Visual neuroprosthesis: present and future perspectives.

The purpose of this study is to provide an overview of the replacements used in lost vision in the form of the bionic eye, to show their deficiencies and outline other possibilities for non-invasive stimulation of functional areas of the visual cortex. The review highlights the damage not only to the primary altered cellular structures, but also to all other horizontally and vertically localised structures. Based on the results of a large number of functional magnetic resonance imaging and electrophysiological methods, the authors focus on the pathology of the entire visual pathway in pigmentary retinopathy (PR) and age-related macular degeneration (AMD). This study provides a recent overview of the possible systems used to replace lost vision. These range from stimulation with intraocular implants, through stimulation of the optic nerve and lateral geniculate nucleus to the visual cortex. The second part deals with the design of image processing technology and its transformation into the form of transcranial stimulation of undamaged parts of the brain, which is protected by a patent. This is comprehensive overview of the current possibilities of replacement of lost vision and a proposal for a new non-invasive methods of stimulation of functional neurons of the visual cortex.

Objectivization of vacuum-compression therapy effects on micro- and macrovascular perfusion in type 2 diabetic patients.

The present study aimed to evaluate the characteristic influence of physical therapeutic procedures of vacuum-compression therapy (VCT) on microvascular perfusion (MiP) and macrovascular perfusion (MaP) of the lower limb in diabetic patients. A sample of nine patients with a medical history of type 2 diabetes was used for the purpose of this study. Most of the subjects' medical conditions included venous and neurological complications of the lower limb, whereas the rest of the subjects entered the treatment due to injury recovery or their phlebological disease. The PeriFlux System 5000 (Perimed, Sweden) diagnostic device was used to measure MiP. The MaP was evaluated based on the perfusion index (PI) using the Extremiter monitoring device (Embitron, Czech Republic) designed to perform VCT procedures. The study found that MiP and MaP increase as an effect of VCT procedures and at the same time PI clearly reflects the effect of the applied vacuum and compression phases, verifying the method's vital influence on peripheral perfusion disorders.

Biofeedback Based Home Balance Training can Improve Balance but Not Gait in People with Multiple Sclerosis.

BACKGROUND: Impaired balance is common in people with multiple sclerosis (MS) and can be present even in those with a mild disability level. With increasing disability, gait, and balance impairment progress, and lead to increased risk of falls. In some recent studies, interactive commercial video games were used for improving balance, but their limitation is their lack of individual training parameter settings needed for rehabilitation purposes. The aim of this study was to evaluate the feasibility and effect of balance exercise in the home setting using the rehabilitation Homebalance® system. METHODS: A single-centre, controlled, single blind study with allocation to intervention group or to control group was utilised. Participants were assessed at baseline, after four weeks of home-based balance training, and follow-up after four weeks. The primary outcomes were the Berg Balance Test (BBT). The secondary outcome measures included the Mini-BESTest, Timed Up, and Go Test (part of Mini-BESTest), and spatio-temporal gait parameter evaluation using the GAITRite instrument. The patient reported outcomes (PRO) included the 12-Item MS Walking Scale, Activities-specific Balance Confidence Scale, and the Falls Efficacy Scale. RESULTS: A total of 39 people with Multiple Sclerosis (10 men) were enrolled into the study. The mean age of participants was 40.69 ± 10.2 years, with a mean disease duration 14.76 ± 9.1 years and mean disability level 3.8 ± 1.9 EDSS (EDSS range 1.5-7). Statistically significant improvements within the home exercise group were present for the BBT and the Mini-BESTest. This improvement was more significant in the subgroup with moderate and higher disability (EDSS 4.5-7). All other gait parameters and PRO did not show any improvement. Follow-up assessment after four weeks showed that the reached improvement persisted for a short time period after finishing the regular training regimen. CONCLUSION: In comparison with no intervention, a short-term programme of home-based balance training using Homebalance® improved balance but not gait performance in a group of people with MS. It seems that home-based balance training tailored according to individual needs by a physiotherapist may be a future approach to consider for telerehabilitation of people with MS.

Postural Stability Evaluation of Patients Undergoing Vestibular Schwannoma Microsurgery Employing the Inertial Measurement Unit.

