Visual cues added to a virtual environment paradigm do not improve motor arrests in Parkinson's disease.

Objective. Elucidating how cueing alleviates freezing of gait (FOG) in Parkinson's disease (PD) would enable the development of more effective, personalized cueing strategies. Here, we aimed to validate a visual cueing virtual environment (VE) paradigm for future use in e.g. neuroimaging studies and behavioral studies on motor timing and scaling in PD patients with FOG.Approach. We included 20 PD patients with FOG and 16 age-matched healthy control subjects. Supine participants were confronted with a VE displaying either no cues, bars or staircases. They navigated forward using alternate suppression of foot pedals. Motor arrests (as proxy for FOG), and measures of motor timing and scaling were compared across the three VE conditions for both groups.Main results. VE cues (bars and staircases) did not reduce motor arrests in PD patients and healthy control subjects. The VE cues did reduce pedal amplitude in healthy control subjects, without effects on other motor parameters.Conclusion. We could not validate a visual cueing VE paradigm to study FOG. The VE cues possibly failed to convey the necessary spatial and temporal information to support motor timing and scaling. We discuss avenues for future research.

Understanding the impetus for major systems change: A multiple case study of decisions and non-decisions to reconfigure emergency and urgent care services.

OBJECTIVE: The optimal organisation of emergency and urgent care services (EUCS) is a perennial problem internationally. Similar to other countries, the Health Service Executive in Ireland pursued EUCS reconfiguration in response to quality and safety concerns, unsustainable costs and workforce issues. However, the implementation of reconfiguration has been inconsistent at a regional level. Our aim was to identify the factors that led to this inconsistency. METHODS: Using a multiple case study design, six case study regions represented full, partial and little/no reconfiguration at emergency departments (EDs). Data from documents and key stakeholder interviews were analysed using a framework approach with cross-case analysis. RESULTS: The impetus to reconfigure ED services was triggered by patient safety events, and to a lesser extent by having a region-specific plan and an obvious starting point for changes. However, the complexity of the next steps and political influence impeded reconfiguration in several regions. Implementation was more strategic in regions that reconfigured later, facilitated by clinical leadership and "lead-in time" to plan and sell changes. CONCLUSION: While the global shift towards centralisation of EUCS is driven by universal challenges, decisions about when, where and how much to implement are influenced by local drivers including context, people and politics. This can contribute to a public perception of inequity and distrust in proposals for major systems change.

Perspectives on the underlying drivers of urgent and emergency care reconfiguration in Ireland.

BACKGROUND: There is an increasing tendency to reconfigure acute hospital care towards a more centralised and specialised model, particularly for complex care conditions. Although centralisation is presented as "evidence-based", the relevant studies are often challenged by groups which hold perspectives and values beyond those implicit in the literature. This study investigated stakeholder perspectives on the rationale for the reconfiguration of urgent and emergency care in Ireland. Specifically, it considered the hypothesis that individuals from different stakeholder groups would endorse different positions in relation to the motivation for, and goals of, reconfiguration. METHODS: Documentary analysis of policy documents was used to identify official justifications for change. Semi-structured interviews with 175 purposively sampled stakeholders explored their perspectives on the rationale for reconfiguration. RESULTS: While there was some within-group variation, internal and external stakeholders generally vocalised different lines of argument. Clinicians and management in the internal stakeholder group proposed arguments in favour of reconfiguration based on efficiency and safety claims. External stakeholders, including hospital campaigners and local political representatives expressed arguments that focused on access to care. A "voter" argument, focused on the role of local politicians in determining the outcome of reconfiguration planning, was mentioned by both internal and external stakeholders, often in a critical fashion. CONCLUSION: Our study adds to an emerging literature on the interaction between a technocratic approach to health system planning advocated by clinicians and health service managers, and the experiential "non-expert" claims of the public and patients.

Daily-life monitoring of stroke survivors motor performance: the INTERACTION sensing system.

