Bacteria imaging

OCT measurements of the normal tympanic membrane (A) and with otitis media (OM) (B) and (C). The OCT intensity images show the presence of middle ear effusion (MEE). The pseudo-color map of the pneumatic stiffness map by applying air pressure. The phase lag is the delay time of the input air pressure and tympanic membrane response.

To study the behaviors of bacteria in biofilms for a clinical purpose, BIL is working to develop label-free imaging techniques to observe wild type bacteria in biofilms. Bacteria biofilms can be characterized by physical, biochemical, and dynamic measures using optical imaging. Thus far, we have made significant progress characterizing middle ear infection with OCT imaging to probe the physical and dynamic properties of otitis media.

 (A) Raman scattering (RS) and the low-coherence interferometry (LCI) configuration. (B) RS spectra of Pseudomonas aeruginosa and Streptococcus pneumonia. Different bacterial strains have different RS spectral responses. (C) The spectral density of Raman peak at 857 cm-1 shows a linear correlation with the bacterial concentration.

  • Won, J., Porter, R. G., Novak, M. A., Youakim, J., Sum, A., Barkalifa, R., Aksamitiene, E., Zhang, A., Nolan, R., Shelton, R., Boppart, S. A., In vivo dynamic characterization of the human tympanic membrane using pneumatic optical coherence tomography, Joun. Bio. Photonics (2020)
  • Won, J., Huang, P-C., Boppart, S. A., Phase-based Eulerian motion magnification reveals eardrum mobility from pneumatic otoscopy without sealing the ear canal, J. of Phys. 2(3), 034004 (2020)
  • Won, J., Monroy, G. L., Huang, P-C., Hill, M. C., Novak, M. A., Porter, R. G., Spillman, D. R., Chaney, E. J., Barkalifa, R., Boppart, S. A., Assessing the effect of middle ear effusions on wideband acoustic immittance using optical coherence tomography, Ear and Hearing, 41(4), 811-824 (2020)
  • Zhang, C., Won, J., Boppart, S. A., Rapid detection of antibiotic-resistant bacteria at the single-cell level using two-photon excitation fluorescence and coherent anti-Stokes Raman scattering microscopy (Conference Presentation), Proc. SPIE 11223, Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2020, 112230B (2020);
  • Zhao, Y., Monroy, G. L., You, S., Shelton, R. L., Nolan, R. M., Tu, H., Chaney, E. J., and Boppart, S. A, Rapid diagnosis and differentiation of microbial pathogens in otitis media with a combined Raman spectroscopy and low-coherence interferometry probe: toward in vivo implementation, Journ. Biomed. Opt. 21(10), 107005 (2016)

AI driven solutions for fluid diagnosis

Using our extensive library of imaging data and years of experience in ear diagnostic imaging, a machine-learning platform was developed that can automatically detect the signs of infection in the middle ear. When an OCT image of the ear is taken using one of our portable systems, the software takes approximately 20 seconds to automatically evaluate the data and identify middle ear fluid or biofilms behind the eardrum, or, if the ear appears normal. With further development, this platform can enable any user to have the diagnostic ability of an expert physician. Armed with precise knowledge of the infection in this patient, physicians can prescribe the ideal treatment for each patient. 

  • Monroy GL, Won J, Dsouza R, Pande P, Hill MC, Porter RG, Novak MA, Spillman DR, Boppart SA. Automated classification platform for the identification of otitis media using optical coherence tomography. Nature Digital Medicine, 2:22. 2019.

Detecting middle ear biofilms in vivo

Recent studies have shown that there is a correlation between recurrent and/or chronic otitis media and the presence of middle ear biofilm. With our portable, handheld OCT system for primary care imaging, bacterial biofilm was non-invasively observed from human subjects with chronic otitis media. The presence of middle ear biofilm visualized from OCT was microbiologically validated. In addition, the subjects with otitis media undergoing the surgical treatment (myringotomy and tympanostomy tube placement) were longitudinally and intraoperatively observed to assess the efficacy of the treatment based on the presence of middle ear fluid and biofilms. A novel analytical technique was also developed to enhance the detection sensitivity of OCT by quantifying nanometer-scale structural changes in the eardrum and biofilm. Furthermore, the presence of middle ear biofilms determined from OCT has also been correlated to acoustic measurements and showed the unique acoustic response of biofilms in the middle ear system.

OCT image of (A) a normal ear and (B) an ear with recurrent acute otitis media. A microbial infection-related structure is found to adhere to the eardrum and within the middle ear cavity in (B). Digital otoscopy images are inset in each panel. White dashed lines indicate the physical location on the eardrum where OCT scan was taken. Representative confocal laser scanning microscope (CLSM) images of fluorescence in situ hybridization (FISH)-tagged sample from the subject with recurrent otitis media. (C) Components identified with the universal bacteria probe, (D) H. influenzae, one of the primary bacteria strains in otitis media, (E) nuclei stain, and (F) overlay of the channels reveals the presence of bacteria dispersed throughout the sample.  

  • Nguyen CT, Jung W, Kim J, Chaney EJ, Novak M, Stewart CN, Boppart SA. Non-invasive in vivo optical detection of biofilm in the human middle ear. Proceedings of the National Academy of Sciences, USA, 109:9529-9534. 2012.
  • Nguyen CT, Tu H, Chaney EJ, Stewart CN, Boppart SA.   Non-invasive optical interferometry for the assessment of biofilm growth in the middle ear.   Biomedical Optics Express, 1:1104-1116. 2010.
  • Monroy GL, Pande P, Nolan RM, Shelton RL, Porter RG, Novak MA, Spillman DR, Chaney EJ, McCormick DT, Boppart SA. Noninvasive in vivo optical coherence tomography tracking of chronic otitis media in pediatric subjects after surgical intervention. J Biomedical Optics, 22:121614. 2017.
  • Monroy GL, Hong W, Khampang P, Porter RG, Novak MA, Spillman DR, Barkalifa R, Chaney EJ, Kerschner JE, Boppart SA. Direct analysis of pathogenic structures affixed to the eardrum during chronic otitis media. Otolaryngology-Head and Neck Surgery, 159:117-126. 2018.
  • Dsouza R, Won J, Monroy GL, Hill MC, Porter RG, Novak MA, Boppart SA. In vivo detection of nanometer-scale structural changes of the human tympanic membrane in otitis media. Scientific Reports, 8:8777. 2018.
  • Won J, Monroy GL, Spillman DR Jr, Huang P-C, Hill MC, Novak MA, Porter RG, Chaney EJ, Barkalifa R, Boppart SA. Assessing the effect of middle ear effusions on wideband acoustic immittance using optical coherence tomography. Ear and Hearing, 41:811-824, 2020.