Publications by Theo Lasser | EPFL Graph Search

Related publications (122)

High speed laser Doppler perfusion imaging system e.g. blood flow imaging system, detects laser Doppler signal and/or laser speckle signal from light reflected from selected blood vessel area, to obtain flow data

An instrument for high-speed laser perfusion imaging comprises a laser source, a detector, a signal-processing unit, data memory, and a screen to display the results. A section of the sample surface is illuminated with laser light; the reemitted light from ...

2013

Quantitative lateral and axial flow imaging with optical coherence microscopy and tomography

Theo Lasser, Arno Pino Bouwens, Tristan Bolmont, Daniel Pawel Szlag

Optical coherence tomography (OCT) and optical coherence microscopy (OCM) allow the acquisition of quantitative three-dimensional axial flow by estimating the Doppler shift caused by moving scatterers. Measuring the velocity of red blood cells is currently ...

Optical Society of America2013

Vectorial retinal blood flow and optical vessel vivisection for 3D angiography with high resolution resonant Doppler OCT

Theo Lasser, Adrian Bachmann, Martin Villiger, Cédric Blatter

PURPOSE: To perform high speed and completely non-invasive 3D angiography at the optic nerve head region and to reconstruct vectorial 3D blood flow from optically segmented blood vessel structure as a pre-requisite for testing retinal function and physiolo ...

2007

Laser perfusion imaging system for acquiring flow-related images of object for medical diagnosis comprises coherent light source and image sensor(s) made by randomly addressed two-dimensional array of integrating photodetectors

Theo Lasser

An instrument for high-speed laser perfusion imaging comprises a laser source, a detector, a signal-processing unit, data memory, and a screen to display the results. A section of the sample surface is illuminated with laser light; the reemitted light from ...

2006

Soliton microcomb based spectral domain optical coherence tomography

Jia-Jung Ho, Tobias Kippenberg, Theo Lasser, Junqiu Liu, Martin Hubert Peter Pfeiffer, Johann Emmeram Riemensberger, Paul James Marchand, Joseph Connor Skehan

Spectral domain optical coherence tomography (OCT) is a widely employed, minimally invasive bio-medical imaging technique, which requires a broadband light source, typically implemented by super-luminescent diodes. Recent advances in soliton based photonic ...

Nature Research2021

Self-Blinking Dyes Unlock High-Order and Multiplane Super-Resolution Optical Fluctuation Imaging

Theo Lasser, Aleksandra Radenovic, Tomas Lukes, Kristin Stefanie Grussmayer

Most diffraction-unlimited super-resolution imaging critically depends on the switching of fluorophores between at least two states, often induced using intense laser light and specialized buffers or UV radiation. Recently, so-called self-blinking dyes tha ...

AMER CHEMICAL SOC2020

Towards high resolution optical imaging of beta cells in vivo

Theo Lasser, Anne Grapin-Botton, Martin Villiger, Joan Goulley, Erica Martin-Williams

Endocrine beta cells produce and release insulin in order to tightly regulate glucose homeostasis and prevent metabolic pathologies such as Diabetes Mellitus. Optical imaging has contributed greatly to our current understanding of beta cell structure and f ...

Bentham Science Publishers2010

Super-resolution orientation estimation and localization of fluorescent dipoles using 3-D steerable filters

Michaël Unser, Theo Lasser, Iwan Märki, François Aguet, Stefan Geissbühler

Fluorophores that are fixed during image acquisition produce a diffraction pattern that is characteristic of the orientation of the fluorophore’s underlying dipole. Fluorescence localization microscopy techniques such as PALM and STORM achieve super-resolu ...

OSA2009

Optical apparatus for dual beam heterodyne Fourier domain optical coherence tomography, has detector that synchronizes phase shift such that sample signal or sample interface moving at arbitrary velocity is detected by phase change

Theo Lasser, Martin Villiger, Adrian Bachmann

NOVELTY - The apparatus has an optical unit for splitting a source field to produce and combine reference and biomedical sample light fields. An optical and electronic unit records a spectral interference pattern between combined light fields. A controlled ...

