What's hot in San Francisco? For attendees to the Photonics West Biomedical Optics (BiOS) symposium, it was the Hot Topics session, which began at 7 pm on Saturday, January 23, and ran for more than 2 hours. About 860 folks resisted the temptation to visit other Bay Area hot spots in favor of hearing from ten leading researchers and witnessing the presentation of the 2010 SPIE/BiOS Lifetime Achievement Award.
Reginald Birngruber from Medizinisches Laserzentrum Lubeck GmbH took the award for his work on ophthalmic laser therapies. In his speech, the honoree reviewed the role of the laser in photothermal, photomechanical, and photochemical treatment and analysis of the eye since 1947. Birngruber explained that much of the work focused on establishing laser safety standards and in understanding the wavelength-dependent absorption of light in various layers of eye tissue. For example, pulse length and duration had much to do with achieving higher precision in photocoagulation with less collateral damage, while analysis of living and dead eyes (in rabbits) revealed the cooling effect of blood on optical power. Birngruber noted that while the past 60 years has been spent understanding laser ophthalmology, the future will address clinical devices and expanded clinical trials for laser therapies.
Cancer therapy, coronary imaging, and more
Opening the series of invited talks by other researchers, Nirmala Ramanujam of Duke University began by stating that 1.5 million women are diagnosed annually with breast cancer, and 1/3 of those die from it, usually because of metastasis. Ramanujam thinks optical technologies can improve the intra-operative assessment of cancer and remove any growths or cancerous tissue before it has the opportunity to spread. She discussed how Raman and fluorescence spectroscopy can each see different tissues (e.g., collagen and muscle) that aid in cancer diagnosis.
Joseph Schmitt, CTO of LightLab Imaging, explained in the next talk how "Intravascular OCT Extends Reach to Clinical Practice" using a MEMS tunable laser developed by Axsun and licensed by LightLabs. This Fourier-domain intra-coronary optical coherence tomography (OCT) system can image in the blood field of a beating heart using a fiber endoscopic imager rotating at 100 frames per second.
After a talk from Amiram Grinvald of Optical Imaging on "Retinal Functional Imaging" that recalled the research described by Birngruber, Brian Pogue from Dartmouth College spoke on "Diffuse Molecular Imaging: Detecting Invisible Changes In Vivo," saying image-guided optical molecular spectroscopy has huge market potential. He plugged www.nirfast.org, Dartmouth's open-source software designed for modeling near-infrared frequency domain light transport in tissue.
Just before I succumbed to sleepiness (the talks ran long, and the late evening schedule challenged some travel-weary listeners!), Irving Bigio from Boston University discussed recent "sizzling" developments in elastic scattering spectroscopy (ESS). The technique has been around since 1991, but it has lately proven able to assess cancer risk by showing how signals in an unaffected part of the colon could point to polyps in another part.
More stalwart attendees got to hear also from Steven Jacques of Oregon Health Sciences University on the topic of "Speckle Imaging, Tissue Spectroscopy," from Jeff Squier of the Colorado School of Mines on "Differential Multiphoton Microscopy," and from Tony Wilson of the University of Oxford who discussed, "Making Light Work In Microscopy."