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

[76915]
Title: Implementation of a high-precision 2-D receiving coil set for {Magnetic Particle Imaging}.
Written by: M. Weber, K. Bente, M. Graeser, T. F. Sattel, and T. M. Buzug
in: <em>{IEEE} Transactions on Magnetics</em>. (2015).
Volume: <strong>51</strong>. Number: (2),
on pages: 1--4
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DOI: 10.1109/TMAG.2014.2331987
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[BibTex]

Note: article

Abstract: In the medical imaging technique magnetic particle imaging, tomographic images of the spatial distribution of superparamagnetic particles are produced in real time. To generate images in a plane, the particles are excited in two dimensions. A specific particle response can be measured via receiving coils and the measured signal gives quantitative information about the particle distribution and local concentration. To achieve a high-spatial resolution with x-space reconstruction, the receiving coils have to feature a preferably homogeneous sensitivity in the field of view. To achieve this for a cylindrical bore, which is the typical medical scenario, an optimized coil set is implemented and tested in this paper. Two orthogonal receiving coil pairs are wound inside a negative form, which is custom made by a 3-D printer. Further, a well performing receiving chain is utilized, which transmits the particle signal from the receiving coils to the data acquisition unit. For performance evaluation, a hardware phantom with three delta samples is used. A field free line is chosen as a selection field, for which the presented coils may be used in an application scenario. The receiving coils perform well in the sense that no coupling in between the data paths is apparent and the recorded signals clearly represent the used phantom.

Conference Proceedings

[76915]
Title: Implementation of a high-precision 2-D receiving coil set for {Magnetic Particle Imaging}.
Written by: M. Weber, K. Bente, M. Graeser, T. F. Sattel, and T. M. Buzug
in: <em>{IEEE} Transactions on Magnetics</em>. (2015).
Volume: <strong>51</strong>. Number: (2),
on pages: 1--4
Chapter:
Editor:
Publisher:
Series:
Address:
Edition:
ISBN:
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/TMAG.2014.2331987
URL:
ARXIVID:
PMID:

[BibTex]

Note: article

Abstract: In the medical imaging technique magnetic particle imaging, tomographic images of the spatial distribution of superparamagnetic particles are produced in real time. To generate images in a plane, the particles are excited in two dimensions. A specific particle response can be measured via receiving coils and the measured signal gives quantitative information about the particle distribution and local concentration. To achieve a high-spatial resolution with x-space reconstruction, the receiving coils have to feature a preferably homogeneous sensitivity in the field of view. To achieve this for a cylindrical bore, which is the typical medical scenario, an optimized coil set is implemented and tested in this paper. Two orthogonal receiving coil pairs are wound inside a negative form, which is custom made by a 3-D printer. Further, a well performing receiving chain is utilized, which transmits the particle signal from the receiving coils to the data acquisition unit. For performance evaluation, a hardware phantom with three delta samples is used. A field free line is chosen as a selection field, for which the presented coils may be used in an application scenario. The receiving coils perform well in the sense that no coupling in between the data paths is apparent and the recorded signals clearly represent the used phantom.