Sickle cell is a hereditary disease that affects an estimated 90,000 Americans, as well as people in all countries of Africa. It is a serious public health issue that, if left undiagnosed, can cause life threatening "silent" strokes and lifelong damage.
Current screening and monitoring programs for newborns can be cumbersome, involving expensive centrifuge equipment, microscopy, and specialized training.
Using a 3D printed device researchers have 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.
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.
A clinician takes a small blood sample from the patient and mixes it with a common, salt-based solution that draws oxygen out of the sickle cells, making them denser and easier to detect. (Healthy red blood cells exposed to the solution are not affected by it.) The sample is then loaded into a disposable micro-capillary that is inserted into the tester attached to the smartphone. (All of this can be done in under one minute.)
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.