The article focuses on a noninvasive method and system of quantifying postural stability of patients undergoing vestibular schwannoma microsurgery. Recent alternatives quantifying human postural stability are rather limited. The major drawback is that the posturography system can evaluate only two physical quantities of body movement and can be measured only on a transverse plane. A complex movement pattern can be, however, described more precisely while using three physical quantities of 3-D movement. This is the reason why an inertial measurement unit (Xsens MTx unit), through which we obtained 3-D data (three Euler angles or three orthogonal accelerations), was placed on the patient's trunk. Having employed this novel method based on the volume of irregular polyhedron of 3-D body movement during quiet standing, it was possible to evaluate postural stability. To identify and evaluate pathological balance control of patients undergoing vestibular schwannoma microsurgery, it was necessary to calculate the volume polyhedron using the 3-D Leibniz method and to plot three variables against each other. For the needs of this study, measurements and statistical analysis were made on nine patients. The results obtained by the inertial measurement unit showed no evidence of improvement in postural stability shortly after surgery (4 days). The results were consistent with the results obtained by the posturography system. The evaluated translation variables (acceleration) and rotary variables (angles) measured by the inertial measurement unit correlate strongly with the results of the posturography system. The proposed method and application of the inertial measurement unit for the purpose of measuring patients with vestibular schwannoma appear to be suitable for medical practice. Moreover, the inertial measurement unit is portable and, when compared to other traditional posturography systems, economically affordable. Inertial measurement units can alternatively be implemented in mobile phones or watches.

Evaluation of the effect of heel lift on postural stability and symmetry of muscle activity.

BACKGROUND: Although a leg length inequality (LLI) has the effect on the performed movement, more complex indices for the evaluation of kinematic variables of postural stability and a symmetry of a muscle activity during standing in subjects with the LLI were never used before. OBJECTIVE: The objective is to present appropriate parameters for an evaluation of kinematic variables of postural stability and muscle activity during standing, i.e. to consider EMG signals, in patients with LLI. METHODS: New indices are offered, such as a sway velocity (i.e. the mCTSIB method) and a modified symmetry index (SI), for a quantitative evaluation of EMG signals. The set of data for evaluating the effect of a heel lift was measured on patients with the LLI and healthy volunteers. RESULTS: Prior to the heel lift application, significant statistic differences were found between the mCTSIB of patients and the CG. These differences were no longer statistically significant after the heel lift was applied. As for the SI, the lowest values were found in the CG, while the greatest values were collected among patients before applying the heel lift. CONCLUSIONS: The results point out the benefits of using the newly applied indices in patients with the LLI. Both methods may become useful tools for the evaluation of the physical state of patients with the LLI in a medical practice.

Volume of confidence ellipsoid: a technique for quantifying trunk sway during stance.

The position of the trunk can be negatively affected by many diseases. This work focuses on a noninvasive method of quantifying human postural stability and identifying defects in balance and coordination as a result of the nervous system pathology. We used a three-degree-of-freedom orientation tracker (Xsens MTx unit) placed on a patient's trunk and measured three-dimensional (3-D) data (pitch, roll, and yaw) during quiet stance. The principal component analysis was used to analyze the data and to determine the volume of 3-D 95% confidence ellipsoid. Using this method, we were able to model the distribution of the measured 3-D data (pitch, roll, and yaw). Eight patients with degenerative cerebellar disease and eight healthy subjects in this study were measured during stance, with eyes open and eyes closed, and statistical analysis was performed. The results of the new method based on the 3-D confidence ellipsoid show that the volumes related to the patients are significantly larger than the volumes related to the healthy subjects. The concept of confidence ellipsoid volume, although known to the biomechanics community, has not been used before to study the postural balance problems. The method can also be used to study, for example, head and pelvis movements or alignments during stance.

Metal alloys in the oral cavity as a cause of oral discomfort in sensitive patients.

OBJECTIVE OF THE STUDY: The occurrence of galvanism with its heterogeneous symptomatology is often the source of considerable problems. Abrasion and corrosion not only damage dental alloys but also burden the organism by release of metallic particles. The objective of this study is to evaluate the hypothesis that measurement of galvanic currents could be a useful diagnostic method. PATIENT GROUPS AND METHODOLOGY: Three hundred fifty-seven persons with dental metal restorations were divided into groups according to abnormal values of galvanic currents and by oral discomfort. In all persons a detailed examination of the oral cavity was performed, and galvanic currents were measured. In one hundred fifty-nine patients abnormal galvanic currents were found. Measurement of metallic elements in saliva was performed in these patients and in a group of 21 healthy volunteers without any metals in the oral cavity. Thirty-three patients agreed to treatment which involved removal of the causative alloys and their replacement by non-metallic restorations. RESULTS: No correlation was found between the values of measured currents and the number of teeth treated by metal restorations. However, patients with metal restorations had significantly higher contents not only of mercury, but also of tin, silver, copper, and gold in the saliva than patients without metallic restorations. After removal of the electro-active restorations, both the contents of metals in saliva and galvanic currents decreased in comparison with the levels before the treatment. CONCLUSIONS: Galvanic effects as well as metal particles may induce a series of local or systemic pathological phenomena in sensitive individuals. The occurrence of pathologically acting galvanic effects is influenced not only by the composition and combination of different dental alloys, but to a significant degree also by the quality of used materials and processing.