(29 days)
The microINR System measures prothrombin time (PT) expressed in International Normalized Ratio (INR), for monitoring oral anticoagulant therapy with warfarin.
The microlNR System consists of a meter and chips (test strips) and uses fresh capillary whole blood from a fingerstick. The microlNR System is intended for patient self-testing use as well as for healthcare professionals at Point of Care settings.
The microlNR System is intended for use in patients 18 years old or older. Patients must be stable on warfarin medication for at least 6 weeks before starting to use the microINR System.
For Self-testing use: The System is intended for properly trained users under specific prescription of a physician. Caution: The microINR System is not in patients who are transitioning from heparin treatment to VKA therapy. The microINR System is not intended to be used for screening purposes.
The modified device microINR System containing the microINR Link Meter is derived from the existing device microINR Meter. The change is for the addition of Bluetooth connectivity to the meter. Bluetooth functionality stays inactive during the testing/measuring process. All the actions related to Bluetooth functionality are set before or after performing the analytical test. The fundamental scientific technology of the modified device and its performance has not changed. No performance changes to the microINR System have been implemented since its clearance on K201185.
This document (K231711) describes a Special 510(k) submission for the microINR System. This type of submission is used when changes are made to a previously cleared device, and it aims to demonstrate that the modified device remains substantially equivalent to the original cleared device. In this specific case, the change introduced is the addition of Bluetooth connectivity to the meter.
Because this is a Special 510(k), the focus of the testing is to demonstrate that the new functionality (Bluetooth) does not adversely affect the device's original performance and does not raise new questions of safety or effectiveness. Therefore, the acceptance criteria and study described are not for the primary device performance (e.g., accuracy of INR measurement), but rather for the impact of the newly added feature.
Here's a breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not provide a specific table detailing acceptance criteria and reported device performance for the primary function of the microINR System (PT/INR measurement accuracy). This is because the original performance was established in the predicate K201185, and this submission focuses on the new Bluetooth functionality.
However, it does state general acceptance regarding the performed testing:
| Acceptance Criteria Category | Reported Device Performance (Satisfied) |
|---|---|
| Radiofrequency | All testing results met pre-determined acceptance criteria. |
| Electromagnetic Compatibility | All testing results met pre-determined acceptance criteria. |
| Electrical Safety | All testing results met pre-determined acceptance criteria. |
| Cybersecurity Analysis | All testing results met pre-determined acceptance criteria. |
| Usability Testing | All testing results met pre-determined acceptance criteria. |
| Software Verification and Validation | All testing results met pre-determined acceptance criteria. |
| Risk Analysis | Concluded no significant detectable risks compared to the predicate; all residual risks deemed acceptable. Bluetooth connectivity features were correctly implemented. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size used for the test set in the context of clinical performance or the data provenance (country of origin, retrospective/prospective). This is because the core analytical performance related to measuring INR was established with the predicate device (K201185). The testing for this Special 510(k) focused on the new Bluetooth functionality, which typically involves engineering or software testing, not patient-based clinical trials for accuracy.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. The testing described for the Bluetooth feature (Radiofrequency, EMC, Electrical Safety, Cybersecurity, Usability, Software V&V) does not typically involve expert clinical ground truth establishment in the same way that a diagnostic accuracy study would.
4. Adjudication Method for the Test Set
Not applicable. As noted above, the testing is for the impact of the new Bluetooth feature, not for diagnostic accuracy, and therefore does not rely on clinical adjudication of results.
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. The microINR System is a prothrombin time test device, not an AI-assisted diagnostic imaging device, and therefore MRMC studies or AI assistance effect sizes are not relevant to this submission.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
The device is a system (meter and test strips) for measuring PT/INR. While the new Bluetooth functionality itself operates without direct human intervention once initiated, the overall device includes human interaction. The "standalone" performance here refers to the device functions for Radiofrequency, EMC, Electrical Safety, Cybersecurity, Usability, and Software verification and validation, all of which were tested without requiring a human operator to compensate for potential deficiencies in the Bluetooth module itself. The document states "Bluetooth functionality stays inactive during the testing/measuring process. All the actions related to Bluetooth functionality are set before or after performing the analytical test." This indicates the Bluetooth module's performance was assessed without interfering with the core measurement, and implicitly, its standalone function (transferring data) was verified.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
For the testing related to the Bluetooth functionality:
- Radiofrequency, Electromagnetic Compatibility, Electrical Safety: Ground truth would be defined by relevant international and national standards and regulations (e.g., ISO, IEC standards for medical devices and radio equipment).
- Cybersecurity Analysis: Ground truth is established by recognized cybersecurity standards, best practices, and vulnerability assessment methodologies.
- Usability Testing: Ground truth is established by user feedback and observation against established usability heuristics and design principles for medical devices, potentially defined by standards like IEC 62366.
- Software Verification and Validation: Ground truth is established by the software requirements specification, design documents, and coding standards, ensuring the software performs as intended according to its formal definition.
For the primary device function (PT/INR measurement accuracy) which was established with the predicate, the ground truth would typically be a laboratory reference method for PT/INR.
8. The Sample Size for the Training Set
Not applicable. This device is not an AI/machine learning device that requires a "training set" in the conventional sense. The testing performed here (Radiofrequency, EMC, Electrical Safety, Cybersecurity, Usability, Software V&V) involves engineering and software validation, not the development of a predictive model.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" for this type of device and submission.
§ 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).