Technology continues to evolve, simplifying every facet of our lives from personal to professional, putting information at our fingertips in a matter of seconds. In a study published by University of Washington, researchers introduce HemaApp, a new application that screens haemoglobin levels using a smartphone flashlight.
HemaApp measures hemoglobin levels and screens for anemia non-invasively by illuminating the patient’s finger with a smartphone’s camera flash (photo: Dennis Wise/University of Washington)
Haemoglobin is a protein that is found on red blood cells, which binds to oxygen and carries it throughout the body. Anaemia is a condition that develops when the blood lacks healthy red blood cells or haemoglobin to carry oxygen to the cells throughout the body. It can be caused by haemorrhage, malnutrition or even a parasitic infection. The World Health Organization (WHO) estimates approximately two billion people around the world are anaemic. Symptoms include dizziness, weakness and severe headaches. Haemoglobin measurement is used in screening for anaemia and as a trending tool for evaluating a patient’s response to treatments such as iron supplementation or red blood cell transfusions.
HemaApp utilises the camera flash on cellphones to shoot different wavelengths of light at a person’s fingertip and performs a chromatic analysis, analysing the colour of the blood and absorption levels. Based on absorption properties of the blood, HemaApp can estimate haemoglobin concentration. HemaApp then uses a regression method to classify data points as either normal or anaemic.
The gold standard blood test for measuring haemoglobin levels still remains the complete blood count test (CBC), which is an invasive procedure that requires a venipuncture in order to obtain the blood. Initial testing of HemaApp in a small trial of 31 patients indicated 69 per cent accuracy compared to the CBC test, using the built in flashlight of a Nexus 5 smartphone. With the addition of a common incandescent light, accuracy rose to 74 per cent. When a small circle LED light was added, accuracy was observed at 82 per cent.
HemaApp proved to be an effective, non-invasive initial screening tool, which could be useful in areas where sophisticated laboratory devices may not available. It correctly diagnosed anaemia in 79 per cent of cases using just the phone camera; the accuracy rose to 86 per cent with the addition of other light sources.
It should be noted that HemaApp is not intended to replace traditional laboratory tests, but may provide a rapid, cost effective, easily accessible, non-invasive method for ascertaining haemoglobin results when there are barriers to a obtaining a CBC. The standard diagnostic test for confirming anaemia still remains a CBC however, although this requires a blood sample to run through an automated instrument to measure several blood components such as RBC, WBC, and platelets. It can take anywhere from hours to several weeks to generate these results.
At home tests, which deliver results within minutes, such as FDA approved HemoCue and Masimo Pronto, allow patients to monitor haemoglobin levels between blood tests. So why is HemaApp the better choice?
HemoCue, used for the detection and prevention of anaemia, uses a small blood sample obtained through a finger prick to determine haemoglobin concentration in one minute with an accuracy of 89 per cent. HemaApp’s noninvasive nature avoids the discomfort of needle sticks and carries no risk of infection. Furthermore, certain populations of patients will reap the benefit of the reduced invasiveness, such as haemophiliacs, who have abnormal clotting pathology, or sickle cell patients, whose veins are often sclerosed, where even a small pinprick can be a challenge.
Masimo Pronto attaches a sensor to the tip of a finger as a non-invasive way to continuously monitor haemoglobin. This technology can be costly, but the invention of HemaApp means that many people already have the technology to measure their haemoglobin levels, and require only a simple download from the app store.
In a global context, HemaApp may be the future for community healthcare workers in developing nations to screen for iron-deficient anaemia and potentially other pathologies. Community healthcare workers are limited in the technology they have access to and often have a finite number of medical tools they take with them in the field. It is already standard to use a smartphone to keep medical records, making such devices the single most valuable piece of technology for medical professionals in tech deficient communities. Co-author Doug Hawkins stated: “The ability to screen quickly [for anaemia] with a smartphone-based test could be a huge improvement to delivering care in limited-resource environments.”
Research continues at the University of Washington on this HemaApp. The initial testing for this app was a small sample size, but showed promising results. Once more data is collected, accuracy rates can be improved further. Researchers want to use the app to screen for sickle cell disease, which also causes anaemia owing to irregular red blood cell shape.
With technology such as HemaApp, how far do the possibilities reach? Will apps eventually replace diagnosticians?
Editors. (September 9, 2016) HemaApp Accurately Estimates Hemoglobin Blood Using Standard Smartphone. Retrieved September 28, 2016, from here
Langston, Jennifer. (September 7, 2016) HemaApp screens for anemia, blood conditions without needle sticks. Retrieved September 28, 2016, from here
Edward Jay Wang, William Li, Doug Hawkins, Terry Gersheimer, Colette Norby-Slycord, and Shwetak N. Patel. 2016. HemaApp: Noninvasive Blood Screening of Hemoglobin using Smartphone Cameras. Retrieved from here
Knight, Will. (September 7, 2016) How to Make a Smartphone Detect Anemia. Retrieved September 28, 2016, from here