New Technology Puts Multi-Spectral Imaging In the Palm of the Hand
2009-01-27 -
Recent breakthroughs have made the production of inexpensive, handheld multispectral imaging systems a reality. Jon Sanford, Director of Georgia Tech’s Center for Assistive Technology and Environmental Access (CATEA), recently announced the development of a simple and cost-effective way to modify existing digital camera imaging chips to transform them for use in multi-spectral imaging systems. This breakthrough was achieved by the joint effort from multi disciplinary engineers and scientists from CATEA and other centers in Georgia Tech: Microelectronics Research Center, Microsystems Manufacturing Packaging Center and the Optics Laboratory and Photonics Research Group in The School of Electrical and Computer Engineering. Engineers at CATEA have used this process to build a prototype multispectral camera based on a readily available CMOS imaging chip to target applications in fields of healthcare and medicine. Multispectral technology enhances what can be seen with the naked eye by filtering out all but a few key wavelengths, making it possible to view surface features that are otherwise obscured or invisible. The basic technology in a bulkier and much for expensive form has been in use for many years in medicine, industry, and in applications such as military spy satellites. CATEA began investigating it following the suggestion of Dr. Stephen Sprigle, who has been investigating technologies for the detection of erythema and bruises through multi disciplinary engineering methods. His project was funded by National Institutes of Health. Senior Research Scientist Dr. Linghua Kong proposed a novel way to manufacture low-cost, multi-spectral imaging chips and cameras for these studies, and he led the development effort for the filter mosaic design, prototyping and fabrication as well as integration with the CMOS sensor. Fengtao Wang, an engineering PhD candidate in the School of ECE, Georgia Institute of Technology successfully integrated the filter mosaic with commercial CMOS and CCD sensors and performed system calibration and testing tasks. The new system captures multispectral images directly in hardware, using an optical filter, eliminating the need for time-consuming image processing and allowing a real-time display.
The basis of the device is a narrow band optical filter applied directly to commercially available CMOS imaging chips of the kind in widespread use in consumer-grade digital cameras. The filters are tailored for specific applications, greatly simplifying both the chip fabrication technique and the complete imaging system.
The benefits of such low-cost multispectral imaging chips are profound, says CATEA Research Scientist Dr. Linghua Kong, who led the development efforts. A prototype handheld multispectral imaging system based on the group’s work is being prepared for clinical trials in Medical School of Emory University. in Atlanta. The system is designed to detect and measure ordinary erythema, or skin redness, that is a precursor of pressure ulcers (bed sores) in hospital patients, the elderly, and people with disabilities. Many patients can be diagnosed by simple examination, but this is made much more difficult when treating dark-skinned patients whose skin may completely obscure the condition. The team at Georgia Tech designed the low-cost handheld system to replace earlier systems that were much larger, more expensive, and could not easily be used at the patient’s bedside.
Where to from here? Multispectral imaging systems are in limited use in dozens of other applications, but modified versions of the invention based system, because they are inexpensive and portable, could greatly expand their use. In medicine, for example, there are a whole range of conditions, from bruising and jaundice to cancer and necrosis, that will benefit from replacing visual diagnosis with the handheld multispectral system. Because multispectral cameras can also be used to examine microscopic objects, they could have scientific applications in drug-delivery and cancer studies, and will have a number of uses in nanomedicine. Industrial applications for the system are nearly limitless; the inspection of meats, fruits and vegetables for bruising and disease, for example, or the sorting of foods in processing plants.
For more Information contact:
David Morton
CATEA, College of Architecture
david.morton@coa.gatech.edu
404-385-0871
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