Researchers at Harvard University and Massachusetts General Hospital have developed a new type of endoscopic imaging catheter. The catheter uses metalenses, which contain nanostructures to focus light, to achieve higher resolution imaging than conventional catheter imaging systems. So far, the researchers have used the new system to image deep into tissue samples and see tissue features with greater clarity.
It can be difficult to accurately identify diseased tissues using current endoscopic imaging technology. The size of endoscopic imaging systems makes it difficult to achieve significant image quality. “Clinical adoption of many cutting-edge endoscopic microscopy modalities has been hampered due to the difficulty of designing miniature catheters that achieve the same image quality as bulky desktop microscopes,” said Melissa Suter, a researcher involved in the study.
To address this issue, the Boston-based team developed a new catheter design that relies on metalenses. The metalenses have a flat structure, but use multiple nanostructures to focus light, rather than a single solid lens, meaning that the researchers can more easily tailor its properties and achieve a very fine focus of light.
Scanning electron micrograph image of a portion of a fabricated metalens.
“Metalenses based on flat optics are a game changing new technology because the control of image distortions necessary for high resolution imaging is straightforward compared to conventional optics, which requires multiple complex shaped lenses,” said Federico Capasso, another researcher involved in the study.
The researchers have called this new class of imaging devices nano-optic endoscopes. To test their new device, the team imaged a variety of tissue samples, including sheep airways and human lung tissue, and found that the new system obtained higher resolution images, allowing them to identify features that would otherwise not be visible. For example, in the human tissue samples, the researchers could identify fine, irregular glands that are a sign of adenocarcinoma.
At present, the research team is designing a new polarization-sensitive version of the catheter that can more easily contrast between tissues containing highly-organized structures, such as smooth muscle and blood vessels.
Top image: Comparison of images of fruit flesh (left) and swine airways (right) obtained using the nano-optic endoscope (b,d) and a conventional catheter (a,c). All images are credited to Harvard University/Massachusetts General Hospital.
Study in Nature Photonics: Nano-optic endoscope for high-resolution optical coherence tomography in vivo…
Via: Harvard University…
