December 27, 2018
These days it seems as thought there are fewer things that our smartphones can’t do then what they can. Heck, they can even measure things now.
Adding to the list of things your smartphone can do, researchers at Georgia Tech have developed an app that uses a photo of someone’s fingernails, rather than having to take blood samples, to determine whether the level of hemoglobin in their blood seems low. This is a non-invasive way to test for anemia — a condition in which you don't have enough healthy red blood cells to carry adequate oxygen to the body's tissues, according to the Mayo Clinic.
The smartphone anemia app is projected to be available commercially for public download as soon as spring of 2019.
Anemia, which affects two billion people worldwide, can lead to fatigue, paleness, and cardiac distress if left untreated. Currently, the gold standard for anemia diagnosis is known as a complete blood count (CBC), Futurity reports.
Per Futurity, the researchers studied fingernail photos and correlated the color of the fingernail beds with hemoglobin levels measured by CBC in 337 people: some healthy, and others with a variety of anemia diagnoses. The algorithm for converting fingernail color to blood hemoglobin level was developed with 237 of these subjects and then tested on 100.
The researchers were able to show that just one image snapped on a smartphone can measure hemoglobin level with an accuracy of 2.4 grams/deciliter with a sensitivity of up to 97 percent.
The app uses image metadata to correct for background brightness and can be adapted to phones from multiple manufacturers. Plus, it only examines fingernail beds, which do not contain melanin, meaning the test can be valid for people with a variety of skin tones —and the accuracy is consistent for all skin tones.
“All other ‘point-of-care’ anemia detection tools require external equipment, and represent trade-offs between invasiveness, cost, and accuracy. This is a standalone app that can look at hemoglobin levels without the need to draw blood,” says principal investigator Wilbur Lam, a clinical hematologist-bioengineer at the Aflac Cancer and Blood Disorders Center of Children’s Healthcare of Atlanta, associate professor of pediatrics at Emory University School of Medicine, and a faculty member in the biomedical engineering department at Georgia Tech.
Rob Mannino, a recent graduate in biomedical engineering, is the first author of a paper in Nature Communications describing the app. Mannino was motivated to conduct the research by his own experience living with beta-thalassemia, an inherited blood disorder caused by a mutation in the beta-globin gene.
Mannino’s disease requires monthly blood transfusions and, ideally, more frequent testing of his hemoglobin levels. However, Mannino finds it hard to get to the hospital for additional blood tests between transfusions, making this app an extremely helpful tool in his treatment.
“He took pictures of himself before and after transfusions as his hemoglobin levels were changing, which enabled him to constantly refine and tweak his technology on himself in a very efficient manner. So essentially, he was his own perfect initial test subject with each iteration of the app,” Lam explains, regarding Mannino’s research of the app.
This app is promising for the self-management of the disease by patients with chronic anemia, allowing them to monitor their disease and to identify the times when they need to adjust their therapies, the researchers theorize. This will likely reduce side effects or complications of having transfusions too early or too late.
The app — which is currently to be used only for detection, not diagnosis — is also thought to be beneficial for pregnant women, women with abnormal menstrual bleeding, runners and athletes. Additionally, the simplicity of the app means it could be useful in developing countries.
While clinical diagnostic tools have strict accuracy requirements, Mannino and Lam believe that with additional research, that app will eventually be able to achieve the accuracy needed to replace blood-based anemia testing for clinical diagnosis.