Peter Telek - Academia.edu (original) (raw)

Papers by Peter Telek

Advances in Electrical and Electronic Engineering

ECG-Derived Respiration (EDR) is a classical method for estimation of respiratory information fro... more ECG-Derived Respiration (EDR) is a classical method for estimation of respiratory information from Electrocardiogram (ECG). This method normally uses flexible electrodes located at standard electrocardiography positions. This study introduces an alternative approach suitable for miniaturized sensors with low inter-electrode separation and electrodes fixed to the sensor encapsulation. Application of EDR amplitude algorithm on a single-lead wireless sensor system with optimized electrode positions shows results comparable with standard robust systems. The modified method can be applied in daily physiological monitoring, in sleep research studies or it can be implemented in smart clothes when standard respiration techniques are not suitable. In this paper we report optimization of the positions of miniaturized device for measurement of ECG and ECG-derived respiration.

2016 26th International Conference Radioelektronika (RADIOELEKTRONIKA), 2016

Optik - International Journal for Light and Electron Optics, 2016

The Eighth International Conference on Advanced Semiconductor Devices and Microsystems, 2010

III-V diluted magnetic semiconductors materials (DMS) allow for the incorporation of ferromagneti... more III-V diluted magnetic semiconductors materials (DMS) allow for the incorporation of ferromagnetic epitaxial layers into advanced structures. In this contribution, we report on the growth of GaAs/InMnAs layers by metalorganic vapour phase epitaxy (MOVPE) over an AlGaAs/GaAs MQW light-emitting diode structure. In particular, results of electrical and structural characterization of structures are presented. We prepared a single-phase ferromagnetic In 1-x Mn x As ternary with x close to 0.075 on (100) GaAs substrates using MOVPE. The material exhibited room temperature ferromagnetic behavior with a Curie temperature close to 330K. In addition, all InMnAs ternary samples showed p-type conductivity. The ferromagnetic material was incorporated into four different AlGaAs/GaAs LED structure.

Journal of Crystal Growth, 2011

AlGaAs/GaAs light emitting diode (LED) structures with an InMnAs ferromagnetic layer were grown b... more AlGaAs/GaAs light emitting diode (LED) structures with an InMnAs ferromagnetic layer were grown by metal organic vapour phase epitaxy. Four different LED structures were studied. Their electroluminescence spectra revealed one peak at an energy of 1.467 eV in accordance with the design of the active quantum-well (QW) region. The incorporation of a 100 nm thick InMnAs layer into one of the LED structures led to a 50% decrease in the total optical output power of the LEDs compared with that of LEDs based on the QW structure that did not have InMnAs (reference structure). LEDs based on the structures with InMnAs exhibited dark currents between 1 mA and 1 mA at V R ¼ À5 V. Those based on the reference LED structure had a dark current of 20 nA. Temperature dependent magnetic measurements proved that the LED structures with InMnAs were ferromagnetic at room temperature.

Procedia Chemistry, 2012

The design of the car driver monitoring system is presented with a novel IDAT microsensor applied... more The design of the car driver monitoring system is presented with a novel IDAT microsensor applied. We have developed new thin film multipurpose microsensors (IDAT) consisting of an impedance sensor based on the interdigital array of microelectrodes which is integrated together with temperature resistive sensor on single chip. The developed microsensor allows monitoring of psychogalvanic reflex, heart pulse and skin temperature using depth impedance analysis of different skin layers by choosing the appropriate size of microelectrodes.

This paper deals with hardware and software methods, which improves wireless sensor network desig... more This paper deals with hardware and software methods, which improves wireless sensor network designed for acquiring human body biosignals. Due to defined parameters, accuracy better than 1ms is needed between samples time stamps, obtained by different wireless probes. Actually these methods are not allowed to affect data rate and performance of whole system. We used two different methods to reach this goal. The first method is based on absolute local time synchronization with respect to network topology and data flow, where ±20μs of absolute time synchronization was achieved. The second is automated software calibration of precision crystal oscillator with 10ppm accuracy, which was improved up to 0.0025ppm, what provides maximum clock error of 40 μs per 20 minutes. In this paper we introduce sensor network, describe developed synchronization methods and present partial experimental results.

