Dr.-Ing. Matthias Gräser

Universitätsklinikum Hamburg-Eppendorf (UKE)
Sektion für Biomedizinische Bildgebung
Lottestraße 55
2ter Stock, Raum 212
22529 Hamburg

Technische Universität Hamburg (TUHH)
Institut für Biomedizinische Bildgebung
Gebäude E, Raum 4.044
Am Schwarzenberg-Campus 3
21073 Hamburg

Tel.: 040 / 7410 25812
E-Mail: matthias.graeser(at)tuhh.de
E-Mail: ma.graeser(at)uke.de

Research Interests

  • Magnetic Particle Imaging
  • Low Noise Electronics
  • Inductive Sensors
  • Passive Electrical Devices

Curriculum Vitae

Matthias Gräser submitted his Dr.-Ing. thesis in january 2016 at the institute of medical engineering (IMT) at the university of Lübeck and is now working as a Research Scientist at the institute for biomedical imaging (IBI) at the technical university in Hamburg, Germany.  Here he develops concepts for Magnetic-Particle-Imaging (MPI) devices. His main aim is to improve the sensitivity of the imageing devices and improve resolution and application possibilities of MPI technology.

In 2011 Matthias Gräser started to work at the IMT as a Research Associate in the Magnetic Particle Imaging Technology (MAPIT) project. In this project he devolped the analog signal chains for a rabbit sized field free line imager. Additionally he developed a two-dimensional Magnetic-Particle-Spectrometer. This device can apply various field sequences and measure the particle response with a very high signal-to-noise ratio (SNR).

The dynamic behaviour of magnetic nanoparticles is still not fully understood. Matthias Gräser investigated the particle behaviour by modeling the particle behaviour with stochastic differential equations. With this model it is possible to simulate the impact of several particle parameters and field sequences on the particle response .

In 2010 Matthias Gräser finished his diploma at the Karlsruhe Institue of Technology (KIT). His diploma thesis investigated the nerve stimulation of magnetic fields in the range from 4 kHz to 25 kHz.

Journal Publications

[76888]
Title: Evaluation of a Cotton-Mouton relaxometer for the characterization of superparamagnetic iron oxide nanoparticles.
Written by: C. Debbeler, M. Graeser, R. F. Knobloch, S. Becker, and K. Lüdtke-\-Buzug
in: <em>International Workshop on {Magnetic Particle Imaging} ({IWMPI}), IEEE Xplore Digital Library</em>. (2015).
Volume: Number:
on pages:
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/IWMPI.2015.7107058
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings

Abstract: When using superparamagnetic iron oxide nanoparticles ({SPIONs}) as contrast agents or tracers in biomedical applications, knowledge of the hydrodynamic diameter is crucial. The hydrodynamic diameter influences the circulation time of the particles in the blood cycle as well as the accessibility of the target structure. Common methods to determine the hydrodynamic diameter include magnetorelaxometry ({MRX}) or photon cross-correlation spectroscopy ({PCCS}). In this work, a combination of the Cotton-Mouton effect and the Brownian relaxation is used. It promises a fast and straightforward determination of the hydrodynamic diameter of {SPIONs}. Earlier publications already showed that the determination of the hydrodynamic diameter of {SPIONs} using a Cotton-Mouton relaxometer is possible. Subsequent, this work addresses the thorough investigation of the reliability of the setup. Studies show that sample temperature affects measurement results. Therefore, a calibration and temperature stabilization of the setup is mandatory. Additionally, the effect of other critical parameters as, for instance, the viscosity (which varies with temperature) or ambient light should be taken into consideration.

Conference Proceedings

[76888]
Title: Evaluation of a Cotton-Mouton relaxometer for the characterization of superparamagnetic iron oxide nanoparticles.
Written by: C. Debbeler, M. Graeser, R. F. Knobloch, S. Becker, and K. Lüdtke-\-Buzug
in: <em>International Workshop on {Magnetic Particle Imaging} ({IWMPI}), IEEE Xplore Digital Library</em>. (2015).
Volume: Number:
on pages:
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/IWMPI.2015.7107058
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings

Abstract: When using superparamagnetic iron oxide nanoparticles ({SPIONs}) as contrast agents or tracers in biomedical applications, knowledge of the hydrodynamic diameter is crucial. The hydrodynamic diameter influences the circulation time of the particles in the blood cycle as well as the accessibility of the target structure. Common methods to determine the hydrodynamic diameter include magnetorelaxometry ({MRX}) or photon cross-correlation spectroscopy ({PCCS}). In this work, a combination of the Cotton-Mouton effect and the Brownian relaxation is used. It promises a fast and straightforward determination of the hydrodynamic diameter of {SPIONs}. Earlier publications already showed that the determination of the hydrodynamic diameter of {SPIONs} using a Cotton-Mouton relaxometer is possible. Subsequent, this work addresses the thorough investigation of the reliability of the setup. Studies show that sample temperature affects measurement results. Therefore, a calibration and temperature stabilization of the setup is mandatory. Additionally, the effect of other critical parameters as, for instance, the viscosity (which varies with temperature) or ambient light should be taken into consideration.