Experimental and theoretical analysis of a novel flexible membrane tactile sensor

In this study, we report the development of a new multi tactile sensor, capable of detecting 2D surface texture image, measuring contact-force, and identifying the difference between stiffness of sensed objects. The designed tactile sensor consists of a chamber and a membrane with a mesa structure. The detecting principle is a combination of membrane deflection and piezoresistante effects. A major advantage of the designed system is that it can be easily miniaturized and micromachined. As a result, it is suitable for using in medical applications, especially in minimally invasive surgery (MIS). © 2008 Science Publications

A Study on Performance and Safety Tests of Defibrillator Equipment

Introduction: Nowadays, more than 10,000 different types of medical devices can be found in hospitals. This way, medical electrical equipment is being employed in a wide variety of fields in medical sciences with different physiological effects and measurements. Hospitals and medical centers must ensure that their critical medical devices are safe, accurate, reliable and operational at the required level of performance. Defibrillators are critical resuscitation devices. The use of reliable defibirillators has led to more effective treatments and improved patient safety through better control and management of complications during Cardiopulmonary Resuscitation (CPR). Materials and Methods: The metrological reliability of twenty frequent use, manual defibrillators in use ten hospitals (4 private and 6 public) in one of the provinces of Iran according to international and national standards was evaluated. Results: Quantitative analysis of control and instrument accuracy showed the amount of the obtained results in many units are critical which had less value over the standard limitations especially in devices with poor battery. For the accuracy of delivered energy analysis, only twelve units delivered acceptable output values and the precision in the output energy measurements especialy in weak battry condition, after activation of discharge alarm, were low. Conclusion: Obtained results indicate a need for new and severe regulations on periodic performance verifications and medical equipment quality control program especially for high risk instruments. It is also necessary to provide training courses on the fundumentals of operation and performane parameters for medical staff in the field of meterology in medicine and how one can get good accuracy results especially in high risk medical devices

A Study on Performance and Safety Tests of Electrosurgical Equipment

Introduction: Modern medicine employs a wide variety of instruments with different physiological effects and measurements. Periodic verifications are routinely used in legal metrology for industrial measuring instruments. The correct operation of electrosurgical generators is essential to ensure patient’s safety and management of the risks associated with the use of high and low frequency electrical currents on human body. Material and Methods: The metrological reliability of 20 electrosurgical equipment in six hospitals (3 private and 3 public) was evaluated in one of the provinces of Iran according to international and national standards. Results: The achieved results show that HF leakage current of ground-referenced generators are more than isolated generators and the power analysis of only eight units delivered acceptable output values and the precision in the output power measurements was low. Conclusion: Results indicate a need for new and severe regulations on periodic performance verifications and medical equipment quality control program especially in high risk instruments. It is also necessary to provide training courses for operating staff in the field of meterology in medicine to be acquianted with critical parameters to get accuracy results with operation room equipment

Comparison of fluoride uptake level by enamel from Iranian school brand and standard NaF mouthrinses

Background and aims. The use of fluoride mouthrinses has been proved to be one of the most effective ways to prevent tooth decay. A community based program using F+ rinse at school has also proved to be well-controlled and efficient. The aim of this investigation was to evaluate fluoride uptake level of a locally prepared NaF rinse used in Iran’s school program during 2005. 
 Materials and methods. A total of 30 freshly extracted sound human premolars were collected and divided into two groups of 15. Each tooth then underwent two steps of sectioning; first the root was amputated from CEJ and then a longitudinal section was performed in bucco-lingual direction to provide two similar samples of the same tooth. A specific hemi-circular area on either of the experimental halves was treated by NaF rinse from USA or a locally prepared NaF used in school programs. Two subsequent biopsies were taken from each half using acid etch enamel biopsy technique. Fluoride and calcium content of the specimens were measured in order to evaluate fluoride uptake level and biopsy depth effect, respectively. Collected data were recorded in the forms provided and statistical analysis, mostly descriptive, was performed for comparison. 
 Results. Based on the data collected, it appears that the use of F+ rinse would clearly improve enamel quality by a rise in fluoride concentration. Statistical analysis using a paired t-test and repeated measure method revealed that with 95% confidence fluoride concentration increases at both levels of biopsy with no statistically significant differences between the samples treated with two rinses. 
 Conclusion. There seem to be reasonable potential for the clinical use of Iranian brand fluoride mouthrinse. There was no significant difference between the level of uptake from NaF from USA and the Iranian product in 2 layers of enamel biopsy

1 A New Fractal-Based Approach for 3D Visualization of Mountains in VRML Standard Abstract

Several factors currently limit the size of Virtual Reality Modeling Language (VRML) models that can be effectively visualized over the Web. Main factors include network bandwidth limitations and inefficient encoding schemes for geometry and its associated properties. The delays caused by these factors reduce the attractiveness of VRML usage for a large range of virtual reality models, CAD data, and scientific visualizations. To solve this problem, we have tried to decrease the size of data by deploying fractal geometry in VRML standard. A novel approach is proposed for generating a “fractal mountain ” using a random Midpoint-Displacement method in VRML standard. Our VRML 2.0 implementation, which is based on two newly defined nodes, TriangleGrid and FractMountain, and uses PROTO mechanism and Java in the Script nodes for the logic, is presented too. It is shown that our approach is more flexible and memory efficient than other approaches for computing mountain structures. Besides, mountains visualized by this approach look much more natural than those generated by other approaches

Optimal selection of cost-effective biological runoff management scenarios at watershed scale using SWAT-GA tool

Study region: Study region: Hablehrood River (HR) watershed in the northern part of the Iranian Central Plateau. Study focus: Finding the most economical management scenarios for implementing biological best management practices (BMPs) in the HR watershed is one way to solve the runoff issue in the study area. As, the best types, quantities, and locations of arid and semi-arid rangeland biological BMPs have not yet been identified or determined using the soil and water assessment tool (SWAT) or genetic algorithm (GA) to maximize runoff reductions at the lowest possible cost in arid and semi-arid rangelands, therefore, to estimate runoff and best identify biological management scenarios at the watershed scale in the current study, the SWAT and a GA model have been used. After determining the hydrological response units (HRUs), eight biological watershed management scenarios were identified through a combination of biological management activities. To determine the best management practice with the highest runoff reduction and the lowest possible cost, optimization was performed by GA based optimization model. New hydrological insights for the region: The simulation results of this study show that all the developed biological BMPs had a significant effect on the surface runoff rate reduction and reduced the surface runoff from 4.4% to 8.2%. The fifth scenario including seeding using machine (SUM) and seeding without machine (SWM) biological activities as optimal and the best scenario with weighted coefficients of 0.95 and 0.05 for runoff reduction and cost, respectively, was determined to be the optimum practice. The results further indicate that runoff would be decreased by 76.4 million cubic meters compared base scenario runoff volume, at a cost of 469.8 billion IR Rials. The lowest volume of surface runoff, however, was related to scenario number eight, while it had the highest cost (1114.3 billion IR Rials) among all scenarios. Using optimization methods, decision-makers and managers may pinpoint the best biological BMP scenarios in terms of kinds, locations, and amounts that might reduce runoff rates as much as possible at the lowest possible cost