A comparison of customised and prefabricated insoles to reduce risk factors for neuropathic diabetic foot ulceration: a participant-blinded randomised controlled trial.

UNLABELLED: BACKGROUND: Neuropathic diabetic foot ulceration may be prevented if the mechanical stress transmitted to the plantar tissues is reduced. Insole therapy is one practical method commonly used to reduce plantar loads and ulceration risk. The type of insole best suited to achieve this is unknown. This trial compared custom-made functional insoles with prefabricated insoles to reduce risk factors for ulceration of neuropathic diabetic feet. METHOD: A participant-blinded randomised controlled trial recruited 119 neuropathic participants with diabetes who were randomly allocated to custom-made functional or prefabricated insoles. Data were collected at issue and six month follow-up using the F-scan in-shoe pressure measurement system. Primary outcomes were: peak pressure, forefoot pressure time integral, total contact area, forefoot rate of load, duration of load as a percentage of stance. Secondary outcomes were patient perceived foot health (Bristol Foot Score), quality of life (Audit of Diabetes Dependent Quality of Life). We also assessed cost of supply and fitting. Analysis was by intention-to-treat. RESULTS: There were no differences between insoles in peak pressure, or three of the other four kinetic measures. The custom-made functional insole was slightly more effective than the prefabricated insole in reducing forefoot pressure time integral at issue (27% vs. 22%), remained more effective at six month follow-up (30% vs. 24%, p=0.001), but was more expensive (UK £656 vs. £554, p<0.001). Full compliance (minimum wear 7 hours a day 7 days per week) was reported by 40% of participants and 76% of participants reported a minimum wear of 5 hours a day 5 days per week. There was no difference in patient perception between insoles. CONCLUSION: The custom-made insoles are more expensive than prefabricated insoles evaluated in this trial and no better in reducing peak pressure. We recommend that where clinically appropriate, the more cost effective prefabricated insole should be considered for use by patients with diabetes and neuropathy. TRIAL REGISTRATION: Clinical trials.gov (NCT00999635). Note: this trial was registered on completion

Numerical and experimental analysis of a planar jet with heated co-flow at medium and low Prandtl-number values

In the present work, we combine experiments and numerical simulations of a planar jet with heated co-flow with medium (air) and low-Prandtl (He-Xe gas mixture) fluids. Jets are recognized as representative test cases to be investigated in large components of pool-type liquid metal-cooled nuclear systems, like the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA), currently under design at SCK•CEN. The present planar jet configuration mimics a closed wind tunnel that is designed and operated at VKI to generate an experimental database for velocity and temperature fields of a turbulent forced-convection flow regime. The performed experiments combine the Particle Imaging Velocimetry (PIV) (in characteristic planes) and thermocouple (single point) measurements. In parallel with experiments, comprehensive numerical simulations have been performed within the RANS modeling framework. Next to the standard eddy-viscosity based two-equation k-ε model, an extended variant based on the low-Reynolds elliptic relaxation concept (so-called ζ-f model) has been applied too. To investigate the low-Prandtl effects on the heat transfer, series of the turbulent heat transfer models have been applied, ranging from a conventional constant turbulent Prandtl number to a more elaborate kθ-εθ model. The combination of the low-Reynolds ζ-f and kθ-εθ models was explored for the first time in the content of nuclear engineering applications. The focus of the numerical studies is to address in details the effects of low-Prandtl fluid in the strongly forced convection flow (central planar cold jet) in presence of a strong shear (hot co-flow). We demonstrate the importance of the proper specification of the inlet boundary conditions in numerical simulations to mimic correctly experimentally observed asymmetrical distributions of the cross-wise profiles of stream-wise velocity, turbulent kinetic energy and temperature. Finally, the minor differences in results between the assumed constant turbulent Prandtl number and more advanced kθ-εθ model of the turbulent heat flux confirmed the overly dominant mechanisms of the strong convection and molecular diffusion in the present configuration.ChemE/Transport Phenomen

Acta Slavica Iaponica : a journal in European languages of the Slavic Research Center of Hokkaido University

In this paper we present the user-centred design of a medicine dispenser for persons suffering from Alzheimer’s disease. The prototype was evaluated in two phases with two caregivers and two Alzheimer’s patients. Caregivers evaluated the device positively. The Alzheimer’s patients faced usability problems while completing tasks due to the virtual interaction medium of the medicine dispenser. However, patients and caregivers found the concept useful for medication intake

Combined Large-Eddy and Direct Numerical Simulations of a Planar Jet with Heated Co-Flow with Medium and Low Prandtl Fluids

In the present work, we have applied a combined dynamic large-eddy simulation (LES) and direct numerical simulation (DNS) approach for a three-dimensional planar jet in a turbulent forced convection regime (Re = 18000) with a heated co-flow. Results from LES are compared with Reynolds Averaged Navier-Stokes (RANS) simulations and experimental data. We have analyzed flow and heat transfer features for four values of the characteristic Prandtl numbers (Pr = 0.71, 0.2, 0.025, and 0.006), which are representatives of air, He-Xe gas mixture, Lead-Bismuth Eutectic (LBE), and sodium, respectively. The latter two low-Prandtl fluids have been considered because of their role as primary coolants in advanced fast pool-type reactor prototypes (such as the Multi-purpose Hybrid Research Reactor for High-tech Applications (MYRRHA) at SCK•CEN, Belgium). We have provided detailed insights into instantaneous and long-term time-averaged behavior of the velocity and temperature fields (the first- and second-order moments). Furthermore, we have analyzed profiles of characteristic velocity and temperature time scales and dissipation rates, as well as the power spectra of the streamwise velocity component and temperature at several characteristic locations. The mean temperature profiles demonstrated rather low sensitivity for various values of the Prandtl number. In contrast, profiles of the temperature standard deviation exhibited larger variations, decreasing in magnitude with lower Prandtl values. Here presented results of the high fidelity numerical simulations (dynamic LES/DNS) for the low-Prandtl working fluids can be used for further development, testing, and validation of the advanced RANS-type turbulence models.ChemE/Transport Phenomen

CFD benchmark for a heavy liquid metal fuel assembly

As part of a Department of Energy International Nuclear Energy Research Initiative (1-NERI), the Dutch Nuclear Research and consultancy Group (NRG), the Belgian Nuclear Research Centre (SCKCEN), Ghent University (UGent) in Belgium and the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) are collaborating with Argonne National Laboratory (ANL) to perform and compare a series of thermal hydraulic simulations representative of a heavy liquid metal fast reactor fuel assembly. Such a widely spaced wire-wrapped fuel assembly is a complex configuration for which few flow data are available for verification and validation of computational fluid dynamics (CFD) simulations. For this benchmark a 19-pin wire-wrapped rod bundle with characteristics representative of the MYRRHA flexible fast research reactor, under design at SCK'CEN in Belgium, is modeled. The heat conduction in the cladding of the fuel rods and the spacer wires is taken into account by conjugate heat transfer. UGent, ENEA and NRG performed their Reynolds Averaged Navier-Stokes (RANS) simulations with commercially available CFD codes. The high-fidelity ANL Large-Eddy Simulation (LES) was performed with Nek5000, used for CFD in the Simulation-based High-efficiency Advanced Reactor Prototyping (SHARP) suite. The paper will show and discuss the comparison of the thermal and hydraulic RANS results and the reference Nek5000 LES results. The comparison with the LES results will indicate to which extent the current liquid metal modeling methods are sufficient and help to highlight remaining issues. The results of the study are very valuable in the design and licensing process for MYRRHA