Catálogo de publicaciones - libros

The aim of the paper is to present new experimental results while using a tracking system for the assessment and training of grip force control in patients with neuromuscular diseases. In conjunction with the Jebsen-Taylor hand test the Grip Force Tracking System proved to be a valuable tool to assess hand dexterity and to quantify the hand rehabilitation process in stroke patients.

The article presents the IRIS Home. IRIS is an acronym for Independent Residing enabled by Intelligent Solutions. It is planned as a demonstration apartment located at the Institute for rehabilitation in Ljubljana. It will be fitted with the latest equipment, technical aids and rehabilitation technology. The aim of the IRIS home is demonstration, testing and application of contemporary technological solutions that compensate for the most diverse kinds of disabilities and thereby improve the quality of life of persons with disabilities and assure their optimal occupational, educational and social integration in society.

Biofeedback method to alter breathing pattern in patients with COPD during physical activity was evaluated. Respiratory muscles EMG was reliably detected during exercise. The relaxation of abdominal muscles in expiratory phase was tested. There was no significant difference between different abdominal muscles activation. In conclusion, the present study showed that the EMG technique is reproducible and sensitive enough to assess changes in respiratory abdominal muscle activity and breathing patterns in patients with COPD.

There is a lack of objective measurement methods for assessing upper limb prosthetic use in adults and children. The aim of the present study was to find out whether haptic interface could be used for that purpose. Fifty-five adults and twenty-three children were included into the study. All were tested by UNB observational test and haptic interface, and they filled in one or two questionnaires. Haptic interface showed differences between hands and prostheses, the results depended on the age of a child or adult and correlated with the amputation level and the stump length. Correlations were also found among the results of haptic interface, UNB test and questionnaires. It was not demonstrated that the results of haptic interface depended on the time from amputation to fitting with the first prosthesis, or amputation of the dominant hand. It was not possible to test subjects after shoulder disarticulation or very high trans-humeral amputation. Haptic interface seems a promising tool for assessing upper limb prosthetic use in adults and children after trans-radial amputation.

To design a customized prosthesis that is tailored to the size and the shape of a unique anatomy provides better medical treatments and outcomes along with improved comfort and quality of life for patients. In this paper an innovative approach to spine implant design is proposed which relies on freeform modeling software and a haptic interface. The system mimics working on a physical replica of the patient’s spine and allows the user to model a prosthesis which might represent a promising concept to fix a curved vertebral column.

Current state of the art in virtual environment development allows different levels of immersion, from graphical environments, where only visual information is conveyed to the user, to haptic environments, where whole set of visual and kinesthetic information is conveyed to the user. This paper presents results of two experimental sets conducted one in a haptic virtual environment (HVE) and second in a graphical virtual experiment (GVE). The grip force response to a haptic or visual cue is investigated and compared. Although the underlying neural control mechanism triggered by haptic or visual cue are different, both responses are well pronounced, have similar shape and can thus be compared. Response triggered by the haptic cue has shorter delay, is stronger and shorter in duration in comparison to the response triggered by the visual cue.

The aim of our work was to design a method for assessment and training of human hand dexterity while manipulating an object. A virtual environment was used to display a target object in various poses. The target poses were first recorded for a single person – a virtual trainer. The poses of a real object, held by the subjects included in the investigation, were assessed by a motion tracking device and displayed within the virtual environment. The subjects were asked to align the 3D images of real object and the target object. The target poses were normalized with respect to the different sizes of arms and hands. In this way all subjects were able to reach the desired target postures. Satisfactory repeatability of hand movements was observed in a single subject and across a group of twelve unimpaired subjects.

Based on a simple robotic toolkit, we have developed a robotic arm control system to be used as a humanoid benchmark for testing trajectory planning models and control hypotheses for both reaching and corrective movements during reaching. The developed system integrates visual sensory feedback of the end-effector of the arm allowing controlling its movement online. The system may operate in 1) open-loop configuration providing the servos at the joints of the robot one point of an initially planned trajectory every 20 ms; 2) correction closed loop configuration using visual feedback only for planning the corrective movement trajectory or 3) continuous closed loop configuration using initial conditions derived from visual feedback information and computing the next trajectory point at every time step. Although the planning and control of reaching movements has been extensively investigated, not much is know on the planning of corrective movements. The research tool we developed will be used to implement and test different trajectory planning and movement control models.

The purpose of this study was to examine the ventilatory, gas exchange, oxygen saturation and heart rate response to reduced breathing frequency during an incremental bicycle exercise. Eight healthy male subjects performed an incremental bicycle exercise test on an electromagnetically braked cycle ergometer twice: first with continuous breathing (CB), and second with reduced breathing frequency (B10), which was defined as 10 breaths per minute. As work rates increased, significantly higher VE, Vco and R were measured during the exercise with SB than during the exercise with B10. Consequently, PETco and PETo2 were higher and lower, respectively, during the exercise with B10 than during the exercise with SB at 150 W. In addition, HR was greater during the exercise with SB than during the exercise with B10; significant differences were achieved at 90, 120 and 150W. However, Vo showed no significant difference between the exercises in two different breathing conditions. In summary, reduced breathing frequency during the incremental bicycle exercise decreased V and consequently decreased So and increased PETco. However, it seemed that this degree of breathing reduction did not influence on aerobic metabolism due to unchanged Vo.

Changes in EMG signal spectral parameters of some arm muscles were monitored during 100 m maximum front crawl swimming. MNF linearly decreased at approximately the same extent in all observed muscles during swimming and no plateau of stabilized MNF values was observed at the end of swim. Yet, when normalized with respect to the endurance level MNF value obtained with the 90-second maximal voluntary isometric contraction after swimming, some differences between the analyzed muscles were shown.