Researchers have come up with an optical gadget which, when attached to a smartphone, can check samples for 12 infectious diseases at once.
The team, led by Lei Li, assistant professor in the School of Mechanical and Materials Engineering at Washington State University, devised the equipment to solve the problem of diagnosis in remote areas.
Although tests are available to help in diagnosis, often a doctor must rely on their judgement of the patient's symptoms or send off samples for checking at a lab. On-site mobile diagnostic devices usually can only handle one sample at a time.
A delay in diagnosis and treatment could become a matter of life or death in some cases.
The device, constructed by Li's team from mostly off-the-shelf parts for the princely sum of $50, features 96 wells into which samples are placed.
Li told The Register: "The wells are provided by suppliers that already have targeting antibodies anchored. The wells can then be used for detecting target disease biomarkers by adding samples and other reagents. We use the device and smartphone to read colours after reaction."
The gizmo increases the viewing field of the smartphone's camera and ensures the angle is correct to allow all wells to be imaged clearly. The subsequent image is then processed by software elsewhere to produce a diagnosis.
Power requirements are minimal, and since it has its own power supply it doesn't slurp precious juice from the attached phone. Li observed: "The power consumption is very low. We didn't change the battery for over a year."
To check the accuracy of the process, the team took 771 de-identified and blind patient samples and checked them for 12 viral or bacterial infections. The results were excellent – the reader achieved between 97.6 per cent and 99.9 per cent analytical accuracy with less than 5 per cent of coefficient variation.
The next step for Li and the team is to get the device (now called the "mReader") into the field and to that end patents have been filed.
Li hopes that commercial-scale manufacturing will bring down the already low cost of the hardware and that the process will undergo the necessary clinical trials for approval for use in otherwise under-served areas.
Image processing still requires a computer, and Li said there was work to be done on developing a suitable smartphone app to simplify taking an image and either doing the analytical work onboard or automatically uploading it elsewhere for online assessment.
The full results of the research can be found in the July 2018 issue of Clinica Chimica Acta ®.