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

[76913]
Title: Receive coil optimization for an open magnetic particle imaging scanner. <em>2013</em>
Written by: W. Tenner, H. Wojtczyk, G. Bringout, M. Graeser, M. Grüttner, J. Haegele, R. L. Duschka, N. Panagiotopoulos, F. M. Vogt, J. Barkhausen, and T. M. Buzug
in: <em>3rd International Workshop on {Magnetic Particle Imaging} ({IWMPI}), IEEE Xplore Digital Library</em>. (2013).
Volume: Number:
on pages:
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/IWMPI.2013.6528336
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings

Abstract: Helmholtz-like coil pairs with a radius of 15 cm have the highest sensitivity for the given geometry. Their homogeneity decreases with higher radius, which is both shown in Fig. 4. Arrays of circular coils show very good homogeneity, which further increases with increasing number of coils, but have comparably poor sensitivity in the {FOV}. D-shaped coils have both decreasing sensitivity and homogeneity with increasing radius. An increasing distance between a D-coil pair increases the homogeneity, but leads to decreasing sensitivity. Nested D-coils can show an improved homogeneity without a loss in sensitivity. Optimized circular and not nested D-shaped coil pairs with a radius of 15 cm were manufactured and the resonance frequency for both geometries was measured to be about 1.9 {MHz} for the tight and 2.6 {MHz} for the loose winding technique.

Conference Proceedings

[76913]
Title: Receive coil optimization for an open magnetic particle imaging scanner. <em>2013</em>
Written by: W. Tenner, H. Wojtczyk, G. Bringout, M. Graeser, M. Grüttner, J. Haegele, R. L. Duschka, N. Panagiotopoulos, F. M. Vogt, J. Barkhausen, and T. M. Buzug
in: <em>3rd International Workshop on {Magnetic Particle Imaging} ({IWMPI}), IEEE Xplore Digital Library</em>. (2013).
Volume: Number:
on pages:
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/IWMPI.2013.6528336
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings

Abstract: Helmholtz-like coil pairs with a radius of 15 cm have the highest sensitivity for the given geometry. Their homogeneity decreases with higher radius, which is both shown in Fig. 4. Arrays of circular coils show very good homogeneity, which further increases with increasing number of coils, but have comparably poor sensitivity in the {FOV}. D-shaped coils have both decreasing sensitivity and homogeneity with increasing radius. An increasing distance between a D-coil pair increases the homogeneity, but leads to decreasing sensitivity. Nested D-coils can show an improved homogeneity without a loss in sensitivity. Optimized circular and not nested D-shaped coil pairs with a radius of 15 cm were manufactured and the resonance frequency for both geometries was measured to be about 1.9 {MHz} for the tight and 2.6 {MHz} for the loose winding technique.