An ordinary PC, digital camera, multifaceted lens, single optical lens, and low-power laser in a Beersheba lab have picked up a real-time image of two chicken-wing bones sandwiched between two pieces of chicken breast.

The Israeli-invented optical system, based on the way a house fly's compound eye functions, constitutes a cheap and simple but ingenious and effective non-invasive, radiation-free medical imaging technology that could replace many computerized tomography (CT) and magnetic resonance instrument (MRI) scans used to diagnose disease.

Prof. Joseph Rosen of the department of electrical and computer engineering at Ben-Gurion University of the Negev has beaten out well-endowed optical-imaging research teams abroad that are working on hefty, expensive, and complicated light-based systems.

These bulky prototypes use extremely sensitive techniques to catch a few photons (ballistic light particles) that go across the scanned media directly without scattering. Special shutters – in the form of sensitive interferometers – an instrument that utilizes the interference of waves for precise determinations – or very expensive cameras with opening times of several picoseconds – let the few photons pass and block the rest.

But Rosen and his doctoral student David Abookasis have developed a portable system that does not block out photons.

Called Noninvasive Optical Imaging by Speckle Ensemble (NOISE), it could be installed in any doctor's or dentist's office or hospital clinic to identify tumors and gum problems. An article on NOISE will be published in the February 1, 2004 issue (Vol. 29, No. 3) of Optics Letters, the journal of the Optical Society of America.

Rosen and Abookasis bought a $1,000 microlens array for another project that didn't work out. Unwilling to let the optical device go to waste, the scientists thought of other applications and came up only last February with the idea of using the array of tiny lenses – each half a millimeter in diameter – for developing a new optical imaging technology.

Thanks to natural selection, the lens in the eye of a fly – which must compete with other predators under poor lighting conditions – evolved into a compound lens that produces many identical images of a single picture; these are then superimposed by the photoreceptors' neural connections into a single image that the fly sees.

Once they agreed on the fly eye-based idea, they wrote a computer program. "Using only 132 of the 1,000 tiny lenses, we clearly saw on the computer screen a good image of the chicken bones, which we had affixed like an X between the chicken breasts. The simple averaging operation produced a real-time image of the object that is not disrupted by environmental 'noise' like vibration and air turbulence," said Rosen.

Utilizing more lenses could make it possible to image objects through thicker biological tissues, said Rosen, adding that the system could be adapted for optical mammography to detect breast tumors without radiation. NOISE won't totally replace expensive CT and MRI scans, he said, because it sees through only soft tissues. But he says it could easily be miniaturized into an endoscope for scanning the intestines or parts of body, while the camera and computer remain outside.

The system took only two or three weeks to build, said Rosen, who completed his BA, MA, and PhD degrees at the Technion and spent two years at the US Air Force lab in Boston and three at the California Institute of Technology before settling in at BGU in 1996.

Surprisingly, Rosen and Abookasis have not registered their technology for patents. "Patent lawyers and registration are very expensive. We care about pure research and want it to benefit mankind. We won't make money out of it; the glory is enough." But they would like to attract investors whose money would help them develop the project further.

With the necessary funds, said Rosen, it would take only about a year to produce a device for clinics that could see through the palm of the hand to the bones or the root of a tooth in the gums. "The components could cost less than $1,000, as doctors and dentists already have PCs in their offices, and digital still cameras are commonplace."