(135 days)
The HemoSense INRatio is an in vitro diagnostic system that provides a quantitative prothrombin time results, expressed in seconds and as an International Normalized Ratio (INR). It uses fresh capillary whole blood and is intended for is intended for quantitative prothrombin time testing of fresh, capillary whole blood for monitoring of oral anticoagulation therapy by trained patients or their caregivers, on the prescription or other order of a treating physician.
The INRatio Prothrombin Time Monitoring System uses a modified version of the one-stage prothrombin time test. After a drop of blood is applied to the test strip, it is drawn into the test area and mixed with reagents that cause coagulation to begin. The test area on the test strip is separated into three channels, each of which contains electrodes for detection of the blood clot. One channel contains the reagents to perform the prothrombin time test on the blood sample. The other two channels contain the reagents to run control tests. No external quality control tests are required for the INRatio system. The meter monitors the reactions, and calculates the PT and INR for the blood sample, which are reported on the display. If the control results are not within a set range, it indicates a problem with the test and an error message is reported on the display instead of a result. The INRatio is the same as the INRatio, except that the labeling has been modified for readability by the lay user.
Here's an analysis of the provided text regarding the INRatio Prothrombin Time Monitoring System's acceptance criteria and related study information:
Note: The provided text is a 510(k) summary and associated FDA correspondence. It does not include detailed study reports or comprehensive acceptance criteria. Therefore, several sections below will indicate "Not explicitly stated in the provided text." or "Not applicable/Not explicitly detailed in the provided text."
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Anticipated) | Reported Device Performance (Summary) |
|---|---|
| Equivalence to established reference method for Prothrombin Time and INR measurements. | The INRatio System was found to perform equivalently when used by trained lay users and healthcare professionals. Furthermore, both user populations generated results found to be equivalent to an established reference method. |
| Performance of internal quality control mechanisms. | The device includes internal control channels. If control results are not within a set range, an error message is reported instead of a result, indicating a problem with the test. |
| Readability/Usability for lay users for self-testing. | Labeling has been modified for readability by the lay user. The device is intended for use by trained patients or their caregivers. |
Explanation: The document strongly emphasizes "equivalence" as the primary performance benchmark against an "established reference method." Specific quantitative acceptance criteria (e.g., specific bias limits, precision thresholds) are not detailed in this 510(k) summary. The performance data section provides a general summary statement about equivalence.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not explicitly stated in the provided text.
- Data Provenance: Not explicitly stated in the provided text regarding country of origin or whether it was retrospective or prospective. The statement "The INRatio System was found to perform equivalently when used by trained lay users and healthcare professionals" suggests a clinical study, which would typically be prospective, but this is an inference.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- Number of Experts: Not explicitly stated in the provided text.
- Qualifications of Experts: Not explicitly stated in the provided text.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly stated in the provided text.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- Was an MRMC study done? Not applicable in the traditional sense for this device. This is an In Vitro Diagnostic (IVD) device that provides a quantitative measurement (PT/INR), not an imaging device requiring human reader interpretation. The study involved comparing results from different user types (lay users vs. healthcare professionals) to a reference method, which is a different type of comparison.
- Effect size of human readers improvement with AI vs without AI assistance: Not applicable/Not explicitly detailed in the provided text. The device itself is not described as an "AI" device as per current definitions, nor does it assist human readers in interpretation; it provides the result.
6. Standalone (Algorithm Only) Performance Study
- Was a standalone study done? Yes, in a way. The device itself calculates the PT and INR. The comparison involved the device's output being assessed against a reference method, performed by both lay users and healthcare professionals. The device, by its nature, functions in a "standalone" capacity to produce a result, with human input being the blood sample and operation of the machine. The key test was the agreement of the device's output (regardless of who operated it) with the reference standard.
7. Type of Ground Truth Used
- Type of Ground Truth: An "established reference method." The specific nature of this reference method (e.g., a laboratory-based gold standard PT/INR test) is not detailed but is implied. For PT/INR, this usually refers to a central lab-based method that is considered the clinical standard.
8. Sample Size for the Training Set
- Sample Size for Training Set: Not explicitly stated in the provided text. IVD devices like this typically undergo extensive calibration and verification during development (which could be considered a form of "training" data for the device's internal algorithms), but precise details are not in this summary.
9. How the Ground Truth for the Training Set Was Established
- How Ground Truth for Training Set Was Established: Not explicitly stated in the provided text. During the development of such a device, ground truth for calibration and internal algorithm optimization would typically be established using a combination of certified reference materials, spiked samples, and clinical samples analyzed by established laboratory reference methods.
§ 864.7750 Prothrombin time test.
(a)
Identification. A prothrombin time test is a device used as a general screening procedure for the detection of possible clotting factor deficiencies in the extrinsic coagulation pathway, which involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis or pulmonary embolism).(b)
Classification. Class II (performance standards).