The objective of the INTERACTION Eu project is to develop and validate an unobtrusive and modular system for monitoring daily life activities, physical interactions with the environment and for training upper and lower extremity motor function in stroke subjects. This paper describes the development and preliminary testing of the project sensing platform made of sensing shirt, trousers, gloves and shoes. Modular prototypes were designed and built considering the minimal set of inertial, force and textile sensors that may enable an efficient monitoring of stroke patients. The single sensing elements are described and the results of their preliminary lab-level testing are reported.

Vibro- and electrotactile user feedback on hand opening for myoelectric forearm prostheses.

Many of the currently available myoelectric forearm prostheses stay unused because of the lack of sensory feedback. Vibrotactile and electrotactile stimulation have high potential to provide this feedback. In this study, performance of a grasping task is investigated for different hand opening feedback conditions on 15 healthy subjects and validated on three patients. The opening of a virtual hand was controlled by a scroll wheel. Feedback about hand opening was given via an array of eight vibrotactile or electrotactile stimulators placed on the forearm, relating to eight hand opening positions. A longitudinal and transversal orientation of the array and four feedback conditions were investigated: no feedback, visual feedback, feedback through vibrotactile or electrotactile stimulation, and addition of an extra stimulator for touch feedback. No influence of array orientation was shown for all outcome parameters (duration of the task, the percentage of correct hand openings, the mean position error, and the percentage deviations up to one position). Vibrotactile stimulation enhances the performance compared to the nonfeedback conditions. The addition of touch feedback further increases the performance, but at the cost of an increased duration. The same effects were found for the patient group, but the task duration was around 25% larger.

Nonspecific vasodilatation during transdermal iontophoresis-the effect of voltage over the skin.

We used laser Doppler perfusion imaging (LDPI) to study nonspecific vasodilatation during iontophoresis. In iontophoresis studies, nonspecific vasodilatation occurs as a result either of galvanic currents or of the applied voltage over the skin. We made dose-response measurements to study the effect of ionic strength of the vehicle on the nonspecific vasodilatation during iontophoresis of sodium chloride and deionized water, while we monitored the voltage over the skin. We found that anodal and cathodal ionotophoresis induced a voltage over the skin that was dependent on the ionic strength of the test solution. The nonspecific vasodilatation during anodal iontophoresis was less pronounced than during cathodal iontophoresis, and was independent of the voltage over the skin. The nonspecific vasodilatation in cathodal iontophoresis was related to the voltage over the skin, and was possibly mediated by depolarization of local sensory nerves. In experiments using cathodal iontophoresis, therefore, the ionic strengths of the vehicle and the drug are important when vasoactive drugs are examined, as the nonspecific vasodilatation needs to be controlled for. As the vasodilatation that we observed was heterogeneously distributed within the area of iontophoresis, LDPI may provide more accurate measurements than conventional laser Doppler perfusion monitoring.

Measurement of depth of burns by laser Doppler perfusion imaging.

Laser Doppler perfusion imaging (LDPI), is a further development in laser Doppler flowmetry (LDF). Its advantage is that it enables assessment of microvascular blood flow in a predefined skin area rather than, as for LDF, in one place. In many ways this method seems to be more promising than LDF in the assessment of burn wounds. However, several methodological issues that are inherent in the LDPI technique, and are relevant for the assessment of burn depth, must be clarified. These include the effect of scanning distance, curvature of the tissue, thickness of topical wound dressings, and pathophysiological effects of skin colour, blisters, and wound fluids. Furthermore, we soon realised that to examine the perfusion image generated by LDPI adequately the process of analysis was appreciably improved by the simultaneous use of digital photography. In the present investigation we used both in vitro and in vivo models and also examined burned patients, and found that the listed factors all significantly affected the LDPI output signal. However, if these factors are known to the examiner, most of them can be adjusted for. If the technique is further improved by minimizing such effects and by reducing the practical difficulties of applying it to a burned patient in the burns unit, the technique may find uses in everyday clinical decision-making.