Project 1.1: Sensors and Wideband Processing of Sensor Signals

Background 

A smart environment, which is the point of departure for ELIKO's research, cannot function without fundamental processes such as data acquisition, signal processing, communication and testing. Research in sensors and wide band, joint time-frequency processing of sensor signals (with applications in medicine, biology, electrochemistry, energy management, material testing, data communications, and context aware systems) with its both theoretical and practical aspects is the key field of interest in ELIKOs research into smart environment. The emphasis is on its properties of energy preservation, robustness, reliability and optimized task specific merger of different aspects to acquire new desired properties.

The work is scientifically lead by Prof. Mart Min and is focused on research of signal processing algorithms and methods, as well as in testing of them in practical implementations. Our work evolves around impedance measurement where the group has made multiple pioneering inventions and has acquired several international patents. Impedance (and not only electrical) is an essential property of materials and substances (electrochemical cells, composition of alloys, fermentation processes and bacterial cultures) interacting with environment. As an example: knowledge regarding electrical bioimpedance ultimately coupled with micromodels for cells and macromodels for blood flow, energy balance of the body, work done by the heart, lungs and other organs allows us to characterize life processes from cellular level to tissues, organs, and eventually in the whole of a human being and ultimately enables achievement of truly disruptive technological results for creation of better, non invasive, ubiquitous, reliable and cost effective diagnostic apparatus for medicine. On a more general note similar data acquisition and processing methods to electrical impedance measurement can be used everywhere where the process flow is impeded by the environment, being it geotechnical engineering or economy.

Focus of the project

Effective data acquisition through the task specific sensor signal processing and data interfacing, for getting a seamless ubiquitous information system from sensing nodes to the end users.

Implementations

Medical diagnosing of life processes in cells, tissues, organs, the whole body, and the technical diagnose of properties of materials and substances, like electrochemical cells, composition of alloys, fermentation processes, bacterial cultures, etc.

Three main tasks:

1. To develop original and more efficient algorithms that are in use today for simultaneous multi-signal impedance measurement in biology and medicine. More precisely, in micro-fluidic devices and cardiovascular monitors.

2. Design and applicability investigation of different spectrally engineered excitation signals in ultra-wideband impedance spectroscopy for material testing tasks, including the biomaterials like cells and droplets.

3. Testing and demonstration of application efficiency of novel signal processing tools and hardware design methods.

Subtasks:

Development of alias-free signal processing methods for mixed analog/digital processing of wideband sensor signals.

Expected results: original patent pending methods, software and hardware for generating and processing of wideband signals.

Possible implementations:  multisensory systems in the fast sonar system and in wideband lab-on-chip analyzer of cells and cell cultures.

Low-complexity hard- and software for implementing novel digitizing and processing methods of impedance- and biomedical signals.

Expected results:  FPGA based application specific signal processors, original patent pending embedded solutions.

Possible implementations: impedance based devices for battery and fuel /solar cell testing; medical devices, which are based on optical and impedance sensing for early discovering of atherosclerosis and edema, also for monitoring of dialysis.

Multi-sensor systems with minimized number of ubiquitous sensors for gathering biological, medical and other information

Expected results:  Principles for the development of context aware sensor systems based on optical, electrical and impedance sensing; wideband and dependable data communication methods connected with urban environment measurement tasks.

Possible implementations:  home healthcare system; smart city systems, (test-platform based on the street lighting system in the city of Tartu); car driver health monitoring systems.

Dissemination

The group mostly publicizes in IEEE Transactions on: Instrumentation & Measurement, Bio-medical Engineering and Biomedical Circuits & Systems. Moreover it has also publicized in Physiological Measurement (IOP), Sensors and Actuators, and Measurement (both Elsevier). Yearly presentations are made at the IEEE Instrumentation & Measurement and Biomedical Engineering Society Conferences, also at the World Congress - Medical Physics and Biomedical Engineering, etc. 

For more specific dissemination results, see section on Research Results.

Demonstrators

Bioimpedance measurement and signal processing platforms.

Street lighting system developed for the City of Tartu.