microINR System
Device Facts
| Record ID | K251564 |
|---|---|
| Device Name | microINR System |
| Applicant | Iline Microsystems, S.L. |
| Product Code | GJS · Hematology |
| Decision Date | Jul 21, 2025 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 864.7750 |
| Device Class | Class 2 |
Indications for Use
The microINR System measures prothrombin time (PT) expressed in International Normalized Ratio (INR), for monitoring oral anticoagulant therapy with warfarin. The microINR System consists of a meter and chips (test strips) and uses fresh capillary whole blood from a fingerstick. The microINR System is intended for patient self-testing use as well as for healthcare professionals at Point of Care settings. The microINR 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 intended for use in patients who are transitioning from heparin treatment to warfarin therapy. The microINR System is not intended to be used for screening purposes.
Device Story
Handheld in vitro diagnostic system; measures prothrombin time (PT) and INR from fresh capillary whole blood (fingerstick). Uses microfluidic test chips containing human recombinant tissue factor, synthetic phospholipids, and stabilizers. Meter employs machine vision detection to analyze blood flow in microcapillary channels. Used by patients (self-testing) or healthcare professionals at point-of-care. Multi-level on-board quality control checks meter function and chip integrity; reports INR results on screen. Enables home monitoring of oral anticoagulant therapy; facilitates clinical decision-making regarding warfarin dosage; improves patient convenience and management of therapy.
Clinical Evidence
Clinical method comparison study (N=1016) compared microINR results to laboratory reference (ACL TOP 500/750), showing slope 1.00, intercept 0.08, r=0.97. Self-testing accuracy study (N=461) compared patient results to HCP results (slope 0.99, r=0.98) and laboratory reference (N=248, slope 0.95, r=0.97). Precision studies (N=502) showed CV% of 4.9% (INR <2.0), 5.0% (2.0-4.5), and 4.9% (≥4.5). Additional precision study for untrained self-testers (N=13) at high INR showed 4.6% CV.
Technological Characteristics
Microfluidic chip with dried human recombinant thromboplastin reagent. Machine vision detection of blood flow viscosity changes. Handheld meter with barcode/manual entry. Automatic calibration via chip-encoded data. Multi-level on-board quality control. Complies with IEC 62304, IEC 60601-1-2, and ISO 14971 standards.
Indications for Use
Indicated for patients 18+ years old, stable on warfarin for at least 6 weeks, requiring INR monitoring. Not for patients transitioning from heparin to warfarin or for screening.
Regulatory Classification
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).
Predicate Devices
Related Devices
- K201185 — microINR System · Iline Microsystems, S.L. · Dec 18, 2020
- K180780 — microINR System · Iline Microsystems, S.L. · Jan 25, 2019
Submission Summary (Full Text)
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FDA
U.S. FOOD & DRUG
ADMINISTRATION
# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
ASSAY AND INSTRUMENT
## I Background Information:
A 510(k) Number
K251564
B Applicant
iLine Microsystems S.L.
C Proprietary and Established Names
microINR System
D Regulatory Information
| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| GJS | Class II | 21 CFR 864.7750 - Prothrombin Time Test | HE - Hematology |
## II Submission/Device Overview:
A Purpose for Submission:
Expansion of measuring range and removal of the Left Ventricular Assist Device (LVAD) limitation.
B Measurand:
International Normalized Ratio (INR)
C Type of Test:
Microfluidic technology with machine vision detection
## III Intended Use/Indications for Use:
A Intended Use(s):
Food and Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993-0002
www.fda.gov
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See Indications for Use below.
## B Indication(s) for Use:
The microINR System measures prothrombin time (PT) expressed in International Normalized Ratio (INR), for monitoring oral anticoagulant therapy with warfarin.
The microINR System consists of a meter and chips (test strips) and uses fresh capillary whole blood from a fingerstick.
The microINR System is intended for patient self-testing use as well as for healthcare professionals at Point of Care settings.
The microINR 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 intended for use in patients who are transitioning from heparin treatment to VKA therapy. The microINR System is not intended to be used for screening purposes.
## C Special Conditions for Use Statement(s):
Rx - For Prescription Use Only
## D Special Instrument Requirements:
microINR Expert Meter
## IV Device/System Characteristics:
### A Device Description:
The microINR System is comprised of a portable measuring device (microINR Expert Meter) and test strips (microINR Chips) in which the capillary blood sample flows through capillary action. The microINR Chip contains a reagent in dried form which consists of thromboplastin, and contains two symmetrical regions, the measuring channel, and a control channel. The microINR Expert Meter measures International Normalized Ratio (INR) based on a prothrombin time (PT) assay carried out in the microINR Chip based on microfluidic technology with machine vision detection.
The microINR System has a multi-level on-board quality control. The microINR Control contains lyophilized human citrated plasma from healthy donors modified by means of a process to simulate an abnormal coagulation sample and a calcium chloride solution. The lyophilized plasma must be reconstituted with the calcium chloride solution before use.
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The changes to the microINR Expert Meter include the expansion of the analytical measuring range up to INR of 8.0 and the removal of the LVAD limitation. The modifications have no impact on fundamental scientific technology and its performance.
