On the Early and Affordable Diagnosis of Joint Pathologies Using Acoustic Emissions, Deep Learning Decompositions and Prediction Machines.

The condition of a joint in a human being is prone to wear and several pathologies, particularly in the elderly and athletes. Current means towards assessing the overall condition of a joint to assess for a pathology involve using tools such as X-ray and magnetic resonance imaging, to name a couple. These expensive methods are of limited availability in resource-constrained environments and pose the risk of radiation exposure to the patient. The prospect of acoustic emissions (AEs) presents a modality that can monitor the joints' conditions passively by recording the high-frequency stress waves emitted during their motion. One of the main challenges associated with this sensing method is decoding and linking acquired AE signals to their source event. In this paper, we investigate AEs' use to identify five kinds of joint-wear pathologies using a contrast of expert-based handcrafted features and unsupervised feature learning via deep wavelet decomposition (DWS) alongside 12 machine learning models. The results showed an average classification accuracy of 90 ± 7.16% and 97 ± 3.77% for the handcrafted and DWS-based features, implying good prediction accuracies across the various devised approaches. Subsequent work will involve the potential application of regressions towards estimating the associated stage and extent of a wear condition where present, which can form part of an online system for the condition monitoring of joints in human beings.

Enhancing Heat Transfer Behaviour of Ethylene Glycol by the Introduction of Silicon Carbide Nanoparticles: An Experimental and Molecular Dynamics Simulation Study.

As the critical component of automotive engine coolant, ethylene glycol (E.G.) significantly matters in heat dissipation. In this study, the key aim is to investigate the heat transfer behaviour of E.G. as nano-additives base fluid. The heat transfer capability of E.G./SiC nanofluid (N.F.) was experimentally and theoretically evaluated via transient hot wire methods and equilibrium molecular dynamics (EMD) simulation, respectively. M.D. simulation exhibited a great ability to accurately forecast the thermal conductivity of N.F. compared with the experiment results. The results confirmed that the thermal stability of N.F. is relatively greater than that of E.G. base fluids. An improvement mechanism of thermal conductivity and thermal stability under an atomic scale via the analysis of mean square displacement (MSD) and radial distribution function (RDF) calculation was elaborately presented. Ultimately, the results indicated that the diffusion effect and the increasing transition rate of liquid atoms are responsible for thermal conductivity enhancement.

What is the fertility-enhancing effect of tubal flushing? A hypothesis article.

Hysterosalpingographies (HSGs) have formed an essential part of the fertility workup for more than a century. More recently, tubal flushing, especially with oil-based contrast, has been shown to significantly improve the natural conception rates. Critically, the mechanism of this fertility-enhancing effect during tubal flushing is still unclear. This article postulates hypotheses, based on published and own research, on the potential mechanisms and root cause of tubal flushing fertility enhancement. Possible explanations for the increased fertility rates, especially with oil-based contrast, are divided into the biochemical and interfacial effects derived from the contrast properties. The biochemical effects may include the immunological response of the endometrium or peritoneum, the impact on the endometrial opioid receptors or the iodine content. The interfacial effects may include improvement of interfacial factors due to the lubricant effect or dislodgement of mucus debris within the Fallopian tubes. Impact StatementWhat is already known on this subject? Tubal flushing during hysterosalpingographies (HSGs) increases natural conception rates, and using oil-based over water-based contrast increases that effect even further. However, the underlying mechanism of the observed fertility-enhancing effect is still poorly understood.What do the results of this study add? This article postulates different hypotheses on the potential mechanisms and root cause of the fertility enhancement from tubal flushing.What are the implications of these findings for clinical practice and/or further research? We suggest additional research on the different hypotheses, intending to determine which subfertile women will benefit most from tubal flushing using oil-based contrast and at which stage of their subfertility. Furthermore, we suggest research on administering tubal flushing with oil-based contrast, besides in HSG.

Towards a Diagnostic Tool for Diagnosing Joint Pathologies: Supervised Learning of Acoustic Emission Signals.

