The first step to diagnosing an illness in any internal organ is usually an endoscopic biopsy where samples are taken from affected areas. But, collecting these samples is complicated because of the inability of the existing endoscopic imaging systems to accurately identify the sites of disease. The traditional optical units, lights, and a camera that are attached to catheters are prone to variations that hinder accurate diagnosis. Addressing this issue, the researches at Harvard University and Massachusetts General Hospital have collaboratively developed a new type of endoscopic imaging catheter that overcomes the limitations of the current systems. Melissa Suter, one of the researches involved in the study says, “The clinical adoption of numerous innovative endoscopic microscopy modalities has been impeded due to the complexity involved in designing miniature catheters that achieve the same level of image quality as that of bulky desktop microscopes.” But, the use of nano-catheters that incorporate metalenses—flat structures that use multiple nanostructures, typically made of titanium dioxide, to focus light—into their design, are expected to dramatically improve the quality, resolution, and functionality of endoscopic microscopy. “This will ultimately enable more sophisticated assessment of cell and tissue microstructure in patients,” adds Suter.
The catheter designed by the researchers uses metalenses to achieve higher resolution imaging. So far, the researchers have used it to examine tissue samples, and have found that the system enables them to obtain high-resolution images. This makes it easier to identify features of the tissue that would otherwise not be visible with a conventional endoscopic microscope. “Metalenses are a game-changing tool because of their ability to control image distortions necessary for high-resolution imaging,” explains Federico Capasso, another researcher involved in the study. “The main advantage of using metalens,” Yao-Wei Huang, a co-author of the research paper apprises, “is that we can design and tailor its specifications to achieve fine focus of the light. This enables us to obtain high-resolution imaging without the need for complex optical components.”
Next, the researchers are working on designing a new version of the endoscopic catheter—a polarization-sensitive nano-optic endoscope—which would allow to more easily differentiate and identify tissues containing highly-organized structures, such as smooth muscle and blood vessels.