An app for anaemia at your fingertips

Researchers have a solution for detecting anaemia literally at their fingertips.
11 December 2018

Interview with 

Robert Mannino - Emory University


Hands holding a phone


Almost two billion people worldwide are affected by anaemia: they have too few red blood cells; this often needs to be monitored, but that monitoring is inconvenient, time consuming and costly. Cue Emory University's Robert Mannino, who spoke to Chris Smith and has a solution - literally - at his fingertips…

Rob - This technology was developed and motivated by the fact that I myself suffer from serious anaemia that requires me to receive regular blood transfusions. And as part of that I get my anaemia levels checked quite frequently. Doing this involves me getting myself to the hospital, waiting around in the waiting room, getting a venous blood draw. So getting stuck. And then waiting for my doctor to tell me the results. And I thought there would be a better way to do this.

And so I have developed a smartphone app that's able to measure the color of someone's fingernails and correlate that color to a person's haemoglobin level. Now haemoglobin is a protein that's found in the blood, gives blood its red color and it's responsible for transporting oxygen throughout the body and low haemoglobin levels are what defines anaemia.

Chris - And the low hemoglobin levels they're reflected in changes in the fingernails how exactly? What are you looking for?

Rob - We're looking for the colour so because haemoglobin is what gives blood its red color, someone with low haemoglobin levels will have paler fingernails.

Chris - So how does it work then? What, you literally take a picture of your fingernails, capture the image and then process the image with the app and it extracts the colour and that's what tells you roughly what your haemoglobin level will be?

Rob - Yes exactly. A user can download the app on their phone and simply take an image of their fingernails. Based on the colour of their fingernails the app gives an estimate of the haemoglobin level.

Chris - How good is it Rob? Is it highly reproducible? If I did this 10 times on myself would it return the same haemoglobin estimation each time?

Rob - So we've shown our results to be on average within plus or minus one gram per deciliter of the gold standard tests for measuring haemoglobin levels. And that's right around plus or minus 10 percent.

Chris - And is that good enough is 10 percent good enough for someone with a condition like yours who needs to know what their hemoglobin level is? Would you be comfortable with 10 percent either side?

Rob - So right now the app cannot be used to diagnose or treat conditions, but the accuracy is acceptable in our opinion for screening. So someone getting an idea of whether or not they should seek treatment based on the results.

Chris - I presume that the system would be frustrated by nail varnish unless it was clear. But what about other defects, lesions, these things, these white marks that we get on our fingernails. Can it get caught out?

Rob - So you've actually hit the nail on the head with that one. Yeah it certainly won't work with nail varnish or nail polish as and like you mentioned certain fingernail bed irregularities can impact the results. Patients with white spots on the fingernails or maybe nail bed injuries would not be able to use the system if a significant portion of their fingernail beds are obscured.

Now I'm in the process of developing quality control methods to try to ignore spots and regions on the fingernails like that.

Chris - The follow on from that is that a significant number of people who have haemoglobin problems linked to anaemia often have dark skin. I'm thinking about conditions like sickle cell anaemia which tend to be in black Africans. Do people with black skin have a problem with your app or is it colour blind as it were?

Rob - So that's actually the great thing about using the fingernails. Under normal circumstances in the fingernail beds there are no skin cells that produce pigment. So in normal circumstances regardless of the subject's skin tone, the colour of the fingernails should be the same. And so we actually did studies with patients for many different skin tones and being in Atlanta Georgia, we actually have a fairly large sickle cell disease population who was included in the clinical studies that we did and we didn't show any correlation between skin tone and error.

Chris - Given that you've got this technology working you can capture an in future you're saying you'll be out a better capture images of the nail bed and extract colour information, could you use this diagnostically or as a screening tool for a range of diseases, not just anaemia? Could you extend this to other possible conditions because we know lots of diseases do manifest with changes in the nails?

Rob - Yes absolutely. So we chose anaemia because anaemia was really the low hanging fruit so to speak. But really this technology could be applied to any condition that manifests in a physical change or discoloration of the fingernails. Jaundice where regions of the body get a yellow color. Some heart conditions manifest in something called cyanosis where the fingertips become more blue due to circulation issues.


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