Acoustic emission (AE) testing detects the onset and progression of mechanical flaws. AE as a diagnostic tool is gaining traction for providing a tribological assessment of human joints and orthopaedic implants. There is potential for using AE as a tool for diagnosing joint pathologies such as osteoarthritis and implant failure, but the signal analysis must differentiate between wear mechanisms-a challenging problem! In this study, we use supervised learning to classify AE signals from adhesive and abrasive wear under controlled joint conditions. Uncorrelated AE features were derived using principal component analysis and classified using three methods, logistic regression, k-nearest neighbours (KNN), and back propagation (BP) neural network. The BP network performed best, with a classification accuracy of 98%, representing an exciting development for the clustering and supervised classification of AE signals as a bio-tribological diagnostic tool.

Capillary rise behavior of lubricant in micropores with spiral bulge structures.

The highly efficient exudation of lubricant in porous self-lubricating materials significantly influences the formation of self-lubricating films. In this paper, micropores with inner spiral bulge structures are considered, and their influence on the capillary behaviors of the lubricant is discussed to reveal the capillary rising mechanism. The results show that the Taylor capillary lift phenomenon is produced in the spiral bulge structure of the micropore, and the capillary lift force is enhanced. The spiral structure decreases the effective diameter of micropores. The magnitudes of the pressure and velocity in the spiral structure pores are larger than those in smooth pores. The liquid in the upper part of the micropores forms a velocity vortex during its upward rotation along the spiral channel, which promotes the capillary rising behavior. For smaller pitches, the velocity vortex increases, and the rising speed of the lubricant grows. The inner spiral bulge structure gives the micropores an excellent capillary rising ability. The quantitative characterization and mechanism reveal that the capillary rising behavior can be used to guide the bionic designs of pores in self-lubricating materials.

Harnessing water fleas for water reclamation: A nature-based tertiary wastewater treatment technology.

Urbanisation, population growth, and climate change have put unprecedented pressure on water resources, leading to a global water crisis and the need for water reuse. However, water reuse is unsafe unless persistent chemical pollutants are removed from reclaimed water. State-of-the-art technologies for the reduction of persistent chemical pollutants in wastewater typically impose high operational and energy costs and potentially generate toxic by-products (e.g., bromate from ozonation). Nature-base solutions are preferred to these technologies for their lower environmental impact. However, so far, bio-based tertiary wastewater treatments have been inefficient for industrial-scale applications. Moreover, they often demand significant financial investment and large infrastructure, undermining sustainability objectives. Here, we present a scalable, low-cost, low-carbon, and retrofittable nature-inspired solution to remove persistent chemical pollutants (pharmaceutical, pesticides and industrial chemicals). We showed Daphnia's removal efficiency of individual chemicals and chemicals from wastewater at laboratory scale ranging between 50 % for PFOS and 90 % for diclofenac. We validated the removal efficiency of diclofenac at prototype scale, showing sustained performance over four weeks in outdoor seminatural conditions. A techno-commercial analysis on the Daphnia-based technology suggested several technical, commercial and sustainability advantages over established and emerging treatments at comparable removal efficiency, benchmarked on available data on individual chemicals. Further testing of the technology is underway in open flow environments holding real wastewater. The technology has the potential to improve the quality of wastewater effluent, meeting requirements to produce water appropriate for reuse in irrigation, industrial application, and household use. By preventing persistent chemicals from entering waterways, this technology has the potential to maximise the shift to clean growth, enabling water reuse, reducing resource depletion and preventing environmental pollution.

Diameter Estimation of Fallopian Tubes Using Visual Sensing.

