Erik Vavrinsky

Preparation of transparent conductive AZO thin films for solar cells

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).

Biomedical signal amplifier for EMG wireless sensor system

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.

Electrode configuration for EMG measurements

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.

Electrical biomonitoring towards mobile diagnostics of human stress influence

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.

Implementation of Microsensor Interface for Biomonitoring of Human Cognitive Processes

Miniaturization of biomedical sensors has increased the importance of microsystem technology in medical applications, particularly microelectronics and micromachining. This work presents a new approach to biomedical monitoring and analysis of selected human cognitive processes. The system is based on our preliminary described theory and experiments (Vavrinsky et al. 2010). We are primarily interested in biomonitoring of human cognitive processes and psychophysiological conditions of car drivers in order to enhance road safety. Actually often used method is evaluation of abnormal car driver actions (sudden changes of direction with no direction indicators or too hard cornering). Main disadvantage of such a system is that they offer no prediction. More effective are prediction systems, which offer enough reaction time before undesirable situations, and so they can minimize human error factors and improve road-traffic safety. Our present research is focused on sensing, processing and analysis of selected physiological signals for mental and medical condition recognition. They are known some studies describing interface between emotional condition and physiological responses, and we want also present some, since new ideas and research in psychological recognition and biomonitoring are very welcome. It is also proved that human decisions and reactions are affected by emotional and physical comfort. Emotional reconnoiter of a car driver conditions is influenced by many cognitive processes, such as mind organization, vigilance, planning or fatigue. Nervous and angry people can be very dangerous for traffic road safety. In our experiments, we have monitored: psycho-galvanic reflex (PGR) – skin conductivity changes, heart rate + electrocardiogram (ECG), body temperature, respiration frequency, emotions. To improve the reliability of our measurements, these parameters have been monitored often by duplicate methods, sometimes at macro level, sometimes by local microsystems technologies. In first step, we implemented our technology to the virtual reality driving simulator but preparations for real implementation have been already started, and the final car implementation will follow.

Monitoring of Psychosomatic Properties of Human Body by Skin Conductivity Measurements using Thin Film Microelectrode Arrays

This paper describes a new modification of non-invasive biomedical monitoring of psychosomatic processes. The proposed method is based on skin conductivity measurements by interdigitated array (IDA) of microelectrodes, which allows continual monitoring and analyzing of complicated physiological, pathophysiological and therapeutic processes. Main goal is to monitor psycho-galvanic reflex of the human skin in medical and psychological experiments

Novel ratio conductance electrochemical sensor based on thin film asymmetric microelectrodes

A novel asymmetric ratio resistance method has been developed to overcome the technological residual defects and imperfections. Accurate and reproducible monitoring of small differences of temperatures and concentrations is also important in biochemical sensors, e.g. calorimetric or electrochemical sensors. We have applied that new principle in the electrochemical conductometry method.

Complex measurement of human physiology using designed miniature wireless sensors

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).

Alternative methods for heart-rate sensing

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.

Monitoring of car driver physiological parameters

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 of car driver physiological parameters. The system is based on our preliminary described theory and experiments [1].