Smartphone provides platform for sickle cell disease test
05 November 2015
US researchers have developed a simple, inexpensive and quick technique for the diagnosis and monitoring of sickle cell disease using a smartphone.
Using a 3D printer, the team - comprising University of Connecticut (UConn) biomedical engineers, working with colleagues from Yale, MIT, and Harvard and led by UConn assistant professor of mechanical engineering Savas Tasoglu - has created a novel testing platform that can accurately diagnose and monitor sickle cell disease in the field or at a remote clinic, using just a few drops of blood. The platform is contained in a lightweight, compact box that can be attached to a common Android smartphone.
"Our technique shows great promise as a broadly applicable tool for both basic and applied research, as well as a screening and diagnosis instrument for point-of-care settings," says Tasoglu.
Current screening and monitoring programs can be cumbersome, involving expensive centrifuge equipment, microscopy, and specialized training.
The key to the new device is magnetic levitation. Sickle cells, because of their unique crescent moon or sickle-like shape, tend to be denser than healthy red blood cells and therefore levitate or float at a lower height when the cells are placed in a paramagnetic solution and subjected to a magnetic field. The approach enables a binary (yes/no) decision for identification of sickle cell disease, even by the naked eye.
During testing, the sample is loaded into a disposable micro-capillary that is inserted into the tester attached to the smartphone. Inside the testing apparatus, the micro-capillary passes between two magnets that are aligned so that the same poles face each other, creating a magnetic field. The capillary is then illuminated with an LED that is filtered through a ground glass diffuser and magnified by an internal lens.
The smartphone's built-in camera captures the resulting image and presents it digitally on the phone's external display. The blood cells floating inside the capillary - whether higher floating healthy red blood cells or lower floating sickle cells - can then be easily observed. The device also provides clinicians with a digital readout that assigns a numerical value to the sample density to assist with the diagnosis. The entire process takes less than 15 minutes.
Tasoglu's lab has filed a provisional patent for the device, and is working on expanding the device's capabilities so it can be applied to other diseases.