Classification of electrocardiogram and auscultatory blood pressure signals using machine learning models

In this paper, two real-world medical classification problems using electrocardiogram (ECG) and auscultatory blood pressure (Korotkoff) signals are examined. A total of nine machine learning models are applied to perform classification of the medical data sets. A number of useful performance metrics which include accuracy, sensitivity, specificity, as well as the area under the receiver operating characteristic curve are computed. In addition to the original data sets, noisy data sets are generated to evaluate the robustness of the classifiers against noise. The 10-fold cross validation method is used to compute the performance statistics, in order to ensure statistically reliable results pertaining to classification of the ECG and Korotkoff signals are produced. The outcomes indicate that while logistic regression models perform the best with the original data set, ensemble machine learning models achieve good accuracy rates with noisy data sets.

Pore pressure effect on slope stability assessment

Slope stability assessment has been an integral problem for geotechnical engineering all these years. While stability of slopes is affected by various factors, pore pressure is one of the common naturalelements that influence slope stability analysis. This paper studies the effect of pore pressure on slope stability assessment by using Limit Equilibrium Method (LEM). The results will be compared to the solutions of Hoek and Bray charts. In this study, slopes with different levels of water table corresponding to those of Hoek and Bray charts are investigated. It’s interesting to observe that the results obtained from the Hoek and Bray charts yielded different factor of safety compare to those in the study here-in. In fact, the different between the factors of safety could be up to 30%. Hence this issue should be taken into consideration during slope design.

An enhanced method for determining the maximum strain a pipeline coating could tolerate

An enhanced mandrel bend testing method has been proposed for the evaluation of the maximum strain level that could be tolerated by an organic coating, and for the understanding of localised coating deformation and cracking behaviours under nonuniform mechanical strains. The aim is to develop a practical method that is suitable for selecting pipeline coatings in order to ensure that the selected coatings have sufficient flexibility to meet the high strain demand during the construction, hydrostatic testing and operation of high pressure pipelines. Two new mandrel bend testing setups have been designed by employing either centre or end clamps in order to improve the uniformity of strain distributions over coated steel coupons, and by using strain gauges to perform in situ measurements of local strains. A series of tests have been carried out to evaluate the new method for testing the flexibility of selected epoxy based pipeline industry coatings. Preliminary computational simulation has also been carried out for assisting the interpretation of mandrel bending test results.

No effect of multivitamin supplementation on central blood pressure in healthy older people: a randomized controlled trial

BACKGROUND AND AIMS: Central blood pressure rises with age, which increases cardiovascular risk. There is some evidence that nutritional supplements may be useful to reduce central blood pressures in older people, but no studies have investigated the effects of multivitamin supplements for this purpose. This randomized, double-blind, placebo-controlled study investigated the effects of 16-weeks supplementation with gender-specific multivitamin and herbal supplements.

METHOD: Participants were healthy individuals, free from heart disease, and included 160 females aged ≥ 50 and 79 males aged 50-65 years. Analyses of co-variance, correcting for baseline cardiovascular assessments, were used to determine the effects of supplementation on central cardiovascular measures including augmentation index, augmentation pressure and pulse pressure. Significance was set at p = 0.016.

RESULTS: No effects of multivitamin supplementation were observed in either males or females (respectively) for central augmentation index (p = 0.841; p = 0.296), central augmentation pressure (p = 0.794; p = 0.442), and central pulse pressure (p = 0.078; p = 0.304). Similarly, there was no treatment effect observed for brachial systolic, diastolic or pulse pressures.

CONCLUSION: Four months multivitamin supplementation does not appear to exert any benefit to measures of central blood pressure in healthy older people.

Nursing documentation of pressure ulcers in nursing homes: comparison of record content and patient examinations

AIM: The aim of this study was to describe the accuracy and quality of nursing documentation of the prevalence, risk factors and prevention of pressure ulcers, and compare retrospective audits of nursing documentation with patient examinations conducted in nursing homes.

DESIGN: This study used a cross-sectional descriptive design.

METHOD: A retrospective audit of 155 patients' records and patient examinations using the European Pressure Ulcer Advisory Panel form and the Braden scale, conducted in January and February 2013.

RESULTS: The prevalence of pressure ulcers was 38 (26%) in the audit of the patient records and 33 (22%) in patient examinations. A total of 17 (45%) of the documented pressure ulcers were not graded. When comparing the patient examinations with the patient record contents, the patient records lacked information about pressure ulcers and preventive interventions.