This paper describes a set of visual tasks performed with a goal to find a correlation between observer"s preoccupation and the observation time. Several aspects of objects differentiation were investigated: shape complexity, colour, uniqueness and size. Four visual tasks were performed by 10 volunteers. The eyeball position was captured with use of the OBER 2 eyetracker based on the infrared beam reflection measurements. Finally the recorded eyeball traces were subject of statistical processing. Interesting findings are the high attractiveness of complicated shapes and no influence of object"s size on the observation time. Another result is an unexpected high inter-observers variation of attention difference in each visual task. The results play a key role in our research on perceptual model of biomedical signals and images. The other applications may be found in the area of visual information usability, ergonomics or perception-like control of automated visual systems.

In this paper an improved method for three-dimensional (3-D) surface reconstruction from computed tomography slices is presented. Marching cubes (MC) is a popular method for extracting iso-surfaces from discrete (3-D) data. We implemented a simplification of marching cubes, commonly known as marching tetrahedrons (MT).

The paper presents the analysis of mechanical properties of human hip joint bone behaviour basing on the finite elements methods (FEM). Models of a hip joint have been worked out. Stress patterns in these biomechanical systems have been determined. The examination covers the analysis of stress patterns in elaborated models for given examples of a femoral bone loading in respective walking phases. It has been stated that prediction of bone remodelling could be based on methods applied in mechanics of materials and data of a bone mineral content and bone mineral density determined by the densitometry method. The work is an attempt of the bone tissue assessment criterion approach useful in implantology problems in which the bone tissue density depends on the bone loading.

Acceleration and deceleration patterns in fetal heart rate (FHR) are widely used as an assessment of fetal condition. The basis for both visual and automated quantitative analysis is correctly determined fetal heart rate baseline. There are many methods for automated fetal heart rate baseline estimation. Since there are no definitive criteria or ‌gold standard” to evaluate algorithms for baseline determination, a clinical expert could be considered as a reference. Taking into account that not the shape of baseline itself but the results of quantitative analysis obtained using this baseline are important, we stated that such evaluation should be done only on the basis of comparison of effects - the recognized accelerations and decelerations. However, the first step for such comparison is to check how well expert meets established FIGO definition of accelerations and decelerations patterns in FHR trace. The paper presents a method for evaluation of expert’s interpretation of these definitions. Two indices describing the inconsistency among fetal monitoring system and experts have been defined. The results obtained indicate the essential differences in procedure of accelerations/decelerations recognition by the computerized system and human expert.

The paper presents an instrumentation set for effective diagnostics of early symptoms of fetal distress in high-risk pregnancy based on bioelectric signals recording. The representative database of records has been established that enabled the complex analysis of signals recorded on a surface of maternal abdomen. As an outcome, the effective algorithms have been developed for processing both the fetal electrocardiogram and the signal of electrical activity of a uterine muscle. This allowed the development of unique diagnostic system based on external biosignal measurement module connected to the standard personal computer. In this system, like in a classical fetal monitor, the fetal heart rate (FHR) signal together with contraction activity signal of uterine muscle and fetal movement become an essential source of information on fetal condition. In addition, there is a possibility for spectral analysis of FHR signal as well as a morphology assessment of fetal ECG signal.

Indirect fetal electrocardiography is a developing diagnostic method in perinatal medicine. Signals of electrical activity being recorded from maternal abdomen surface contain more information than in till now used method of mechanical heart activity measurement based on ultrasound signals. The main problem relies on separation of basic useful component from a signal containing also dominant maternal electrocardiogram and muscles activity artifacts. The algorithms of maternal electrocardiogram suppression via subtraction are commonly used. Although regarding their complexity, these algorithms have limited applicability in systems for long-term monitoring of fetal heart activity. Other solution relies on simple blanking of maternal QRS complexes. However, in case of coincidence of fetal and maternal QRS complexes, this leads to partial loss of information about fetal heart rate variability. For evaluation of how often such coincidence of both complexes takes place, the algorithm has been developed which is described in this paper.

