Imagine this. You feel a bit under the weather, so you reach into your medicine cabinet and grab a standard urine test strip. After using it, you take a photo with your smartphone’s camera. In an instant, a smart app analyzes the strip and gives an accurate medical report, which can be immediately emailed to a doctor, who can prescribe the right medication. No more going to the doctor—medical care could soon be available in your pocket!
This is the scenario that a team of researchers from the University of Cambridge is working towards. Their app, Colorimetrix, is accurate enough to monitor conditions such as diabetes, kidney disease, and urinary tract infections. The best part? It works on cheap smartphones too, so that could make this into a truly portable medical diagnostic device, not to mention more widely usable in the developing world. "By quickly getting medical data from the field to doctors or centralized laboratories, it may help slow or limit the spread of pandemics,” says Ali Yetisen, a PhD student in the Department of Chemical Engineering & Biotechnology, who led the research.
Going Beyond Fitness Apps
“There are so many apps out there trying hard to have an impact, they all provide a ‘service’ but no substantial impact on society,” says researcher Dr. Leo Martinez, who developed the app. “You can count steps and jumps without a phone. But how do you relate technology with our body beyond the jumping and counting steps apps? That was the Eureka moment!”
The implications of the Colorimetrix app are widespread. “In the short term, this app can be used for home testing of common tests such as glucose, urea, pH, etc., for patients that monitor diabetes,” Dr. Martinez says. “We have [gotten] emails from different people and institutions trying to use the app for their home testing of disease from renal failure to hepatic anomalies.”
In the long term, Colorimetrix could have much wider use. While health is the priority, it could find applications in monitoring indoor gaseous environments, contaminants in water, soil acidity, and quality control or safety monitoring in chemical or biologics production plants, to name a few examples.
How It Works
The Colorimetrix app is based on standard colorimetric tests, which are commonly used for medical monitoring due to their portability and ease of use. These are small strips that produce color change in a solution to determine its concentration. The accuracy of these tests lies in how they are read—doing it by eye can often lead to mistaken readings, while using clinical equipment is too costly.
The Cambridge researchers believe they’ve come up with the ideal go-between. Here’s how it works: After testing urine, saliva, or other bodily fluid with a colorimetric test, the user takes a photo of the test with the phone’s camera. The Colorimetrix app uses the camera and an algorithm to convert data from colorimetric tests into a numerical concentration value, which is displayed on the screen within a few seconds. This result can then be stored, sent to a healthcare professional, or directly analyzed by the phone for diagnosis.
The study, published in the journal Sensors and Actuators B: Chemical, found that Colorimetrix was accurate in reporting glucose, protein, and pH concentrations from commercially-available urine strips. This is the first time an app has been used this way in a lab setting, the scientists say. Buoyed by the results, the Cambridge team is expanding its scope. They are looking to partner with test strip providers so that Colorimetrix can be used with a pre-recorded calibration.
But the user can record one too, says Dr. Martinez, pointing to this video to see how easy it is:
Making Mobile Healthcare Real In The Developing World
“We used an iPhone 5 as well as a Samsung Galaxy i5500 and found that there is no substantial variability from phone to phone,” says Dr. Martinez. Variation can still occur due to the environment or the component being measured, but the type of phone is not a determining factor. “The idea was to prove that it is possible to do the same with a cheap old phone, thus the impact on the developing world where mobile phone markets are very strong.”
“This app has the potential to help in the fight against HIV, tuberculosis and malaria in the developing world, bringing the concept of mobile healthcare to reality,” Yetisen adds.
In keeping with this thinking, the scientists are concentrating on an Android version of the Colorimetrix app since “Android is more cost-effective.” Dr. Martinez is working on development to release the app for public download by the end of summer, and estimating the costs. “It should be as inexpensive as possible,” he says. “This app can substitute for laboratory equipment, saving money to clinics and research institutions.” The team is planning to use the app for clinical testing of kidney function and infections in clinical testing at Addenbrooke’s Hospital in Cambridge.
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