Ali Yetisen and Leo Martinez have tested a smartphone app that validates its use as a scientific instrument. Users will be able to collect quantitative data from point-of-care diagnostics and submit to clinicians for immediate review.
Decentralisation of healthcare through low-cost and highly portable point-of-care diagnostics has the potential to revolutionise current limitations in patient screening. Diagnosis can be hindered by inadequate infrastructure and shortages in skilled healthcare workers, particularly in the developing world. Overcoming such challenges by developing accessible diagnostics could reduce the large burden of disease.
Point-of-care tests strips are widely used to quantify the concentration, or to detect the presence of medically-relevant compounds. Such tests are used for urinalysis, immunoassays, veterinary screening, food safety, environmental monitoring, biothreat detection and drug abuse. Their formats are ubiquitous because of the portability, compactness, ease-of-use and equipment-free approach they provide.
Colorimetric tests are typically read by comparing the colour of the reaction zones with a reference chart. However, subjective interpretation may result in erroneous diagnosis. Benchtop equipment such as spectrophotometers or test-specific readers can be used to automate the readouts with high sensitivity, however they are costly and bulky.
To reduce costs and improve portability, the researchers have developed and tested an app, which can quantify colorimetric tests for both Android and iOS. The app was used to read commercial tests for pH, protein and glucose in urinalysis. Their studies were published in Sensors and Actuators B: Chemical journal.
The app allows analytical collection of data with improved accuracy when compared to semi-quantitative visual readouts. The strips used in the study are widely used in clinical practice for monitoring renal, urinary, hepatic and metabolic disorders.
“This smartphone app has the potential to help to combat HIV, tuberculosis and malaria in the developing world,” states Ali Yetisen.
The app enables transmission of medical data in real time, which may allow timely mitigation of endemics and pandemics. This app may bring the concept of telemedicine to reality by transmitting personal clinical data for immediate review by health professionals.
“Point-of-care diagnostic tests sometimes give false positive or negative results unless they are analytically quantified. Our app solves this problem by providing a semi-quantitative evaluation,” says Dr. Leo Martinez.
The team is planning to use the app for clinical testing of kidney function and infections in Addenbrooke’s Hospital. This work was a multidisciplinary effort bringing together researchers from Professor Christopher R. Lowe’s laboratory and the Department of Engineering (Dr. Angel Garcia). Updates of the app can be found at www.colorimetrix.com.