Wearable robotic exoskeleton for overground gait training in sub-acute and chronic hemiparetic stroke patients: preliminary results

BACKGROUND: Recovery of therapeutic or functional ambulatory capacity in post-stroke patients is a primary goal of rehabilitation. Wearable powered exoskeletons allow patients with gait dysfunctions to perform over-ground gait training, even immediately after the acute event.AIM: To investigate the feasibility and the clinical effects of an over-ground walking training with a wearable powered exoskeleton in sub-acute and chronic stroke patients.DESIGN: Prospective, pilot pre-post, open label, non-randomized experimental study.SETTING: A single neurological rehabilitation center for inpatients and outpatients.POPULATION: Twenty-three post-stroke patients were enrolled: 12 sub-acute (mean age: 43.8\ub113.3 years, 5 male and 7 female, 7 right hemiparesis and 5 left hemiparesis) and 11 chronic (mean age: 55.5\ub115.9 years, 7 male and 4 female, 4 right hemiparesis and 7 left hemiparesis) patients.METHODS: Patients underwent 12 sessions (60 min/session, 3 times/week) of walking rehabilitation training using Ekso\u2122, a wearable bionic suit that enables individuals with lower extremity disabilities and minimal forearm strength to stand up, sit down and walk over a flat hard surface with a full weight-bearing reciprocal gait. Clinical evaluations were performed at the beginning of the training period (t0), after 6 sessions (t1) and after 12 sessions (t2) and were based on the Ashworth scale, Motricity Index, Trunk Control Test, Functional Ambulation Scale, 10-Meter Walking Test, 6-Minute Walking Test, and Walking Handicap Scale. Wilcoxon's test (P<0.05) was used to detect significant changes.RESULTS: Statistically significant improvements were observed at the three assessment periods for both groups in Motricity Index, Functional Ambulation Scale, 10-meter walking test, and 6-minute walking test. Sub-acute patients achieved statistically significant improvement in Trunk Control Test and Walking Handicap Scale at t0-t2. Sub-acute and chronic patient did not achieve significant improvement in Ashworth scale at t0-t2.CONCLUSIONS: Twelve sessions of over-ground gait training using a powered wearable robotic exoskeleton improved ambulatory functions in sub-acute and chronic post-stroke patients. Large, randomized multicenter studies are needed to confirm these preliminary data.CLINICAL REHABILITATION IMPACT: To plan a completely new individual tailored robotic rehabilitation strategy after stroke, including task-oriented over-ground gait training

Comparison of corneal morphologic parameters and high order aberrations in keratoconus and normal eyes

The aim of this study is evaluating the influence of corneal geometry in the optical system’s aberrations, and its usefulness as diagnostic criterion for keratoconus.159 normal eyes (normal group, mean age 37.8 ± 11.6 years) and 292 eyes with the diagnosis of keratoconus (keratoconus group, mean age 42.2 ± 17.6 years) were included in this study. All eyes received a comprehensive ophthalmologic examination. A virtual 3D model of each eye was made using CAD software and different anatomical parameters related with surface and volume were measured. Statistically significant differences were found for all anatomical parameters (all p < 0.001). AUROC analysis showed that all parameters reached values above 0.7, with the exception of the total corneal surface area (TCSAA-S). In conclusion, the methodology explained in this research, that bases in anatomical parameters obtained from a virtual corneal model, allow to analyze the diagnostic value of corneal geometry correlation with optical aberrations in keratoconus pathology.This publication has been carried out in the framework of the Thematic Network for Co-Operative Research in Health (RETICS), reference number RD16/0008/0012, financed by the Carlos III Health Institute–General Subdirection of Networks and Cooperative Investigation Centers (R&D&I National Plan 2013–2016) and the European Regional Development Fund (FEDER)

Presbyopia:Effectiveness of correction strategies

Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states “presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements”. Presbyopia is inevitable if one lives long enough, but intrinsic and extrinsic risk factors including cigarette smoking, pregnancy history, hyperopic or astigmatic refractive error, ultraviolet radiation, female sex (although accommodation is similar to males), hotter climates and some medical conditions such as diabetes can accelerate the onset of presbyopic symptoms. Whilst clinicians can ameliorate the symptoms of presbyopia with near vision spectacle correction, bifocal and progressive spectacle lenses, monovision, translating or multifocal contact lenses, monovision, extended depth of focus, multifocal (refractive, diffractive and asymmetric designs) or ‘accommodating’ intraocular lenses, corneal inlays, scleral expansion, laser refractive surgery (corneal monovision, corneal shrinkage, corneal multifocal profiles and lenticular softening), pharmacologic agents, and electro-stimulation of the ciliary muscle, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is gives on presbyopic correction evaluation techniques

