Phone gadget to diagnose disease 手机小程序可检测疾病

Researchers have developed an add-on to a mobile phone that can take detailed images and analyse them to diagnose diseases such as tuberculosis.

研究人员已经研究出一个移动电话的附加装置，可以检测和分析诸如肺结核等疾病。

The prototype of the device

The CellScope works as a so-called fluorescence microscope（荧光显微镜） that can identify the markers of disease.

It is hoped the device will be useful in the developing world, where such medical diagnostics are rare but mobile ownership and coverage are common.

The research is published in the free-access journal PLoS ONE.

The CellScope is made up of conventional（普通的，常见的） microscope optics（光学） as well as some equipment to make it function as a fluorescence microscope.

Fluorescence occurs when certain molecules are illuminated（阐释，说明） with a certain colour and "shine" for a period in a different colour.

Fluorescent "tagging" molecules can be specially designed to latch on to, for instance, the bacteria that are a sign of tuberculosis (TB).

But diagnosing tuberculosis requires a fluorescence microscope, which can illuminate a blood sample that has been treated with "tagging" molecules and detect just the light that those molecules emit（发出，放射） with great sensitivity.

However, typical fluorescence microscopes are bulky（庞大的）, expensive devices limited to hospitals and laboratories.

"There are other people who have been working on developing portable fluorescent microscopes," said David Breslauer, a University of California Berkeley researcher and lead author of the study.

"The innovation on our front is that we've integrated that with a cell phone rather than just making a standalone（独立的，单独的） microscope."

The researchers used a standard Nokia handset with a 3.2 megapixel camera, developing a "snap-on" addition that includes the microscope optics and a holder for blood samples on glass slides.

The CellScope uses cheap commercial light-emitting diodes（发光二极管） as the light source - in place of the high-power, gas-filled lamps used in laboratory versions of the device, and cheap optical filters to isolate the light coming from the fluorescent（荧光的） tags.

The device has a resolution of just over one millionth of a metre, and the team was able to identify tuberculosis bacteria in a sample. Several other tagging molecules are in development to address the diagnosis of other diseases.

Upon the removal of the filters, they were able to use the CellScope as a standard, white-light microscope, identifying malaria（疟疾） parasites（寄生效应） and the misshapen（残缺的，畸形的） cells typical of sickle（镰刀） cell anaemia（贫血）.

'Portable clinic'

Mr Breslauer says that more than just a camera, the incorporation of a mobile phone "gives us access to the computational power of the phone as well as the mobile communications aspect".

That computational（计算的） power could be put to use in running image analysis software, which could easily be built into a small application that the phone runs.

But it is the mobile communication aspect that makes the device particularly useful for use "in the field".

"In many developing world and rural areas, you could be hundreds of miles from hospitals or miles away from power - but the mobile infrastructure is well-established and pretty much blanketing the globe," Mr Breslauer said.

"So if you can have a portable, battery-operated system to take these images, analyse, and transfer them, you're creating a portable healthcare clinic. Your doctor can see your samples without actually having to be present."

The team is now making a more robust（强壮的，强健的）, "field-ready" version of the device, which will be used in field testing and clinical trials in the future.