Andžela Šešok

Physico-Mathematical Simulation of a Homogeneous Thermal Field of Multichannel Raster Matrixes for Sensors of Oxygen

In the paper, an opportunity for the development of multichannel transcutaneous raster matrixes for sensors of oxygen on the basis of an electrochemical cell sensor is described. An analysis of the influence of heat sources on the distribution of the temperature pattern of a raster matrix for sensors of oxygen had been carried out, and their optimum configuration had been found. The application of such matrixes will enable one to obtain information about the distribution of the partial pressure of oxygen from the skin cover of the object of research in dynamics, to assess its functional health pattern in a more comprehensive way and to control the effect of possible remedial actions.

INVESTIGATION OF THE DYNAMICS OF BODY OXYGEN STATUS UPON LIMITED LOADS

This paper discusses the dynamics of oxygen partial pressure in intercellular fluid upon a limited load and a subsequent post-ischemic hyperemia in healthy individuals and individuals with vascular pathologies of the lower limbs. Within the framework of the phenomenological approach, which takes into consideration the qualitative peculiarities of the gas exchange processes in the body, a formal theory describing the dynamics of oxygen (O2) concentration dependently on the conditions of blood supply to the tissues has been developed. It was shown that certain parameters, for instance the relaxation time upon the conditions of artificial ischemia and the characteristic time of return of spontaneous blood circulation in the post-ischemic period, depend on the degree of pathology of the vascular system and may be used for assessing the functional status of a biological body.

BIOMECHANICAL COMPARISON OF THE CORACOCLAVICULAR SPACE FIXATION USING THREE DIFFERENT SUTURE TECHNIQUES

Coracoclavicular space fixation with suture loops is a well-known surgical technique for the treatment of dislocations. However, out of 100 different surgical treatments no single one has been established as a gold standard. The following research aims to improve the technique and focuses on a development of new fixation technique using composite sutures, which would withstand forces during ligament healing process. Three different fixation techniques (one loop and two separate suture loops and W-system) were tested on a custom built mechanical testing device. Applied load was continuously increased at a loading rate of 30N/min until the failure of the sutures. Ultimate tensile strength and suture elongation at failure were measured. The W-system had statistically significant higher load to failure and higher stiffness compared to one loop and two separate loops techniques. Biomechanical properties of a suture fixation technique can be improved by connecting them into one system to create particular arrangement of the sutures. The measurements can be easily repeated and this testing protocol can serve as a good starting point to standardize procedures of evaluation of different joint fixation techniques and to develop new ones.

Experimental Research of the Durability and Wearing of UHMWPE with Different Coatings

In the paper UHMWPE coating with different materials is analysed. Such coatings are made using magnetron sputtering method. The friction tests of these coatings are accomplished. SPM surface morphology images of coatings are analysed before and after the friction test. It was determined that Co+TiO2 coating altered the least after the friction tests. For this reason, its durability and wear resistance is the highest in comparison with all the analysed coatings.

ORTOPEDINIŲ ĮDĖKLŲ ĮTAKOS SLĖGIO PASISKIRSTYMUI PĖDOJE TYRIMAS

The article examines the influence of individual orthopaedic inserts on pressure distribution in the foot. Feet deformations, types of orthopaedic inserts, materials and pressure in the foot testing methods are discussed. Experimental computer measurements of pressure in the foot before and after the use of inserts have been done. During research, the inserts made of different kinds of materials selected according to human weight, pathology, skin sensitivity and many other reasons has been used. It has been determinated that orthopaedic inserts have a more noticeable impact on children whose feet is adjusted easier if compared with those of adults.

Investigation into Influences of Visual Apparatus Sensor and Executor Characteristics on the Quality of Information Transmission to Sensory Organs

Analysis into the effects of parametric characteristics of visual aid on the perception level of information transmitted has led to the possibility of examining and determining the quality of the reading level as a function of certain parameters of a digital apparatus (sensor), the distance to the text, the size of letters and the intensity of light. Efforts have been made to evaluate the effect of the specifications of the executor as well as the information transfer (by tactile way) speed onto the sensory organs of the disabled person at the perception level. A choice has been made of rational information transfer speeds and appropriate visual aid characteristics to facilitate an adequate perception level.