The computational modeling conversation continues…

By By Yansong Zhu, Johns Hopkins University | Posted: 15 April 2016

The final session from Day 1 of the Incubator was Performance Metrics/Task-based Assessment. Andrew Watson, from NASA Ames Research Center focused on visual performance metrics for imaging systems. He analyzed the problems of traditional models and discussed improvements that could be made using new approaches. His used examples of letters, aircraft, and watercraft to further illustrate his improvements. Next, Meredith Kupinski, from the University of Arizona, discussed model observation for image quality evaluation. She mentioned that image quality is statistical and can never be defined with a single image. The optimal observer for detection and estimation requires a full characterization of image statistics and characterizing image statistics usually requires an unrealistic quantity of sample images. She also gave some examples to show the performance of her model. After she concluded her discussion, the first day of Computational Modeling Incubator came to the end.

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​OSA Incubator on Computational Modeling & Performance Metrics for Imaging System Design & Evaluation – Day 1

By Yansong Zhu, Johns Hopkins University | Posted: 14 April 2016

During the OSA Incubator on Computational Modeling & Performance Metrics for Imaging System Design & Evaluation hosts Joseph Reynolds, from the Night Vision and Electronic Sensors Directorate of the U.S. Army, and Christian Graff, from the U.S. Food and Drug Administration, gave the overview of what they wanted to accomplish. The goal of this meeting is to share information among researchers in different fields with common problems, to foster future collaborations, to identify areas in need of further research, and to develop strategies for incorporating computer simulations in imaging device performance evaluation. Their hope was to bring together defense and medical imaging science communities to share methods, lessons learned, issues, and future directions for modeling and simulation of complex imaging systems. After the overview presentations, 

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Adaptive Structured Illumination Incubator

By Marcia Lesky | Posted: 19 November 2015

  • What are the barriers for super-resolution at depth?
  • What are the fundamental limits in fibre imaging (resolution, correction, speed)?
  • What are the challenges of using structured illumination for in vivo imaging?

These are just a few of the questions that were explored at last week’s Adaptive Structured Illumination Incubator. Hosted by Meng Cui from Purdue University, US, and Kishan Dholakia and Michael Mazilu from the University of St. Andrews, UK, this Incubator used invited talks and moderated group discussion to allow experts to cross-fertilize ideas in applications of structured illumination throughout photonics.

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Photobiomodulation – Overcoming the Hurdles

By Johnathan George | Posted: 1 September 2015

Group discussion

 

After a morning discussing how the technology, and community, have developed over the years, the afternoon of the Photobiomodulation Incubator began with a panel discussion on overcoming the hurdles facing Photobiomodulation (PBM). Panelists David Ozar Ph.D., Loyola University Chicago, Gail Siminovsky, CAE, Academy of Laser Dentistry, and Scot Faulkner, Kinexum Pharmaceuticals, discussed the ethical, organizational and leadership issues facing PBM. Their talks led to an open-ended brain storming session in which participants collected their ideas for the future of PBM and scored them by implementation difficulty and return on investment (ROI).

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Photobiomodulation – where it started and where is it going?

By Johnathan George | Posted: 31 August 2015

Juanita-Anders speaks on Photobiomodulation

 

 

Today’s kick-off of the OSA’s second Photobiomodulation (PBM) Incubator brings together scientists, practitioners, and industry to discuss the latest research, future, and hurdles for PBM’s acceptance as a mainstream medical therapy.

The day began with hosts Michael Hamblin Ph.D. and Donald Patthoff DDS introducing the goal of the Incubator: to come together to bring a coherent message about the scientific validity and potential for PBM. They said there will be an expectation of no spectators and an “all hands on deck” attitude at the Incubator, where all attendees are expected to participate.

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The Body Optic - Molecular Probes Save Lives

By Arlene Smith, Ph.D. | Posted: 1 July 2014

Colorectal cancer is the third most commonly diagnosed cancer in the world; in fact, the American Cancer Society estimates 96,830 new cases of colorectal cancer cases in the United States for 2014 alone. Barratt’s Esophagus, which is strongly associated with esophageal adenocarcinoma, affects up to 10% of patients suffering from long-term acid reflux.

 

Diseased areas can be difficult to detect, even with a high-resolution imaging tool. I work in optical modelling of imaging systems for early cancer detection. I am a member of a multidisciplinary research group comprising electrical and mechanical engineers (and me, the physicist!) and molecular biologists. The biology team develop molecular probes, which, when excited with light of a certain wavelength, fluoresce, and act as a guide as to whether areas of tissue are normal (cancer-free) or pre-malignant mucosa (dysplasia). This fluorescence property is particularly useful when cancer is at an early stage when it is most likely to respond to treatment.  The molecular probe can highlight dysplastic regions during routine endoscopic procedures, increasing the likelihood of a correct diagnosis.

