Next generation MEMS-VCSEL technology for ultra-low-cost dental and periodontal swept source optical coherence tomography imaging

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This proposal aims to enable a new generation of high-speed, low-cost, wavelength-flexible swept source optical coherence tomography (SS-OCT) imaging device technology targeting applications in dental imaging and based on microelectromechanical systems vertical cavity surface emitting lasers (MEMS-VCSELs) and planar lightwave circuits (PLCs). MEMS-VCSELs provide an unmatched combination of high and variable axial scan rate, dynamic single mode operation enabling long imaging range, and the potential for low-cost volume manufacturing through wafer scale fabrication and testing. The proposed effort involves a collaboration between Praevium Research, which pioneered MEMS-VCSELs for SS-OCT, and the University of Washington (UW), a world leader in SS-OCT structural and angiographic imaging in dentistry. This work seeks both to advance dental imaging science through new imaging tools and promote commercialization in cost-sensitive dental markets. Praevium Research will develop new high axial scan rate MEMS-VCSEL swept sources near water absorption minima at 1700nm and 2200nm, to enable longer imaging range due to reduced scattering at longer wavelengths. Imaging at these wavelengths may be particularly important in improving the ability of OCT to noninvasively determine periodontal pocket depth. In addition, Praevium will combine emerging electrically pumped MEMS-eVCSELs at 1310nm with advanced PLC technology, replacing bulky and environmentally sensitive fiber networks commonly employed in SS-OCT by lithographically defined waveguide devices. This will allow a radically miniaturized low-cost and stable SS-OCT subsystem with MEMS-VCSEL, optical amplifier, wavelength monitoring, and MZI interferometers on a single chip in a compact butterfly package, overcoming long-standing cost barriers to SS-OCT in dentistry. UW collaborators will use various generations of high axial scan rate MEMS-VCSELs, starting at 1310nm and migrating to 1700nm and 2200nm as these latter sources are developed, to develop real-time wide field of view (FOV) whole mouth structural (OCT) and label-free angiographic (OCTA) periodontal imaging. Current methods for assessing periodontal disease rely on invasive probing, induce unnecessary pain and bleeding, and are error-prone due to inconsistent frequency and force of probing and due to the complexity of gingival thickness and appearance. The proposed SS-OCT technology, by contrast, has the potential to create qualitative and quantitative imaging of microstructure and vasculature in gingival tissue. This will enable a comprehensive periodontal imaging diagnostic suite which can assess periodontal attachment, alveolar bone quality and level, gingival inflammation, sub gingival calculus plaque and tissue biotype. Such a system can also provide an objective means to determine and evaluate the prognosis of periodontal, regenerative and restorative therapies, improve computer-aided design and machining (CAD/CAM) for dental restorative procedures and planning, and become a reliable tool for long term monitoring and maintenance in clinical practice for oral health.