Portable Blood Analyzer Could Improve Anemia Detection Worldwide

Close-up view of the optical analyzer.
Credit: Nikita Taparia,
University of Washington
About one quarter of the world's population suffers from anemia, a disease caused by a concentration deficiency of hemoglobin in red blood cells. Hemoglobin transports oxygen throughout the body, and if the concentration decreases and body becomes starved of oxygen, it often result in dizziness, fatigue, shortness of breath and abnormal heart rate. Severe cases can even lead to increased maternal and child mortality, as well as impair cognitive and physical development in children.

To reduce the burden, health officials need a better picture of the disease's global impact, an understanding made viable by a portable and affordable way to analyze blood. Researchers at the University of Washington developed a device smaller than a toaster that can detect the level of hemoglobin in whole blood samples using optical absorbance. The work is published in AIP Advances.

Blood analyzers currently on the market measure hemoglobin by chemically rupturing the red blood cells in a sample. This technique requires hands-on expertise to prepare and run a sample, limiting the ability to monitor anemia in many parts of the world. The new device uses whole blood and does not require additional steps and reagents to prepare a sample, only a few drops of blood. 

The analyzer takes advantage of the optical properties of blood, such as absorption and scattering, to measure hemoglobin concentration. Anemic blood transmits more light compared to normal blood, so the severity of anemia can be measured as a ratio of transmitted to original light intensity.

To simulate anemia, the researchers diluted blood samples with a buffer solution. The blood analyzer was effective at predicting cases of moderate to severe anemia, defined as less than 10 grams per deciliter of hemoglobin in a sample. The analyzer did not produce any false negative results.

The optical density of samples did not increase linearly, so a higher concentration of hemoglobin defines the upper limit of detection for the device.

The current design is a prototype that could be integrated with other microfluidic devices to analyze whole blood samples in parallel to diagnose anemia and other underlying factors that could contribute to the disease.