicable for this type of conventional IVD instrument. These are not AI/ML devices that undergo "training" on a data set. Their "training" or calibration involves standard laboratory procedures and calibration materials according to manufacturer protocols.

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

• Not applicable. As stated above, there is no "training set" in the AI/ML sense for this traditional laboratory instrument.

Ask a specific question about this device

The STA Compact Max® is a fully automatic clinical analyzer designed to perform tests on human plasmas, the results of which aid in the diagnosis of coagulation abnormalities or in monitoring anticoagulant therapy.

Diagnostica Stago's STA Compact Max® is a fully automatic clinical laboratory designed as a modification to the company's previously cleared STA Compact® analyzer (K093167). It performs tests which aid in the diagnosis of Haemostatic disorders and the monitoring of anticoagulant treatment. The device consists of a cuvette, a metal ball, three needles, oscillation amplitude detection, a light source and sensor, and software.

The STA Compact Max® is a modified version of the legally marketed device, STA Compact® (K093167). The modifications primarily involve updates to the onboard computer, operating system, and user interface, as well as minor external design changes. The company claims that these modifications do not alter the fundamental technological characteristics, principles of operation, or performance of the device.

Here's an analysis of the acceptance criteria and study information provided:

1. Table of Acceptance Criteria and Reported Device Performance

The provided document does not explicitly present a table of acceptance criteria with numerical performance targets (e.g., sensitivity, specificity, accuracy) for the STA Compact Max®. Instead, the acceptance criteria are implicitly stated through the claim of "comparable performances" to the predicate device and the assertion that "no new questions were raised regarding the Safety, Effectiveness, Performance, Indication for Use, Technology and the Principles of Operation."

The device performance is described as:

The essential acceptance criterion is that the STA Compact Max® demonstrates "comparable performances" to the predicate device (STA Compact® K093167) despite the internal and external modifications. The study performed aims to demonstrate this equivalence. The specific performance metrics (e.g., precision, accuracy, linearity) that were likely evaluated to establish "comparable performances" are not detailed in the provided summary, but would have been part of the Verification and Validation utilized as part of the Design Controls.

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

The provided 510(k) summary does not explicitly state the sample size used for the test set or the data provenance (e.g., country of origin, retrospective or prospective). It refers to "Validation Studies" and "Risk Assessment" but does not provide details of these studies. Given that this is a Special 510(k) for modifications to an existing device, the focus is on demonstrating that the changes do not adversely affect performance. The validation studies would have focused on verifying that the new hardware and software components perform as expected and do not introduce new risks or alter the previously established performance characteristics of the predicate device.

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

This information is not provided in the document. For a coagulation analyzer, "ground truth" would typically be established by comparing results to reference methods, other established analyzers, or clinical outcomes, perhaps interpreted by medical professionals. However, the details of expert involvement are not mentioned in this summary.

4. Adjudication Method for the Test Set

This information is not provided in the document.

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

This information is not applicable to the STA Compact Max® device. This device is an automated clinical analyzer for in vitro coagulation studies and does not involve human readers interpreting images or data with AI assistance. It performs measurements directly on plasma samples.

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

The STA Compact Max® is an automated device, meaning it operates in a standalone manner without human-in-the-loop performance influencing its measurement results. The results are generated by the instrument's mechanical, optical, and software components. Human interaction is primarily for loading samples, reagents, and interpreting the output. So, in essence, its core function is "algorithm only" in terms of its diagnostic output. However, the document doesn't explicitly describe a separate "standalone study" in the context often associated with AI diagnostic algorithms. Rather, its inherent operation is standalone.

7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)

The document does not explicitly state the type of ground truth used for the validation studies. However, for coagulation analyzers, ground truth often involves:

• Reference methods: Comparing results to established, highly accurate laboratory reference methods.
• Certified reference materials/standards: Using materials with known analyte concentrations.
• Comparison to predicate device: A primary method in a 510(k) where modifications are made to an existing device. The performance of the modified device would be compared against the predicate device using patient samples and quality control materials.

The study's goal was to demonstrate "comparable performances" to the predicate device, implying that the predicate's performance served as a de-facto 'ground truth' or benchmark for the new device.

8. The Sample Size for the Training Set

This information is not provided and is generally not applicable in the same way it would be for machine learning or AI-based devices. The "training" for this type of device involves engineering design, calibration, and verification/validation processes rather than a data-driven training set for an algorithm to learn from. The software migration and new graphical user interface were likely developed and tested against defined functional requirements rather than a "training set."

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

As explained above, the concept of a "training set" with established ground truth is not directly applicable to this type of automated medical device in the same way it is for AI algorithms. The "ground truth" for the development and testing of the device's components (hardware, firmware, and software) would be based on engineering specifications, physical laws, chemical reactions, and established principles of coagulation measurement, rather than a dataset with labeled medical conditions. The previous STA Compact® (predicate device) and its proven performance would serve as the benchmark for how the new device should function and deliver results.

Ask a specific question about this device