Research Topics

Elevated temperature is the dominant cause of electronic systems failures, accounting for 55% of them. Thus, there is a need for thermal characterization of electronic circuits. One of main methods of describing their thermal properties is the thermal impedance approach. The mathematical foundations for such measurements were laid down in the JEDEC JESD51 standards series. A system for thermal impedance measurements using a fast, single detector IR sensor was designed and tested, along with dedicated software for thermal characterization of electronic circuits, based on upper surface temperature measurement.

Explosive and poisoned gases leakage causes the danger for people both in industry and at home. The example is the methane in coal mines. The imaging systems presenting the distribution of gas concentration from a distance is the alternative for widely-used single detector sensors. Moreover, due to the warming effect, climate changes and environment protection, there is a growing interest of using remote gas imaging systems. We do both the research and developments in this field. As the example, the high-sensitive bolometer cameras we have successfully used for detection methane, ammonia and carbon dioxide (CH4, NH3, and CO2).

Thermal management is one of the most important issues for electronic devices producers. The market of electronic devices grows very fast as well as power densities dissipated in electronic components. Dimensions of the devices and their packages are getting smaller. Electronic devices are operating well in specified range of temperature. Overheating of electronic elements leads to their shorter lifetime, malfunction (e.g. logic errors in microprocessors) or even immediate breakdown. As the result of above pointed facts, there is a need to design and produce advanced cooling systems that would fulfil the thermal management requirements in a superior way.

Fiber optics are used as various sensors of different physical quantities for years. Distributed measurement systems are ones of the very promising applications of fiber optics today. Huge interest of fiber optics results from the amount of valuable information optical fibers can deliver. The environmental changes around the optical fiber cause changes of the optical fibers’ parameters, such as attenuation, dispersion, refractive index and light scattering. Optical fiber-based measurements systems are becoming popular due to the low cost, immunity to electromagnetic interferences, durability and high sensitivity.

For years, radiation temperature measurement was the classical application of IR thermography. Nowadays, we observe new, the unconventional use of this technique in numerous domains for indirect process monitoring and measurement. One of the example of such application is the RMS electrical current measurement in outdoor power cables with eliminated effect of convective cooling and solar radiation. Furthermore, there is a need of measuring distributions of temperature changes at the very low level, below the noise limits of today’s IR systems.

Artificial Magnetic Conductor (AMC) structures [1, 2] also known as High Impedance Surface (HIS). One of most interesting application of AMC is in the design of efficient and low-profile antennas [3–7]. Currently known AMCs are inherently frequency-selective and suffer from narrow band property which limits their applications in wideband or multiband antenna applications. The particular area of interest in this study is the investigation into the possibility of employing automatic optimization of elementary AMC cell geometry to tune its frequency characteristics i. e. its center frequency and bandwidth.

Metamaterials have become a very active research area because of the possibility of creating materials which exhibit unusual EM responses not attainable with natural materials. Some application examples are in superlensing, cloaking, artificial magnetic conductance and more generally, coordinate transformation material design [1]. To realize such functionalities, periodic or semi-periodic arrays of resonant structures such as split-ring resonators (SRRs) have been successfully used [2]. Metasurfaces can be successfully analyzed using full electromagnetic simulation. Unfortunately, however numerical simulations are methods of high computational complexity, and need a long time to computing.

Electromagnetic fields cannot be controlled inside a real, homogeneous material. However, these fields can be controlled by changing a local value of effective permeability and/or permittivity. It's may be done by use a some periodic structures (unit cell). Transformation optics (TO) [5–7] is one technique for designing periodic structures that are macroscopically inhomogeneous. The TO technique takes a spatial transform as the input, applies it to Maxwell's equations, pulls the transform out of the spatial coordinates and incorporates it into the constitutive parameters. Next step is generating the geometry of spatially variant lattices. This is a big challenging because the electromagnetic properties of the lattice depend on the size, direction and shape of the unit cells. Also often require adjacent unit cells to be the same, and shapes changing should be continuous, without distortion. This structure may be made (printed) by 3D printer.

Echolocation is the ability to perceive one’s environment using reflected sounds. Many blind persons have and train this ability, although normally sighted persons can also learn to utilize it. As part of a completed GameInn project the echolocation skills of blind adults, sighted adults and blind children were compared in various tests: static and mobile, indoor and outdoor, in an echoic and in an acoustically padded environment. Results of real life tests were also compared to binaural recordings made with a dummy microphone and virtual audio renders.

The main objective of the computer vision based sensory substitution systems designed for visually impaired users is to provide the representation of their surroundings with the use of alternative senses. After processing and encoding, visual information is conveyed to the user via one of the intact senses, rather than through the regular visual pathway which is highly degraded or interrupted.

Building an electronic travel aid (ETA) is a difficult interdisciplinary challenge. In this work we demonstrate how to build a simple model of 3D scenes for the purpose of presenting the environment nonvisually to the visually impaired.

Human–System Interaction (HSI) is currently actively pursued as a separate research field dedicated to the development of new technologies facilitating human communication with systems. Depending on the application, such interaction systems are also referred to as Human–Computer Interfaces (HCI) or more generally human–machine interfaces. The purpose of the research is to develop a hands-free head-gesture controlled interface that can support persons with disabilities to communicate with other people and devices, e.g. the paralyzed to signal messages or the visually impaired to handle electronic travel aids.

Cardiovascular diseases are the leading cause of death worldwide. Their prevention and treatment require accurate, noninvasive and personalized diagnostic techniques. At present, the leading technique is magnetic resonance (MR) tomography. It allows acquisition of three-dimensional images of blood filling the vessels and tissues, without use of contrast agents or X-ray radiation.

The visually impaired indicate limited mobility as one of the main problems affecting almost all activities of daily living. In this work we demonstrate how the technique of interactive sonifcation can be applied in a simple travel aid for the blind. We use the so-called depth images and their histograms termed "U-depth" which are simpler for auditory representation of the environment to the blind user.

Nowadays, a healthy, active lifestyle is more and more important to us. Many people use sports watches or fitness bands to plan their workouts. This type of devices usually collect data such as number of steps and heart rate. In the case of heart rate signal the accuracy of the data recorded from optical sensors is of key importance. Conducted research include development of methods for preprocessing and analysis of heart rate signal recorded using of non-invasive techniques, as well as for the determination of time-frequency parameters. Another aspect concerns development of methods for visualization of patterns occurring in time series in relation to heart rate variability, which may carry important information about the patient's health.