Researchers at Emory University and Georgia Tech built a smartphone app that photographs the fingernail bed, a tissue with no melanin, and estimates hemoglobin level from its color.
Tested on 337 participants split into development and validation groups, the app estimated hemoglobin within about 2.4 grams per deciliter of lab blood test results and caught 97 percent of anemia cases in the validation group.
Because the test relies on color rather than a direct blood measurement, it is meant to flag people who likely need a confirmatory blood test, not to replace one, and the validation group, while promising, was still modest in size. With personal calibration, its accuracy improved to within about 0.9 grams per deciliter in a small group of patients.
Read the original study
Mannino et al., Nature Communications, 2018 · doi.org/10.1038/s41467-018-07262-2
A fingernail photo stood in for a blood draw.
Source
- Mannino, R. G., Myers, D. R., Tyburski, E. A., Caruso, C., Boudreaux, J., Leong, T., Clifford, G. D., & Lam, W. A. (2018). Smartphone app for non-invasive detection of anemia using only patient-sourced photos. Nature Communications, 9(1), 4924. https://doi.org/10.1038/s41467-018-07262-2