App to diagnose anemia… from fingernails

Mobile apps are increasingly changing the way we initially diagnose illnesses. For instance, you wake up in the morning feeling miserable and the app on your phone confirms that you had a fitful sleep. In the bathroom a sensor strip tests your urine to reveal that most metabolites are fine but for an increase in nitrite levels. Further tests show that heart rate and blood oxygen are fine, but inflammation levels are higher than normal, and that vitamin D is on low side. You swab your nose and a bedside reader tells you in just a few moments exactly what is wrong; you have the flu. A quick scan of the flu map on my phone confirms that 10 percent of my neighborhood have the flu and that I am just another dot on the map.

Most of the technologies described above already exist, and a lot more are being added to the market. In addition to just monitoring your health as many apps and devices currently do, the new apps and technologies also deliver diagnoses and recommendations. The age of DIY diagnostics is clearly on the horizon.

Now a new smartphone app claims to diagnose anemia by analyzing the color of a person’s fingernails through a photograph.

Anemia, a condition which affects over two billion people worldwide, is characterized by low levels of hemoglobin — the oxygen carrying pigment in healthy red blood cells. If untreated, it can cause severe fatigue, heart problems and complications in pregnancy.

At present anemia is tested by taking blood samples and testing them on specialized equipment that are often not easily accessible in low income countries where anemia is most prevalent. Scientists at Emory University in Georgia, in the United States have now developed a simple mobile app that provides a low-cost alternative to blood sample analysis machines.

Previous studies have shown that the degree of paleness in some body tissues, including the fingernail beds, is a reliable indicator of how anemic a person is. Since the skin beneath fingernails does not contain pigment, hemoglobin is the main source of color.

By downloading the app, people can obtain a hemoglobin measurement in seconds by photographing their fingernails and tapping the screen to indicate where the nails are in the image. The app uses the photo metadata to account for and factor out ambient lighting conditions.

The measurement is based on a database of photos of fingernails from people with known hemoglobin levels. Although not as accurate as a blood test analysis machine, it is sensitive enough to be useful for screening groups that have a high risk of anemia, such as the elderly, pregnant women and young children. However, it will need further testing with larger numbers of people to confirm its accuracy before being made available widely in the market, said the researchers.

The app can be made more accurate by personalizing it with a specific person’s measurements and thereby allowing them to regularly monitor their anemia painlessly at home. The researchers are also working on other smartphone apps to assess jaundice, the yellowing of the skin and eyes caused by liver disease.

Another system being developed, this time by the Oxford University Institute of Biomedical Engineering, is for managing chronic obstructive pulmonary disease (COPD), a condition that affects millions of people worldwide. Patients with COPD will be able to use a finger probe to measure their heart rate and blood oxygen saturation every day and enter the results into an app. After three months of measurements, the app learns to recogniz a patient’s specific range of normal oxygen saturation levels, and issues an alert to clinicians when the measurement falls below that range. In a 12-month clinical trial, the COPD app reduced hospital admissions by 17 percent and visits by doctors by 40 percent.