Proceedings of the 4th International Symposium on Applied Sciences in Biomedical and Communication Technologies - ISABEL '11, 2011

Following paper concerns the heart rate monitoring issue. Proposed sensing methods employ standar... more Following paper concerns the heart rate monitoring issue. Proposed sensing methods employ standard sensors, designed for bio-electric signal measurement, however, they focus on sensing of different phenomenon. In order to create an integrated multipurpose sensor, suitable for detection of several characteristic bio-signals within a single device, we have researched subsidiary functionalities of few dedicated sensing devices and their principles.

Corrosion Science, 2014

The electrical Ca test is a standard method for the estimation of the water vapour transmission r... more The electrical Ca test is a standard method for the estimation of the water vapour transmission rate through the encapsulation barriers. Here, we discuss the corrosion process of thin Ca films under different preparation conditions, and the impact of the substrate temperature. It is demonstrated that without vacuum drying of substrate, the Ca films corrode from the substrate side, even though they are encapsulated. The thickness dependence revealed its influence on lifetime, but not on its electrical properties. These observations reveal the strong impact of the Ca fabrication technology and measurement procedure on the corrosion process of Ca thin films.

Procedia Chemistry, 2012

Following sensor system, described in this article is composed of portable units, intended for in... more Following sensor system, described in this article is composed of portable units, intended for in-time wireless measurement and evaluation of electrical activity, produced by skeletal muscles. It brings a lot of advantages to biomedical electronics and medical care. In order to optimize the performance of novel proposed smart biomedical instrument we have focused on measurement of the known electromyography (EMG) signal characteristics at periodic muscle motion with constant load (physical exercise). Except for very precise measurement features, which characterize this device (high gain, low noise, wireless data transfer, multi-probe measuring), some special features as low voltage and ultra-low power consumption were reached by application of the described amplifier in order to achieve its longer performance.

Synthetic Metals, 2013

Photogenerated carriers in active double-layer 3,4,9,10-perylenetetracarboxylic dianhydride/coppe... more Photogenerated carriers in active double-layer 3,4,9,10-perylenetetracarboxylic dianhydride/copper phthalocyanine (PTCDA/CuPc) organic field-effect transistor (OFET) have been investigated. The PTCDA and CuPc layers have n-and p-type conductivities, respectively; thus, PTCDA can be assumed as an acceptor and CuPc as a donor in the meaning of photovoltaic device. It has been found that the charges are generated in the bulk of the organic material rather than close to the organic-organic interface. Hence, it is suggested that exciton dissociation takes a place on the oxygen-and hydrogen-related defects in the organic film and supported by the molecular simulation of defects' energy states.

Journal of Applied Physics, 2012

Interfacial reaction-dominated full oxidation of 5nm diameter silicon nanowires J. Appl. Phys. 11... more Interfacial reaction-dominated full oxidation of 5nm diameter silicon nanowires J. Appl. Phys. 112, 094308 (2012) Enhancement and control of carrier lifetimes in p-type 4H-SiC epilayers J. Appl. Phys. 112, 064503 (2012) The origin of high surface spin-flip rate in metallic nonlocal spin valves Surface plasmon resonance of gold and silver nanoparticle (NP) layers is investigated by the experiment as well as simulations. Although the good agreement was found for gold NP film, a significant mismatch in the resonance energy for silver NP film was observed. The deviation was assigned to the presence of silver oxide (Ag 2 O) in silver NPs. As an alternative to the NP sizedependent Drude model, the analysis based on effective medium approximation for refractive index of Ag-Ag 2 O material system is carried out and compared with the core-shell model. Both Mie's model and numerical simulation results illustrate shift of the surface plasmon resonance due to silver NP surface oxidation. V C 2012 American Institute of Physics. [http://dx.