This work concentrates on the developing a method of the contraction and polymerisation temperature testing for the surgical cement. The linear contraction and maximum polymerisation temperature values have been determined for the pure Palacos R cement and for the same cement with Al2O3 admixture. The investigations were performed into metal mould at initial temperature 19 0C and 37 0C. Basing on the examination results it can be stated that on the contraction and polymerisation temperature the following factors have the influence: - temperature of the mould, - kind of the admixture, - a size of the admixture particles.

Electrocardiography (ECG) is commonly used non-invasive procedure for recording electrical activity of the heart. It is a powerful clinical non-invasive tool for proper diagnosis and therapy of cardiac abnormalities. Thus, accurate reproduction of the ECG is required especially if diagnosis making process is supported by automatic measurements and their interpretation. The paper presents an assessment of low-frequency response of selected ECG recorders in relation to international requirements. Four recorders have been selected and tested according to IEC draft 62D: 60601-2-51/Ed.1 and the results have been discussed.

The paper describes implementation of a new technology of digital systems design in case of medical measurement interface of IMPULS system used for acquisition of ECG signal from pacemaker patients. Similarly as in other applications, the processor circuit is a base of digital system, however - regarding large number of performed tasks - it is assisted by additional peripheral logic circuits. At the beginning, there were used standard elements (logic gates, counters, registers, etc.), however a growing complexity of beyond processor operations encouraged designers to apply the programmable circuits. The paper presents the stages of digital system development that has been implemented in medical measurement interface. It is the excellent example of possibility to integrate several standard elements in one integrated circuit.

At present, in mandibular fractures surgical treatment reposition and titanium miniplates osteosynthesis is the most common method used. The treatment results are assessed on the basis of comparative analysis of two radiograms taken before and after fixations of fractures. In this article the objective method of radiological assessment of osteosynthesis is presented. The crucial part of the method is the computer program which was created at The Institute of Computer Biomedical Systems, Silesian University in Katowice. Comparison of placement of bone fragments on a pair of pantomograms taken before and after a particular surgical operation was done. To make the process of the results evaluation an objective one a new parameter - the relative dislocation coefficient - was implemented. Achieved results enable to assess correctness of bone fracture reposition on the pantomographical pictures taken twice, once before and the next time after osteosynthesis.

The article presents studies of the superelastic NiTi and shape memory TiNiCo devices for the experimental distraction of mandibular bones in young pigs. The new method of gradual bone lengthening has two variants. In the first one distraction devices make use of two U-shaped NiTi superelastic springs that are extend, with constant force, the corpus of the mandible enfeebled by the decortication. The other variant uses double Ω-shaped springs that use the shape memory effect during gradual heating by the electric current in the temperature range 40-55oC drawing the bone fragments after osteotomy. On the basis of the X-ray phase analysis and the DSC analysis the wires which after special treatment show superelasticity in ambient temperature and shape memory in the desirable temperature range of about 40 to 55oC were chosen. Prototypes of the distractors were fabricated, suitable shapes and dimensions were selected, and different ways to fix them to the bones were tested on the models. Forces of the superelastic arches generated during stretching and unloading and distraction forces of the shape memory distractors generated during the process to regain the shape while being heated by the electric current were measured. In animal experiments the operations were performed on two pigs where NiTi superelastic distraction devices and TiNiCo shape memory distractors were used and placed subcutaneously, immediately on the bone under the periosteum. As a result of animal experiments about 10 mm lengthening of the pig mandible was obtained with the use of superelastic distraction devices.

In this paper we present new method of computer text analyser and computer Polish speech (words) generator. In the described computer program the grammatical characteristics of Polish speech and accents in some words have been taken into consideration. All users’ actions are commented by artificial, computer voice. The group of blind students of University of Silesia have examined and tested the presented final program for over one year. Described software tool has in a lot of cases better parameters than others, commercial products.