Multifractal analysis of human peripapillary atrophy

Multifractal characteristics of the retinal vascular networks in healthy patients and patients with peripapillary atrophy (PPA) are compared in the paper. Segmented and skeletonized fundus images from the DRIVE database were analyzed over the image region corresponding to the macular area and over the whole image. The regional and overall multifractal characteristics of fundi could serve as further clues in detecting human PPA and for quantifying the pathological stages of PPA cases

Shape Analysis of a Parametric Human Lens Model based on Geometrical Constraints

Several simple models, such as conicoid models, are usually adopted to describe the surfaces of the human crystalline lens; unfortunately they do not provide a continuous junction between the anterior and the posterior surface of the lens and then they cannot qualify for biomechanical simulation. Vice versa, more complex mathematical models give a continuous junction between the anterior and the posterior surface, but do not provide a geometrical or optical interpretation of the coefficients of the model. In this work we propose a continuous curvature lens model in which the coefficients are derived by geometrical constraints. In this way, both the continuity in the junction zone and a geometrical-physical interpretation of the coefficient involved in the model are obtained. Shape, volume and curvature of the proposed model were compared with four models presented in the literature: two independent conic equations, two interdependent figuring conicoid equations, conic patches model and modulated hyperbolic cosine

Using kinematic analysis to evaluate constraint-induced Movement therapy in chronic stroke patients

Objective. This preliminary study aims to verify if the method of kinematic analysis proposed here may be suitable for evaluating the effects of constraint-induced movement therapy (CIMT) in chronic stroke patients and may be of help in the study of the mechanisms underlying functional improvement following CIMT. Methods. Clinical and kinematic data were collected from a group of chronic stroke patients and from an age-matched healthy control group. Affected and less affected upper-limb kinematics related to hand-to-mouth and reaching movements were acquired before and immediately after 2 weeks of CIMT. Healthy subjects were submitted to kinematic analysis of the nondominant side and reevaluated after 2 weeks. Results. The clinical results were consistent with those reported in the literature and showed motor function improvement of the hemiparetic limb after CIMT. Kinematic data of the healthy control group showed high test-retest reliability. Statistically significant differences between the affected limb and both the less affected limb and the healthy subjects' nondominant limb were observed. After CIMT, kinematic data showed improvement in the speed of movement and in measures related to the capacity for coordination. Conclusions. The method of kinematic analysis was sensitive for an assessment of motor recovery induced by CIMT. The kinematic results suggest that the increase in the use of the paretic limb in activities of daily living after the intervention is not only attributable to the patient's increased attention to it and better hand dexterity, but it is also a consequence of the improved speed of movement and better coordination between shoulder and elbow joints. Copyright \ua9 2008 The American Society of Neurorehabilitation

Using kinematic analysis to evaluate constraint-induced movement therapy in chronic stroke patients

Objective. This preliminary study aims to verify if the method of kinematic analysis proposed here may be suitable for evaluating the effects of constraint-induced movement therapy (CIMT) in chronic stroke patients and may be of help in the study of the mechanisms underlying functional improvement following CIMT. Methods. Clinical and kinematic data were collected from a group of chronic stroke patients and from an age matched healthy control group. Affected and less affected upper-limb kinematics related to hand-to-mouth and reaching movements were acquired before and immediately after 2 weeks of CIMT. Healthy subjects were submitted to kinematic analysis of the nondominant side and reevaluated after 2 weeks. Results. The clinical results were consistent with those reported in the literature and showed motor function improvement of the hemiparetic limb after CIMT. Kinematic data of the healthy control group showed high test-retest reliability. Statistically significant differences between the affected limb and both the less affected limb and the healthy subjects’ nondominant limb were observed. After CIMT, kinematic data showed improvement in the speed of movement and in measures related to the capacity for coordination. Conclusions. The method of kinematic analysis was sensitive for an assessment of motor recovery induced by CIMT. The kinematic results suggest that the increase in the use of the paretic limb in activities of daily living after the intervention is not only attributable to the patient's increased attention to it and better hand dexterity, but it is also a consequence of the improved speed of movement and better coordination between shoulder and elbow joints