Development of limb volume measuring system

The mechanisms underlying the reductions in orthostatic tolerance associated with weightlessness are not well established. Contradictory results from measurements of leg volume changes suggest that altered venomotor tone and reduced blood flow may not be the only contributors to orthostatic intolerance. It is felt that a more accurate limb volume system which is insensitive to environmental factors will aid in better quantification of the hemodynamics of the leg. Of the varous limb volume techniques presently available, the ultrasonic limb volume system has proven to be the best choice. The system as described herein is free from environmental effects, safe, simple to operate and causes negligible radio frequency interference problems. The segmental ultrasonic ultrasonic plethysmograph is expected to provide a better measurement of limb volume change since it is based on cross-sectional area measurements

Apparatus for determining changes in limb volume

Measuring apparatus for determining changes in the volume of limbs or other boty extremities by determining the cross-sectional area of such limbs many comprise a transmitter including first and second transducers for positioning on the surface of the limb at a predetermined distance there between, and a receiver including a receiver crystal for positioning on the surface of the limb. The distance between the receiver crystal and the first and second transducers are represented by respective first and second chords of the cross-section of the limb and the predetermined distance between the first and second transducers is represented by a third chord of the limb cross section

Verification of ZVS boost converter with resonant circuit & modelling of an accurate two-diode PV array system simulator using MATLAB simulink

This thesis proposes a MATLAB Simulink simulator for Photo Voltaic (PV) Array system. The main contribution is the utilisation of a Two-Diode model to represent a PV cell. This model is preferred because of its better accuracy at low irradiance levels. A PV of Kyocera (KC200GT) 50*10 Array is taken & the characteristics curves are plotted. The same simulator can be interfaced with MPPT algorithms & Power Electronics converters for better efficiency. The P-V & I-V Curves of this simulator is found in exact with that given by the manufacturers. It is expected that the proposed work can be very useful for PV professionals who require a simple, fast & accurate PV simulator in order to design their systems. A detailed analysis of a resonant circuit based soft-switching boost-converter for PV applications is also performed. The converter operates at Zero Voltage Switching (ZVS) turn-on and turn-off of the main switch, & Zero Current Switching (ZCS) turn-on and ZVS turn-off of the auxiliary switch due to resonant circuit incorporated into the circuit. Detailed operation of the converters, analysis of various modes, simulation as well as experimental results for the design has also been aptly presented. The systems are modelled & simulated in MATLAB 2013a 64-bit version and the output waveforms are shown

Use of a simple pain model to evaluate analgesic activity of ibuprofen versus paracetamol

Objective: To evaluate the analgesic activity of ibuprofen against paracetamol using a simple pain model.Design: A double-blind study.Setting: Twenty general practitioners in Harare, Zimbabwe.Patients: Adults with acute sore throat of a maximum of two days’ duration.Interventions: One hundred and thirteen patients with acute pain associated with tonsillopharyngitis randomly received either 400mg ibuprofen or 1000mg paracetamol. The study design included repeated administration up to 48 hours to assess tolerability.Main outcome measures: At hourly intervals for six hours after the first dose of treatment, the patients evaluated pain intensity on swallowing, difficulty in swallowing and global pain relief according to visual analogue scales.Results: Ibuprofen 400mg was significantly more effective than paracetamol 1000mg in all three ratings, at all time-points for pain intensity and difficulty in swallowing, and from two hours onwards for pain relief. There were no serious adverse effects and no statisticallysignificant difference in the incidence of adverse effects in the two treatment groups.Conclusions: Sore throat pain provided a sensitive model to assess the analgesic efficacy of class I analgesics and discriminated between the analgesic efficacy of ibuprofen and paracetamol

Predicting Blast-Induced Ground Vibrations in Some Indian Tunnels: a Comparison of Decision Tree, Artificial Neural Network and Multivariate Regression Methods

The present study compares three different techniques (decision tree, artificial neural network and multivariate regression analysis) for predicting blast-induced ground vibrations in some Indian tunnelling projects. The performance of these models was also compared to site-specific conventional predictor equations. A database consisting of 137 vibration records was randomly divided into training and testing sets for model generation. Eight input parameters (total charge, tunnel cross-section, maximum charge per delay, number of holes, hole diameter, distance from blasting face, hole depth and charge per hole) were selected for model development using bivariate correlation analysis. Results indicated that the decision tree is best suited for predicting vibrations. The decision tree further suggested that the intensity of near-field ground vibrations is mainly affected by total charge fired in a round, whereas the intensity of far-field vibrations is governed by maximum charge per delay and charge per hole. Conventional ground vibration predictors and machine learning techniques such as neural networks do not depict the relationship between input and output parameters. However, the present study substantiates that the decision tree can be a good tool for precise prediction of ground vibrations. Further, the decision tree can classify and relate different blast design parametersfor refining blast designs to control ground vibrations on site

Evaluation of stress intensity factor of multiple inclined cracks under biaxial loading

A finite rectangular plate of unit thickness with two inclined cracks (parallel and non parallel) under biaxial mixed mode condition are modelled using finite element method. The finite element method is used for determination of stress intensity factors by ANYSIS software. Effects of crack inclination angle on stress intensity factors for two parallel and non parallel cracks are investigated. The significant effects of different crack inclination parameters on stress intensity factors are seen for lower and upper crack in two inclined crack.The present method is validated by comparing the results from available experimental data obtained by photo elastic method in same condition

Image Segmentation and Classification for Medical Image Processing

Segmentation and labeling remains the weakest step in many medical vision applications. This paper illustrates an approach based on watershed transform which are designed to solve typical problems encountered in various applications, and which are controllable through adaptation of their parameters. Two of these modules are presented: the lung cancer detection, a method for the segmentation of cancer regions from CT images, a watershed algorithm for image segmentation and brain tumor detection from MRI images. Various GLCM features along with some statistical features are used for classification using Neural network and Support Vector Machine (SVM). We describe the principles of the algorithms and illustrate their generic properties by discussing the results of both applications in 2D MRI images of Brain tumor and CT images of lung cancer

Image Processing for Medical Image Analysis: A Review

Image processing techniques are used widely in medical areas for improving the image in earlier detection and treatment stages, it is very important to discover the abnormality issues in given images, specially in various cancer, tumours such as lung cancer, breast cancer, etc. Image quality and accuracy is the main factors of this work, image quality improvement and assessment are depending on the enhancement stage where pre-processing techniques is used. The principal objectives of this course are to provide basic introduction and techniques for medical image processing and to promote for further study and research in medical image processing