Mobile Phone Microscope Aids Malaria Diagnosis

Developed by researchers at Texas A&M University (TAMU; College Station, TX, USA), the low-cost, lightweight, high quality mobile-optical-polarization imaging device (MOPID) offers 40–100x magnification, sufficient to image pigmentation of the hemozoin crystal, a waste product produced by ‎Plasmodium falciparum, the parasite that causes malaria. To perform the test, a glass slide with a blood smear is inserted into the device; the cell phone camera then takes a picture, and the photo shows the presence (or absence) of malaria.

The MOPID system consists of a commercial Apple iPhone 5S cellular phone, a snap on 3D-printed cartridge with individual compartments that allowed for polarized microscopy, two polarizer sheets, low-power white light emitting diodes (LEDs), and a plastic lens assembly configuration allowing for appropriate magnification, resolution, and field of view (FOV) for diagnosing the presence of the malaria parasite. The analyzer can be rotated to vary the degree of polarization, thus allowing for birefringence measurements from the hemozoin crystal.

The researchers are moving forward to construct a more durable, compact, and cheaper device for in vivo field-testing in Rwanda. They envision that the final product could be available for less than USD 1.00 per test result, not including the cost of the mobile phone attached to the MOPID device. A study describing the system and comparing performance to a Leica Microsystems (Wetzlar, Germany) DMLM polarized white light microscope was published on August 25, 2015, in Nature Scientific Reports.

“Because of the lack of access to lab testing, many health-care providers rely on rapid diagnostic tests, which are the equivalent of a pregnancy test for parasites. They are not always reliable and can lead to misdiagnosis and overtreatment. Giving medicine to those who don’t need it is causing drug-resistant strains of malaria to develop,” said lead author biomedical engineer Casey Pirnstill, BSc. “The device could be used by a nurse or other health outreach workers. The original photos would be saved in case further interpretation by a doctor is required.”

There are more than 200 million new malaria cases yearly, and high-quality microscopy is still the most accurate method for detection of infection. Microscopy, however, requires well-trained personnel and can be very time-consuming. As a result, less than half of the suspected malaria cases in Sub-Saharan Africa in 2012 received a diagnostic test.

Related Links:
Texas A&M University
Leica Microsystems