Search

Currently available human stress monitoring devices are either very inaccurate or rely on a strictly controlled laboratory environment. In this paper, we present the novel concept of a practical portable device for long-term monitoring of human stress in natural environment and an algorithm for calculation of the stress phenomenon. The concept envisages two synchronized blocks measuring a wider range of physiological parameters. One device will be placed on the forearm or fingers of the non-dominant hand, the other on the chest.

This article describes modern wireless sensor devices and their application in the measurements of the human physiology. We used our own advanced ECG Holter device and EEG helmet to record the heart and brain activity impacted by different environments, materials, colors or body positions during work. In this paper, we want to show the interactions between humans and architecture design, which modify human work performance and well-being. This paper is a conclusion of the 3 different pilot studies, where different scopes of human-space interaction were explored. In the experiments, we aimed mostly at wood materials and their beneficial effects on the nervous system. The research in its actual state is primarily focused on optimizing the methods of the ECG data analysis from our Holter device and the EEG data from helmet. Based on these data, we will improve the methodology of the experiments for the next enhanced research with aspiration to automate data analysi

Porous silicon (PSi) is a semiconductor produced by a dissolution p-type silicon wafers in hydrofluoric acid (HF) solution by applying a positive potential to a silicon electrode. We investigate the effect of etching time on morphology, structure and photoluminescence of PSi produced by a solution of hydrofluoric acid (HF) and methanol without UV irradiation. We found that surface structure depends strongly on etching time. From Fourier transform infrared spectroscopy and grazing incidence X-ray diffraction we suggest formation towards less-ordered amorphous phase of PSi. All samples reveal red-band photoluminescence. Although we observe different morphology of samples (channel-like morphology versus nanometer-sized hillocks morphology) slight effect on PL active structures (small red shift) was observed. We suggest that source of luminescence in our experiment is hydrogenated amorphous silicon structures and various HySiOx complexes. We cannot rule out the effect of SixFyO complexes. Surface morphology has small effect on photoluminescence.

A classical method for estimation of respiratory information from electrocardiogram (ECG), called ECG - derived respiration (EDR), is using flexible electrodes located at standard electrocardiography positions. This work introduces an alternative approach suitable for miniaturized sensors with low inter-electrode separation and electrodes fixed to the sensor encapsulation. Application of amplitude EDR algorithm on 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 studies or implemented in smart clothes when standard respiration techniques are not suitable.

The paper presents the application of natural materials, especially wood, which are relevant for human well-being in built environments of health, social, and day care facilities. These properties were tested by a complex methodology in a case study in the wooden waiting room at National Oncology Institute in Bratislava. In this space, experimental tests of physiological responses were further executed on 50 volunteers moving in the waiting room for 20 min. In this article, the EEG (electroencephalograph) (four persons) and emotions from the faces of all our volunteers before entering and after a stay in a wooden waiting room were recorded. Specifically, the ECG (electrocardiograph), heart rate (HR), and respiration activity were measured by using our own designed ECG holter (40 persons), and also blood pressure and cortisol levels were observed. The usage of wooden materials verifies their regenerative and positive impact on the human nervous system, through the appealing aesthetics (color, texture, and structures), high contact comfort, pleasant smell, possibility to regulate air humidity, volatile organic compound emissions (VOC-emissions), and acoustic well-being in the space.

This article describes successive development of electrodermal activity monitoring sensor system. Our aim is to improve existing systems to be more practical and suitable for long-term monitoring. Therefore, compared to conventional devices, our system must be easily wearable, without limiting the examined person in ordinary life, with low power consumption, battery operated and reducing the impact of negative artefacts. Specifically, we describe here three devices. The first is serving mainly to familiarize with the methodology, extensive testing and optimization of measurement parameters. Based on the obtained result, we constructed second system in form of small ring - "EDA ring". Last sensor system is developed with the effort to integrate the monitoring of electrodermal activity in e-health and smart clothes.

In this paper, we describe an application of modern wireless sensors in monitoring of physiological parameters during interaction between humans and environment design. Our goal was not only to record these interactions but also to optimize the methodology of measurement and evaluation.

Zinc oxide (ZnO) and aluminium-doped zinc oxide (ZnO:Al) thin films were prepared by RF diode sputtering at varying deposition conditions. The effects of negative bias voltage and RF power on structural and optical properties were investigated. X-ray diffraction measurements (XRD) confirmed that both un-doped and Al-doped ZnO films are polycrystalline and have hexagonal wurtzite structure. The preferential 〈0 0 1〉 orientation and surface roughness evaluated by AFM measurements showed dependence on applied bias voltage and RF power. The sputtered ZnO and ZnO:Al films had high optical transmittance (>90%) in the wavelength range of 400–800 nm, which was not influenced by bias voltage and RF power. ZnO:Al were conductive and highly transparent. Optical band gap of un-doped and Al-doped ZnO thin films depended on negative bias and RF power and in both cases showed tendency to narrowing.

The paper deals with simultaneous psychological application of two biosensor probes developed by two research groups. The first biosensor “Biosense” measures human surface biopotentials (namely cardiac activity (ECG)) and physical activity (acceleration). The second sensor “EDA-ring” measures resistance of human skin, so called electro-dermal activity (EDA).

This paper explains problematic of EMG (electromyography) signal measurements. Described experiments are partition of complex project “MEDISYS” dedicated to design of modern medical equipment, consisting the latest technologies and IC. The design is based on low noise wireless measurement block (for ECG, EMG and EEG monitoring) followed by actuator block with mechanical constructions and control electronic.

This work presents differential amplifier designated as a part of modular biomedical sensor system (MBSS) used for EMG (electromyography) signal measurements. Except the standard features which characterize this type of device (high gain, low noise), some special requirements comprising very low supply voltage and low power consumption could be reached by application of the described amplifier. The amplifier provides switch-able 60/80dB gain at 15 Hz – 1kHz frequency bandwidth. A fourth order anti-aliasing filter for next processing block (AD converter) is included as well.

Miniaturization of biomedical sensors has increased the importance of microsystem technology in medical applications, particularly microelectronics and micromachining. This paper presents a new approach to biomedical monitoring and analysis of selected human cognitive processes. The proposed technique measures human skin conductivity and heart rate using a dedicated measurement system which offers continuous bio-monitoring in a completely safe and non-invasive manner. This technique also has no undesired influence on natural physiological processes. The main goal is monitoring of the psycho-galvanic reflex (PGR) of the human skin that might be very useful for human stress diagnosis that is performed in different medical as well as psychological experiments.

This paper presents a new approach of the non-invasive biomedical monitoring of selected psychosomatic processes. The proposed method measures human skin conductivities (psycho-galvanic reflex - PGR) using the interdigitated array (IDA) of microelectrodes as well as skin temperature and skin reflectance using optical spectrometer, which will allow continual monitoring and analysis of complicated physiological and therapeutic processes. The psychological test was focused on short-time stress situation with a large scale of tasks.

A study of the effect of technology parameters (sputtering power, substrate temperature and post-deposition annealing) on structural, electrical and optical properties of aluminium-doped zinc oxide (AZO) thin films was carried out. The optimal technology parameters of preparation were found to get necessary properties of AZO thin films for application in solar cells - the high figure of merit (F ges 4 %/Omega), low electrical sheet resistance (Rs les 10 Omega/square) and high optical transmittance (T ges 82%, including the glass substrate).

Transparent conductive oxide thin films (indium tin oxide, zinc oxide and Al doped zinc oxide) were prepared by RF diode sputtering. Selected properties of these films (structure, resistivity and transparency) were investigated with the aim to use them in thin film solar cells.

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.

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.