Office of Technology Transfer – University of Michigan

Droplet-based microrheometer for real-time monitoring of blood viscosity

Technology #6695

According to the U.S. Centers for Disease Control, blood coagulation disorders could affect as many as 900,000 Americans. Up to 100,000 Americans die each year of deep vein thrombosis or pulmonary embolism (DVT/PE). Of those who survive, half will have long-term complications, including recurrence of DVT. In the United States, up to 5 million patients who have atrial fibrillation are also at risk of developing blood clots. The most common anticoagulation drug used, warfarin, requires regular blood coagulation monitoring to ensure proper dosing. Existing blood coagulation tests exhibit low sensitivity, poor reproducibility across laboratories, and have failed to become standardized. There is a need for accurate, cost-effective point-of-care and patient self-monitoring tests for hemostasis management. The development of highly sensitive, point-of-care hemostasis tests is driving the growth of the global blood coagulation analyzer market, which is expected to reach a market size of $3.58 billion by 2019.

Microfluidic viscometer for real-time blood coagulation monitoring

The technology developed in Prof. Burns’ lab consists of a droplet-based microfluidic rheometer that can monitor the blood coagulation process continuously over a period of several hours. Droplets of blood samples are generated in the device after the patient has provided a sample. The size and color of the droplets, the time of droplet generation, and the spacing between droplets are all correlated to the sample viscosity, which can be measured as a function of time. To monitor blood coagulation for an hour, a low sample volume of less than 5 µL is needed. The device is able to measure the viscosity of whole blood with a sensitivity of about 1cP. The microfluidic rheometer is much smaller in size than current bench-top devices, and is portable. This enables convenient patient self-testing and point-of-care use.


  • Low sample consumption
  • Portable device
  • Device measures absolute viscosity of biological fluids with high sensitivity


  • Real-time blood coagulation monitoring
  • Viscosity measurement of small-volume biological samples