Turning a mobile into a low-cost microscope
10 Apr 2013 by hdpqmpdbhq.d hdpqmpdbhq.d
A cheap glass lens, a strip of double sided sticky tape and a simple torch are all you need to turn your iPhone into a field microscope, according to a team of researchers working in rural Tanzania. The group used this makeshift product to successfully detect intestinal worm infections in children. Their study is published American Journal of Tropical Medicine and Health.
The team used the mobile device in Pemba Island to evaluate 199 children’s stool samples, prepared on a typical laboratory slide and compared its efficiency to a light microscope.
“There’s been a lot of tinkering in the lab with mobile phone microscopes, but this is the first time the technology has been used in the field to diagnose intestinal parasites,” said lead author Issac Bogoch, an infection disease specialist at Toronto General Hospital.
Intestinal worms such as hookworms and roundworms infect around two billion people worldwide, hindering mental and physical development in children by causing anaemia and malnutrition. But if the cases are quickly diagnosed, there are several relatively inexpensive drugs that will provide effective treatment. However, current diagnosis with a conventional light microscope costs about £140 per sample and requires electricity.
The researchers estimate that the mobile phone microscope can be set-up in around five minutes at a cost of less than £10 beyond the cost of the phone.
To examine each stool sample, the scientists covered the slide in cellophane, used the double-sided tape to attach it to the phone’s camera, lit it from underneath with the torch and then took a photograph.
Overall, the mobile phone microscope managed to detect evidence of intestinal worm infections (by revealing eggs) in about 70 per cent of samples deemed infected according to the light microscope. While the phone’s success rate was high, its sensitivity varied greatly depending on the type of worm and the intensity of the infection.
Bogoch and colleagues from Massachusetts General Hospital and the Swiss Tropical and Public Health Institute believe that a “mobile phone microscope would likely be of clinical use when it is sensitive enough to detect 80 per cent of infections.”
They say that there are new approaches to mobile phone microscopes under development that should soon meet or exceed this threshold.
“I’m confident that in the near future we will see cell phone microscopes widely used in low-resource settings. They’re easy to make, portable and today, you can find mobile phones with cameras even in some of the most remote regions of the world,” added Bogoch.
