271 research outputs found

    A Low-Cost Microprocessor-Controlled Stance-Control Knee Orthosis for Pediatric Mobility Impairments

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    Knee-ankle-foot orthoses (KAFOs) are commonly prescribed for individuals with knee instability or quadriceps weakness resulting from a variety of conditions such as spinal cord injury, stroke, spina bifida, and cerebral palsy. A locking KAFO fixes the leg fully straight and is the most prescribed orthotic intervention for these conditions. However, the functional benefits of lower extremity orthoses are maximally realized in stance-controlled knee-ankle-foot orthoses (SC-KAFOs) which allow free knee motion during swing but lock during stance. Existing SC-KAFO options are generally unreliable or expensive, and thus an unmet need exists for a reliable, versatile orthosis which can be manufactured at relatively low cost. The SC-KO team is working to meet this need by developing an intelligent stance-controlled knee orthotic with an any-angle locking mechanism controlled by a microprocessor based on information received from onboard inertial gait-phase sensing. The resulting device will allow for reliable knee locking for support during the stance phase, easy unlocking even under load for the free swing phase, and predictable, safe behavior on stairs and uneven terrain. The system is being developed as a knee-only orthosis but can be adapted for a full knee-ankle-foot orthosis, with ankle support being prescribed as needed. The first system developed will be configured for pediatric use to address mobility impairments arising from cerebral palsy and spina bifida with CURE Ethiopia serving as the clinical partner for the development and testing. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1017/thumbnail.jp

    Force Characterization and Manufacturing of a Dynamic Unilateral Clubfoot Brace

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    Clubfoot is a musculoskeletal birth defect characterized by an inward twisting of an infant’s feet. Currently, a series of casts are used to correct the clubfoot, and a boots-and-bar brace is used to maintain the correction. However, this method has concerns with compliance, comfort, and social stigma. Hope Walks and their clinic in Kijabe, Kenya are interested in implementing a new maintenance brace that addresses these concerns. Mr. Jerald Cunningham, CPO, designed and is utilizing a unilateral clubfoot maintenance brace called the Cunningham Clubfoot Brace. He asserts his brace reduces treatment time, lessens social stigma, and increases child mobility. However, to date, there is not enough published research on its biomechanics and patient success rates to confirm his findings. The Cunningham Clubfoot Brace Collaboratory project seeks to validate the effectiveness of the Cunningham design through biomedical testing and increase brace availability through sustainable manufacturing. To do this, the team is measuring the biomechanical forces applied by the brace with multiple force sensor systems and an infant foot model. The team is assisting Mr. Cunningham in his plans to use injection molding to increase brace production by scanning and creating CAD files of the brace. The team is also completing a failure and reuse analysis of the Cunningham Brace for the clinic in Kijabe. Furthermore, the ongoing clinical study at CURE International\u27s hospital in Kijabe, Kenya, and Dr. Emily Farrar’s research paper will provide greater insight into the effectiveness of the Cunningham Brace. These collaborative efforts will allow for further understanding of the effectiveness of the Cunningham Brace and its acceptance as an alternative clubfoot maintenance brace.https://mosaic.messiah.edu/engr2021/1001/thumbnail.jp

    Gravity from Spinors

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    We investigate a possible unified theory of all interactions which is based only on fundamental spinor fields. The vielbein and metric arise as composite objects. The effective quantum gravitational theory can lead to a modification of Einstein's equations due to the lack of local Lorentz-symmetry. We explore the generalized gravity with global instead of local Lorentz symmetry in first order of a systematic derivative expansion. At this level diffeomorphisms and global Lorentz symmetry allow for two new invariants in the gravitational effective action. The one which arises in the one loop approximation to spinor gravity is consistent with all present tests of general relativity and cosmology. This shows that local Lorentz symmetry is tested only very partially by present observations. In contrast, the second possible new coupling is severely restricted by present solar system observations.Comment: New material on absence of observational tests of local Lorentz invariance, 21 pages, to appear in Phys.Rev.

    Force Characterization and Manufacturing of a Dynamic Unilateral Clubfoot Brace

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    Clubfoot is a musculoskeletal birth defect that is characterized by an inward twisting of an infant’s feet. The current method for correction involves several casts and a bilateral boots-and-bar maintenance brace. This method of maintenance requires 5 years of bracing and has issues with compliance, comfort, and social stigma. CURE International in Kijabe, Kenya is currently using the boots-and-bar brace but is interested in implementing a design that reduces these concerns. Mr. Jerald Cunningham, CPO, designed and is utilizing a unilateral clubfoot maintenance brace, the Cunningham Brace, which he expects will reduce treatment time to 2-3 years, lessen the social stigma, and increase the child’s mobility. However, there is not enough published research on its biomechanics and patient success rates to confirm his findings. The Collaboratory Cunningham Clubfoot Brace project seeks to validate the effectiveness of this design and increase accessibility through force testing and standardized manufacturing. We are working on measuring the biomechanical forces created and applied by the brace with a series of force sensors that are attached to the child’s brace. In addition, a new wrapping process for manufacturing the Cunningham Brace is being developed to increase the productivity and reproducibility of brace manufacturing in Kenya. Along with a clinical study that was started in Kenya, this testing and manufacturing will allow for further understanding of the effectiveness of the Cunningham Brace and provide more research for the medical community for it to potentially be accepted as an alternative clubfoot maintenance brace.https://mosaic.messiah.edu/engr2020/1014/thumbnail.jp