2008

Total internal reflection fluorescence correlation spectroscopy (TIR-FCS) with low background and high count-rate per molecule

Theo Lasser, Marcel Leutenegger, Kai Hassler, Ramachandra Rao

We designed a fluorescence correlation spectroscopy (FCS) system for measurements on surfaces. The system consists of an objective-type total internal reflection fluorescence (TIRF) microscopy setup, adapted to measure FCS. Here, the fluorescence exciting ...

2005

Continuous Wavelet Transform Ridge Extraction for Spectral Interferometry Imaging

Michaël Unser, Theo Lasser, Michael Stefan Daniel Liebling

The combination of wavelength multiplexing and spectral interferometry allows for the encoding of multidimensional information and its transmission over a mono-dimensional channel; for example, measurements of a surface's topography acquired through a mono ...

SPIE2005

Object i.e. aneurysm, examining method for brain of patient, involves evaluating sequence of images by associating pixels with analysis image value depending on temporal changes of image values of pixels in specified frequency range

Theo Lasser, Marcel Leutenegger, Antonio Lopez, Erica Martin-Williams

NOVELTY - The method involves illuminating an object i.e. aneurysm, with measuring light with wavelengths ranging from 790 nanometer to 820 nanometer, and recording a sequence of images (21, 22) i.e. white light image, of the illuminated object. The sequen ...

2009

Massively parallel data processing for quantitative total flow imaging with optical coherence microscopy and tomography

Theo Lasser, Daniel Pawel Szlag, Paul James Marchand, Marcin Antoni Sylwestrzak

We present an application of massively parallel processing of quantitative flow measurements data acquired using spectral optical coherence microscopy (SOCM). The need for massive signal processing of these particular datasets has been a major hurdle for m ...

Elsevier2017

Image formation in fluorescence coherence-gated imaging through scattering media

Theo Lasser

Recently, we have experimentally demonstrated a new form of cross-sectional, coherence-gated fluorescence imaging referred to as SD-FCT (‘spectral-domain fluorescence coherence tomography’). Imaging in SD-FCT is accomplished by spectrally detecting self-in ...

2007

Steerable filters for orientation estimation and localization of fluorescent dipoles

Michaël Unser, Theo Lasser, François Aguet, Iwan Märki, Stefan Geissbühler

Fluorescence localization microscopy (i.e., PALM, STORM) has enabled optical imaging at nanometer-scale resolutions. The localization algorithms used in these techniques rely on fitting a 2-D Gaussian to the in-focus image of individual fluorophores. For f ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

Detection efficiency in total internal reflection fluorescence microscopy

Theo Lasser, Marcel Leutenegger

We present a rapid and flexible framework for the accurate calculation of the detection efficiency of fluorescence emission in isotropic media as well as in the vicinity of dielectric or metallic interfaces. The framework accounts for the dipole characteri ...

2008

Multiple scattering in optical coherence tomography. I. Investigation and modeling

Theo Lasser, Marcel Leutenegger, Stéphane Bourquin, Boris Clément Karamata, Markus Laubscher

We present a new model of optical coherence tomography (OCT) taking into account multiple scattering. A theoretical analysis and experimental investigation reveals that in OCT, despite multiple scattering, the field backscattered from the sample is general ...

2005

High volume confinement in two-photon total-internal- reflection fluorescence correlation spectroscopy

Theo Lasser, Marcel Leutenegger, Iwan Märki

We report results on two-photon total-internal-reflection fluorescence correlation spectroscopy with radially polarized light. The combination of liquid crystal spatial light modulator, providing radial polarization, with ultrafast laser (picosecond Nd:GdV ...

AIP American Institute of Physics2009

Phase sensitive Fourier domain optical coherence tomography

Theo Lasser, Adrian Bachmann

Optical Coherence Tomography (OCT) is an imaging technique with high axial resolution in the micro-meter-scale range combined with a high sensitivity allowing for example to probe weakly back-scattering structures beneath the surface of biological tissues ...

2006

Combined Optical Coherence and Fluorescence Microscopy to assess dynamics and specificity of pancreatic beta-cell tracers

Theo Lasser, Anne Grapin-Botton, Arno Pino Bouwens, Antonio Lopez, Corinne Berclaz, Daniel Pawel Szlag, Christophe Pache

The identification of a beta-cell tracer is a major quest in diabetes research. However, since MRI, PET and SPECT cannot resolve individual islets, optical techniques are required to assess the specificity of these tracers. We propose to combine Optical Co ...

Nature Publishing Group2015