Ergonomic evaluation of hospital bed design features during patient handling tasks

Patient handling tasks (e.g., transportation and repositioning) are important causes of musculoskeletal disorders among healthcare workers. The purpose of this study was to evaluate, during two patient handling tasks, the physical demands resulting from alternative hospital bed design features. Twenty-four novice participants were involved in two laboratory-based studies. The effects of a steering lock and adjustable push height were evaluated during a patient transportation task using perceptual responses and measures of performance and physical demands, and the effect of a bed contour feature was determined based on patient sliding distance during repeated bed raising/lowering. Use of the steering lock reduced the number of adjustments during bed maneuvering by 28% and decreased ratings of physical demands. Use of the adjustable push height reduced shoulder moments by 30%. With the contour feature, patient sliding distance was reduced by ∼40% over 12 raise/lower cycles. These results suggest that the steering lock and adjustable push height features can reduce physical demands placed on healthcare workers during patient transportation tasks. Although patient sliding distance was reduced using the contour feature, assessing direct effects of this feature on physical demands (e.g., reduced need for workers to reposition patients) will require further investigation.

Relevance to industry

Hospital bed design features have the potential to reduce physical demands required of healthcare workers, yet there have been only limited empirical studies of these. Findings of the two current studies suggest that proactive ergonomic considerations in hospital bed design can reduce these physical demands.     

Detecting localized homogeneous anomalies over spatio-temporal data

The last decade has witnessed an unprecedented growth in availability of data having spatio-temporal characteristics. Given the scale and richness of such data, finding spatio-temporal patterns that demonstrate significantly different behavior from their neighbors could be of interest for various application scenarios such as—weather modeling, analyzing spread of disease outbreaks, monitoring traffic congestions, and so on. In this paper, we propose an automated approach of exploring and discovering such anomalous patterns irrespective of the underlying domain from which the data is recovered. Our approach differs significantly from traditional methods of spatial outlier detection, and employs two phases—(i) discovering homogeneous regions, and (ii) evaluating these regions as anomalies based on their statistical difference from a generalized neighborhood. We evaluate the quality of our approach and distinguish it from existing techniques via an extensive experimental evaluation.     

Nanocomposites based on transition metal oxides in polyvinyl alcohol for EMI shielding application

In the present work, the nanocomposites based on different transition metal oxides like iron oxide (Fe₂O₃), zinc oxide (ZnO), silicon dioxide (SiO₂), zirconium dioxide (ZrO₂), and titanium dioxide (TiO₂) in PVA matrix have been studied for their suitability as electromagnetic interference (EMI) shielding materials in the frequency range of 4–8 GHz (C-band) and 8–12 GHz (X-band). The nanocomposites containing 0.1, 0.5, 1.0, 5.0, and 10.0 wt% of oxides in the matrix were synthesised by solvent casting method. The EMI attenuation studies in 4–12 GHz frequency range were carried out using the Vector Network Analyzer R & S: ZVA40 method by measuring the loss due to reflection. The minimum reflectivity values for the composites containing Fe₂O₃, ZnO, SiO_2, ZrO₂, and TiO₂ in PVA matrix at 10 wt% concentration level in the matrix were found to be ?38.85 dB (10.4 GHz), ?33.65 dB (10.4 GHz), ?41.90 dB (10.4 GHz), ?24.90 dB (11.0 GHz), and ?32.90 dB (9.76 GHz), respectively. Based on these results, the SiO₂- and Fe₂O₃-based composites, which also exhibit high thermal stability and mechanical strength, are found to be low-cost and efficient EMI shielding materials.     

Synthesis, properties and biomedical applications of poly(glycerol sebacate) (PGS): A review

Poly(glycerol sebacate) (PGS) is a biodegradable polymer increasingly used in a variety of biomedical applications. This polyester is prepared by polycondensation of glycerol and sebacic acid. PGS exhibits biocompatibility and biodegradability, both highly relevant properties in biomedical applications. PGS also involves cost effective production with the possibility of up scaling to industrial production. In addition, the mechanical properties and degradation kinetics of PGS can be tailored to match the requirements of intended applications by controlling curing time, curing temperature, reactants concentration and the degree of acrylation in acrylated PGS. Because of the flexible and elastomeric nature of PGS, its biomedical applications have mainly targeted soft tissue replacement and the engineering of soft tissues, such as cardiac muscle, blood, nerve, cartilage and retina. However, applications of PGS are being expanded to include drug delivery, tissue adhesive and hard tissue (i.e., bone) regeneration. The design and fabrication of PGS based devices for applications that mimic native physiological conditions are also being pursued. Novel designs range from accordion-like honeycomb structures for cardiac patches, gecko-like surfaces for tissue adhesives to PGS (nano) fibers for extra cellular matrix (ECM) like constructs; new design avenues are being investigated to meet the ever growing demand for replacement tissues and organs. In less than a decade PGS has become a material of great scrutiny and interest by the biomedical research community. In this review we consolidate the valuable existing knowledge in the fields of synthesis, properties and biomedical applications of PGS and PGS-related biomaterials and devices.     

