The incredibly photogenic Mantis shrimp is not just a pretty face that packs a powerful punch. These brightly coloured crustaceans, which often grace the pages of National Geographic and other nature magazines, are proving to be real-life superheros.
Mantis shrimp have incredibly complex eyes, known as compound eyes, which give them a keen sense of vision. In fact, their vision is so sharp that they are able to see cancer inside the human body even before any symptoms of the disease appear!
Compound eyes are able to detect polarised light, which is reflected differently by different kinds of body tissue, including tissue that is healthy and that which is cancerous. This unique characteristic gives the Mantis shrimp this incredible ability.
Now scientists are trying to mimic these superhero qualities by building cameras that can do the same. This will enable us to detect cancer before symptoms appear and to pinpoint tumours within the body so they can be removed in the early stages of growth.
Mantis shrimps, which in fact are neither a mantis nor a shrimp, but rather fall under the order Stomatopoda, have one of the most advanced visual systems of all the organisms out there. Their compound eyes, which are similar to that of the house-fly, consists of thousands of receptors — known as ommatidia — that trap light. What makes the mantis shrimp’s eyes unique is its ability to perceive polarized light, which is invisible to the human eye.
Sunlight is made up of different wavelengths which are scattered in all directions. But some materials, for example polarised sunglasses or fish scales, are able to change the light they transmit or reflect, arranging it so that it moves in a single direction rather than being scattered around.
The human eye is not able to detect this, as we cannot distinguish between polarised and non-polarised light. But the incredibly powerful eyes of the mantis shrimp are able to tell the difference between the two. Now scientists are using this incredible feat to help them detect fast-growing cancer cells, which have been shown to reflect polarised light in a different way to healthy cells. Although the difference between healthy and cancerous cells is invisible to us, the mantis shrimp is easily able to distinguish between the two. What makes this really exciting in terms of early detection, is that the difference in the way polarised light is reflected appears in early stage cancer before any other symptoms develop.
There are now teams hard at work all over the world building cameras that mimic the compound eyes of arthropods such as the mantis shrimp and butterflies, which are being developed specifically to detect early stage cancer.
“Looking at nature can help us design better and more sensitive imaging techniques,” Viktor Gruev, who leads a team at the University of Illinois at Urbana-Champaign, told NPR.
Gruev and his colleagues have designed cameras that are not only able to detect polarisation patterns on the surface of animal tissue, including that of humans, but they have also designed cameras small enough so they can be used for internal examinations in endoscopes and colonoscopies.
Gruev and his colleagues recently used their cameras to search for any signs of colon cancer in mice. Cameras traditionally used in colonoscopies submit black and white images which doctors examine for any signs of abnormally shaped body tissue, indicative of cancerous polyps. However, not all forms of cancer start off as lumps; in some cases they may be flat and therefore not readily distinguishable from the surrounding tissue, and thus easily missed during a colonoscopy examination.
But the new cameras based on the eyes of the mantis shrimp that Gruev and his team have developed are able to capture these polarisation patterns and submit real-time colour images back to the examiners, giving doctors a far more accurate picture of where the cancerous tissue exists. Furthermore, different types of cancer cells appear to exhibit different polarisation signatures, while the polarisation signatures of healthy tissue is typically consistent.
“The polarisation structure makes the cancer apparent,” said Gruev, who calls the technology a cancer ‘moonshot’. “Right now, we are still detecting cancer way too late in the game.”
These cancer-detecting cameras could help doctors to diagnose cancer earlier and with more accuracy, and could enable surgeons to remove tumours in their entirety, which would improve recovery rates.