Cellphone camera adapted into a mini-microscope

11 Dec 2013

Simple and inexpensive, the Finnish developments are latest low-tech weapons in fight against tropical infectious diseases.

A test sample is placed directly onto the surface of the (cellphone's) image sensor.

Microscopy is the universal diagnostic method for detection of most globally significant parasitic infections. Methods developed in well-equipped laboratories are, however, difficult to use at the basic levels of many field health care systems around the world, due to lack of adequately trained personnel and resources.

Now researchers at the Institute for Molecular Medicine Finland, FIMM, University of Helsinki and Karolinska Institutet, Sweden, have demonstrated that new, simple and economical techniques for high-resolution image gathering and transfer over data networks may be utilized to solve these diagnostic problems.

The team led by Dr. Johan Lundin and Dr. Ewert Linder have modified inexpensive imaging devices, such as a webcam selling for €10 and a mobile phone camera, into a mini-microscope. The test sample is placed directly onto the exposed surface of the image sensor chip after the optics have been removed. The resolution of such mini-microscopes depends on the pixel size of the sensor, but is sufficient for identification of several pathogenic parasites.

In their study published in the journal PLOS Neglected Tropical Diseases, the researchers used the mini-microscopes to produce images of parasitic worm eggs present in urine and stools of infected individuals.

On-chip contact images of helminth eggs and larvae from stool samples.

Real results

The team first utilized this novel approach to detect urinary schistosomiasis, a severely under diagnosed infection affecting hundreds of millions, primarily in sub-Saharan Africa. For diagnostics at the point-of-care they developed a highly specific pattern recognition algorithm that analyses the image from the mini-microscope and automatically detects the parasite eggs.

Lundin commented, "The results can be exploited for constructing simple imaging devices for low-cost diagnostics of urogenital schistosomiasis and other neglected tropical infectious diseases. With the proliferation of mobile phones, data transfer networks and digital microscopy applications, we are offering alternatives to conventional microscopy in endemic areas."

About the Author

Matthew Peach is a contributing editor to optics.org.