Blends of cardanol-based epoxidized novolac resin and CTBN for application in surface coating: a study on thermal,mechanical, chemical,and morphological characteristics

Blend samples of cardanol-based epoxidized novolac resin and different weight percentages of carboxyl-terminated butadiene acrylonitrile (CTBN) were developed and cured with stoichiometric amounts of aliphatic amine. The formation of various products during the curing of blend samples has been studied by Fourier-transform infrared spectroscopy. The dynamic differential scanning calorimeter scans showed that the pure epoxies and their blend samples with CTBN cured in the temperature range of 100–150°C. The blend sample containing 15 wt% CTBN showed the least cure time (at 120°C) among all other blend samples. Upon evaluation, it was found that blend samples exhibit better properties compared to pure epoxy resin in terms of increase in impact strength and elongation-at-break of the casting and gloss, scratch hardness, adhesion, and flexibility of the film. The improvement in these properties indicates that the rubber modified resin would be more durable than the epoxy based on cardanol. Chemical and morphological properties of the formulated resins were also determined. The thermal stability of the blend samples containing 15 wt% CTBN in epoxy resin was the highest among all other prepared systems. The blend morphology, studied by scanning electron microscope, showed the presence of precipitated discrete rubber particles, which dispersed throughout the epoxy matrix—i.e., they revealed the presence of two-phase morphological features.     

Fabrication of layered polydimethylsiloxane/perfluoropolyether microfluidic devices with solvent compatibility and valve functionality

The development of multilayer soft lithography methodology has seen polydimethysiloxane (PDMS) as the preferred material for the fabrication of microfluidic devices. However, the functionality of these PDMS microfluidic chips is often limited by the poor chemical resistance of PDMS to certain solvents. Here, we propose the use of a photocurable perfluoropolyether (PFPE), specifically FOMBLIN^® MD40 PFPE, as a candidate material to provide a solvent-resistant buffer layer to make the device substantially impervious to chemically induced swelling. We first carried out a systematic study of the solvent resistance properties of FOMBLIN^® MD40 PFPE as compared with PDMS. The comparison presented here demonstrates the superiority of FOMBLIN^® MD40 PFPE over PDMS in this regard; moreover, the results permitted to categorize solvents in four different groups depending on their swelling ratio. We then present a step-by-step recipe for a novel fabrication process that uses multilayer lithography to construct a comprehensive solvent-resistant device with fluid and control channels integrated with a valve structure and also permitting easy establishment of outside connections.     

A green chemistry approach for the synthesis and characterization of bioactive gold nanoparticles using Azolla microphylla methanol extract

This article reports the environmentally benign synthesis of gold nanoparticles （GNPs） using methanol extract of Azolla microphylla as the stabilizing and reducing agent. The GNPs were characterized by UV-vis spectrophotometry and FTIR, and the morphological characteristics were analyzed by XRD, FESEM-EDX and HRTEM. The GNPs could be formed in very short time, even in less than 30 min. The nanoparticles measured by UV-spectrophotometer demonstrated a peak at 540 nm corresponding to surface plasmon resonance spectra, and the peaks showed by FTIR suggested the presence of organic biomolecules on the surface of the GNPs. XRD results confirmed the crystalline nature of the GNPs, and FESEM-EDX and HRTEM analyses had been performed in the size ranges of 17-40nm and 1.25-17.5nm respectively. The synthesized GNPs showed excellent antioxidant activity. This study shows the feasibility of using plant sources for the biosynthesis of GNPs.     

Bi-phasic bio-conversion of sulfur present in model organo-sulfur compounds and hydro-treated diesel

Bacterial strain of Rhodococcus sp. (JUBT1) isolated from petrol/diesel station has been used for the desulfurization of different model organo-sulfur compounds like DBT, substituted DBT, etc. which are difficult to remove in the conventional hydro-desulfurization of diesel fraction. The initial concentration of organo-sulfur compounds has been varied in the range of 100–1000 mg/dm³. Under the present experimental range, the bacterial growth has been observed to follow Haldane-type kinetics characterizing the presence of substrate inhibition. The extent of inhibition by the substrate has been observed to increase with the number of substituents in the same range of initial concentration of different organo-sulfur compounds. The values of intrinsic kinetic parameters, like maximum desulfurization rate, v_max, half saturation constant, K_S, inhibition constant, K_Si and the maximum substrate concentration, C_Smax, corresponding to the maximum uninhibited rate of desulfurization, have been determined using each organo-sulfur compound having different number of substituents as limiting substrate. Relative changes in the values of the kinetic parameters have been correlated to the number of substitutions. Separate studies have also been conducted to determine the kinetics of bio-desulfurization of a hydro-treated diesel fraction. The concentration of sulfur in diesel was selected in the range of 100–500 mg/dm³.

The effect of aqueous to non-aqueous ratio on the rate of specific desulfurization of hydro-treated diesel fraction in the range from 1:9 to 9:1 has also been studied in the present investigation. Mathematical models have been developed to predict the conversion of sulfur during batch-type bio-desulfurization of model compounds as well as diesel having known distribution of organo-sulfur compounds. The predictions of the model satisfactorily compare with the experimental results.