Advances in Electrical and Electronic Engineering

ECG-Derived Respiration (EDR) is a classical method for estimation of respiratory information fro... more ECG-Derived Respiration (EDR) is a classical method for estimation of respiratory information from Electrocardiogram (ECG). This method normally uses flexible electrodes located at standard electrocardiography positions. This study introduces an alternative approach suitable for miniaturized sensors with low inter-electrode separation and electrodes fixed to the sensor encapsulation. Application of EDR amplitude algorithm on a single-lead wireless sensor system with optimized electrode positions shows results comparable with standard robust systems. The modified method can be applied in daily physiological monitoring, in sleep research studies or it can be implemented in smart clothes when standard respiration techniques are not suitable. In this paper we report optimization of the positions of miniaturized device for measurement of ECG and ECG-derived respiration.

2016 26th International Conference Radioelektronika (RADIOELEKTRONIKA), 2016

Optik - International Journal for Light and Electron Optics, 2016

The Eighth International Conference on Advanced Semiconductor Devices and Microsystems, 2010

III-V diluted magnetic semiconductors materials (DMS) allow for the incorporation of ferromagneti... more III-V diluted magnetic semiconductors materials (DMS) allow for the incorporation of ferromagnetic epitaxial layers into advanced structures. In this contribution, we report on the growth of GaAs/InMnAs layers by metalorganic vapour phase epitaxy (MOVPE) over an AlGaAs/GaAs MQW light-emitting diode structure. In particular, results of electrical and structural characterization of structures are presented. We prepared a single-phase ferromagnetic In 1-x Mn x As ternary with x close to 0.075 on (100) GaAs substrates using MOVPE. The material exhibited room temperature ferromagnetic behavior with a Curie temperature close to 330K. In addition, all InMnAs ternary samples showed p-type conductivity. The ferromagnetic material was incorporated into four different AlGaAs/GaAs LED structure.

Journal of Crystal Growth, 2011

AlGaAs/GaAs light emitting diode (LED) structures with an InMnAs ferromagnetic layer were grown b... more AlGaAs/GaAs light emitting diode (LED) structures with an InMnAs ferromagnetic layer were grown by metal organic vapour phase epitaxy. Four different LED structures were studied. Their electroluminescence spectra revealed one peak at an energy of 1.467 eV in accordance with the design of the active quantum-well (QW) region. The incorporation of a 100 nm thick InMnAs layer into one of the LED structures led to a 50% decrease in the total optical output power of the LEDs compared with that of LEDs based on the QW structure that did not have InMnAs (reference structure). LEDs based on the structures with InMnAs exhibited dark currents between 1 mA and 1 mA at V R ¼ À5 V. Those based on the reference LED structure had a dark current of 20 nA. Temperature dependent magnetic measurements proved that the LED structures with InMnAs were ferromagnetic at room temperature.

Procedia Chemistry, 2012

The design of the car driver monitoring system is presented with a novel IDAT microsensor applied... more The design of the car driver monitoring system is presented with a novel IDAT microsensor applied. We have developed new thin film multipurpose microsensors (IDAT) consisting of an impedance sensor based on the interdigital array of microelectrodes which is integrated together with temperature resistive sensor on single chip. The developed microsensor allows monitoring of psychogalvanic reflex, heart pulse and skin temperature using depth impedance analysis of different skin layers by choosing the appropriate size of microelectrodes.

This paper deals with hardware and software methods, which improves wireless sensor network desig... more This paper deals with hardware and software methods, which improves wireless sensor network designed for acquiring human body biosignals. Due to defined parameters, accuracy better than 1ms is needed between samples time stamps, obtained by different wireless probes. Actually these methods are not allowed to affect data rate and performance of whole system. We used two different methods to reach this goal. The first method is based on absolute local time synchronization with respect to network topology and data flow, where ±20μs of absolute time synchronization was achieved. The second is automated software calibration of precision crystal oscillator with 10ppm accuracy, which was improved up to 0.0025ppm, what provides maximum clock error of 40 μs per 20 minutes. In this paper we introduce sensor network, describe developed synchronization methods and present partial experimental results.

