Prof. Rainer Macdonald Profile

Prof. Rainer Macdonald

Head of Dept at Physikalisch-Technische Bundesanstalt

SPIE Involvement:

Author

Publications (56)

Proceedings Article | 9 December 2021 Paper

Reconstruction of absorption maps by digital tomosynthesis

Nicolás Carbone, Demian Vera, Daniela Iriarte, Juan Pomarico, Rainer Macdonald, Dirk Grosenick

Proceedings Volume 11920, 1192015 (2021) https://doi.org/10.1117/12.2615346

KEYWORDS: Absorption, Data modeling, Tumor growth modeling, Optical spheres, Breast, Finite element methods, Scattering, Cameras, Algorithm development, Optical properties

Read Abstract +

Proceedings Article | 11 July 2019 Paper

Spatially-enhanced time-domain NIRS for determination of optical properties in layered structures

Lin Yang, Pranav Lanka, Heidrun Wabnitz, Rinaldo Cubeddu, Thomas Gladytz, Sanathana Konugolu Venkata Sekar, Dirk Grosenick, Antonio Pifferi, Rainer Macdonald

Proceedings Volume 11074, 110740A (2019) https://doi.org/10.1117/12.2527032

KEYWORDS: Absorption, Near infrared spectroscopy, Optical properties, Scattering, Monte Carlo methods, Tissue optics, Tissues, Brain

Read Abstract +

Proceedings Article | 27 February 2019 Paper

Digital phantom for time-domain near-infrared spectroscopy of tissue: concept and proof-of-principle experiments

Heidrun Wabnitz, Lin Yang, Rainer Macdonald, Jeeseong Hwang

Proceedings Volume 10870, 108700K (2019) https://doi.org/10.1117/12.2510405

KEYWORDS: Optical fibers, Spatial light modulators, Tissues, Tissue optics, Picosecond phenomena, Oximeters, Near infrared spectroscopy, Optical phantoms

Read Abstract +

In the clinically relevant field of tissue oximetry, there is an urgent need to develop phantom-based methods for validation. Physical phantom approaches based on solid or liquid turbid media containing hemoglobin with variable oxygenation have limited capabilities to represent real tissues regarding optical properties, structure and variability. Digital phantoms are an alternative with high flexibility. Rather than physically simulating the process of light propagation, they provide the detector with light signals mimicking the signals detected in vivo. We present a technique to produce digital phantoms for time-domain diffuse optical spectroscopy that mimic arbitrary photon time-of-flight distributions (DTOFs) by creating a time-dependent attenuation. The setup contains a spatial light modulator (SLM) and a set of optical fibers of different lengths corresponding to a stepwise delay. The light pulse entering the arrangement is spatially dispersed and illuminates the SLM which controls the intensity at each pixel. The SLM array is imaged onto the entrance faces of the delay fibers. The amount of photons received by each individual fiber can be adjusted. Finally, the light transmitted through all fibers are combined and fed to the detector of the timedomain instrument under test. In this way, DTOFs of any desired shape can be obtained. For first proof-of-principle experiments to demonstrate the general feasibility of the concept we used a liquid-crystal SLM and a set of four graded-index fibers differing in length by about 100 mm. The tests were performed with a timedomain instrument based on time-correlated single photon counting, with picosecond diode and supercontinuum laser sources and a single-photon avalanche diode as well as a hybrid photomultiplier as detectors. This large separation in fiber lengths allowed the performance regarding amplitude and temporal shape to be assessed for each delay independently. The generation of arbitrary DTOFs was simulated by realizing various patterns of target amplitudes. Temporal position and width of the measured pulse profiles for all fibers were in agreement with the expectations. Amplitude linearity was reasonable while the contrast between highest and lowest amplitude values was not yet satisfactory. Steps of further development are discussed.

Proceedings Article | 28 July 2017 Paper

Retrieval of the optical properties in a semiinfinite three layers phantom: theory, experiments, and simulations

H. García, D. Iriarte, J. Pomarico, D. Grosenick, R. Macdonald

Proceedings Volume 10412, 104120S (2017) https://doi.org/10.1117/12.2285446

KEYWORDS: Optical properties, Multilayers, Reflection

Read Abstract +

Proceedings Article | 28 July 2017 Paper

Fluorescence-guided mapping of sentinel lymph nodes in gynecological malignancies

Ole Hirsch, Łukasz Szyc, Mustafa Zelal Muallem, Iulia Ignat, Radoslav Chekerov, Rainer Macdonald, Jalid Sehouli, Ioana Braicu, Dirk Grosenick

Proceedings Volume 10412, 104120L (2017) https://doi.org/10.1117/12.2285933

KEYWORDS: Lymphatic system, Luminescence, Cancer

Read Abstract +

Proceedings Article | 28 July 2017 Paper

Non-contact time-domain imaging of functional brain activation and heterogeneity of superficial signals

H. Wabnitz, M. Mazurenka, L. Di Sieno, D. Contini, A. Dalla Mora, A. Farina, Y. Hoshi, E. Kirilina, R. Macdonald, A. Pifferi

Proceedings Volume 10412, 104120J (2017) https://doi.org/10.1117/12.2286077

KEYWORDS: Brain activation, Biomedical optics

Read Abstract +

Proceedings Article | 17 February 2017 Paper

Sentinel lymph node detection in gynecologic malignancies by a handheld fluorescence camera

Ole Hirsch, Lukasz Szyc, Mustafa Zelal Muallem, Iulia Ignat, Radoslav Chekerov, Rainer Macdonald, Jalid Sehouli, Ioana Braicu, Dirk Grosenick

Proceedings Volume 10059, 100591B (2017) https://doi.org/10.1117/12.2250723

KEYWORDS: Lymphatic system, Luminescence, Cancer, Imaging systems, Surgery, Cameras, Cervical cancer, Ovarian cancer, Tissues, Near infrared spectroscopy, Light emitting diodes

Read Abstract +

Proceedings Article | 18 March 2016 Paper

Characterization of homogeneous tissue phantoms for performance tests in diffuse optics

Heidrun Wabnitz, Dieter Richard Taubert, Tsukasa Funane, Masashi Kiguchi, Hideo Eda, Antonio Pifferi, Alessandro Torricelli, Rainer Macdonald

Proceedings Volume 9700, 970004 (2016) https://doi.org/10.1117/12.2209038

KEYWORDS: Diffuse optical imaging, Scattering, Transmittance, Tissue optics, Near infrared spectroscopy, Optical properties, Absorption, Signal attenuation, Sensors, Power meters, Solids, Diffusion

Read Abstract +

SPIE Journal Paper | 2 November 2015 Open Access

Optimal estimation reconstruction of the optical properties of a two-layered tissue phantom from time-resolved single-distance measurements

Fabrizio Martelli, Samuele Del Bianco, Lorenzo Spinelli, Stefano Cavalieri, Paola Di Ninni, Tiziano Binzoni, Alexander Jelzow, Rainer Macdonald, Heidrun Wabnitz

JBO, Vol. 20, Issue 11, 115001, (November 2015) https://doi.org/10.1117/12.10.1117/1.JBO.20.11.115001

KEYWORDS: Optical properties, Tissues, Absorption, Tissue optics, Picosecond phenomena, Biological research, Data modeling, Reconstruction algorithms, Brain, Scattering

Read Abstract +

DOWNLOAD PAPER