Publications de Joowon Lim | EPFL Graph Search

Computational segmentation of nuclei and vacuoles based on statistical inference for tomographic phase microscopy in flow cytometry

Identifying intracellular organelles within the 3D label-free tomograms of cells’ refractive indexes recorded in flow cytometry is challenging. Here we present a method for the 3D statistical segmentation of nuclei and vacuoles in flowing cells. ...

Optical Society of America2024

MaxwellNet: Physics-driven deep neural network training based on Maxwell's equations

Demetri Psaltis, Joowon Lim

Maxwell's equations govern light propagation and its interaction with matter. Therefore, the solution of Maxwell's equations using computational electromagnetic simulations plays a critical role in understanding light-matter interaction and designing optic ...

AIP Publishing2022

Stain-free identification of cell nuclei using tomographic phase microscopy in flow cytometry

Demetri Psaltis, Joowon Lim, Daniele Pirone

The accurate identification of the three-dimensional quantitative shape of a cell nucleus is now possible without fluorescent staining by applying computational segmentation to refractive index tomograms recorded in the flow cytometry mode. ...

Nature Publishing Group2022

3D reconstruction of weakly scattering objects from 2D intensity-only measurements using the Wolf transform

Demetri Psaltis, Joowon Lim, Elizabeth Elena Antoine, Ahmed Ayoub

A new approach to optical diffraction tomography (ODT) based on intensity measurements is presented. By applying the Wolf transform directly to intensity measurements, we observed unexpected behavior in the 3D reconstruction of the sample. Such a reconstru ...

2021

Polarization-sensitive optics diffraction tomography

Demetri Psaltis, Joowon Lim, Elizabeth Elena Antoine, Amirhossein Saba Shirvan, Ahmed Ayoub

Polarization of light has been widely used as a contrast mechanism in two-dimensional (2D) microscopy and also in some three-dimensional (3D) imaging modalities. In this paper, we report the 3D tomographic reconstruction of the refractive index (RI) tensor ...

2021

Computer generated optical volume elements by additive manufacturing

Demetri Psaltis, Christophe Moser, Niyazi Ulas Dinç, Eirini Kakkava, Joowon Lim

Computer generated optical volume elements have been investigated for information storage, spectral filtering, and imaging applications. Advancements in additive manufacturing (3D printing) allow the fabrication of multilayered diffractive volume elements ...

2020

Three-Dimensional Optical Diffraction Tomography With Lippmann-Schwinger Model

Michaël Unser, Demetri Psaltis, Thanh-An Michel Pham, Emmanuel Emilien Louis Soubies, Joowon Lim, Ahmed Ayoub, Ahmed Bassam Sayed Ayoub Mohamed Emam

A broad class of imaging modalities involve the resolution of an inverse-scattering problem. Among them, three-dimensional optical diffraction tomography (ODT) comes with its own challenges. These include a limited range of views, a large size of the sampl ...

2020

Learning approaches to high-fidelity optical diffraction tomography

Joowon Lim

Optical diffraction tomography (ODT) provides us 3D refractive index (RI) distributions of transparent samples. Since RI values differ across different materials, they serve as endogenous contrasts. It, therefore, enables us to image without pre-processing ...

EPFL2020

A method for assessing the fidelity of optical diffraction tomography reconstruction methods using structured illumination

Michaël Unser, Demetri Psaltis, Thanh-An Michel Pham, Joowon Lim, Ahmed Ayoub

2020

Three-dimensional tomography of red blood cells using deep learning

Demetri Psaltis, Joowon Lim, Ahmed Ayoub

We accurately reconstruct three-dimensional (3-D) refractive index (RI) distributions from highly ill-posed two-dimensional (2-D) measurements using a deep neural network (DNN). Strong distortions are introduced on reconstructions obtained by the Wolf tran ...

2020