Highlights from the SPIE/OSA European Conferences on Biomedical Optics in Munich
Overhead view of the International Year of Light Happy Hour reception, held on Wednesday in Munich.
Advances in instrumentation and technology
The Diffuse Optical Imaging conference, part of the European Conferences on Biomedical Optics, included a session Wednesday entitled "Advances in Instrumentation and Technology." The session featured three presentations from the group of Turgut Durduran at the Institut de Ciencies Photoniques (ICFO) in Spain. Miguel Mireles described a non-contact diffuse optical spectrometer and diffuse correlation spectroscopy system. This hyperspectral imaging system not only combines modalities and provides fast data acquisition but also overcomes issues with contact probe schemes in which probe placement can be a time consuming and challenging process. Results of the instrument were presented for both optical phantoms and in vivo cases for measurements of such parameters as blood flow, hemoglobin content and blood oxygenation level. Tanja Draojevic presented work on a laser speckle imaging arrangement utilizing a single photon avalanche diode array detection scheme. The system provides high frame rates of 100K frames/second with 35ns dead time and low dark current along with no readout noise. Demonstrations on phantoms and in vivo with a mouse model illustrated the capability of this arrangement. Parisa Farzam discussed work with a multi-distance diffuse correlation spectroscopy system. Algorithms developed allow for simultaneous measurements of blood flow and tissue properties. The approach has been validated in work with phantoms and in vivo with murine tumors.
Other talks in the session included Davide Contini of Politechnico di Milano who described a compact time-domain (TD) probe comprised of VCSEL's serving as pulsed sources and silicon photomultipliers as detectors and utilizing a single photon avalanche detector in the gating scheme. The probe was tested both on phantoms and in vivo showing results consistent with current state-of-the-art approaches. Kyle Nadeau of the Beckman Laser Institute and Medical Clinic presented a high speed spatial frequency domain imaging (SFDI) system operating at video rates and using binary square wave patterns for a structured illumination approach. The system has been demonstrated in vivo for such measurements as tissue oxygen saturation. The session concluded with a presentation from Judy Zouaoui of CEA-LETI who described a time-resolved, multispectral diffuse optical tomography setup for quantifying chromophore concentration through sample depth. The method has been demonstrated to date on phantoms.
Overall, the six talks in this session illustrated the ongoing progress in the technologies and instrumentation in the area of diffuse optical imaging.
Students lead the way
The Best Student Oral Paper Was awarded to two presenters at the ECBO plenary. Tianshi Wang (Erasmus MC) won for the paper "Heartbeat optical coherence tomography" (9541-39). And Thomas Chaigne (Institut Langevin) for the paper "Photoacoustic-guided wavefront shaping: towards deep tissue photo acoustic imaging and light focusing" (9539-27).
The Best Student Oral Paper Runner-ups are Frederic Lange (Univ. of California, Santa Barbara) for the paper "A hyperspectral time resolved DOT system to monitor physiological changes of the human brain activity" (9536-35); and David Moreau (XLIM Institut de Recherche) for the paper "Optical measurement of temperature in biological cells under infrared laser light exposure (λ=800 nm)" ( 9540-16).
The Best Student Poster Paper was awarded to Sebastian Karpf (Ludwig-Maximilians-Univ. München) for the paper "Nanosecond Two-photon excitation fluorescence imaging with a multi color fiber MOPA laser" (9536-27).
The Best Student Poster Paper Runner-ups were Michael Clancy (The Univ. of Birmingham) for the paper "Monitoring the injured brain: registered, patient specific atlas models to improve accuracy of recovered brain saturation values" (9538-42); and Yi-Hsien Hsiao (National Taiwan Univ) for the paper "Development of a movable diffuse reflectance spectroscopy system for clinical study of esophageal precancer" (9537-63).
Biophotonics industry profile, poster session
SPIE Industry and Market Strategist Stephen Anderson presented analysis of the size of the photonics industry and new data specific to biophotonics and biomedical optical systems including economic impact, geographic distribution, and associated revenue trends.
