Microwavephysics and Atmospheric Physics
Biomedizinische Photonik
HS 2017  ·  FS 2017
HS 2016  ·  FS 2016
HS 2015  ·  FS 2015
HS 2014  ·  FS 2014
HS 2013  ·  FS 2013
HS 2012  ·  FS 2012
HS 2011  ·  FS 2011
Ultrafast Science and Technology
Last update: 18.10.2017
FS 2016: Seminare über Biomedizinische Photonik
Wednesday 10-12
Vorträge, die innerhalb der nächsten Tage stattfinden, sind speziell markiert.
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Mittwoch, 03.02.2016

Implementation of Displacement Compensated Averaging (DCA) for clutter reduction in deep optoacoustic imaging within the fullphase project

Zeit: 10:15 Uhr
Hörsaal: A97
 
Christian Schneeberger
Institute of Applied Physics
University of Bern

 
Montag, 08.02.2016

Fluorescence life-time measurement of Fluorescein using Time Resolved Fluorescence Spectroscopy

Zeit: 13:15 Uhr
Hörsaal: A97
 
Maryam Mostafaei
Institute of Applied Physics
University of Bern

 
Mittwoch, 10.02.2016

In vivo measurements of oxygen partial pressure in biological tissue by luminescence lifetime spectroscopy

Zeit: 10:15 Uhr
Hörsaal: A97
 
Dr. Georges Wagnières
Institut des Sciences et Ingénierie Chimiques
Ecole Polytechnique Fédérale de Lausanne

Oxygen partial pressure (pO2) in biological tissues plays an important role in the destruction mechanisms induced by radiotherapy and photodynamic therapy (PDT). Thus, monitoring that parameter in real-time is useful to predict the outcome of these treatments. One minimally-invasive approach to assess pO2 in biological tissues is to measure the oxygen-dependent luminescence lifetime "τ" of molecular probes. The relation between tissue pO2 and τ is governed by the Stern-Volmer equation. The applications of this approach can be classified into two main categories: measuring the luminescence lifetime 1) of a photosensitizer used for PDT, or 2) of poorly photosensitizing exogenous molecular probes for other applications. Both pO2 measurement approaches have their specific advantages and drawbacks. We are working on solutions to avoid their drawbacks. Results obtained in vivo and in real time in the chicken egg’s chorioallantoic membrane (CAM) with our dedicated optical fiber-based time-resolved spectrometer are presented.

 
Donnerstag, 17.03.2016

Detection of Malaria-Mediated Changes in the Brain Vasculature of Mice using Optoacoustic Microscopy

Zeit: 10:15 Uhr
Hörsaal: B78
 
Florentin Spadin
Institute of Applied Physics
University of Bern

 
Mittwoch, 23.03.2016

Liquid water in no-man's land

Zeit: 10:15 Uhr
Hörsaal: A97
 
Chen Qiu
Institute of Applied Physics
University of Bern

 
Mittwoch, 20.04.2016

Engineering of Fiber Reinforced Bone Cements

Zeit: 10:15 Uhr
Hörsaal: A97
 
Elias Mulky
Institute of Applied Physics
University of Bern
and RMS Foundation, Bettlach

Self-setting calcium phosphate based scaffolds are used as bone fillers when excellent biocompatibility is required. Their disadvantages lie in their poor mechanical properties. Reinforcement with polymer fibers has produced mixed results in the past. This talk presents a method to consistently improve the mechanical properties of scaffolds by improving the fiber dispersion within. The presentation shows the mechanical and structural properties of cements manufactured with this method and introduces an approach to quantify the fiber dispersion within the composite.

 
Mittwoch, 27.04.2016

Adhesion and toxicity - cell culture experiments with the laser-soldered electrospun patch

Zeit: 10:15 Uhr
Hörsaal: A97
 
Annemarie Schönfeld
Institute of Applied Physics
University of Bern

 
Mittwoch, 04.05.2016

Revisting the Fresnel coefficients in the frame of Monte Carlo simulations

Zeit: 10:15 Uhr
Hörsaal: A97
 
Dr. Günhan Akarçay
Institute of Applied Physics
University of Bern

Modern computational powers offer a plethora of possibilities as for the modeling of light propagation. For instance, researchers in the field of computer graphics can use the powerful tools at their disposal to model light transport for the rendering of highly intricate virtual sceneries. However, the focus thereby lies on generating aesthetically pleasing images, rather than performing physically accurate calculations. A rigorous modeling of the light propagation needs to account for, inter alia, the vectorial nature of the light (i.e., the polarization of the light): the major difficulty here resides in the correct handling of the coordinate systems and conventions used throughout the work. This holds particularly true when modeling "Fresnel-like" reflection and refraction processes from a dielectric surface. A good example of this is the peculiar yet recurrent confusion that arises among students who wish to calculate reflection at normal incidence: "at normal incidence, are the Fresnel coefficients of equal or opposite sign?". In this Seminar, we shall on the one hand answer the question above and on the other hand present the modeling work we have carried out to calculate the reflection/refraction of a beam from non-trivial 3D geometries in our Monte Carlo program.

