Smartphone app measures hemoglobin without blood test

Researchers have developed a way to use smartphone images of a person’s eyelids to assess blood hemoglobin levels. The ability to perform one of the most common clinical lab tests without a blood draw could help reduce the need for in-person clinic visits, make it easier to monitor patients in critical conditions, and improve care in low- and middle-income countries where access to testing laboratories is limited, according to Scienmag.

“Our new mobile health approach paves the way for bedside or remote testing of blood hemoglobin levels for detecting anemia, acute kidney injury, and hemorrhages, or for assessing blood disorders such as sickle cell anemia.” said research team leader Young Kim from Purdue University. “The COVID-19 pandemic has greatly increased awareness of the need for expanded mobile health and telemedicine services.”

Kim and colleagues from the University of Indianapolis, Vanderbilt University School of Medicine in the US, and Moi University School of Medicine in Kenya report the new approach in Optica, The Optical Society’s journal for high impact research.

The researchers used software to transform the built-in camera of a smartphone into a hyperspectral imager that reliably measures hemoglobin levels (a measure of the oxygen-carrying capacity of blood) without any hardware modifications or accessories. A pilot clinical test showed that prediction errors for the smartphone technique were within 5 to 10 percent of those measured with clinical laboratory blood.

“This new technology could be beneficial for detecting anemia, which is characterized by low levels of blood hemoglobin,” said Kim. “This is a major public health problem in developing countries, but can also be caused by cancer and cancer treatments.”