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Turning a Cell Phone Into a Microscope
stupendou writes with this excerpt from the New York Times: "Microscopes are invaluable tools to identify blood and other cells when screening for diseases like anemia, tuberculosis and malaria. But they are also bulky and expensive. Now an engineer, using software that he developed and about $10 worth of off-the-shelf hardware, has adapted cellphones to substitute for microscopes." But not based on optical magnification: the article explains that Aydogan Ozcan, a UCLA assistant professor of electrical engineering, has combined the wireless transmission abilities and imaging sensors now typical in wireless phones to make the phones capable of detecting cell abnormalities and more by capturing wave interference patterns from body fluids — like blood — and sending them on for analysis.
Update 20091108 15:03 GMT by timothy: Dave Bullock mentions this gallery he shot last year for Wired showing how a phone is hacked to add microscope abilities. "The new version looks a bit more polished, to say the least," he writes.
Update 20091108 15:03 GMT by timothy: Dave Bullock mentions this gallery he shot last year for Wired showing how a phone is hacked to add microscope abilities. "The new version looks a bit more polished, to say the least," he writes.
A high-throughput on-chip imaging platform that can rapidly monitor and characterize various cell types within a heterogeneous solution over a depth-of-field of ~4mm and a field-of-view of ~10 cm^2 is introduced. This powerful system can rapidly image/monitor multiple layers of cells, within a volume of ~4 mL all in parallel without the need for any lenses, microscope-objectives or any mechanical scanning.
In this high-throughput lensless imaging scheme, the classical diffraction pattern (i.e., the shadow) of each micro-particle within the entire sample volume is detected in less than a second using an opto-electronic sensor chip. The acquired shadow image is then digitally processed using a custom developed ‘‘decision algorithm’’ to enable both the identification of the particle location in 3D and the characterization of each micro-particle type within the sample volume.
Through experimental results, we show that different cell types (e.g., red blood cells, fibroblasts, etc.) or other micro-particles all exhibit uniquely different shadow patterns and therefore can be rapidly identified without any ambiguity using the developed decision algorithm, enabling high-throughput characterization of a heterogeneous solution.
http://www3.interscience.wiley.com/journal/121401991/abstract
http://www3.interscience.wiley.com/cgi-bin/fulltext/121401991/PDFSTART
This topic was also covered a few months ago -- with better results, but using actual lenses instead of just the bare CCD sensor:
http://science.slashdot.org/story/09/07/24/1440227/Use-Your-Cell-Phone-To-Diagnose-Blood-Diseases
Tricorders ..... as we do already have the flip open communicator in standard use.
Hmmm.... has any cell phone company even thought to license and/or make a functional cell phone of the replica of the Star Trek communicator of the original series? Or would that be like to Galaxy Quest .....
CELL PHONE
Need a mass spectrometer? There's an app for that!
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
....but I am more interested in turning a cell phone into explosives.
Qxe4
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Microbiology Feed @ Feed Distiller
This is likely to be helpful in those countries where cell phones are abundant and where health care is so deficient. Diagnostic could even be offered remotely by western medical centers.
I do have to question the rationale behind this and other "inventions."
Basically, the theory is we can improve third world medical care by making (crappy) cell phone microscopes and I've also seen a shoddy centrifuge made from an eggbeater. Thing is, perfectly working USED first world medical equipment (aka a 50 year old microscope or centrifuge) is still going to be overwhelmingly better than this stuff. Moreover, the cost of the equipment is generally not the problem in the U.S. : it's the cost of training the people to do the work. I would imagine that the same bottleneck on trained personnel is ultimately the limiting factor in the third world as well.
From TFA:
The adapted phones may be used for screening in places far from hospitals, technicians or diagnostic laboratories, Dr. Ozcan said.
"Right now you need a microscope, and you need trained people," Dr. Bryson said. "But this device would allow you to work without either in a remote area. "
M. Fatih Yanik, an assistant professor of electrical engineering and computer science at the Massachusetts Institute of Technology, said, "This makes it possible for ordinary people to gather medical information in the field just by using a cellphone adapted with cheap parts."
Cellphones tend to be pocket-sized and easily replaceable if lost or damaged. FAR easier than that used equipment you refer to.
Older equipment from the "first world" is bulky, difficult to service and repair, and needs actual experts to work it. Often, it also needs specific work conditions (such as certain flavor of electricity) not readily available "in the field".
Also, it is rather hard to write software for those old optical/mechanical devices you mention.
Which is kinda important, since it is the software that does the pathogen detection in these mobile-phone-microscopes.
And that greatly reduces those training costs you mention.
Mit der Dummheit kämpfen Götter selbst vergebens
From Dr. Ozcan's list of refereed papers :
Lensfree on-chip cytometry towards wireless health
Looking through their paper they show diffraction patterns that are roughly 4 pixels across on a sensor with 9 micron pixels (36 microns) for red blood cells which are 5 microns. This implies roughly 7.2x magnification, which means their actual field-of-view is about 18 mm^2 or 1/55th of their claimed field of view.
There's some serious issues with their idea of cost, too. Most field clinics in India (I have a brother who works as a malaria epidemiologist there) use microscopes that cost around $100-150, to claim replacing that with a $300+ camera phone (admittedly, the whole cell phone things looks like a huge marketing gimmick since they just use a high-end kodak interline CCD anyways) is "inexpensive" is more than a little disingenuous.
I've ranted before on the science behind the LUCAS system before, so I'll try not to repeat myself, but the utility of such as system would be limited primarily to RBC/WBC counts which are typically done either in counting chambers on a microscope or in an automated system measuring light scatter (both are called hemocytometers). While I can believe that they could very well do what an automated hemocytometer does using a lower cost instrument, applications in screening for disease causing agents such as malaria parasites and mycobacteria are doubtful except at very high parasitemia (when a high enough density of parasites are present to scatter a detectable quantity of light) or at very high concentrations of bacteria in sputum (same story) at which point microscopy would be easier and cheaper to detect the objects. When objects start getting down to the 1 micron size-scale, it becomes exceedingly difficult to scatter light with them. Even looking at their published results, some of their diffraction patterns are already barely above background with cells in the 5-10 micron range. Trying to detect a minute variation inside one of those diffraction patterns (from a malaria parasite within an RBC, for example) while perhaps possible would not be very clinically reliable when you have no control over what might be in your samples.