An inexpensive optical system inspired by the design in the
fly's eye is leading to new medical imaging devices.
The benefits provided by the use of magnetic imaging devices in medical
diagnosis and therapy are indisputable. Israeli scientists are currently
working to develop a new device in this field. They hope that this new
apparatus, which is still in the development stage, will offer a significant
advantage over those devices presently in use. That advantage is that
it will be much more economical than the imaging technology employed in
existing devices. Therefore, in the event that this project becomes a
reality people will have the opportunity of having frequent health scans.
The current magnetic resonance imaging (MRI) or potentially damaging X-ray
mammography are expensive in these terms:
In order to make use of light in medical imaging the small number of
photons (light particles) emitted from the object being scanned have to
be perceptible. This represents something of a problem in existing devices.
The tissue in front of the object being scanned causes noise in the image
by blurring light. In the methods currently employed this problem is overcome
with expensive cameras with special shutters that block the "noise"
caused by the light scattered by the tissue. That increases costs.
Researchers Joseph Rosen and David Abookasis from Ben-Gurion University
in Israel have now come up with a new method. Scientists collect a number
of images of the object being scanned and combine these in such a way
as to produce a good image of the object. So, they get an average of the
images, and the light scattered by the tissue, that is, the "noise"
in the image, becomes eliminated. This combination represents a concrete
solution to the difficulties encountered in existing devices. The design
that constitutes the intellectual source behind this combinatorial solution
is no man-made device, however. In seeking this solution the scientists
were inspired by the "compound eye" that flies have been using
for hundreds of millions of years. Indeed, the title they gave their study
is "Seeing through biological tissues using the fly eye principle."(1)
Taking the design in the fly eye as their starting point, the scientists
prepared a microlens array of 132 tiny lenses. To test their ideas, the
researchers took two chicken breasts and hid a wing bone between them.
They then illuminated one side of the meat with low-power optic laser
and placed the microlens array on the other side. The images from the
microlens were transmitted to a digital camera with a conventional lens.
A computer subtracted most of the noise produced by the scattered light,
revealing a clearer image of the concealed wing bone.
" 'With more microlenses and other refinements, it should be possible
to boost the resolution,' Rosen says. 'With investment to develop it
further, our system could in a year be seeing the bones in the palm
of the hand or the root of a tooth.' " (2)
Rosen states that this device, which works on the principle of the fly
eye, is promising, and imparts the welcome news that with the use of this
device the uncomfortable endoscopes or "pill cameras" that have
to be swallowed in abdomen scans will be a thing of the past.
The Design in the Fly's Eye
A fly moving through the air is wonderfully agile. It can change direction
in a moment in reaction to the smallest movement directed towards it.
It can choose whether to land on the floor, wall or ceiling of a room.
The fact that the fly possesses a very superior visual system is of great
importance in this. Close inspection of the fly immediately gives an idea
of the reason for this agility. The fly's eye possesses a design known
as the "compound eye" and which permits it to see through a
large number of lenses and at a wide angle.
Image of the fly eye taken under an electron
A fly's compound eye consists of a large number of optical units, each
with its own optic lens, and produces a large number of images. Neural
circuits from each unit take an average of the image, and a clearer image
than the parasite ridden background is obtained. The fly's eye can perceive
a light vibration 330 times a second. From that point of view, it is six
times more sensitive than the human eye. (3) At the
same time it can also detect ultraviolet frequencies in the light spectrum
that are invisible to us. This system makes it easy for flies to evade
their enemies, especially in dark environments.
The compound eye of the fly is a most important organ that plays a role
in the visual system, a vital function with regard to the animal's survival.
When this organ is examined, we see lenses that specially diffuse the
light form a concave surface that provides a wide field of view and concentrates
the image on one centre. The edges of these optical units on the surface
are hexagonal. Thanks to their hexagonal shape, the units are located
contiguously to one another. In this way no unwelcome gaps that would
occur if other geometrical shapes were used, arise; the most productive
use of the area is made. Although the rays from a large number of lenses
would be expected to lead to a confused picture, this never happens, and
the fly can see a wide field in a single image.
There is a superior design in the fly eye. This engineering principle,
which has been used in human beings for the last few hundred years, has
been used in flies of around 390 million years. A more general look at
natural history shows that the compound eye design (in trilobites in the
Cambrian period) goes back some 530 million years.
Flies have had this eye structure since the day they came into being.
To Whom Does the Design in the Fly's Eye Belong?
The question that arises is this: scientists imitate the design in the
fly's eye in developing their devices. The fact tat the fly eye is used
as a source of inspiration in modern technology is a clear indication
of its superior design. The various components in the eye can be seen
to have been arranged for a particular purpose. So how did the fly come
by this design? Who arranged all these components in this way and designed
the fly eye?
All the arrangements in the fly's eye show that this design was bestowed
on the insect by an entity with a superior intellect. There is no doubt
that it is Almighty God, the Lord of the Worlds, Who created the fly together
with this perfect visual system. This superior creation in the fly is
a sign of God's infinite might.
In one verse from the Qur'an God reveals:
Humanity! an example has been made, so listen to it carefully.
Those whom you call upon besides God are not even able to create a single
fly, even if they were to join together to do it. And if a fly steals
something from them, they cannot get it back. How feeble are both the
seeker and the sought! (Qur'an, 22:73)
1- Joseph Rosen
and David Abookasis, "Seeing through biological tissues using the
fly eye principle", http://www.ee.bgu.ac.il/%7Erosen/fly_eye.pdf
2- Judy Siegel-Itzkovich, "Fly's-eye
view shines a light on disease", New Scientist vol. 181 no. 2429
- 10 January 2004, p. 23
3- Dr. Julie Palmer, University of Texas, Austin. http://www.esb.utexas.edu/palmer/bio303/group25/DROSOPHILA/compound_eye.htm