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The integration of optical technologies to manipulate and monitor biological samples

By Kyle Quinn | Posted: 29 April 2014

This morning at the BIOMED meeting, there were back-to-back talks in the Optical Molecular Biophysics / Neurophotonics session that highlighted the unique insights that can be obtained by integrating different optical technologies. Anna-Karin Gustavsson from Dr. Caroline Adiels group gave an interesting talk that integrated multifluidics, optical trapping, and NADH autofluorescence measurements to monitor glycolytic oscillations in individual yeast cells. Optical trapping was used to maintain and calibrate specific cell-cell distances, while a microfluidic flow chamber provided the influx of different concentrations of glucose, cyanide, and acetaldehyde to the cells. Glycolytic oscillations could then be monitored through NADH autofluorescence fluctuations measured by an EM-CCD. Using this controlled environment, fundamental studies to understand cell-cell communication and cell coupling are being explored.

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Speeding up multi-photon microscopy

By Kyle Quinn | Posted: 29 April 2014

As someone with strong research interests in multiphoton microscopy (MPM), I was excited to hear Dr. Peter So’s plenary talk on Day 3 of the BIOMED meeting. Dr. So provided an overview of the development of his multiphoton tissue cytometry equipment over the years, and its applications in neurobiology. MPM has emerged as key tool in neuroscience to non-invasively image deeper within the brain. Although multiphoton microscopy is well-positioned to provide high content information throughout the cortex of rodents and other smaller species, his work has primarily been motivated by efforts to maximize the throughput of this technology. By imaging faster and over a wider field of view, important questions regarding the functional and structural plasticity of neurons can be addressed.

Traditionally MPM involves raster scanning to produce an image one pixel at a time, but Dr. So’s work has involved the development of wide-field MPM techniques that utilize a CCD or multi-anode PMTs for the simultaneous collection of points. There are a number of technical challenges associated with the different approaches to wide-field MPM imaging, and Dr. So provided insight into the different solutions to these problems (e.g. temporal focusing, eliminating issues of dead space between PMTs, non-descanned detection) and the many iterations of his microscopes. In addition to imaging faster through these wide-field techniques, his group can take advantage of the inherent high content of microscopy techniques to acquire spectral data, such as fluorescence lifetime and phosphorescence lifetime imaging. Phosphorescence lifetime imaging is typically challenging because it requires very long image acquisition times, but his temporal-focusing wide-field MPM approaches can substantially reduce imaging times to enable relatively fast, high resolution imaging of oxygen distributions in the brain.

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The OSA BIOMED Meeting Day 1: Things are heating up in Miami

By Kyle Quinn | Posted: 28 April 2014

Greetings from Miami! BIOMED has gotten off to great start with a pair of plenary talks by Dr. Xingde Li and Dr. Adam Wax. As I mentioned in a previous post, Dr. Li has been developing and refining endomicroscopic probes to facilitate non-linear optical microscopy in hard to reach places such as the kidney, intestine, and cervix. Dr. Wax, on the other hand, has taken a different approach to delivering and detecting photons from deeper within the body through the use of low coherence interferometry (LCI).

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The Binding Finding of a Fluorescence Lifetime

By Ken Tichauer | Posted: 27 April 2014

In this afternoon’s session on Luminescence and Absorption on Cellular and Tissue Levels, Prof. Victor Chernomordik gave an overview of the extensive work he and his colleagues have been undertaking to make fluorescence molecular imaging more quantitative. Much of their work has focused specifically on how to quantify human epidermal growth factor receptor 2 (HER2) concentrations (a key receptor of interest in breast cancer) using kinetic models, and they have a number of publications in this area that I urge you to check out;1-5 however, what I was most intrigued by was there recent results demonstrating a dependence of fluorescence lifetime on the binding state of a targeted fluorescent tracer. In simpler terms, what they found was that the timing characteristics of fluorescence emission was significantly different depending on whether their fluorescent tracer was bound to the target of interest or not.6,7

This offers their group a window into separating non-specific uptake of a tracer, a major problem in conventional molecular imaging of tumors, from the more interesting bound fraction of the targeted tracer. Moreover, for reversible binding tracers (tracers that can dissociate from there targeted molecule), the ratio of the bound fraction of a tracer to the unbound fraction of tracer is directly proportional to the concentration of the targeted biomolecule.8 Therefore, as Prof. Chernomordik and his colleagues unearth the exact relationship between bound fraction and fluorescence lifetime, there is a clear pathway forward to using this approach to directly quantify HER2 concentration, something that is impossible to do with other conventional single tracer approaches in tumors.9

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The Role of Chance in Biomedical Imaging

By Kyle Quinn | Posted: 7 April 2014

Much of my work as a postdoctoral trainee at Tufts University has focused on utilizing endogenous sources of optical contrast to assess tissue development and disease. To this end, our lab has utilized non-linear optical microscopy to non-destructively characterize tissue organization and metabolic function with an emphasis on understanding and detecting stem cell differentiation and precancerous transformations. As I think about all the researchers, past and present, that have provided fundamental contributions to my area of research, no one looms larger than Dr. Britton Chance. (Article continues below.)

