A Hardware-Software System for Accurate Segmentation of Phonocardiogram Signal

Background: Phonocardiogram (PCG) signal provides valuable information for diagnosing heart diseases. However, its applications in quantitative analyses of heart function are limited because the interpretation of this signal is difficult. A key step in quantitative PCG is the identification of the first and second sounds (S1 and S2) in this signal. Objective: This study aims to develop a hardware-software system for synchronized acquisition of two signals electrocardiogram (ECG) and PCG and to segment the recorded PCG signal via the information provided in the acquired ECG signal. Material and Methods: In this analytical study, we developed a hardware-software system for real-time identification of the first and second heart sounds in the PCG signal. A portable device to capture synchronized ECG and PCG signals was developed. Wavelet de-noising technique was used to remove noise from the signal. Finally, by fusing the information provided by the ECG signal (R-peaks and T-end) into a hidden Markov model (HMM), the first and second heart sounds were identified in the PCG signal. Results: ECG and PCG signals from 15 healthy adults were acquired and analyzed using the developed system. The average accuracy of the system in correctly detecting the heart sounds was 95.6% for S1 and 93.4% for S2.   Conclusion: The presented system is cost-effective, user-friendly, and accurate in identifying S1 and S2 in PCG signals. Therefore, it might be effective in quantitative PCG and diagnosing heart diseases

Hydraulic Performance of Seawater Intake System Using CFD Modeling

In recent years, tapping the sea for potable water has gained prominence as a potential source of water. Since seawater intake systems are often used in the infrastructure industry, ensuring proper efficiency in different operating conditions is very important. In this paper, CFD modeling is used to show general hydraulic design (flow patterns, stream flow, vortex severities, and pre-swirl) principles and performance acceptability criteria for pump intakes in different conditions. The authors explore scenarios for avoiding or resolving hydraulic problems that have arisen as a result of hydraulic model studies. The results show that the designer should make every effort to avoid small entrance and filtration areas from the basin to the intake forebay bottom, which could result in jet outlet and/or supercritical flow; too small logs at the basin outflow, which could result in high velocity flow jets; and sudden area contractions at the forebay to pump bay junction. There should be enough submergence at the pumps to reduce harmful vortex severities and pre-swirl. Curtain walls, baffles, fillets, and splitters, as well as flow redistributors, can all aid in improving approach flow patterns. Reduced flow separations and eddies will be greatly assisted by rounding corners and providing guide walls. Using a numerical model to figure out what is wrong and how to fix it will help the facility’s costs and maintenance decrease in the long run

Soil Contamination with Toxocara Spp. Eggs in Public Parks of Mashhad and Khaf, North East of Iran

Background: Toxocariasis is an important disease caused by the larvae of parasitic worms such as Toxocara canis and T. cati. Public parks can be the source of toxocariasis for small children. This survey was conducted to de-termine the prevalence of Toxocara spp. ova in parks of Mashhad and Khaf northeastern Iran. Methods:In this descriptive cross-sectional study, performed in November 2011 to June 2012, overall, 340 soil samples were collected from 39 parks of Mashhad and 29 parks in Khaf city. Flotation method and direct smear were used, and the samples were evaluated using a light microscope. The results were analyzed using SPSS version 19 and Chi-square test. Results:In the evaluation of 195 and 145 soil samples, 18 (9.2%) and 16 cases (11.3%) of contamination with Toxocara spp. eggs were detected, re-spectively. Conclusion:Although the prevalence of Toxocara eggs in soil samples was low, parks can be a source of Toxocara infection of children in these areas

Hydraulic Performance of Howell–Bunger and Butterfly Valves Used for Bottom Outlet in Large Dams under Flood Hazards

Floods control equipment in large dams is one of the most important requirements in hydraulic structures. Howell–Bunger valves and butterfly valves are two of these types of flow controls that are commonly used in bottom outlet dams. The optimal longitudinal distance (L) between the two Howell–Bunger and butterfly valves is such that the turbulence of the outlet flow from the butterfly valve should be dissipated before entering the outlet valve. Subsequently, the flow passing through the butterfly valves must have a fully developed flow state before reaching the Howell–Bunger valve. Therefore, the purpose of this study was to evaluate the optimal longitudinal distance between the Howell–Bunger and butterfly valves. For this purpose, different longitudinal distances were investigated using the Flow-3D numerical model. The ideal longitudinal distance obtained from the numerical model in the physical model was considered and tested. Based on the numerical study, the parameters of flow patterns, velocity profiles and vectors, turbulence kinetic energy, and formation of flow vorticity were investigated as criteria to determine the appropriate longitudinal distance. In addition, the most appropriate distance between the butterfly valve and the Howell–Bunger valve was determined, and the physical model was evaluated based on the optimal distance extracted from the numerical simulation. A comparison of the results from the numerical and the laboratory models showed that the minimum distance required in Howell–Bunger valves and butterfly valves should be equal to four times the diameter of the pipe (L=4D) so as not to adversely affect the performance of the bottom outlet system