Calculating an accurate diameter of arbitrary vessel-like shapes from 2D images is of great use in various applications within medical and biomedical fields. Understanding the changes in morphological dimensioning of the biological vessels provides a better understanding of their properties and functionality. Estimating the diameter of the tubes is very challenging as the dimensions change continuously along its length. This paper describes a novel algorithm that estimates the diameter of biological tubes with a continuously changing cross-section. The algorithm, evaluated using various controlled images, provides an automated diameter estimation with higher and better accuracy than manual measurements and provides precise information about the diametrical changes along the tube. It is demonstrated that the automated algorithm provides more accurate results in a much shorter time. This methodology has the potential to speed up diagnostic procedures in a wide range of medical fields.

A method for the assessment of the coefficient of friction of articular cartilage and a replacement biomaterial.

Replacement biomaterials for articular cartilage should encourage a coefficient of friction similar to the natural joint. Whilst the literature has assessed the coefficient of friction of articular cartilage against that of a potential biomaterial, it is unknown what the friction of articular cartilage in sliding against a surface defect, repaired with a biomaterial is. This evaluation is crucial to allow for the development of effective biomaterials to closely have the behaviour of articular cartilage. Thus, the aim of this study was to develop a novel technique for the assessment of the coefficient of friction of replacement biomaterials within articular cartilage, with this original testing configuration. For this study, a biomaterial was induced within an artificial defect perforated on the surface of bovine articular cartilage, whilst the material was assessed in sliding against articular cartilage itself. Calcium alginate was selected as the sample biomaterial for evaluation in this study. The tests were performed in sliding on a pin-on-disc tribometer in Ringer's solution. Two further tests were carried out, one as a benchmark comparison of a cartilage pin against a cartilage plate, as well as a cartilage pin against an aluminium plate. A constant induced stress of 0.06 MPa was applied at a frequency of 1 Hz. For the cartilage-cartilage, cartilage/hydrogel-cartilage and cartilage-aluminium test, the overall median coefficient of friction extracted across six repeats was of 0.36, 0.38 and 0.32, respectively. Statistical insignificance was identified across all three groups tested (p > 0.05). Similarity was observed in the coefficient of friction of cartilage-cartilage and cartilage/hydrogel-cartilage tests, however high-speed data identified the greatest wear for the cartilage/hydrogel-cartilage test.

Design and material evaluation for a novel lumbar disc replacement implanted via unilateral transforaminal approach.

The degeneration of the intervertebral disc is one of the principal causes of low back pain. Total disc replacement is a surgical treatment that aims to replace the degenerated disc with a dynamic implant to restore spine biomechanics. This paper proposes the first design of an elastomeric lumbar disc replacement that is implanted as a pair of devices via unilateral transforaminal surgical approach. Furthermore, several biomaterials (Polyurethanes (PU) and Polycarbonate Urethanes (PCU)) are evaluated for the purpose of the implant to mimic the axial compliance of the spine. Bionate II 80A (a pure PCU), Elast Eon 82A E5-325 (a PU with polydimethylsiloxane and polyhexamethylene oxide), Chronosil (a PCU based silicone elastomer) 80A with 5% and 10% of silicone were obtained and injection moulded according to the shape of the implant core, which was defined after a stress distribution analysis with the finite element method. The dimensions for each specimen were: 14.6 × 5.6 × 6.1 mm (length, width and height). Quasistatic compression tests were performed at a displacement rate of 0.02 mm/s. The obtained stiffness for each material at 1 mm displacement was: Bionate II 80A, 448.48 N/mm; Elast Eon 82A E5-325, 216.55 N/mm; Chronosil 80A 5%, 127.73 N/mm; and Chronosil 80A 10%, 126.48 N/mm. Dimensional changes were quantified after two quasi-static compression tests. Plastic deformation was perceived in all cases with a total percentage of height loss of: 4.1 ±â€¯0.5% for Elast Eon 82A E5-325; 3.2 ±â€¯0.5% for Chronosil 80A 10%; 2.7 ±â€¯0.3% for Chronosil 80A 5% and 1.1 ±â€¯0.2% for Bionate II 80A. The mechanical behaviour of these biomaterials is discussed to assess their suitability for the novel disc replacement device proposed.