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Above-knee amputation severely reduces the mobility and quality of life of millions of individuals. Walking with available leg prostheses is highly inefficient, and poor walking economy is a major problem limiting mobility. Here we show that an autonomous powered hip exoskeleton assisting the residual limb significantly improves metabolic walking economy by 15.6 [plus or minus] 2.9% (mean [plus or minus] s.e.m.; two-tailed paired t-test, P = 0.002) in six individuals with above-knee amputation walking on a treadmill. The observed metabolic cost improvement is equivalent to removing a 12-kg backpack from a nonamputee individual. All participants were able to walk overground with the exoskeleton, including starting and stopping, without notable changes in gait balance or stability. This study shows that assistance of the user's residual limb with a powered hip exoskeleton is a viable solution for improving amputee walking economy. By significantly reducing the metabolic cost of walking, the proposed hip exoskeleton may have a considerable positive impact on mobility, improving the quality of life of individuals with above-knee amputations. In individuals with above-knee amputation, a powered hip exoskeleton, which reduces the metabolic cost of walking by adding energy at the hip joint, greatly improves walking economy and has the potential to improve mobility., Author(s): Marshall K. Ishmael [sup.1] , Dante Archangeli [sup.1] , Tommaso Lenzi [sup.1] Author Affiliations: (1) Department of Mechanical Engineering and Robotics Center, University of Utah, Salt Lake City, USA [...]

Background: Acanthamoeba keratitis (AK) is ever more frequently reported in industrialized countries. The loss of the corneal surface integrity consequent to secondary microtrauma produced by the use of contact lens (CL) favors the penetration of the parasite into the corneal tissue. Objectives: A scientific review was performed to investigate the association of CL wear as an Acanthamoeba keratitis (AK) risk factor. Methods: A computerized screening of 7834 Medline articles (4623 from PubMed; 3211 from Scopus) used a strict selection criteria of case-control studies involving CL wear and/or trauma. Results: The search yielded five case-control studies published from 1995 to 2012. All studies included showed a statistically significant positive association between AK and CL use, with a combined odds ratio (OR) of 10.21 (95%, confidence intervals [CI]; 3.57-27.64). Statistical analysis: All studies included showed a statistically significant positive association between AK and CL use, though with differing OR values. Conclusion: Though rare, AK should be held in higher consideration when ophthalmologists are faced with CL users exhibiting simplex-like lesions associated with circular stromal infiltrates and disproportionate ocular pain in respect to the objective clinical picture. [ABSTRACT FROM AUTHOR]

Background: This randomized double-blind study examined the use of a new anesthetic agent, levobupivacaine 0.5%, which is the S(-)-enantiomer of a racemic mixture of bupivacaine, for peribulbar anesthesia and compared it with racemic bupivacaine 0.5% alone or in combination with hyaluronidase 10 IU/mL. Methods: A total of 160 patients undergoing ophthalmic surgery were randomized into four groups (n = 40 each) to receive inferotemporal peribulbar injection of levobupivacaine 0.5% (group L), racemic bupivacaine 0.5% (group B), levobupivacaine + hyaluronidase 10 IU/mL (group LH), or racemic bupivacaine + hyaluronidase 10 IU/mL (group BH) by two anesthetists and two ophthalmologists in a ratio of 25% each. Ocular akinesia and orbicularis oculi function were evaluated using a three-point scale; a value < 5 points was considered as requiring surgery, and movements were re-evaluated the day following surgery to confirm regression of the block. Results: The time to onset (12 ± 2.6 minutes versus 13 ± 2.8 minutes) and duration of anesthesia (185 ± 33.2 minutes versus 188 ± 35.7 minutes) were similar between groups L and B. Complete akinesia (score 0) was obtained more frequently when hyaluronidase was used in addition to the anesthetic, with occurrences of 72.5% versus 57.5% in group LH versus L, respectively, and 67.5% versus 45% in group BH versus B. Moderate hypotension (,30% of baseline) was observed in four patients (10%) in group L, two (5.0%) in group B, one (2.5%) in group LH, and three (7.5%) in group BH. The time to onset was significantly different between groups L and BH, B and BH, and LH and BH, and the duration of anesthesia differed significantly between groups B and LH, B and BH, and L and LH. The akinesia score differed significantly between groups L and LH and between groups B and LH (P = 0.043 and P = 0.018, respectively), and the number of patients with a score of 0 differed significantly between groups B and LH and between groups B and BH (P = 0.004 and P = 0.017, respectively). Conclusion: Levobupivacaine is a long-lasting local anesthetic with limited cardiotoxicity and neurotoxicity, and may be considered the landmark for vitreoretinal surgery in elderly patients. [ABSTRACT FROM AUTHOR]

Electromyographical (EMG) signals have been frequently used to estimate human muscular torques. In the field of human-assistive robotics, these methods provide valuable information to provide effectively support to the user. However, their usability is strongly limited by the necessity of complex user-dependent and session-dependent calibration procedures, which confine their use to the laboratory environment. Nonetheless, an accurate estimate of muscle torque could be unnecessary to provide effective movement assistance to users. The natural ability of human central nervous system of adapting to external disturbances could compensate for a lower accuracy of the torque provided by the robot and maintain the movement accuracy unaltered, while the effort is reduced. In order to explore this possibility, in this paper we study the reaction of ten healthy subjects to the assistance provided through a proportional EMG control applied by an elbow powered exoskeleton. This system gives only a rough estimate of the user muscular torque but does not require any specific calibration. Experimental results clearly show that subjects adapt almost instantaneously to the assistance provided by the robot and can reduce their effort while keeping full control of the movement under different dynamic conditions (i.e., no alterations of movement accuracy are observed). [ABSTRACT FROM PUBLISHER]