Biosens

bSens.INR

PT/INR strip test

bSens.INR is in preparation for the Anvisa registration process. It is not yet on sale.

Point-of-care strip test that uses graphene to measure prothrombin time, expressed as the PT/INR value (International Normalized Ratio).

  • Result: the measured INR value, shown on the bSens One reader.
  • Intended use: being defined, as part of the preparation for Anvisa registration.

Names you may hear for the same test: coagulation test, PT/INR, prothrombin time.

Talk to BiosensSee how it works
A bSens.INR strip being inserted into the bSens One reader, held in one hand.

How it works

Three steps between the drop and the result.

bSens.INR is designed to take the coagulation test (INR) from the laboratory to where care happens.

  1. 1

    Prepare the strip and the sample.

    The bSens.INR strip goes into the bSens One reader, which gets ready to measure. One drop of blood goes on the sample area, at the tip of the strip.

  2. 2

    Measure clotting time.

    The drop reacts with the chemistry on the strip, and the printed electrode turns the reaction into a signal. The reader measures that signal and calculates INR.

  3. 3

    Read the INR value.

    The reader shows the measured INR value. Its interpretation depends on each person's clinical context and is made by the healthcare professional.

The system

One reader, one strip, one cloud.

The three parts are designed to work as a single system.

Scientific context

What the studies say.

Data from scientific papers and books. They describe the condition, the field and the technology, not bSens products.

  • 62.6%

    At three public anticoagulation clinics in Belo Horizonte (2014 to 2015), 801 people taking warfarin spent on average 62.6% of the time within their INR therapeutic range. An international meta-analysis of atrial fibrillation studies published from 1990 to 2013 found 61%. 1,2

  • 28 trials

    A 2016 Cochrane review pooled 28 randomized trials with 8,950 people on oral anticoagulation. Those who tested their own INR at home had fewer thromboembolic events than with standard monitoring (moderate-quality evidence); major bleeding and overall mortality did not decrease. The authors note that self-testing is not feasible for everyone and requires identifying and educating suitable patients. 3,4

  • 148 people

    In a retrospective study at a single hospital in China, 148 people with a mechanical heart valve taking warfarin chose between INR monitoring at the hospital and self-testing with a portable device, with remote guidance from their doctors through an app. Over 12 months, 68.9% of the 74 who self-tested and 39.2% of the 74 at the hospital had at least 60% of their INR tests in the target range. The measure counts tests, not time, and self-testing called for more frequent tests. 5

  • The INR (international normalized ratio) expresses the prothrombin time on a common scale and is calculated with the ISI, a calibration index referenced to a WHO international standard. The target range depends on the clinical indication and is set for each person by the healthcare professional. The Brazilian valve disease guideline says the INR is usually checked once a month. 6,7,8,9

  • In a US national estimate for 2007 to 2009, warfarin was implicated in 33.3% of emergency hospitalizations for adverse drug events in people aged 65 or older. In the same estimate, insulins were implicated in 13.9%. 10

  • Under the 2025 Brazilian atrial fibrillation guideline, direct oral anticoagulants are preferred, except for people with a mechanical heart valve or moderate to severe mitral stenosis. In these cases a vitamin K antagonist such as warfarin remains indicated, based on trials in which there were more events with direct anticoagulants. 8,11,12,13

References

  1. 1.Viana CC, Praxedes MFDS, Abreu MHNG, et al. Quality of Oral Anticoagulation Control with Warfarin According to Sex: A Cross-Sectional Study. Int J Environ Res Public Health. 2025;22:65. doi:10.3390/ijerph22010065
  2. 2.Mearns ES, White CM, Kohn CG, et al. Quality of vitamin K antagonist control and outcomes in atrial fibrillation patients: a meta-analysis and meta-regression. Thromb J. 2014;12:14. doi:10.1186/1477-9560-12-14
  3. 3.Heneghan CJ, Garcia-Alamino JM, Spencer EA, et al. Self-monitoring and self-management of oral anticoagulation. Cochrane Database Syst Rev. 2016;7:CD003839. doi:10.1002/14651858.CD003839.pub3
  4. 4.Heneghan C, Ward A, Perera R; Self-Monitoring Trialist Collaboration. Self-monitoring of oral anticoagulation: systematic review and meta-analysis of individual patient data. Lancet. 2012;379:322-334. doi:10.1016/S0140-6736(11)61294-4
  5. 5.Huang L, Ouyang C, Ye X, Ren M, Da Q, Han Z. Anticoagulation monitoring using point-of-care testing combined with mobile remote management in postoperative cardiac valve replacement patients receiving warfarin therapy: A single-center cross-sectional study. Medicine (Baltimore). 2026;105:e47395. doi:10.1097/MD.0000000000047395
  6. 6.Ageno W, Gallus AS, Wittkowsky A, Crowther M, Hylek EM, Palareti G. Oral anticoagulant therapy. Chest. 2012;141(2 Suppl):e44S-e88S. doi:10.1378/chest.11-2292
  7. 7.Dorgalaleh A, Favaloro EJ, Bahraini M, Rad F. Standardization of Prothrombin Time/International Normalized Ratio (PT/INR). Int J Lab Hematol. 2021;43:21-28. doi:10.1111/ijlh.13349
  8. 8.Cintra FD, Pisani CF, Rezende AGDS, et al. Diretriz Brasileira de Fibrilação Atrial - 2025. Arq Bras Cardiol. 2025;122:e20250618. doi:10.36660/abc.20250618
  9. 9.Tarasoutchi F, Montera MW, Ramos AIO, et al. Atualização das Diretrizes Brasileiras de Valvopatias - 2020. Arq Bras Cardiol. 2020;115:720-775. doi:10.36660/abc.20201047
  10. 10.Budnitz DS, Lovegrove MC, Shehab N, Richards CL. Emergency hospitalizations for adverse drug events in older Americans. N Engl J Med. 2011;365:2002-2012. doi:10.1056/NEJMsa1103053
  11. 11.Eikelboom JW, Connolly SJ, Brueckmann M, et al. Dabigatran versus warfarin in patients with mechanical heart valves. N Engl J Med. 2013;369:1206-1214. doi:10.1056/NEJMoa1300615
  12. 12.Wang TY, Svensson LG, Wen J, et al. Apixaban or Warfarin in Patients with an On-X Mechanical Aortic Valve. NEJM Evid. 2023;2:EVIDoa2300067. doi:10.1056/EVIDoa2300067
  13. 13.Connolly SJ, Karthikeyan G, Ntsekhe M, et al. Rivaroxaban in Rheumatic Heart Disease-Associated Atrial Fibrillation. N Engl J Med. 2022;387:978-988. doi:10.1056/NEJMoa2209051

Frequently asked questions

Is it a final diagnosis?
No. bSens.INR measures and shows the INR value. Interpretation and the clinical decision belong to the healthcare professional.
Do I need internet?
The reader is designed to measure without internet and to sync with bSens Cloud, which is in development, when there is a network.
Is the data stored?
bSens Cloud, in development, is designed to keep each result in a history.
How is an INR value interpreted?
INR is a value related to blood clotting. It is interpreted by the healthcare professional, in the context of each person's clinical situation.

Contact

Results at the Point of Care

Get in touch to learn about the bSens system.

Please do not send health information by e-mail. Biosens does not interpret test results or guide treatment.

E-mail

contact@biosens.tech

Address

Av. Theodomiro Porto da Fonseca 3101, Building 3, Room 1, 93022-715, São Leopoldo, RS, Brazil