The Biomedical Optics conference in Munich, organized in 2015 by SPIE, is a forum for nearly 450 scientists, researchers, and engineers to share their recent results with the global community. Tuesday afternoon began with a well-attended, interactive poster session that helps people from around the world present their developments and discuss possibilities in the field of biomedical optics and biophotonics.
ECBO Poster Session
Late breaking developments
The European Conferences on Biomedical Optics featured six papers with late-breaking developments in today's special post-deadline session. Daichi Matsui of Osaka University described the development of a multispectral angioscope operating at wavelengths around 1200nm and demonstrated the capability of the instrument in enhancing deeply located plaque phantoms.
The ability to do 3D high resolution imaging with low light intensities and rapid imaging speeds by combining multiphoton RESOLFT (reversible saturable optical fluorescence transitions) microscopy and spatial light modulator techniques was the topic of the presentation given by Yi Xue of the Massachusetts Institute of Technology.
Giannis Zacharakis of the Foundation for Research and Technology-Hellas discussed the use of selective plane illumination microscopy (SPIM) in 3d volumetric imaging of live tumor spheroids and cited future applications of the technique in areas such as cell invasion studies, chemotherapeutic drug assessment, time lapse live cell imaging studies, and developing patient derived cancer cell spheroids for personalized medicine.
Results obtained within the past few weeks using a portable time-resolved diffuse optical tomography instrument at cot-side in infant brain imaging studies were shared by Laura Dempsey of the University College London. The instrument uses a supercontinuum laser providing a wide wavelength range and can collect a full imaging spectrum in 75 seconds.
Nerves are the longest cellular structure in the body and real-time visualization of nerves during surgery can greatly improve the results of the surgical procedure and patient recovery. Kenneth Chin of the University of Amsterdam detailed a polarized light imaging method and demonstrated that nerves as small as 50 microns in size can be seen with this scheme.
Thomas Lanvin of EPFL described combining ultrafast laser ablation methods with optical coherence tomography to ablate atherosclerotic plaque preserving the fibrous cap with continuous monitoring of the process.
Overall, the six presentations in the post-deadline session demonstrated exciting, cutting-edge results and technologies all with the promise of improving diagnostics and therapeutics in the health care field.
Light for Life!
On Sunday, the Hot Topics session of the European Conferences on Biomedical Optics featured presentations from eight conference chairs. Moderated by 2011 SPIE President Katarina Svanberg, Lund University Hospital, the session, entitled, "Light for Life," provided updates and highlighted emerging developments in key technologies and discussed translation to clinical use.
|2011 SPIE President
Brett Bouma of the Wellman Center for Photomedicine and Harvard University traced progress in endoscopic optical coherence tomography (OCT) from first prototypes in 1996 through the inception of Fourier Domain OCT which provided high speed, large field imaging capabilities. More recent advances in the field include heartbeat OCT, the use of OCT in multimodal schemes, and improvements in components such as lasers and probes. Commercial applications in cardiology and gastrointestinal endoscopy are being realized although full clinical adoption remains in the future.
The future of surgical oncology was the subject of the presentation by J. Quincy Brown of Tulane University. Challenges remain in the surgical theater when differentiating between cancerous and normal tissue which impact patient prognosis and experience. Emerging solutions include optical molecular imaging, spectroscopic techniques for tissue composition analysis and microscopic/multi-scale imaging as a histopathology replacement. Brown presented results from his group on video rate structured illumination microscopy which enables high resolution, optically sectioned images of biopsies in timeframes consistent with the needs of surgical pathologists.
