HemaApp Graphic (IMAGE) University of Washington Caption HemaApp uses illumination sources from a smartphone and algorithms that analyze the color of a patient's blood to estimate hemoglobin levels. Credit University of Washington Usage Restrictions with credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.