(19 days)
The HEMOCHRON ® Response is intended for professional use for hemostasis management in a variety of clinical settings for the quantitative determination of an assortment of coagulation test assays including the following HEMOCHRON Whole Blood Coagulation Assays Activated Clotting Time (ACT) - All HEMOCHRON types Activated Partial Thromboplastin Time (APTT) - All HEMOCHRON types Prothrombin Time (PT) - All HEMOCHRON types Thrombin Time (TT) Heparin Neutralized Thrombin Time (HNTT) High Dose Thrombin Time (HiTT) Fibrinogen (FIB) Protamine Dose Assay (PDA) - All HEMOCHRON types Heparin Response Time (HRT) - All HEMOCHRON types Protamine Response Time (PRT) - All HEMOCHRON types For In Vitro Diagnostic Use Only
The Hemochron Response instrument/system described herein is a software upgrade (Version 2.0) to the current Hemochron Response Instrument, which has been cleared under K983475 (May 1999). The HEMOCHRON® Response is a portable, dual-well microprocessor-controlled coagulation instrument with an integral barcode reader, laboratory communication interface and a printer designed to perform whole blood coagulation tests using fresh or citrated whole blood. The system is intended for use in many clinical settings requiring point-of-care testing. The modified Response instrument performs the same assays as the predicate instrument. There are no changes to the clot detection algorithm. The patented clot detection mechanism is an electro-mechanical system consisting of two test wells into which disposable test tube assays are inserted. The test tube assays contain specific reagent for the test performed and a precision magnet. Immediately after adding a blood sample to the test tube and pressing the start button, the test tube is placed in the test well and is automatically rotated at a slow controlled speed and incubated at 37°C. When a fibrin clot begins to form, it causes the magnet in the test tube to be displaced. Two magnetic detectors located in the test well continuously monitor the precise position of the magnet. When a pre-determined displacement occurs, the elapsed time form the start of the test and the clot endpoint is displayed as the coagulation time in seconds.
The provided document describes a 510(k) submission for a software upgrade (Version 2.0) to the HEMOCHRON® Response Instrument/System, which is a whole blood coagulation test system. The study compares the performance of the new version (V2.00) with the predicate device (V1.52) to demonstrate substantial equivalence.
Here's an analysis of the acceptance criteria and the study, structured according to your request:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" in a numerical or threshold format. Instead, it demonstrates equivalence to a predicate device, implying that the new device's performance is acceptable if it is comparable to the established predicate. The performance is assessed through linear correlation for accuracy and precision (CV%) for reproducibility.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance (HR V2.00 vs HR V1.52) |
|---|---|---|
| Linear Correlation (Accuracy) | Strong linear correlation ($r \ge 0.95$) between new and predicate device measurements for various assay groups. | ACT Tubes: $y=0.98x-9.36$, $r=0.995$ |
| Specialty Tubes: $y=1.04x-0.45$, $r=0.954$ | ||
| RxDx Tubes: $y=1.00x-16.32$, $r=0.998$ | ||
| Precision (Reproducibility) | Comparable Coefficient of Variation (CV%) between new and predicate device measurements for various assays and control levels. | ACT: Level 1 CV% (V2.00: 6.0%, V1.52: 6.2%), Level 2 CV% (V2.00: 5.1%, V1.52: 3.4%) |
| APTT FWB: Level 1 CV% (V2.00: 7.5%, V1.52: 8.5%), Level 2 CV% (V2.00: 5.3%, V1.52: 5.2%) | ||
| PRT: Level 1 CV% (V2.00: 5.1%, V1.52: 5.6%), Level 2 CV% (V2.00: 4.2%, V1.52: 2.7%) | ||
| HiTT: Level 1 CV% (V2.00: 14.4%, V1.52: 13.5%), Level 2 CV% (V2.00: 15.7%, V1.52: 13.0%) |
Note: The phrase "The linear correlations between the instruments were excellent" explicitly supports the device meeting the implied acceptance criterion for accuracy. For precision, the CV% values for V2.00 are generally very similar to or slightly better/worse than V1.52, indicating comparable reproducibility.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set (Accuracy/Correlation Studies):
- Sample Size:
- ACT Tubes: 18 (n=18)
- Specialty Tubes: 15 (n=15)
- RxDx Tubes: 17 (n=17)
- Data Provenance: Blood samples were drawn from "four different donors and heparinized in vitro." This suggests controlled laboratory conditions. The country of origin is not specified but implicitly US, given the FDA submission. The data is prospective for the purpose of this submission, as it was generated specifically to compare V2.00 and V1.52.
- Sample Size:
- Test Set (Precision Studies):
- Sample Size: "n=10 per instrument type" (2 V1.52 and 2 V2.00 instruments) for each of two control levels per assay. This means 10 measurements per instrument per control level, totaling 20 measurements per assay per instrument type (e.g., for ACT, 20 for V2.00 and 20 for V1.52 at each control level).
- Data Provenance: Laboratory studies using assay-specific controls. Implicitly US, prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This document does not describe studies needing expert adjudication or ground truth establishment in the way typically seen for image analysis or diagnostic interpretation by human experts. The "ground truth" in this context is the measurement provided by a predicate device (HEMOCHRON® Response V1.52) and highly controlled, standardized laboratory controls. Therefore, no human experts are mentioned for establishing ground truth for the test set.
4. Adjudication Method for the Test Set
Not applicable. The study involves direct comparison of instrument measurements (new vs. predicate, or new vs. its own repeated measurements for precision) rather than human interpretation requiring adjudication.
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 is not a study comparing human reader performance with or without AI assistance. It’s a comparison of two versions of an automated coagulation instrument.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The studies presented are standalone in the sense that they evaluate the performance of the instrument (V2.00) itself, comparing its measurements to a predicate instrument (V1.52) or against laboratory controls. There is no human-in-the-loop performance evaluated or described in these specific performance studies. The system is designed for professional use, but the reported performance data focuses solely on the device's measurement capabilities.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- For Accuracy/Correlation Studies: The ground truth is established by the measurements from the predicate device (HEMOCHRON® Response V1.52). The goal is to show the new version correlates well with the previously cleared and accepted device.
- For Precision Studies: The ground truth is the assigned value of the assay-specific controls, against which the instrument's reproducibility is measured.
8. The Sample Size for the Training Set
This document does not describe a machine learning algorithm or a new diagnostic model that requires a training set. The changes primarily involve a software upgrade to activate existing functionalities (like the RxDx module) and enhance user programming, not to develop a new analytical algorithm. Therefore, there is no training set mentioned or applicable in this context.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set is described.
§ 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.