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The recent evolution of biomedical optics in one graphic*

By Kyle Quinn | Posted: 27 March 2014

OSA
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Day 1 continued: Learning to See Through Walls

By David Norris | Posted: 7 March 2014

Is it possible to look inside an object using only light reflected off the front?  Can you transmit more light through an attenuating medium by making it even thicker?  Could a bank verify your identity using the pattern of light scattered off your teeth? 

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Reducing Drug Trial Costs with Imaging Technology

By Ken Tichauer | Posted: 4 March 2014

95% of new cancer therapeutics fail to make it past Phase II clinical trials. This means that while it should only cost about $50 million per drug for FDA approval, incorporating the cost of failures leads to an estimated cost of $1 billion per drug (1), with a recent Forbes article suggesting that this number is considerably higher (2).So why are so many drugs failing in clinical trials?

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How to fit a laser-scanning microscope into a 2mm diameter tube

By Kyle Quinn | Posted: 28 February 2014

Optical microscopy can provide high-resolution images of cellular morphology and matrix organization, which can be utilized to diagnose disease or trauma. However, achieving an adequate signal-to-noise ratio at imaging depths exceeding 1mm is very challenging.  As a result, the initial clinical applications for optical microscopy techniques have largely focused on skin pathology.  One approach to unlocking a wider spectrum of clinical applications for biomedical optics is miniaturizing the distal end of microscopes into endoscopic probes.

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Pushing the limits of imaging resolution and penetration depth

By Kyle Quinn | Posted: 28 February 2014

The development of labeling techniques capable of providing customizable molecular specificity has made optical microscopy a fundamental technique in the biomedical research, and the standard compound microscope remains a fixture in just about any clinic or biomedical lab. The popularity of optical microscopy was also driven by the ability to provide resolution at the cellular level that traditional clinical imaging modalities (e.g. ultrasound, x-ray CT, and MRI) simply cannot meet. The finer structural details of biological tissues were further elucidated through the development of transmission electron microscopy, which enabled unparalleled views at the scale of proteins and molecules. However, like all imaging technologies, there is a tradeoff between imaging resolution and penetration depth, and electron microscopy has extremely limited penetration depth.

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It takes blood, sweat, and SERS to image single cells

By Ken Tichauer | Posted: 20 February 2014

Throw out those old dusty fluorescent molecules and welcome in the next generation of optical contrast agents. SERS (Surface Enhanced Raman Scattering/Spectroscopy) nanoparticles are sophisticated new contrast agents that offer some distinct advantages over conventional fluorescent molecules for investigating molecular biology.

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Where would biomedicine be without optics?

By Kyle Quinn | Posted: 10 February 2014

Much of the emphasis in biomedical optics research has been placed on the clinical translation of our technologies -- and rightfully so!  As my fellow blogger Dr. Ken Tichauer indicates, the potential impact in the clinic is great and the future remains bright.  But as we gear up for OSA BIOMED 2014 in Miami, I will be excited to learn about some of the latest applications in basic science research where biomedical optics continues to play a key role. The field of optics has provided researchers advanced tools that are needed in a variety of other disciplines to optimize complex laboratory protocols, to elucidate the underlying mechanisms of disease, and to speed the preclinical development of novel therapies. Optogenetics






















 

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Photoimmunotherapy (PIT) busts open the doors for drug delivery

By Ken Tichauer | Posted: 6 February 2014

Over the last decade alone, it is estimated that over $200 billion has been spent just by governments to fund cancer research [1]. Despite this enormous investment, the recently released 2014 World Heath Organization (WHO) Cancer Report suggests that cancer incidence rates and deaths from cancer are on the rise, both in more developed and less developed nations.

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Beginning of a new era? Recent advances in biomedical optics light the way to long-awaited clinical translation

By Ken Tichauer | Posted: 29 January 2014

For decades biomedical optics has been touted as an ideal tool for diagnosing, monitoring and/or treating a vast array of health conditions owing to low-cost instrumentation, use of non-ionizing radiation, and incomparable sensitivity. All great characteristics; nonetheless, adoptions of optical devices in the clinic have been few and far-between. One could blame regulations, the high cost of clinical trials, and provider inertia; but these hurdles would be behind us if the optical approaches on health and healthcare costs made more more significant impact. We're not there yet.

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