Summary:
UCLA researchers in the Department of Electrical and Computer Engineering have developed a new optical coherence tomography system for clinical imaging applications.
Background:
Optical coherence tomography (OCT) is a non-invasive imaging technique that is used in many clinical settings. OCT is used in ophthalmology to visualize layers of the retina and in cardiology to image plaque deposition and vessel structure in the coronary arteries. This approach images biological tissue using interferometry, where a light source coupled to a beam splitter is directed at a reference mirror and tissue sample. The reflected light is then recombined into an interference pattern to produce detailed images. However, OCT imaging suffers from resolution issues and is intrinsically limited by the light source driving image production. In addition, current OCT systems rapidly lose sensitivity the deeper they image into tissue samples. It is necessary to develop new optical engineering solutions that enhance OCT image quality, improve imaging depth range, and maintain low operating costs.
Innovation:
Dr. Wong and colleagues have developed a new OCT platform that can be easily customized for many imaging depths, has improved imaging resolution, and is inexpensive to develop. This innovation relies on a 1 µm Kerr frequency comb to replace a traditional broadband light source along with a custom spectrometer. Kerr frequency combs are inexpensive and last much longer than standard broadband light sources, thereby reducing equipment costs. When these parts are integrated with a commercially available OCT system, imaging depths of 0.75 mm are achievable with resolutions comparable to standard broadband light sources. To demonstrate the efficacy of this method, high quality OCT images of pig retinas were generated with this platform. By using broader frequency combs could further increase the imaging depth and potentially produce image qualities that surpass that of the standard lit OCT systems. Overall, this new optical design represents significant potential to replace current OCT systems for several clinical indications, including more precise and accurate diagnosis of ophthalmologic diseases.
Potential Applications:
• Ophthalmology
• Laparoscopic cardiology
• Vascular surgery
• Metrology
Advantages:
• Inexpensive
• High resolution imaging
• Improved field of depth
• Compatible with existing OCT hardware/software
• Device longevity
Development-To-Date:
The invention has been built and validated on porcine tissue samples.
Related Papers:
Melton, T., McMillan, J., et al. High-Resolution Millimeter-Depth Optical Coherence Tomography with 1-um 100-GHz Chip-Scale Laser Frequency Microcombs. CLEO, 2022. https://opg.optica.org/abstract.cfm?uri=CLEO_SI-2022-SM3L.7
Reference:
UCLA Case No. 2023-036
Lead Inventor:
Professor Chee Wei Wong, UCLA Department of Electrical and Computer Engineering