## B Principle of Operation:
The microINR System is a handheld in vitro diagnostic medical device that uses microfluidic technology with machine vision detection to measure the prothrombin time from a fresh capillary (fingerstick) whole blood sample. The fresh capillary (fingerstick) whole blood sample is applied to the microINR Chip (test strip) for testing. The microINR Chip is inserted into the analyzer. Inside the test strip, the applied blood sample is separated into two channels and mixed with the reagents contained in each micro-reactor. The coagulation cascade is triggered instantly after mixing with the reagents (start time of the Prothrombin Time assay). When the blood coagulates its viscosity increases due to fibrin clot formation, which generates a sharp change in blood flow behavior. The Prothrombin Time measures how long it takes to form the fibrin clot after tissue thromboplastin has been added to the sample. The microINR Meter measures the INR based on the Prothrombin Time assay carried out in the microINR Chip and displays the INR on the screen.
## C Instrument Description Information:
1. Instrument Name:
microINR Expert Meter
2. Specimen Identification:
Barcode scanner or keyboard for manual entry
3. Specimen Sampling and Handling:
Capillary fingerstick
4. Calibration:
Automatic, encoded on disposable chip, no end user input
5. Quality Control:
Multi-level on-board quality controls
## V Substantial Equivalence Information:
### A Predicate Device Name(s):
microINR System, microINR System
### B Predicate 510(k) Number(s):
K243543, K180780
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C Comparison with Predicate(s):
| Device & Predicate Device(s): | K251564 | K243543 | K180780 |
| --- | --- | --- | --- |
| Device Trade Name | microINR System | Same | microINR System |
| General Device Characteristic Similarities | | | |
| Intended Use/Indications For Use | The microINR System measures prothrombin time (PT) expressed in International Normalized Ratio (INR), for monitoring oral anticoagulant therapy with warfarin. The microINR System consists of a meter and chips (test strips) and uses fresh capillary whole blood from a fingerstick. The microINR System is intended for patient self-testing use as well as for healthcare professionals at Point of Care settings. The microINR 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 intended for use in patients who are transitioning from heparin treatment to warfarin therapy. The microINR System is not intended to be used for screening purposes. | Same | The microINR System (consisting of the microINR Meter and the microINR Chip) is intended for multiple-patient use by professional healthcare providers for the determination of International Normalized Ratio (INR), to monitor Oral Anticoagulation Therapy (OAT) with warfarin. The microINR system uses fresh capillary whole blood. The microINR System is intended for in vitro diagnostic use at the point-of-care. The microINR System is intended for use in patients 18 years of age and older. Patients must be stabilized (≥6 weeks) on warfarin. Caution: The microINR System is not intended for use in patients who are transitioning from heparin treatment to warfarin therapy. The microINR System is not intended to be used for screening purposes. |
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| | VKA therapy. The microINR System is not intended to be used for screening purposes. | | |
| --- | --- | --- | --- |
| Sample type | Capillary whole blood. | Same | Same |
| Operating Principle/Technology | Microfluidic technology with machine vision detection. | Same | Same |
| Test Strip Reagent | Human recombinant thromboplastin | Same | Same |
| Calibration traceability | Each lot of test strips is calibrated to a reference lot traceable to the WHO International Reference Preparation. | Same | Same |
| Reference Range | INR: 0.8 to 1.2 | Same | Same |
| Calibration | Automatic, encoded on disposable, no end user input possible. | Same | Same |
| Test Strip Stability | 15 months. | Same | Same |
| Test Strip Use Time | 6 hours. (Limited to 15 minutes in IFU). | Same | 6 hours |
| Sample Volume | A minimum of 3 μL. | Same | Same |
| On-Board Quality Control | Multi-level on-board quality controls. | Same | Same |
| General Device Characteristic Differences | | | |
| Measuring Range | 0.8 – 8.0 INR | 0.8 – 6.0 INR for professional use*.
0.8 – 4.5 INR for self-testing use.
(* INR visualization up to 4.5. Both uses commercialized under the same reference) | 0.8 – 6.0 INR for professional use
NA for self-testing |
| Software | Remains the same as K243543 but INR upper range up to 8.0. | INR range to 4.5 | INR range to 8.0 |
| Limitations of POC settings | The microINR System is intended to be used in Point of Care settings such as physicians’ offices and | Same | No limitations |
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| | anticoagulation clinics, as well as home settings. It is not intended to be used in nursing homes, emergency rooms or intensive care units. | | |
| --- | --- | --- | --- |
| LVAD Patients | No interference observed. | Excluded | Same |
VI Standards/Guidance Documents Referenced:
CLSI EP05-A3 – Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline – Third Edition.
CLSI H21-A5. Collection, Transport, and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays and Molecular Hemostasis Assays; Approved Guideline-Fifth Edition.
CLSI H54-A. Procedures for Validation of INR and Local Calibration of PT/INR Systems; Approved Guideline.
ANSI AAMI ISO 14971:2019. Medical Devices- Applications of risk management to medical devices.