Diffuse optical tomography with the goal of being able to perform bedside imaging was discussed by Hamid Deghani of the University of Birmingham. Vasilis Ntziachristos of the Helmholtz Zentrum Munchen GmbH cited the traditional 0.5-1mm limit of traditional optical microscopy and reviewed progress towards overcoming this barrier using techniques such as fluorescence molecular tomography and photoacoustics. Challenges in creating multi-level maps of the brain due to the need for a large optical dynamic range and the promise of 2,2'-thiodiethanol (TDE) as a clearing agent that works with electron microscopes thereby opening a pathway to go from the centimeter scale of optical microscopes to the nanometer scales of electron microscopes was the topic of the presentation from Francesco Pavone of the European Laboratory for Nonlinear Spectroscopy. Peter So of MIT described the challenges of obtaining quantitative data in coherent contrast phase microscopy and highlighted recent successes in tomographic phase microscopy in collecting quantitative three-dimensional data for living cells.
A tour through clinical applications of light-based technologies was the subject of the presentation from Ronald Sroka of Laser Foschungslabor. Techniques discussed included fluorescence guided resection, photodynamic therapy, laser assisted stapes implant fixation, endoluminal laser vein closure, and laparoscopic partial nephrectomy. The session concluded with a presentation from Alex Vitkin of the Ontario Cancer Institute who presented on the topic of tissue polarimetry and the uses of polarized light in assessing and diagnosing tissue with applications in myocardial characterization, urology and tumor differentiation.
Overall, the session provided attendees with a rapid, focused review from the leading experts in the field on the status, progress and future of light-based technologies on the verge of improving the human condition.
||J. Quincy Brown
Nobel recipients discuss their ground-breaking work
Attendees at the International Year of Light plenary session had the opportunity to hear from two of the scientists who shared the 2014 Nobel Prize in Chemistry for their work in super-resolution fluorescence mircroscopy. Stefan Hell of the Max Planck Institute Göttingen began his presentation discussing the nature and history of the diffraction effects
|Stefan Hell and Eric Betzig
limiting resolution and citing the value of optical microscopy as a tool that can peer into the workings of cells in a minimally invasive means. Such value could be improved if a way could be found around the diffraction limit and the stimulated emission depletion (STED) technique developed by Hell enables such a work-around through the selective activation and deactivation of fluorophores within the focal region of the sample under study. Hell emphasized this 'on-off' transition as a key feature of the technique that can be utilized in other methods such as ground state depletion (GSD) microscopy and reversible saturable optical fluorescence transition (RESOLFT) microscopy. Together, these three techniques allow the use of ever-decreasing light intensities to study phenomena at high resolution on lengthening timescales.
Eric Betzig of the Janelia Research Campus, Howard Hughes Medical Institute, described his early career working on near-field scanning optical microscopy (NSOM) techniques followed by seven years in industry at his family's machine business before learning about the discovery of green fluorescent protein and re-engaging in a scientific career which would lead to the development of photoactivated light microscopy (PALM), the super-resolution method that would lead to his sharing the 2014 Nobel Prize in Chemistry. Betzig discussed some of the details and results obtained with the technique and also discussed the method in the larger context of super-resolution and other enhanced resolution techniques including structural imaging microscopy (SIM), light sheet microscopy and adaptive optics techniques for weakly scattering living specimens. Betzig's presentation made it clear that these various modalities all provide valuable means by which to examine living samples and that much work and opportunity remains in the field.
Training for the future's leaders
SPIE student chapter leaders from around the world gathered in Munich on Saturday for an all-day leadership training. The Student Chapter Leadership Workshop, moderated by Jean-luc Doumont, Principiae, focused on the qualities of a good leader and how to apply those when running their student chapter. Students had the opportunity to problem solve real life chapter problems and network with other students from 30 countries and 18 different chapters.
"The comprehensive experience provided by the SPIE workshop fosters a greater realization for student leaders than simply professional growth," said Haley Marks, student chapter president at Texas A&M University. "The more important, more emotional realization for me was the take-away message that it is empathy and positive interactions within a team that allow for our future success as leaders."
Attending a Student Chapter Leadership Workshop is one of the benefits SPIE provides to its chapters, helping building leaders in their communities and in optics and photonics.
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