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

[145078]
Title: Receive path calibration to exchange system matrix data of different receivers.
Written by: M. Graeser, P. Szwargulski, F. Förger, F. Thieben, P. Ludewig, T. Knopp
in: <em>International Journal on Magnetic Particle Imaging</em>. (2020).
Volume: <strong>6</strong>. Number: (2),
on pages: 1-3
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.18416/IJMPI.2020.2009044
URL: https://journal.iwmpi.org/index.php/iwmpi/article/view/278
ARXIVID:
PMID:

[www] [BibTex]

Note: inproceedings

Abstract: In Magnetic Particle Imaging the determination of the system matrix is a time-consuming process. As the transfer function differs depending on the electronics of the receive chain, a system matrix recorded with one chain cannot be used for reconstruction of measurement data using a different receive chain. This leads to huge amounts of data as system matrices have to be recorded for every set of drive field strength, particle system and receiver chain setting. In this paper the complexity of this is reduced by the factor of the receiver electronics. For each receive path of our MPI system the transfer function is recorded and stored on the measurement device. When loading the data, the transfer-function is corrected which allows the exchange of the system matrices data between receiver chains. To demonstrate this system matrix data is compared and a successful reconstruction of an in vivo dataset is shown.

Conference Proceedings

[145078]
Title: Receive path calibration to exchange system matrix data of different receivers.
Written by: M. Graeser, P. Szwargulski, F. Förger, F. Thieben, P. Ludewig, T. Knopp
in: <em>International Journal on Magnetic Particle Imaging</em>. (2020).
Volume: <strong>6</strong>. Number: (2),
on pages: 1-3
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.18416/IJMPI.2020.2009044
URL: https://journal.iwmpi.org/index.php/iwmpi/article/view/278
ARXIVID:
PMID:

[www] [BibTex]

Note: inproceedings

Abstract: In Magnetic Particle Imaging the determination of the system matrix is a time-consuming process. As the transfer function differs depending on the electronics of the receive chain, a system matrix recorded with one chain cannot be used for reconstruction of measurement data using a different receive chain. This leads to huge amounts of data as system matrices have to be recorded for every set of drive field strength, particle system and receiver chain setting. In this paper the complexity of this is reduced by the factor of the receiver electronics. For each receive path of our MPI system the transfer function is recorded and stored on the measurement device. When loading the data, the transfer-function is corrected which allows the exchange of the system matrices data between receiver chains. To demonstrate this system matrix data is compared and a successful reconstruction of an in vivo dataset is shown.