 
Mittwoch, 11.05.2016

Towards clutter free epi-optoacoustic imaging: Acoustic radiation force mediated localized vibration tagging (LOVIT)

Zeit: 10:15 Uhr
Hörsaal: A97
 
Tigran Petrosyan
Institute of Applied Physics
University of Bern

 
Mittwoch, 18.05.2016

Determine aberration delays from pulse-echo phase: The mysterious factor two

Zeit: 10:15 Uhr
Hörsaal: A97
 
Dr. Michael Jaeger
Institute of Applied Physics
University of Bern

 
Mittwoch, 25.05.2016

Spectral correction of optoacoustic signals using multiple-irradiation sensing

 

Zeit: 10:15 Uhr
Hörsaal: A97
 
Gerrit Held
Institute of Applied Physics
University of Bern

 
Mittwoch, 01.06.2016

Setting up and testing a confocal fluorescence microscope

Zeit: 10:15 Uhr
Hörsaal: A97
 
Maryam Mostafaei
Institute of Applied Physics
University of Bern

 
Mittwoch, 08.06.2016

Er-YAG laser coupling into fiber

Zeit: 10:15 Uhr
Hörsaal: A97
 
Arushi Jain
Institute of Applied Physics
University of Bern

 
Mittwoch, 29.06.2016

On Polarimetric Patterns

Zeit: 10:15 Uhr
Hörsaal: A97
 
Manes Hornung
Institute of Applied Physics
University of Bern

 
Mittwoch, 06.07.2016

Presentation of Master's Theses:

Determining the refractive index of highly scattering media by means of imaging, using an ellipsometric setup (Patrick Stähli)

The Influence of a Counter Bearing on the Injury Threshold of the Skull for Blunt Force Trauma (Michael Strehl)

Zeit: 10:15 Uhr
Hörsaal: A97
 
Patrick Stähli
Michael Strehl
Institute of Applied Physics
University of Bern

Patrick Stähli:
In this Seminar, I would like to present the progress I have made in the frame of my ongoing Master's project on determining the refractive index of highly scattering media, such as biological tissues. In the first part of this talk, I will give a reminder of the underlying theoretical concepts and give a short overview of the state of the art in this field. In the second part, I will present the setup - based on imaging - I have built and present the first calibration results on scattering colloidal suspensions.

Michael Strehl:
Blunt force trauma is a vast field in forensic science and biomedical engineering featuring many different areas of research. Although studies on head injuries and its preventions are a major topic for commercial products, impact testing is mostly done with the skull being fixed at percussion. In this study I will set up an experiment where the skull is allowed to move under variable resistances and try to find its correlation to the fracture mechanics.

 
Mittwoch, 20.07.2016

Recent Advances in Photoacoustic Image Reconstruction

Zeit: 10:15 Uhr
Hörsaal: A97
 
Phaneendra K. Yalavarthy, Ph.D.
Department of Computational and Data Sciences (CDS)
Indian Institute of Science, Bangalore
India 560012.

Photoacoustic imaging is a versatile imaging modality, which combine both near infrared optics and acoustics to reveal the tissue pathophysiology. The main stream reconstruction methods are typically analytical in nature, which require large amounts of data. The limited-data cases, which are more appealing in clinical scenarios, requires a model-based image reconstruction to be deployed to get good quality photoacoustic images.

The talk mainly outlines our group’s work in terms improving these model-based image reconstructions via deployment of least squares QR decomposition. This talk will briefly outline the error estimate utilisation for computing regularisation parameter in these schemes as well as utilisation of exponential filtering of singular values to improve the photoacoustic imaging. Few example results pertaining to Total variation based denoising of reconstructed photoacoustic images to enhance the image quality will also be presented.

Biography: Phaneendra K. Yalavarthy received his MSc degree in engineering from the Indian Institute of Science (IISc), Bangalore, India, and his PhD in biomedical computation from Dartmouth College, Hanover, New Hampshire, USA in 2007. He is an associate professor at the Department of Computational and Data Sciences, IISc. His research interests include medical image computing, medical image analysis, and biomedical optics. He is visiting University of Bern as part of Indigo Lab linking programme between IISc, University of Bern and University of Twente.