Microwavephysics and Atmospheric Physics
Biomedizinische Photonik
HS 2018  ·  FS 2018
HS 2017  ·  FS 2017
HS 2016  ·  FS 2016
HS 2015  ·  FS 2015
HS 2014  ·  FS 2014
HS 2013  ·  FS 2013
HS 2012  ·  FS 2012
Ultrafast Science and Technology
Last update: 21.08.2018
HS 2018: Seminare über Biomedizinische Photonik
Wednesday 10-12
Vorträge, die innerhalb der nächsten Tage stattfinden, sind speziell markiert.
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Mittwoch, 26.09.2018

Polarimetric microscopy : Preliminary study with PVDFhfp scaffolds

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

Light propagation in fibrous tissue plays a fundamental role in the development of novel and minimally invasive diagnosis techniques. For this purpose, we use a polarimetric microscope that operates in the backscattering geometry. Our apparatus has been thoroughly calibrated and verified with experiments and Monte Carlo simulations on well characterized colloidal suspensions. In this study, we investigate the feasibility of retrieving structural information on multiply scattering, fibrous electrospun scaffolds consisting of PVDFhfp nanofibers. These nanofibers display various degrees of structural alignment and the structural anisotropy manifests itself in optical birefringence. We probed these scaffolds with a focused near-infrared light beam at three pairs of crosspolarized states and recorded images of the Stokes vector elements of the light backscattered at the surfaces of the scaffolds. Our preliminary results demonstrate that it is possible to structurally differentiate the scaffolds by analyzing the spatial variations of the degree of linear polarization. We will additionally show the possibility of retrieving the orientation of the fibers from the Stokes vector elements.

 
Mittwoch, 03.10.2018

Optoacoustic multiple irradiation sensing for the determination of blood oxygen saturation levels in vivo: data analysis and preliminary results

Zeit: 10:15 Uhr
Hörsaal: A97
 
Leonie Ulrich
Institute of Applied Physics
University of Bern

Multi-wavelength optoacoustic (OA) imaging allows for the assessment of blood oxygen saturation (SO2) levels in vessels. However, the wavelength-dependent attenuation of light in tissue leads to a spectral distortion of the OA signals and thus to an erroneous estimation of SO2. To correct the OA spectra, we use multiple irradiation sensing: OA images are acquired with multiple irradiation positions, and a semi-empirical model is applied to estimate the effective attenuation coefficient of the probed tissue. SO2 levels are then determined by pixelwise performing numerical fits of blood spectra to the corrected data, and a statistical analysis is carried out to reduce the uncertainty of the outcomes. This work is a continuation of research that has previously been conducted in our group. Based on the latest in vivo data sets acquired in a forearm of a volunteer, we are revising the analysis of the data and investigating the challenges of a robust quantitative evaluation in an in vivo setting. In this seminar, we will have a closer look at the different steps of the analysis and discuss first preliminary results.

 
Mittwoch, 10.10.2018

Computed Ultrasound Tomography in Echo Mode for Speed of sound imaging towards Arterial Plaque imaging: Progresses and Constraints

Zeit: 10:15 Uhr
Hörsaal: A97
 
Dr. Maju Kuriakose
Institute of Applied Physics
University of Bern

Computed Ultrasound Tomography in Echo Mode (CUTE) has been developed to image speed of sound of the biological tissues using the clinical ultrasound data. CUTE was developed based on transmit beam steering approach. This would make difficulties in flowing (like blood) biological regions. So, a new approach based on receive beam steering is developed in order to tackle these issues. In this seminar I will discuss about the progresses in this new approach and the practical constraints that we face for in vivo situations.

 
Mittwoch, 17.10.2018

No seminar

Zeit: 10:15 Uhr
Hörsaal: A97
 

 
Mittwoch, 24.10.2018

Echo motion tracking in ultrasound imaging

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

Tracking echo motion is important in various application of medical ultrasonography. The most classical use is maybe for blood flow imaging, but newer applications include elastography and speed-of-sound imaging. In this talk I will introduce various different techniques that have been used for motion tracking in ultrasonography, and discuss their specific properties. This leads to some of my own developments, which recently became important for our Cvent project where the challenge is to track the carotid artery wall for motion compensation of optoacoustic images.

 
Mittwoch, 31.10.2018

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Zeit: 10:15 Uhr
Hörsaal: A97
 
Patrick Stähli
Institute of Applied PhysicsUniversity of Bern

 
Mittwoch, 07.11.2018

tba

Zeit: 10:15 Uhr
Hörsaal: A97
 
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Mittwoch, 14.11.2018

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Zeit: 10:15 Uhr
Hörsaal: A97
 
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Mittwoch, 21.11.2018

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Zeit: 10:15 Uhr
Hörsaal: A97
 
Florentin Spadin
Institute of Applied Physics
University of Bern

 
Mittwoch, 28.11.2018

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Zeit: 10:15 Uhr
Hörsaal: A97
 
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Mittwoch, 05.12.2018

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Zeit: 10:15 Uhr
Hörsaal: A97
 
Grace Bramer
Institute of Applied Physics
University of Bern

 
Mittwoch, 12.12.2018

tba

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

 
Mittwoch, 19.12.2018

tba

Zeit: 10:15 Uhr
Hörsaal: A97
 
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