An approach to measuring RBC haemolysis and profiling RBC mechanical fragility

Abstract

Red blood cells (RBC) can be damaged by medical products, from storage or from disease. Haemolysis (cell rupture and haemoglobin release) is often a key indicator, with mechanical fragility (MF) offering the potential to assess sub-haemolytic damage as well. This article reports on a unique approach to measuring haemolysis, without the need for centrifugation or other sample separation. It also reports on employing that in measuring blood fragility (susceptibility to haemolysis) under shear stress, utilising an electromagnet to cause a bead to oscillate within a cartridge that contains the sample. Cycling between stressing and optical measurement of induced haemolysis at progressively increasing durations of stress provides a fragility profile. Sub-system-level testing shows high accuracy for the haemolysis measurements and fair consistency for MF profiling. Improving accuracy and precision of profiling is a current focus and a fully integrated and automated version of this system is under development.

Keywords:

• Red blood cells (RBC)
• haemolysis
• blood damage
• fragility
• engineering design

Acknowledgements

The authors thank Dr. Robertson Davenport and Ms Theresa Downs of the University of Michigan for providing RBC samples for testing. Also acknowledged are Blaze employees Sumita Chakraborty, Randall Bath and Marina Muchnik for their work on experiments helping inform system design; independent machinist Steven Hampel for making parts used in preliminary testing; and in2being employees Terrance Boyd, Aaron Kehrer, Chris Ridgard and Shepherd Smith for their contributions in the development process.

Disclosure statement

The presented work was funded entirely by Blaze Medical Devices, an early stage company working to develop and commercialise blood analysis technology and which fully owns the proprietary technology presented. Authors Alfano and Tarasev have equity and employment with Blaze. The other authors are with in2being, which is contracted by Blaze for development work. Aspects of the presented subject matter are described in patent material of Blaze.