11.2014

SPIE Visiting Lecturer Prof Virgil-florin Duma

SCANNING IN OPTICAL COHERENCE TOMOGRAPHY

Optical Coherence Tomography (OCT) is an established, yet dynamic biomedical imaging technique. With micrometer resolution and milimeter penetration depth, it can provide transversal sections, as well as en face imaging and volumetric reconstructions of a sample. It is applied in a variety of fields, from biomedical (e.g, in ophthalmology, dentistry, skin, and endoscopy) to industrial. It allows for non-invasive ex vivo or in vivo investigations of tissue, as well as real time, in situ monitoring of industrial processes. Numerous techniques are involved in OCT, including interferometry, scanning, microscopy, and adaptive optics. This lecture is focussed on aspects related to scanning in OCT. We first point out the main types of scanners involved – not only in OCT, but also in other biomedical imaging techniques, such as Confocal Microscopy. The stress will be put on galvanometer scanners, polygon mirror, and Risley prism scanners.

For galvanometer scanners (GSs) we demonstrated theoretically that the optimal scanning function (i.e., the one that produces the maximum duty cycle/time efficiency of the scanning process) is linear plus parabolic, in contrast to the previous state-of-the-art, where the linear plus sinusoidal scanning has been considered best from this point of view. Experimentally, we demonstrated that the triangular scanning regime provides the most artefact-free OCT images, in comparison with sinusoidal and sawtooth scanning. For sinusoidal scanning the images have to be post-processed - as it is often the case with MEMS (Micro-Electro-Mechanical Systems). For sawtooth scanning, an overlapping of individual scans has to be done in order to compensate the artefacts and to be able to imagine larger samples. In all the cases the GS inertia has to be taken into account. Our study provided the necessary rules-of-thumb for that, by considering the different parameters of the process: scan frequency, scan amplitude, and duty cycle.

To move the OCT systems from lab to clinic, handheld scanning probes are necessary. We have approached this problem by designing, constructing and testing simple, low cost and light handheld probes equipped with a 1D GS. Several such devices are presented, from those built almost only with off-the-shelf components (including for educational purposes) to ergonomic ones. Challenges related to handheld probes with 2D scanners are also discussed. Applications in dentistry and in the study of metallic fractures are presented; for the latter we recently demonstrated that OCT can replace the costly and more time consuming scanning electron microscopy (SEM).

Polygon mirror scanners are presented, especially in relationship with swept sources/tunable laser filters for OCT. Mathematical, as well as constructive and functional issues are discussed for these devices that have the advantage of a much rapid scan than GSs. The latter have replaced polygons in most systems, but there are niche applications where polygons prove best.

Risley prisms scanners are presented, with the exact modelling we have introduced for them, and with remarks regarding their use in biomedical imaging (including for micro-devices). In this respect, the presentation is concluded by an insight into a hot topic: endoscope probes for OCT, employing a variety of scanning solutions. Directions of research in our group, as well as active collaborations are also pointed out.

01.2014

TOMI Group develops Nanosensitive OCT

The TOMI group has recently developed a novel label-free depth resolved sensing technique based on optical coherence tomography (OCT) to detect structural changes at the nanoscale, dramatically improving the sensitivity. Full Text

To demonstrate this new technique, OCT images of a sample consisting of two layers of polystyrene nanospheres of sizes 614±18 nm and 644±20 nm (mean ± standard deviation) were taken. These layers of nanosphere aggregates have sizes well beyond the resolution limit of the OCT system and so the mean difference between them of 30nm cannot be detected. But the nsOCT approach permits us to visualize such difference as a difference in corresponding spatial periods. By selecting points in each layer and looking at the position of the maximum in the axial spatial period profiles for these points, it is seen that this maximum is shifted to larger spatial periods corresponding to larger dominant sizes of structure for the layer with the larger nanospheres. Thus we can tell that the sizes of the axial structure in one layer are larger than in the other and so it is possible to clearly distinguish the two layers with different nanostructures.

The ability of nsOCT to probe human skin in vivo has also been shown and we expect that the technique could be applicable in early detection and treatment of disease.

01.2014

Graduation

We are delighted that Susan McElligott-Daly and Paul McNamara (pictured here with their supervisor, Prof. Martin Leahy) from the TOMI group have been conferred with their PhD degrees at the University of Limerick on January 29th, 2014.

11.2013

Visit of Prof. Steve L. Jacques

In late October and early November 2013 Steven L. Jacques, Professor of Biomedical Engineering at Oregon Health & Science University visited the TOMI group. Prof. Jacques has a background in biology, biochemistry and electrical engineering. His research interests include biomedical optics, laser–tissue interactions and the development of diagnostic and therapeutic devices for medicine and biology using optical technologies. Prof. Jacques delivered a seminar entitled "Probing nano–, micro– and meso–architecture of tissues using light scattering, and probing biomolecules using light absorption, fluorescence and non–linear effects.".

11.2012

European centers for outreach in photonics

European Centres for Outreach in Photonics (ECOP) is an alliance committed to create long-term partnerships for enhanced engagement in Photonics outreach. ECOP’s goal is to promote the importance, potential, pervasiveness and ubiquity of Optics and Photonics - “The Science and Technology of Light”. Its long-term mission is to impact all levels of European society, from students and teachers, industry, entrepreneurs, citizens of all ages to multidisciplinary institutions at large, and raise awareness of the importance of Photonics in a sustained way.

