Light Amplification Continuously Monitors Blood Coagulation

A novel optical device can facilitate real-time monitoring of blood clotting in the operating room (OR), according to a new study.

Developed by researchers at the University of Central Florida, the new device involves an optical fiber sensor that uses coherence-gated light scattering to constantly monitor blood coagulation. The device is based on accurate measurement of the non-ergodic, complex fluid dynamics of flowing blood by controlling and quantifying its spatiotemporal optical coherence under heterodyne amplification, or in other words the amplification of an optical signal by frequency conversion.

The device does so y beaming light at flowing blood passing through standard vascular-access tubing, and detects it as it bounces back. The light backscatter then determines how rapidly the red blood cells (RBCs) in the blood are vibrating; slow vibration is a sign that the patients’ blood is clotting, and using a blood-thinner may become necessary. The optical fiber-based tool can be directly incorporated into a range of medical devices to replace standard coagulation tests. The study describing the device was published online on February 10, 2017, in Nature Biomedical Engineering.

“I absolutely see the technique having potential in the intensive care setting, where it can be part of saving the lives of critically ill patients with all kinds of other disorders,” said study co-author Professor William DeCampli, MD, of UCF College of Medicine, and chief of pediatric cardiac surgery at Arnold Palmer Hospital for Children (Orlando, FL, USA). “These things come about because of collaboration between a top-ranked engineering university and a top-ranked children's hospital, all in one city. I think it's the perfect way to make advances in medicine that are at the engineering frontiers.”

Complex fluids are binary mixtures that demonstrate coexistence between two phases; blood is an example of such a complex fluid, as a solid–liquid suspension of macromolecules. Its non-ergodic nature is demonstrated by unusual mechanical responses that show transitions between solid-like and fluid-like behavior, as well as fluctuations. The mechanical properties can be attributed to characteristics such as high disorder, caging, and clustering on multiple length scales.