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Biosensors

The research group Biosensors is involved in the following activities:

Research areas include diagnostic and therapeutic approaches and their closed-loop combination in portable Health Care Engineering. Electric, acoustic, optic, and magnetoelastic sensors for biomedical applications are developed, e.g., for sleep, anaesthesia, and fitness monitoring as well as for apneas detection and heart rate variability monitoring. Electrical Impedance Tomography - enhanced by computer tomography - is developed for a novel individual setting of lung ventilators. Modelling of physiological signals and systems is performed for the voluntary breath holding (apnea diving) and the associated fitness assessment. Electric auricular vagus nerve stimulation is developed to realise Point-of-Care therapy in pain and arterial disease therapy, and in triggering healing of diabetic chronic wounds. Extensive expertise is available in adaptive, multiparametric, clinically-relevant processing of hybrid biomedical signals in the time, spectral, and space domains, and in wearable hardware/software concepts for diagnostic/therapeutic biomedical devices.

Diagnostic systems

  • Electric, optic, and acoustic sensors for Point-of-Care diagnostics
  • Hybrid/multiparametric sensors for anaesthesia/sleep/fitness/pain/perfusion monitoring
  • CT-enhanced Electrical Impedance Tomography for personalized lung ventilation and monitoring of hemodynamic
  • Diving pathophysiology monitoring

Therapeutic systems

  • Electrical stimulation of auricular vagus nerve for pain/perfusion/ulcers/cerebrovascular/stroke management (feedback-based)
  • Thermal body stimulation for sleep management (feedback-based)

Advanced biomedical signal processing

  • Heart rate variability analysis (e.g., as prognostic factor for perioperative outcome)
  • Cerebral autoregulation, pulse wave analysis
  • Involuntary/voluntary apnea detection/analysis, individual perioperative fitness/reserve monitoring

Teaching projects

  • Three Springer book volumes on Biomedical Signals and Sensors I, II, III
  • Educational projects - ERASMUS coordination for two foreign universities
  • Chair of the study affairs commission for Biomedical Engineering

Industrial engagement

  • SpinOff SzeleStim GmbH

Circuit Design

The workgroup circuit design is working on integrated circuit design. There are two main research areas, on the one hand analogue integrated circuits and on the other hand optoelectronic integrated circuits.

In the area of analogue integrated circuit design the integration of analogue circuits, e.g. operational amplifiers, mixers or filters, in state-of-the art nanometer CMOS technologies is the main focus. With the ongoing shrinking of the technology the supply voltages drop as well as the characteristics of the devices gets worse and worse. These limiting conditions necessitate new concepts and innovative ideas in circuit design.

The second focus is on optoelectronic integrated circuits. The integration of photosensitive devices in CMOS and BiCMOS silicon technologies is the first step, the next one is the integration of complete optical receivers and signal processing.

Both research areas require beside careful design also the characterization of the realized microchips, which can be done in the own laboratory.

Microwave Engineering

The Microwave Engineering Group covers a variety of research areas from basic to applied research. A state-of-the-art microwave laboratory as well as a variety of circuit, system-, and electromagnetic field simulators make this possible. In the microwave laboratory, almost all types of measurements can be performed ranging from on-wafer to whole systems.

A special feature of the group is the broad knowledge of the researchers, which goes far beyond the microwave technology. This is particularly evident in the implementation of research projects with FPGA-based real-time signal processing, the design of complex microwave systems and the use of strong signal processing algorithms.

Much of the groupīs activity is focused on communication applications. In particular, the group is working on efficient, linear, and robust transceivers. On the transmission side, this includes, for example, switched mode power amplifiers; on the receiver side, the group is investigating interference-proof receivers. Basic research is currently focused on improving polyharmonic distortion (PHD)based nonlinear models.

In the field of UHF RFID, the group has extensive knowledge in the field of reader design and tag localization. As the newest research area, the Microwave Engineering Group investigates the description, modeling and emulation of interference in shared frequency bands (as part of the EFRE Interreg project InterOp).

Technical Magnetism

Research Areas

The focus of the recent activites is given by the following five fields of research:

I. Combined 2D/3D assembling of ultra-thin sensor bands (with ABB-Transformers, Sweden; FWF-project "Mag Foil Sensors)

A computer-controlled assembler is developed that allows for the manufacturing of multiple sensors on a substrate foil of about 20 µm; thickness and up to 1 m length. 2D printing technologies are combined with 3D ones, in specific ways for conducting and non-conducting print materials. Detected quantities comprise 3D magnetic induction components, mechanical strain (magnetostriction), temperature (energy losses) and vibrations. Minimum thickness of complex sensors take a advantage of thin nano-crystalline or amorphous sensor-nuclei. The detector bands are designed for flexible arrangement in machine cores at different locations, connections to electronics being arranged externally. For diagnoses of machine faults, it is planned that the detector bands remain within the core in permanent ways, to be contacted in cases of demand.

II. Experimental analyses of magnetic machine cores

The focus is put on 3D distributions of magnetic fluxes, energy losses, strains and audible noise generation in transformer cores assembled of novel laser-scribed silicon iron. We apply very different sensor types that partly are moved by a computer-controlled scanning system. This enables detailed analyses though fully-automatic over-night processing. As a main conclusion of current work, modern cores represent complex 3D systems, due to their multi-package design. The individual packages prove to be in interactions that vary with time. In comparisons to model cores, industrial cores reveal less defined mechanisms.

III. Numerical analyses of magnetic machine cores (with ABB-Transformers, Sweden) -

Apart from applying Finite Element Modelling, the focus is put on MACC (Magnetic Anisotropic Circuit Calculations), a completely novel own methodology. With very rapid processing, it yields compact numerical images of flux distributions, including data on local flux distortions and dynamic rotational magnetization. For straigt-forward optimization of the involved algorithms, the next step will be concentrated on theoretical aspects of modelling.

IV. Rotational magnetization tests (with JFE Steel Corp., Japan, and Nippon Steel & Sumitomo Metal Corp., Japan) -

Rotational magnetization enhances both losses and audible noise in all three transformers, shunt reactors and rotating machines. With a world-wide unique hexagonal Rotational Single Sheet Tester (RSST), we characterize novel types of materials, e.g. of minimum thickness, with novel stress coatings, or for compact motors that are specifically designed for electro-mobility. The industrially relevant results of the RSST concern time patterns of induction vector and field vector, energy losses, magnetostriction and domain configurations.

V. To-be-standardized magnetic metrology (with ABB-Transformers, Sweden, and voestalpine Linz) -

Since more than hundred years, energy losses of magnetic materials are determined by means of testers that simulate complete magnetic circuits. In particular, this is valid for Single Sheet Testers and Epstein Frame Testers. In recent theoretical work, we found that these IEC-standardized testers exhibit systematic errors, since not considering dynamic changes of instantaneous flux distributions. We now developed a concept for a novel methodology that should enable "physically correct" results, actual demand coming from severe world-wide energy politic and from electro-mobility. The final target is to suggest the method for international standardization.

THz Electronics

Research Activities Overview:

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