Hingeless arm for space robotics actuated through shape memory alloys

Operating outside the spacecraft via remotely controlled structures is an important opportunity in different space applications. The research in this area is focused on designing robots that are sufficiently flexible to allow inspection in locations where access is difficult or impossible for astronauts, while minimizing weight and bulk. The purpose of the research is to design a borescope for space applications with no hinges or other mechanisms, exploiting biomimetic design concepts. This is pursued by giving to the borescope a backbone exoskeleton provided by a continuous structure made of fibre reinforced composite material and using NiTi wires as tendons, taking advantage of their low weight and dimensions, which allow them to be embedded between the composite layers during the lamination process. After a study of the state of the art of flexible structures, concentrated in the medical and robotic fields, the research work unfolded in two phases. In the first design phase, several composite layup solutions were considered and analysed using finite element models, leading to the definition of the borescope geometrical parameters and to an initial estimate of the displacements that can be achieved. In the second experimental phase, seven prototypes were produced and tested, with one or more wires, to validate the design and to search for a configuration that can be actuated in different directions. The borescope prototypes resulted flexible enough to achieve an extended degree of bending and at the same time sufficiently rigid to allow complete rearm of the NiTi wires. The numerical and experimental study led to the definition of the design parameters, the number of wires, and the manufacturing technique to integrate NiTi actuators

The prevalence of vegetative and minimally conscious states: A systematic review and methodological appraisal

OBJECTIVES: To systematically review prevalence studies of vegetative state (VS) and minimally conscious state (MCS) in geographically defined populations, to appraise study methods and assess sources of heterogeneity. METHODS: MEDLINE, EBM Reviews, and EMBASE databases were searched using key terms. Two reviewers independently identified pertinent articles and screened the references for additional studies. Studies measuring the prevalence of VS and/or MCS in a defined population were included, and information on characteristics, methods, and results was extracted. Heterogeneity was quantified through the statistic I. RESULTS: We identified 5 cross-sectional prevalence surveys of VS and 1 of MCS. Prevalence ranged from 0.2 cases per 100,000 inhabitants to 3.4 for VS and was 1.5 per 100,000 for MCS. Relevant heterogeneity (I = 99.0%) prevented us from calculating a summary estimate. The prevalence of trauma cases varied from 21.9% to 53.8%. Variability pertaining to diagnostic criteria, definition of case, and methods of ascertainment was found. CONCLUSION: In the few prevalence studies of VS and MCS that were identified, the estimates showed high variability and could not be pooled. Future studies should consider using comparable methods for the definition, ascertainment, and confirmation of cases

Interference From Retrieval Cues in Parkinson's Disease

Objective: Existing studies on memory interference in Parkinson's disease (PD) patients have provided mixed results and it is unknown whether PD patients have problems in overcoming interference from retrieval cues. We investigated this issue by using a part-list cuing paradigm. In this paradigm, after the study of a list of items, the presentation of some of these items as retrieval cues hinders the recall of the remaining ones. Method: We tested PD patients' (n = 19) and control participants' (n = 16) episodic memory in the presence and absence of part-list cues, using initial-letter probes, and following either weak or strong serial associative encoding of list items. Results: Both PD patients and control participants showed a comparable and significant part-list cuing effect after weak associative encoding (13% vs. 12% decrease in retrieval in part-list cuing vs. no part-list cuing -control- conditions in PD patients and control participants, respectively), denoting a similar effect of cue-driven interference in the two populations when a serial retrieval strategy is hard to develop. However, only PD patients showed a significant part-list cuing effect after strong associative encoding (20% vs. 5% decrease in retrieval in patients and controls, respectively). Conclusions: When encoding promotes the development of an effective serial retrieval strategy, the presentation of part-list cues has a specifically disruptive effect in PD patients. This indicates problems in strategic retrieval, probably related to PD patients' increased tendency to rely on external cues. Findings in control conditions suggest that less effective encoding may have contributed to PD patients' memory performance

The validity of the hospital anxiety and depression scale and the Geriatric Depression Scale in Parkinson‘s disease

Abstract. We assessed the concurrent validity of the Hospital Anxiety and Depression Scale (HADS) and the Geriatric Depression Scale (GDS) against the Hamilton Rating Scale for Depression (Ham-D) in patients with Parkinson's disease (PD). Forty-six non-demented PD patients were assessed by a neurologist on the Ham-D. Patients also completed four mood rating scales: the HADS, the GDS, the VAS and the Face Scale. For the HADS and the GDS, Receiver Operating Characteristics (ROC) curves were obtained and the positive and negative predictive values (PPV, NPV) were calculated for different cut-off scores. Maximum discrimination between depressed and non-depressed PD patients was reached at a cut-off score of 10/11 for both the HADS and the GDS. At the same cut-off score of 10/11 for both the HADS and the GDS, the high sensitivity and NPV make these scales appropriate screening instruments for depression in PD. A high specificity and PPV, which is necessary for a diagnostic test, was reached at a cut-off score of 12/13 for the GDS and at a cut-off score of 11/12 for the HADS. The results indicate the validity of using the HADS and the GDS to screen for depressive symptoms and to diagnose depressive illness in PD

