G. Maguluri, D. Mehta, J. Kobler, J. Park, and N. Iftimia, “Synchronized, concurrent optical coherence tomography and videostroboscopy for monitoring vocal fold morphology and kinematics,” Biomedical Optics Express, vol. 10, no. 9, pp. 4450-4461, 2019. Publisher's VersionAbstract
    Voice disorders affect a large number of adults in the United States, and their clinical evaluation heavily relies on laryngeal videostroboscopy, which captures the medial-lateral and anterior-posterior motion of the vocal folds using stroboscopic sampling. However, videostroboscopy does not provide direct visualization of the superior-inferior movement of the vocal folds, which yields important clinical insight. In this paper, we present a novel technology that complements videostroboscopic findings by adding the ability to image the coronal plane and visualize the superior-inferior movement of the vocal folds. The technology is based on optical coherence tomography, which is combined with videostroboscopy within the same endoscopic probe to provide spatially and temporally co-registered images of the mucosal wave motion, as well as vocal folds subsurface morphology. We demonstrate the capability of the rigid endoscopic probe, in a benchtop setting, to characterize the complex movement and subsurface structure of the aerodynamically driven excised larynx models within the 50 to 200 Hz phonation range. Our preliminary results encourage future development of this technology with the goal of its use for in vivo laryngeal imaging.
    D. Mehta, J. B. Kobler, G. Maguluri, J. Park, E. Chang, and N. Iftimia, “Integrating optical coherence tomography with laryngeal videostroboscopy,” Proceedings of the Acoustical Society of America. 2017.Abstract

    Special Session: New trends in imaging for speech production (Speech Communication Technical Committee)

    During clinical voice assessment, laryngologists and speech-language pathologists rely heavily on laryngeal endoscopy with videostroboscopy to evaluate pathology and dysfunction of the vocal folds. The cost effectiveness, ease of use, and synchronized audio and visual feedback provided by videostroboscopic assessment serve to maintain its predominant clinical role in laryngeal imaging. However, significant drawbacks include only two-dimensional spatial imaging and the lack of subsurface morphological information. A novel endoscope will be presented that integrates optical coherence tomography that is spatially and temporally co-registered with laryngeal videoendoscopic technology through a common path probe. Optical coherence tomography is a non-contact, micron-resolution imaging technology that acts as a visual ultrasound that employs a scanning laser to measure reflectance properties at air-tissue and tissue-tissue boundaries. Results obtained from excised larynx experiments demonstrate enhanced visualization of three-dimensional vocal fold tissue kinematics and subsurface morphological changes during phonation. Real-time, calibrated three-dimensional imaging of the mucosal wave and subsurface layered microstructure of vocal fold tissue is expected to benefit in-office evaluation of benign and malignant tissue lesions. Future work calls for the in vivo evaluation of the technology in patients before and after surgical management of these types of lesions.

    J. H. Van Stan, D. D. Mehta, and R. E. Hillman, “Recent innovations in voice assessment expected to impact the clinical management of voice disorders,” Perspectives of the ASHA Special Interest Groups, vol. 2, no. SIG 3, pp. 4-13, 2017. Publisher's VersionAbstract

    This article provides a summary of some recent innovations in voice assessment expected to have an impact in the next 5–10 years on how patients with voice disorders are clinically managed by speech-language pathologists. Specific innovations discussed are in the areas of laryngeal imaging, ambulatory voice monitoring, and “big data” analysis using machine learning to produce new metrics for vocal health. Also discussed is the potential for using voice analysis to detect and monitor other health conditions.

    G. Maguluri, E. Chang, N. Iftimia, D. Mehta, and J. Kobler, “Dynamic vocal fold imaging by integrating optical coherence tomography with laryngeal high-speed video endoscopy,” Proceedings of the Conference on Lasers and Electro-Optics (CLEO), pp. 1-2, 2015.Abstract

    We demonstrate three-dimensional vocal fold imaging during phonation by integrating optical coherence tomography with high-speed videoendoscopy. Results from ex vivo larynx experiments yield reconstructed vocal fold surface contours for ten phases of periodic motion.

    D. D. Mehta and R. E. Hillman, “The evolution of methods for imaging vocal fold phonatory function,” Perspectives on Speech Science and Orofacial Disorders, vol. 22, no. 1, pp. 5-13, 2012. Publisher's VersionAbstract

    In this article, we provide a brief summary of the major technological advances that led to current methods for imaging vocal fold vibration during phonation including the development of indirect laryngoscopy, imaging of rapid motion, fiber optics, and digital image capture. We also provide a brief overview of new emerging technologies that could be used in the future for voice research and clinical voice assessment, including advances in laryngeal high-speed videoendoscopy, depth-kymography, and dynamic optical coherence tomography.