Catálogo de publicaciones - libros

Multichannel devices are used for deep brain stimulation in patients suffering from Parkinson’s disease. A non invasive method to inspect each single output of these devices was applied in 12 patients. The clinician programmer indicates an electrode impedances beyond standard values in these patients or a non explainable loss of the therapeutic effect was given. A small device was developed to measure and display the stimulation impulse via surface electrodes. The results from the measurement pointed at an incorrect measurement by the programmer in 9 cases, broken electrode leads in 2 patients and an IPG failure in 1 patient. Leads and IPG was exchanged and inspected by light or electron microscopy. Each failure prognosis was confirmed by these examinations. The non invasive measurement of the stimulation pulse via surface electrodes turned out as an easy and accurate method for the detection of incomplete IPG malfunctions.

We present advantages of the “intelligent matrix electrode” for providing selective correction of drop-foot in hemiplegic individuals. The matrix electrode which integrates stimulating and sensing parts could allow the emulation of the appropriate electrode shape and size; thereby, provision of selective stimulation that leads to functional movement and online adaptation of the electrode during the application. The need for selective stimulation follows recent findings about therapeutic effects of electrical stimulation in neurorehabilitation. The matrix electrode comprises small fields that can be made conductive and a controller that allows computerized selection of the fields being conductive. Here we present results from a study in nine hemiplegics. The matrix electrode was positioned over the peroneal nerve and primary dorsiflexor muscles and we estimated the movement of the foot by measuring the ankle joint angle. We found that the branched tree type shape and size of the electrode vary substantially when stimulating over the dorsiflexor muscles individuals in the study. We confirmed very high sensitivity to the position of small electrode when stimulating over the nerve.

The technique of magnetic stimulation of nerve fibres represents a new direction of research in modern medicine. This study starts from a major limitation of the coils used for magnetic stimulation: their inability to specifically stimulate the target tissue, without activating the surrounding areas. The first goal of this study was to determine the optimal configuration of coils for some specific applications and evaluate the distribution of the electric field induced. Once the coil configuration established, we address other issues that need to be solved: achieving smaller coils, reducing power consumption (the low efficiency of power transfer from the coil to the tissue is a major drawback) and reducing coil heating.

The objective of this study was to investigate the capability of Force Sensitive Resistors (FSR) to characterize perturbations of gait produced by electrically evoked withdrawal reflexes. Reflexes were evoked by cutaneous electrical stimulation at 4 locations on the sole of the left foot and delivered at 3 different phases in early swing. Force changes were measured by 4 FSR's attached to each foot. The vertical ground reaction force was estimated by summing the force signals for each foot separately. Response measures were mean peak force and peak slope evaluated in 5 gait sub-phases immediately after the stimulus: 1^st double support, 1^st right single support, 2^nd double support, 1^st left single support and 3^rd double support. The results showed that perturbation of gait could be detected by the selected features and that stimulation led to a weight shift from the ipsilateral to contralateral leg starting with a more rapid unloading of the ipsilatteral leg, supported by a rapid loading of the contralateral leg in the 1st double support.

This paper presents a two-level control strategy for bipedal walking model that accounts for implicit control of push-off and power absorption on the between-step control level and tracking of imposed holonomic constraints on kinematic variables via feedback control on within-step control level. The proposed control strategy was tested in a biologically inspired model with minimal set of segments that allows evolution of human-like push-off and power absorption. We evaluated the performance of the biped walking model in terms of how variations in torso position and gait velocity relate to push-off and power absorption. The results show that the proposed control strategy can accommodate to various trunk inclinations and gait velocities in a similar way as seen in humans.

Our knowledge on altered neurocontrol of walking due to weakness of various muscle groups of lower extremities is still limited. The aim of this study was to assess kinematic and kinetic walking patterns in a functionally similar group of seven subjects with spinal muscular athrophy, type III (SMA group) and compare them with normal data obtained in nine healthy subjects (CONTROL group) in order to identify characteristic compensatory changes. Kinematic and kinetic patterns were assessed during free walking of a SMA and CONTROL groups. The results showed characteristic changes in ankle plantarflexion moment and associated control of centre of pressure during loading response and midstance that facilitated minimization of external flexion moment acting on the knee and hip in SMA group. Additionally, we identified distinct and consistent changes also in the control of hip rotators and abductors that act in a way to rapidly bring hip in the extension early in the stance phase and delay weight shift onto the leg entering the stance phase, respectively.

In this paper we outline an interactive electronic book that teaches high school students about human locomotion. Today the most common teaching methods are lectures or reading a static textbook where the student’s participation is passive and they do not engage in the learning process. When learning about human gait, students not only learn anatomy and kinesiology but also have the opportunity to grasp theoretical subjects such as mathematics, physics, biomechanics as well as concepts of modeling and simulation to carry out experiments. In this paper we outline an interactive electronic book where the student becomes engaged in the learning processes, they can add/remove text, images, video, create models and perform simulation in one environment. The Gait E-book combines the theoretical lecture with the interactive learning process of modeling and simulation. Two different simulation platforms will be supported in the E-book, OpenModelica and OpenSim. Modelica is a powerful modern equation based simulation language where students can focus on learning mathematical and physical behavior.

Functional electrical stimulation (FES) training of paralyzed muscles is effective for incomplete spinal cord injured patients in the early period of the rehabilitation process. Information of lower limb joint angles and gait phases are very important to assist walking and to restore motor function with FES. It is considered that a small and inexpensive gyroscope is useful to construct a practical sensor system in clinical. In this paper, we examined the simultaneous measurement method of the lower limb joint angles and the gait phases by using the gyroscopes. From the result of the walking analysis with normal subjects, it was indicated that the sensor system could measure the joint angles with sufficient accuracy and could detect practicably the swing phase and the stance phase without mistake. Therefore, the sensing system of lower limb condition with appropriate accuracy that could be used in clinical would be constructed compactly at inexpensive by using the gyroscopes.

Within the post genomic era a new type of medicine was born: “personalized medicine”. It makes it possible to study how to synthesize new drugs for the treatment of different kind of diseases at the individual level. It is necessary to handle a large amount of data coming from genomics and proteomics analysis. For this purpose we propose a way to make data available in a standardized format, using the international standard HL7. Another important topic is the link between clinical and genomics/proteomics data to have a general view in order to facilitate their analysis.

Today can be noticed the rash development of medicine and pharmacy. Nowadays appears the necessity of modernizations in systems of medical and pharmaceutical information of the post-USSR countries because of the wide range of diseases, methodic of treatment and quantity of available drugs on the markets. Existing systems in modern circumstances, in conditions of limited labor and financial resources, and large implantation of evidence-base medicine, often can’t effectively satisfy the requirements of population and health professionals in medical and pharmaceutical information. The work was based on the study of Ukrainian project Doctor.UA. Introducing of Doctor.UA is scheduled in several stages. First of all in January, 2003 was opened fouryears test project, which was the part of corporative site of the company (http://apteka-doctor.com). It was named Pre- Doctor.UA and it in simplified form modeled Doctor.UA. During first decade of January, 2007 the results of activity of Pre- Doctor.UA were drew up. For deciding given tasks was analyzed following information: statistics systems, usabilitytesting, interviewing the visitors.