In the paper an evaluation and optimisation framework for medical data access systems user interface is presented. User interface design seems to be of crucial importance for clinical data access applications acceptance, in particular for the applications running on handheld computers where the interface tools are significantly limited. The ease of program use depends strongly on the correct user interface design and on the algorithms which try to predict the user decisions and interactions made in the process of data access or modification. If the program is able to correctly predict the user actions and fetch him reasonable defaults then the number of interface actions which the user must do is significantly reduced. The method presented here focuses on typical functions available in clinical mobile data access systems: medication prescriptions and diagnostic and laboratory tests orders. The user interaction with an application is considered as the sequence of decisions. Using the records stored in the hospital database, the algorithm finds the most probable decisions at the subsequent stages of the interaction and uses it as defaults presented to the user. In this way instead of entering the data from the keyboard the user can much faster select it from the list.

The method of objective assessment of the correctness mandible bones fracture slit was proposed in the research. At present, treatment results are evaluated by comparing pantomographic pictures made before and after integration. It is not an objective method; the estimation of the integration correctness coefficient is not possible, either. The use of computer processing enables introducing the relative mandible faction dislocation coefficient. Thanks to this, measurable determination of bone faction reposition correctness on pantomograms made after osteosynthesis is possible.

Interest of the biomagnetic fields results from necessity of the using of non-invasive methods of early diagnosis of many diseases like heart attack, cerebral stroke, tumours. The magnitude of the induction of the biomagnetic fields values are in the range of 10 fT- 50 pT. SQUIDs can register the magnetic field of the induction as low as even 0,1 fT. The fundamental condition of the practical application of SQUIDs is preparation of the shields, which would protect a subject against the electromagnetic smog (the average magnitude of the magnetic induction - about 50 T). Theoretically, magnetic field oughtn’t to penetrate into superconducting materials only. Because this material must be continuous (without cracks), so it seems that only superconducting layer shields can fulfil this condition. This paper shows preliminary results of investigation on synthesis of superconducting YBCO layers by the MOCVD method on dielectric substrates.

In this paper solution of straight problem was introduced in electrical impedance tomography with help of method of junction’s potentials with utilisation of computer program "Spice”. Preliminary investigations of model were introduced based on mesh of resistance artificially disturbances of schedule of resistance. Created images of boundary potentials permit onto estimation of errors introduced through model.

This work presents new possibilities for interpreting blood pressure measurements of children and adolescents with the use of Internet. A dynamic web site allows for such interpreting and archiving blood pressure measurements in developmental age. Stored measurements results can become a basis for national pressure norm considering specificity of development of Polish children and adolescents. The interpretation system of blood pressure measurements in developmental age can be used both at school and home.

The paper describes an analysis of measuring errors that are responsible for not satisfactory conclusion quality. The analysis concerns the PSW (Parotec System for Windows) [1] equipment developed for walking abnormality diagnosis. The paper shows the analysis principles that indicate what kind of faults are acceptable, for an adequate disease classification.

Digital fundus eye images have been compressed in different standards. Diagnoses based merely on the uncompressed and compressed images have been made by independent ophthalmologists. The results concerning both the lossy and lossless compression effects and their impact on the diagnoses have been presented and discussed.

The purpose of presented work is to create a project and computer implementation of complex decision support system used in an important medical field, which is cardiology. This system is applied to support physical diagnosis concern different kinds of myocardial infraction. The system - called NEUROGEN v.01, is a kind of hybrid system, which is a combination of Genetic Algorithm (GA) and Neural Network (NN). The idea of this specific combination is that GA is used as a evolutionary method of learning of NN. In accordance with this special task, the NN is a three-layer feedforward network with eight numbers of input neurons, six numbers of hidden and five number of output neurons. The number of neurons in each layer was appointed on the base of data of the task. In this work, the purpose was to look for the optimal values of the parameters of algorithm, which are: crossover probability, mutation probability, the number of individuals in population, the number of generations of the algorithm and λ - parameter of function of activation which characterize neurons in NN. An extra task is to check if the beginning population has any influence on effectiveness of the system. In this paper there will be presented the way of rising of NEUROGEN v.01 and achieved results.