IEC 62304:2006/AMD1:2015 Medical device software - Software life cycle processes.
IEC 60601-1-2:2014 Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance – Collateral Standard: Electromagnetic disturbances – Requirements and tests.
IEC 60601-1-2:2014/AMD1:2020 Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance – Collateral Standard: Electromagnetic disturbances – Requirements and tests.
IEC 60601-4-2:2024. Medical electrical equipment - Part 4-2: Guidance and interpretation - Electromagnetic immunity: performance of medical electrical equipment and medical electrical systems.
VII Performance Characteristics (if/when applicable):
A Analytical Performance:
1. Precision/Reproducibility:
The reproducibility and intermediate precision of the microINR System is maintained from K180780 and K201185 for INR detection up to 4.5.
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A repeatability study was performed to access the precision of the microINR System above INR of 4.5. The repeatability study was performed at three Point of Care (POC) sites designed to simulate the Home Use setting. The study tested paired capillary samples collected and tested by 15 untrained patient self-testers (PST) on warfarin. The same 15 patients had paired capillary samples collected and tested by healthcare professionals (HCP). A total of four microINR Meters and two microINR Chip lots were included in the study. All test results met the pre-defined acceptance criteria. The Table below summarizes the repeatability study results.
| Repeatability Summary | | | | |
| --- | --- | --- | --- | --- |
| | No. of Test Pairs | Mean INR | SD (95% CI) | % CV (95% CI) |
| PST | 13 | 5.64 | 0.26 (0.18, 0.38) | 4.6 (3.3, 7.1) |
| HCP | 14 | 5.35 | 0.28 (0.16, 0.36) | 5.2 (2.8, 6.4) |
2. Linearity:
Not applicable.
3. Analytical Specificity/Interference:
Refer to K180780.
4. Assay Reportable Range:
The assay reportable range of the microINR System was established through analytical studies and the method comparison studies. The reportable range for INR is 0.8–8.0.
5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):
Each lot of microINR Chips is factory calibrated to a reference lot of human recombinant thromboplastin traceable to the World Health Organization International Reference Preparation. Separate microINR Chip lots manufactured by iLine Microsystems have been calibrated using the rTF/09 (WHO 4th International Standard Thromboplastin, Human, Recombinant, Plain) and the rTF/16 (WHO 5th International Standard Thromboplastin, Human, Recombinant, Plain).
6. Detection Limit:
Refer to K180780.
7. Assay Cut-Off:
Not applicable.
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# B Comparison Studies:
1. Method Comparison:
A method comparison study was performed to evaluate the performance of the microINR System above INR of 4.5. The method comparison study was performed at three sites. The study was conducted with four microINR Meters and two microINR Chip lots. A venipuncture was performed for INR determination on the reference analyzer (ACL TOP 750 (K242127) with HemosIL RecombiPlasTin 2G (K070005)) and for the hematocrit assessment. After confirming subjects INR was > 4.5, subjects were enrolled in the study. The enrolled subjects had two paired capillary samples collected by an HCP and tested on the candidate device. 13 of the subjects enrolled self-collected and self-tested two paired capillary samples on the candidate device. To support the INR range expansion, a pooled analysis was performed using method comparison data from K180780 and K201185 and the above-mentioned method comparison study (n=1,016) for the regression analysis. All test results met the pre-defined acceptance criteria. The Table below summarizes the combined method comparison study results.
| INR Range | Sample Number | Slope (95% CI) | Intercept (95% CI) | Correlation Coefficient (r) |
| --- | --- | --- | --- | --- |
| INR < 4.5 | 946 | 1.01 (1.00, 1.03) | 0.05 (0.03, 0.08) | 0.96 |
| INR ≥ 4.5 | 70 | 0.87 (0.74, 1.05) | 0.43 (-0.48, 1.14) | 0.87 |
Data analysis was performed to evaluate the effect of disease states and conditions of patients in POC settings that could interfere with the microINR System device. A review of 17 patients enrolled in the method comparison study performed in K180780 with Left Ventricular Assist Devices (LVAD) was performed to demonstrate the accuracy of the microINR System in this subpopulation. As in K180780, with the data from the method comparison study, the effect of the LVAD condition in the microINR System has been analyzed and the microINR System demonstrates acceptable performance when compared to the predicate (Coaguchek XS, K062925) and the reference method (Instrumentation Laboratory ACL TOP 500 laboratory analyzer, K160276 using HemosIL RecombiPlasTin 2G, K070005).
| Condition | N | Candidate vs Predicate | | Candidate vs Reference Method | |
| --- | --- | --- | --- | --- | --- |
| | | %Bias | %SD of Bias | %Bias | %SD of Bias |
| LVAD | 17 | -5.28 | 13.15 | 0.32 | 10.63 |
2. Matrix Comparison:
Refer to K180780.
C Clinical Studies:
1. Clinical Sensitivity:
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Not applicable.
2. Clinical Specificity:
Not applicable
3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):
Not applicable.
D Clinical Cut-Off:
Not applicable.
E Expected Values/Reference Range:
Refer to K180780.
VIII Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.
IX Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
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