Hydraulic Performance of Howell–Bunger and Butterfly Valves Used for Bottom Outlet in Large Dams under Flood Hazards

Floods control equipment in large dams is one of the most important requirements in hydraulic structures. Howell–Bunger valves and butterfly valves are two of these types of flow controls that are commonly used in bottom outlet dams. The optimal longitudinal distance (L) between the two Howell–Bunger and butterfly valves is such that the turbulence of the outlet flow from the butterfly valve should be dissipated before entering the outlet valve. Subsequently, the flow passing through the butterfly valves must have a fully developed flow state before reaching the Howell–Bunger valve. Therefore, the purpose of this study was to evaluate the optimal longitudinal distance between the Howell–Bunger and butterfly valves. For this purpose, different longitudinal distances were investigated using the Flow-3D numerical model. The ideal longitudinal distance obtained from the numerical model in the physical model was considered and tested. Based on the numerical study, the parameters of flow patterns, velocity profiles and vectors, turbulence kinetic energy, and formation of flow vorticity were investigated as criteria to determine the appropriate longitudinal distance. In addition, the most appropriate distance between the butterfly valve and the Howell–Bunger valve was determined, and the physical model was evaluated based on the optimal distance extracted from the numerical simulation. A comparison of the results from the numerical and the laboratory models showed that the minimum distance required in Howell–Bunger valves and butterfly valves should be equal to four times the diameter of the pipe (L=4D) so as not to adversely affect the performance of the bottom outlet system

The effect of a semi-rigid thoracolumbosacral orthosis (TLSO) on foot pressure in elderly subjects presenting with spinal hyperkyphosis

Purpose: The ageing process can be accompanied by a degeneration of the spine and increase the risk of thoracic hyperkyphosis (excessive spinal forward curvature) amongst elderly people. This condition can in turn impair mobility, reduce balance, and increase the risk of falling and mortality in affected individuals. The use of corrective orthotic bracing has been shown to improve spinal posture, and increase stability and balance amongst the elderly. However, there is little evidence that evaluates the use of corrective braces on foot pressure changes in these subjects. Methods: In this study, we evaluated the use of a thoracolumbosacral orthosis (TLSO) on 19 subjects over 60 years old who presented with hyperkyphosis. We measured foot pressure using the Pedar-X system before (without brace) and after (with brace) immediate using a TLSO in both static (quite standing) and dynamic (walking on a 5 meters freeway) scenarios. Results: The results demonstrated that using a TLSO immediately decreases forefoot pressures in stasis, and around the first metatarsal, as well as pressures relating to the second to fifth metatarsals under dynamic conditions. Hindfoot pressures were increased, but not significantly. Conclusion: This study showed that using a TLSO can be beneficial for elderly people with hyperkyphosis. Implications for rehabilitation The ageing process can be accompanied by a degeneration of the spine and increase the risk of thoracic hyperkyphosis. The use of corrective orthotic bracing has been shown to improve spinal posture, and increase stability and balance amongst the elderly. Using a TLSO decreases forefoot pressures in stasis, and around the first metatarsal, as well as pressures relating to the second to fifth metatarsals under dynamic conditions

Molecular Identification of Leishmania Species Using Samples Obtained from Negative Stained Smears

Background: Cutaneous Leishmaniasis (CL) is a parasitic skin disease. Diagnosis primarily is based on clinical signs and microscopic observation of parasite on direct stained smears or tissue sections. Sensitivity of direct smear is not as high as molecular methods. The aim of this study was to identify and characterize Leishmania species among the negative direct smears obtained from skin ulcers sus­pected to CL by PCR method.Methods: Among 81 patients with suspicious skin lesions to CL referred to the Parasitology lab, nega­tive Giemsa stained smears were collected. DNA extraction performed by scraping stained smears, then PCR was performed.Results: Among the DNA extracted from smears, L. tropica was isolated from 9 (11.1%) of the smears and L.major was not isolated from any samples.Conclusion: Direct microscopy on stained smears for diagnosis of leishmaniasis is not enough accu­rate. PCR is recommended for clinically suspected lesions with negative result of direct smear