    Galaxy Zoo: Dust in Spirals

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    We investigate the effect of dust on spiral galaxies by measuring the inclination-dependence of optical colours for 24,276 well-resolved SDSS galaxies visually classified in Galaxy Zoo. We find clear trends of reddening with inclination which imply a total extinction from face-on to edge-on of 0.7, 0.6, 0.5 and 0.4 magnitudes for the ugri passbands. We split the sample into "bulgy" (early-type) and "disky" (late-type) spirals using the SDSS fracdeV (or f_DeV) parameter and show that the average face-on colour of "bulgy" spirals is redder than the average edge-on colour of "disky" spirals. This shows that the observed optical colour of a spiral galaxy is determined almost equally by the spiral type (via the bulge-disk ratio and stellar populations), and reddening due to dust. We find that both luminosity and spiral type affect the total amount of extinction, with "disky" spirals at M_r ~ -21.5 mags having the most reddening. This decrease of reddening for the most luminous spirals has not been observed before and may be related to their lower levels of recent star formation. We compare our results with the latest dust attenuation models of Tuffs et al. We find that the model reproduces the observed trends reasonably well but overpredicts the amount of u-band attenuation in edge-on galaxies. We end by discussing the effects of dust on large galaxy surveys and emphasize that these effects will become important as we push to higher precision measurements of galaxy properties and their clustering.Comment: MNRAS in press. 25 pages, 22 figures (including an abstract comparing GZ classifications with common automated methods for selecting disk/early type galaxies in SDSS data). v2 corrects typos found in proof

    Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials.

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    BACKGROUND: Treatment efficacy of physical agents in osteoarthritis of the knee (OAK) pain has been largely unknown, and this systematic review was aimed at assessing their short-term efficacies for pain relief. METHODS: Systematic review with meta-analysis of efficacy within 1-4 weeks and at follow up at 1-12 weeks after the end of treatment. RESULTS: 36 randomised placebo-controlled trials (RCTs) were identified with 2434 patients where 1391 patients received active treatment. 33 trials satisfied three or more out of five methodological criteria (Jadad scale). The patient sample had a mean age of 65.1 years and mean baseline pain of 62.9 mm on a 100 mm visual analogue scale (VAS). Within 4 weeks of the commencement of treatment manual acupuncture, static magnets and ultrasound therapies did not offer statistically significant short-term pain relief over placebo. Pulsed electromagnetic fields offered a small reduction in pain of 6.9 mm [95% CI: 2.2 to 11.6] (n = 487). Transcutaneous electrical nerve stimulation (TENS, including interferential currents), electro-acupuncture (EA) and low level laser therapy (LLLT) offered clinically relevant pain relieving effects of 18.8 mm [95% CI: 9.6 to 28.1] (n = 414), 21.9 mm [95% CI: 17.3 to 26.5] (n = 73) and 17.7 mm [95% CI: 8.1 to 27.3] (n = 343) on VAS respectively versus placebo control. In a subgroup analysis of trials with assumed optimal doses, short-term efficacy increased to 22.2 mm [95% CI: 18.1 to 26.3] for TENS, and 24.2 mm [95% CI: 17.3 to 31.3] for LLLT on VAS. Follow-up data up to 12 weeks were sparse, but positive effects seemed to persist for at least 4 weeks after the course of LLLT, EA and TENS treatment was stopped. CONCLUSION: TENS, EA and LLLT administered with optimal doses in an intensive 2-4 week treatment regimen, seem to offer clinically relevant short-term pain relief for OAK

    Organizational characteristics of European pediatric onco-critical care: An international cross-sectional survey

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    BACKGROUND Intensified treatment protocols have improved survival of pediatric oncology patients. However, these treatment protocols are associated with increased treatment-related morbidity requiring admission to pediatric intensive care unit (PICU). We aimed to describe the organizational characteristics and processes of care for this patient group across PICUs in Europe. METHODS A web-based survey was sent to PICU directors or representative physicians between February and June 2021. RESULTS Responses were obtained from 77 PICUs of 12 European countries. Organizational characteristics were similar across the different countries of Europe. The median number of PICU beds was 12 (IQR 8-16). The majority of the PICUs was staffed by pediatric intensivists and had a 24/7 intensivist coverage. Most PICUs had a nurse-to-patient ratio of 1:1 or 1:2. The median numbers of yearly planned and unplanned PICU admissions of pediatric cancer patients were 20 (IQR 10-45) and 10 (IQR 10-30, respectively. Oncology specific practices within PICU were less common in participating centres. This included implementation of oncology protocols in PICU (30%), daily rounds of PICU physicians on the wards (13%), joint mortality and morbidity meetings or complex patients' discussions (30% and 40%, respectively) and participation of parents during clinical rounds (40%). CONCLUSION Our survey provides an overview on the delivery of critical care for oncology patients in PICU across European countries. Multidisciplinary care for these vulnerable and challenging patients remains complex and challenging. Future studies need to determine the effects of differences in PICU organization and processes of care on patients' outcome

    The fundamental constants and their variation: observational status and theoretical motivations

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    This article describes the various experimental bounds on the variation of the fundamental constants of nature. After a discussion on the role of fundamental constants, of their definition and link with metrology, the various constraints on the variation of the fine structure constant, the gravitational, weak and strong interactions couplings and the electron to proton mass ratio are reviewed. This review aims (1) to provide the basics of each measurement, (2) to show as clearly as possible why it constrains a given constant and (3) to point out the underlying hypotheses. Such an investigation is of importance to compare the different results, particularly in view of understanding the recent claims of the detections of a variation of the fine structure constant and of the electron to proton mass ratio in quasar absorption spectra. The theoretical models leading to the prediction of such variation are also reviewed, including Kaluza-Klein theories, string theories and other alternative theories and cosmological implications of these results are discussed. The links with the tests of general relativity are emphasized.Comment: 56 pages, l7 figures, submitted to Rev. Mod. Phy
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