The ECOP Alliance connects nodes in European countries by building a network of Photonics research groups and outreach teams that aim to strengthen links with their local community. This is accomplished by developing tailor-made programmes and activities to address schools, universities, museums, media, industry, hospitals, etc. to communicate the importance of Photonics, the latest scientific research, discoveries, and innovations.

ECOP is enthusiastic to team up with scientists, educators, artists, museums, industry and other entities across Europe that are as passionate about science communication, public awareness and understanding of Photonics. The Alliance aims to establish hubs of outreach activities in Photonics across Europe.

NUI Galway is proud to be a founding member.

06.2012

Bigss 2012 : june 7^th - 13^th 2012 

The Biophotonics and Imaging Graduate Summer School (BIGSS) was held in Galway from June 7^th - 13^th2012. This was our 4^thsummer school and structured in the same way as the previous summer school. The speakers covered wide range  of topics in biophotonics such as Optical Coherence Tomography (OCT), Photoacoustic Tomography (PAT), Phase Microscopy, and much more.

Here are some pictures. (Coming Soon !!!)

Here are all the recorded lectures

You could also visit our Facebook Page for more BIGSS 2012 pictures

04.2012

Steve Jacques at nuig: May 1^st/2^nd

SHORT COURSE - Tissue optics and moving biophotonics into the clinic

TUTOR:         Steven L. Jacques, OHSU and NUI Galway

VENUE:         NUI Galway, Ireland; School of Physics, Room AO208

DATE:            May 1, 11:00 to May 2, 13:00

WEB:              www.nuigalway,ie/tomi

Session 1: Tissue optical properties, Spectroscopy/Imaging

Session 2: Monte Carlo simulations of light transport, Photochemical interactions

Session 3: Photothermal interactions, Photomechanical interactions

Real world examples including BiliChek – (Philips) and a polarisation camera for cancer margin detection will be discussed as they arise.

Register now via: http://www.imaging.nuigalway.ie/shortcourses/stevejacquesbookingform.html

03.2012

BIGSS 12 Notifications: Friday, March 16th

Successful applicants to this years BIGSS will be notified on or before this coming Friday, 16th March 2012. A standard Letter of Support (LoS) form will be attached with each email.  We strongly encourage students to fill this in, and return it to us for signing as soon as possible, as the visa application process can be lengthy.

For any further queries contact Dr Marie-Louise O'Connell: Marie-Louise.OConnellul.ie

PhD Studentships now available at TOMI Group

Applications are invited from suitably qualified candidates for PhD studentships with the School of Physics, National University of Ireland, Galway. We are looking for highly motivated students who wish to hone their knowledge of physics, engineering and/or software development to deliver new tools for clinical and pre-clinical investigation of the eye, skin and brain. Applications are invited from suitably qualified candidates for PhD studentships with the School of Physics, National University of Ireland, Galway. We are looking for highly motivated students who wish to hone their knowledge of physics, engineering and/or software development to deliver new tools for clinical and pre-clinical investigation of the eye, skin and brain. Check out the OCT news feature now.

To submit an application contact Prof Martin Leahy directly : Martin.Leahynuigalway.ie

Prof Steve L. Jacques: short course: tissue optics and moving biophotonics into the clinic

In recognition of his contributions to the field of photomedicine, Prof Steve L. Jacques was appointed Adjunct Professor at the School of Physics, NUI Galway in 2012. For more on his prolific contributions to imaging and spectroscopy read his profile on our staff page.

Prof Jacques will conduct a short course concerning tissue optics and its translation into the clinic on location at NUI              Galway, in May this year. For more details and to register your interest, see our resources page.

L'Oreal "women in science" fellowship 2012

L'Oreal-UNESCO Fellowships For Women In Science (FWIS) 2012 now has the pleasure to announce the call for applications and invite all eligible female postdoctoral researchers at your institution to consider this call. If you are interested in applying, please read the information below:

http://www.womeninscience.co.uk/  CLOSING DATE MARCH 23^RD2012

BIGSS 12 registration extended to march 2nd

Due to poular demand the BIGSS 12 organising committee has extended the registration deadline until March 2nd 2012. Submitted applications from the previous deadline will receive a notification confirming their submission soon. All              successful applicants will be notified in early March. In the meantime, stay tuned for more programme and funding updates!

For further details please contact: Dr. Marie-Louise O'Connell: Marie-Louise.OConnellul.ie

Deadline Feb 15th: SPIE Educational Scholarship

To be eligible to apply, students must:

• Be a Member* of SPIE
• Be enrolled in an optics, photonics, imaging, or optoelectronics program or related discipline (e.g., physics,              electrical engineering) at an accredited school for the full year beginning Fall 2012 (Sept 2012-July 2013)
• Be in high school or secondary school, undergraduate or post-secondary school, undergraduate, or graduate                school

This is an amazing opportunity for potential BIGSS applicants to attend the school FULLY FUNDED. Go to the SPIE website     and fill in the necessary details: http://spie.org/x7236.xml

BIGSS 12 REGISTRATION NOW OPEN!

Go to: http://imaging.nuigalway.ie/bigssbookingform.html and fill in all relevant fields including research motivations and poster title and abstract. Registration closes in two weeks time on Friday, 17th February 2012. Remember, places are limited so please apply early. Successful applicants will be notified by the end of the month.

For further details please contact Dr Marie-Louise O'Connell

TOMI Researcher awarded Newport-Spectra Physics Research Excellence Award

The Newport Spectra-Physics Research Excellence Travel Awards Program provides funding for university students to attend the two largest meetings of SPIE, where they will present their research. Ms Susan Daly of the TOMI research     group was amongst this years Photonics West awardees.