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  • Author: Branislav Hučko x
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Simulation of Upper Limb Movements

Simulation of Upper Limb Movements

The paper deals with controlling an upper limb prosthesis based on the measurement of myoelectric signals (MES) while drinking. MES signals have been measured on healthy limbs to obtain the same response for the prosthesis. To simulate the drinking motion of a healthy upper limb, the program ADAMS was used, with all degrees of freedom and a hand after trans-radial amputation with an existing hand prosthesis. Modification of the simulation has the exact same logic of control, where the muscle does not have to be strenuous all the time, but it is the impulse of the muscle which drives the motor even though the impulse disappears and passed away.

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Glaucoma vs. Biomechanical Properties of Cornea

Abstract

The paper deals with the influence of various biomechanical parameters on the intraocular pressure (IOP). The IOP is a very important factor in more accurate diagnosis and better management of glaucoma. To get a more realistic value of IOP the measurement methodology must reflect the patient’s individual biometric and biomechanical parameters, for example age, sex, race, biomechanical properties of cornea, etc. Many measuring methods are based on the applanation of cornea during its loading by the measuring device - tonometers. These tonometers apply the Imbert – Fick law [1], which determines their size. This work also addresses the current approaches to creating more realistic IOP data.

Open access
The Effects of Piezoelectricity Matrix Constants on the Charge of a Thin Membrane

Abstract

This article is devoted to the comparison of the influence of the piezoelectric matrix properties on the magnitude of the resulting charge when a thin piezoelectric membrane of circular cross section, made from aluminium gallium nitride (Al-GaN), is loaded. The size of change of the electric charge was determined by the numerical analysis and the by the change of the properties of the piezoelectric matrix. The matrix constants were obtained from various sources introduced in world databases.

Open access
Dedicated to Dr. H. C. Mult. Prof. Ing. František Trebuňa, CSC. on the Occasion of his 70th Birthday

Abstract

The article deals with the contribution of Dr.h.c. mult. prof. Ing. František Trebuňa, CSc to the field of engineering. Born in 1947, he studied and subsequently remained at the Faculty of Mechanical Engineering, Technical University of Košice since 1965. Under his leadership 25 dissertation theses were defended in the study programs Applied mechanics, Mechatronics and Forensic engineering. He is author to 14 monographs, 16 textbooks, 5 other books, 12 university textbooks and more than 350 original scientific papers published in domestic and foreign journals and conference proceedings. Professor Trebuňa is currently the dean at the faculty and is known as a gifted educator.

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Force Analysis of Bench Press on Stable and Unstable Base

Abstract

The contribution reviews current technologies for the measurement of performance in athletes during stationary exercise and validates the technology utilizing accelerometry. The behaviours of force during the bench press exercise on a stable and unstable base are reviewed and the results are presented. It was found that, training on an unstable base can be exploited by athletes to maximize their performance.

Open access
Experimental Device for Determining Deviations in the Thoracolumbar Part of the Human Back

Abstract

The article deals with the design and construction of an experimental device for measuring deviations in the thoracolumbar area of the human back. The article describes the devices construction, processing of measured data in the program MATLAB and the interpretation of the data in the form of a 3-D model. From this experimental device we would like to contribute to existing measuring devices with similar accuracy albeit in a more compact and user friendly package, which doesn’t require a high degree of qualification to operate.

Open access
Postural Response Signal Characteristics Identified by Method of Developed Statokinesigram

Abstract

Human postural system is taken as complex biological system with specific input and output time characteristics, in this study. Evaluation of measured output characteristics is useful in medical diagnostics or in describing postural system disorders. System theory principle provide suitable basis for postural signals analysis. Participating volunteers were instructed to maintain quiet upright stance posture on firm support surface of stabilometric platform for 60s. Postural system actuation was realized by vibration stimuli applied bilaterally on Achilles tendons for 20s. Postural reaction signal, its time profile and static and dynamic characteristics were evaluated by Method of Developed Statokinesigram Trajectory (MDST).

Open access
ANALYSIS OF PIEZOELECTRIC MATERIALS FOR IMPLANTABLE DEVICES

Abstract

The article deals with the analysis of piezoelectric materials and their possible application as alternative sources of electrical energy in implantable devices. Materials composed of GaN, ZnO, CdS and PZT-4 were considered under this study. The samples had three fundamental geometry which was a circle, square and rectangle with maximum area of 20 mm2 and thickness of 0.1 mm. After considering the criterion for biocompatibility an analysis was done in software ANSYS which output voltage values. The most suitable piezoelectric material was found to be Gallium Nitride with a circular shape.

Open access
Ultrasonic Defect Detection of Structural Plates Using Quasi-Rayleigh Waves

Abstract

This article discusses the application of so-called ultrasonic quasi-Rayleigh waves to detect surface defects of mechanical constructions, namely plate structures. The application of quasi-Rayleigh waves allows the extension of the scope of detection using conventional ultrasonic methods that are based on bulk waves. This extension means larger distances as well as higher sensitivity of the detection of surface defects such as fatigue or corrosion cracks. An advantage of this method is the transfer of wave energy from one side of a plate to another, which helps to overcome one-sided obstacles (such as cross-pieces, reinforcement elements). The article describes characteristic properties of quasi-Rayleigh waves that are important for the proper (in terms of frequency in particular) design of the excitation of waves towards the structure. FEM simulation results then provide information regarding the sensitivity of the wave response to the presence and sizes of surface defects (perpendicular slots) in an isotropic material with the properties of steel. The theoretical knowledge is set against experimental measurements obtained with the use of a steel plate with cross-pieces welded to it.

Open access