Proceedings of the 4th International Symposium on Applied Sciences in Biomedical and Communication Technologies - ISABEL '11, 2011

Following paper concerns the heart rate monitoring issue. Proposed sensing methods employ standar... more Following paper concerns the heart rate monitoring issue. Proposed sensing methods employ standard sensors, designed for bio-electric signal measurement, however, they focus on sensing of different phenomenon. In order to create an integrated multipurpose sensor, suitable for detection of several characteristic bio-signals within a single device, we have researched subsidiary functionalities of few dedicated sensing devices and their principles.

Corrosion Science, 2014

The electrical Ca test is a standard method for the estimation of the water vapour transmission r... more The electrical Ca test is a standard method for the estimation of the water vapour transmission rate through the encapsulation barriers. Here, we discuss the corrosion process of thin Ca films under different preparation conditions, and the impact of the substrate temperature. It is demonstrated that without vacuum drying of substrate, the Ca films corrode from the substrate side, even though they are encapsulated. The thickness dependence revealed its influence on lifetime, but not on its electrical properties. These observations reveal the strong impact of the Ca fabrication technology and measurement procedure on the corrosion process of Ca thin films.

Procedia Chemistry, 2012

Following sensor system, described in this article is composed of portable units, intended for in... more Following sensor system, described in this article is composed of portable units, intended for in-time wireless measurement and evaluation of electrical activity, produced by skeletal muscles. It brings a lot of advantages to biomedical electronics and medical care. In order to optimize the performance of novel proposed smart biomedical instrument we have focused on measurement of the known electromyography (EMG) signal characteristics at periodic muscle motion with constant load (physical exercise). Except for very precise measurement features, which characterize this device (high gain, low noise, wireless data transfer, multi-probe measuring), some special features as low voltage and ultra-low power consumption were reached by application of the described amplifier in order to achieve its longer performance.

Synthetic Metals, 2013

Photogenerated carriers in active double-layer 3,4,9,10-perylenetetracarboxylic dianhydride/coppe... more Photogenerated carriers in active double-layer 3,4,9,10-perylenetetracarboxylic dianhydride/copper phthalocyanine (PTCDA/CuPc) organic field-effect transistor (OFET) have been investigated. The PTCDA and CuPc layers have n-and p-type conductivities, respectively; thus, PTCDA can be assumed as an acceptor and CuPc as a donor in the meaning of photovoltaic device. It has been found that the charges are generated in the bulk of the organic material rather than close to the organic-organic interface. Hence, it is suggested that exciton dissociation takes a place on the oxygen-and hydrogen-related defects in the organic film and supported by the molecular simulation of defects' energy states.

Journal of Applied Physics, 2012

Interfacial reaction-dominated full oxidation of 5nm diameter silicon nanowires J. Appl. Phys. 11... more Interfacial reaction-dominated full oxidation of 5nm diameter silicon nanowires J. Appl. Phys. 112, 094308 (2012) Enhancement and control of carrier lifetimes in p-type 4H-SiC epilayers J. Appl. Phys. 112, 064503 (2012) The origin of high surface spin-flip rate in metallic nonlocal spin valves Surface plasmon resonance of gold and silver nanoparticle (NP) layers is investigated by the experiment as well as simulations. Although the good agreement was found for gold NP film, a significant mismatch in the resonance energy for silver NP film was observed. The deviation was assigned to the presence of silver oxide (Ag 2 O) in silver NPs. As an alternative to the NP sizedependent Drude model, the analysis based on effective medium approximation for refractive index of Ag-Ag 2 O material system is carried out and compared with the core-shell model. Both Mie's model and numerical simulation results illustrate shift of the surface plasmon resonance due to silver NP surface oxidation. V C 2012 American Institute of Physics. [http://dx.