Biomedical Engineering Reference
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Figure 11.15 Practical applications of artificial lobster eyes. (a) Schematic showing reflections from different
channels redirected to form different parts of a focal pattern. (b) Example of x-ray image by using a microchannel
plate with a point source at 1.5 keV. (c) By using the lobster eye in reverse, parallel x-rays may be generated.
11.3.3
Hybrid Appositional or Superpositional Compound Eyes
In 2004, Szema et al. z proposed a new kind of compound eye based on both the superpositional and
appositional arrangements. While not found in nature, the design attempts to combine the advan-
tages of both types of systems. It begins with a standard superpositional compound eye modified by
attaching optical shutters to each of the facets. In this way, images are acquired from individual
ommatidia separately, as in the appositional arrangement. However, the use of a single retina
simulates the superpositional compound eye.
Such a design not only reduces bandwidth and parallel processing requirements, but also has an
additional advantage by recovering useful information that is lost in a typical superpositional arrange-
ment. Namely, when images from multiple lenses are projected simultaneously onto a common retina,
it is difficult to correlate image points to their originating facets (see Figure 11.16). This is significant
because by knowing the relative position of the lenses and the objects in their respective fields of view,
it is possible to derive three-dimensional information (Figure 11.17).
Fibre optic
(a)
(b)
(c)
Figure 11.16 A hybrid appositional/superpositional eye (a) schematic of operation, (b) illustration of operation, (c)
illustration of different points of view from each facet. (From Szema, R., Rastegar, J., and Lee, L. Journal of Medical
Engineering and Technology 2004: 28(3), 117-240. With permission.)
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