Mental Time Line Distortion in Right-Brain-Damaged Patients: Evidence From a Dynamic Spatiotemporal Task

Time is an elusive phenomenon that is difficult to grasp with our senses. Recent work has shown how spatial representations often lie beneath temporal ones, as shown by a family of spatiotemporal congruency effects. For instance, individuals who have been exposed to left-to-right orthographic systems are better at judging short durations with their left effector and long durations with their right effector than vice versa, a phenomenon known as the spatial-temporal association of response codes (STEARC) effect. In the present neuropsychological study, we aimed to provide evidence that spatial attention mechanisms play a crucial role in generating this spatially organized mental time line

Polypharmacy and the use of medications in inpatients with acquired brain injury during post-acute rehabilitation: A cross-sectional study

Background: This study assessed the use of medications during inpatient post-acute rehabilitation for acquired brain injury (ABI).Materials and methods: All inpatients with ABI undergoing post-acute rehabilitation in centres identified through the roster of the Italian Society for Rehabilitation Medicine were included. A designated physician in each centre collected information through a structured questionnaire. This study calculated (a) prevalence of medication use, (b) logistic regression Odds Ratio (OR), with 95% confidence interval (95% CI), of polypharmacy ( 65 6 medications).Results: A total of 484 patients (median age = 52 years, 63.4% men, median time from acute event = 18.5 weeks) were included; 33.8% had Rancho Los Amigos Levels of Cognitive Functioning Scale (RLAS) score 1-2, 8.1% had a score of 7-8, of whom 92.0% received medications, 51.8% had a score of 6-10, of whom 83.9% had at least one psychotropic medication and 66.9% had two or more; 51.8% received anti-epileptics, 32.1% anti-depressants, 14.5% anti-psychotics, peaking in RLAS 4 (37.3%) and decreasing in RLAS 7-8. Polypharmacy was directly associated with age (55-64 years, OR = 2.1; 95% CI = 1.1-4.1; 65 65 years, OR = 1.7; 95% CI = 0.9-3.3), inversely with RLAS score (1-2 vs 7-8, OR = 4.3; 95% CI = 1.9-9.8).Conclusion: Polypharmacy and concurrent use of psychotropic medications was common, raising concern about drug-drug interactions. Safety and effectiveness of medications should be monitored, particularly when used concurrently

Polypharmacy and the use of medications in inpatients with acquired brain injury during post-acute rehabilitation: A cross-sectional study

<p><i>Background</i>: This study assessed the use of medications during inpatient post-acute rehabilitation for acquired brain injury (ABI).</p> <p><i>Materials and methods</i>: All inpatients with ABI undergoing post-acute rehabilitation in centres identified through the roster of the Italian Society for Rehabilitation Medicine were included. A designated physician in each centre collected information through a structured questionnaire. This study calculated (a) prevalence of medication use, (b) logistic regression Odds Ratio (OR), with 95% confidence interval (95% CI), of polypharmacy (≥ 6 medications).</p> <p><i>Results</i>: A total of 484 patients (median age = 52 years, 63.4% men, median time from acute event = 18.5 weeks) were included; 33.8% had Rancho Los Amigos Levels of Cognitive Functioning Scale (RLAS) score 1–2, 8.1% had a score of 7–8, of whom 92.0% received medications, 51.8% had a score of 6–10, of whom 83.9% had at least one psychotropic medication and 66.9% had two or more; 51.8% received anti-epileptics, 32.1% anti-depressants, 14.5% anti-psychotics, peaking in RLAS 4 (37.3%) and decreasing in RLAS 7–8. Polypharmacy was directly associated with age (55–64 years, OR = 2.1; 95% CI = 1.1–4.1; ≥ 65 years, OR = 1.7; 95% CI = 0.9–3.3), inversely with RLAS score (1-2 vs 7–8, OR = 4.3; 95% CI = 1.9–9.8).</p> <p><i>Conclusion</i>: Polypharmacy and concurrent use of psychotropic medications was common, raising concern about drug–drug interactions. Safety and effectiveness of medications should be monitored, particularly when used concurrently.</p