9 research outputs found

    Extraction of Nucleolus Candidate Zone in White Blood Cells of Peripheral Blood Smear Images Using Curvelet Transform

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    The main part of each white blood cell (WBC) is its nucleus which contains chromosomes. Although white blood cells (WBCs) with giant nuclei are the main symptom of leukemia, they are not sufficient to prove this disease and other symptoms must be investigated. For example another important symptom of leukemia is the existence of nucleolus in nucleus. The nucleus contains chromatin and a structure called the nucleolus. Chromatin is DNA in its active form while nucleolus is composed of protein and RNA, which are usually inactive. In this paper, to diagnose this symptom and in order to discriminate between nucleoli and chromatins, we employ curvelet transform, which is a multiresolution transform for detecting 2D singularities in images. For this reason, at first nuclei are extracted by means of K-means method, then curvelet transform is applied on extracted nuclei and the coefficients are modified, and finally reconstructed image is used to extract the candidate locations of chromatins and nucleoli. This method is applied on 100 microscopic images and succeeds with specificity of 80.2% and sensitivity of 84.3% to detect the nucleolus candidate zone. After nucleolus candidate zone detection, new features that can be used to classify atypical and blast cells such as gradient of saturation channel are extracted

    Designing and implementing bioimpedance spectroscopy device by measuring impedance in a mouse tissue

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    Studies show that any complications including hemorrhage, lack of blood supply, lack of oxygen supply and death of cells in a tissue, will have a clear effect on electrical properties of that tissue. Thus, by measuring impedance of a set of tissues, potential problems of the damaged tissue may be found. Since electrical impedance is closely related to the measuring frequency, obviously, every tissue exhibits its own specific impedance according to its electrical properties at each frequency. This research project investigates design and manufacture method of a device for measuring tissue impedance at different frequencies. To this end, design of a multi frequency sinusoidal current source is required. This current source is built using a single harmonic Generator sample (Direct Digital Synthesizer AD9835) with working frequency (design-point frequency) between 1 Hz and 10 MHz and accuracy of 1 Hz and microcontroller (PIC16F628) capability. For measurement and display of tissue impedance, ARM AT91SAMs256 microcontroller was used. Thus, with this hardware created, it shows that there are significant impedance changes between mouse tissues

    A 3-Degree-of-Freedom MEMS Mirror with Controllable Static and Dynamic Motion for Beam Steering

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    A 3 Degree-of-Freedom (DOF) MEMS mirror is presented which can direct the light beam on an objective point and also operate in a continuous resonance 2 DOF mode. The micro-mirror is actuated by Lorentz force and has 4 actuators embedded in 4 sides of a square mirror. By enabling the actuators, different types of tilting and linear motion can be achieved. The micro-mirror is able to work in either static mode by applying dc current or dynamic mode by applying an ac current at the mirror resonance frequency. The mirror showed a maximum tilt angle of 14.5° and 20° for an input rms power of 2 mW in the resonance mode. A linear motion of 200 µm was achieved by 65 mW of dc power

    Application of WHO model for evaluating Patient Safety Friendly Hospital Initiatives (PSFHI) in an Eye hospital in Tehran, Iran

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    Background: Patient safety is one of the major issues concerning the medical community and the World Health Organization (WHO) in most countries. This study aimed to evaluate the patient safety status in an Eye Hospital in Tehran, using the WHO model for Patient Safety Friendly Hospital Initiatives (PSFHI) in 2012. Methods: This Cross-Sectional study was done in an Eye Hospital in Tehran. Measurement tool was a checklist related to the PSFHI, including 140 standards in three groups of critical, core and developmental. It was covering five domains of: a) Leadership and management, b) Patient and public involvement, c) Safe evidence-based clinical practices, d) Safe environment, and e) Lifelong learning. Results: Compliance with critical, core and developmental standards were 77.78%, 75.29%, and 21.42% respectively. The Rates of Meeting Standards in the leadership and management, patient and public involvement, safe evidence-based clinical practices, secure environment and for lifelong learning were 66.89%, 42.85%, 75.68%, 73.68%, and 63.63% respectively. Conclusions: The PSFHI standards play important role in improving patient safety using leadership, safety practices and creating good working conditions and environment for the staff. So focus on these standards is essential in improving the patient safety in hospitals in Iran

    Performance evaluation of complex electricity generation systems

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    To evaluate the performance of complex electricity generation systems, a new dynamic network-based data envelopment analysis (DNDEA) approach is presented. Past data envelopment analysis (DEA) studies on energy system efficiency have often ignored the dynamics of each process of the system individually. Here a network-based DEA method is built, which considers the interrelationships of the operations to determine the efficacy of the system. For assessing the performance over successive periods, with time-based dependencies between the successive periods, a dynamic DEA (DDEA) model is proposed. In DDEA, a linear combination of the efficiencies in successive periods is used as the complement of the system. The network-based and dynamic features of the created model enable measuring the performance of each sub-system process and the entire system in multi-period planning horizons simultaneously. These features make the DEA model identify changes in system efficiencies so much better than the current approaches. The created model is comprehensively implemented in the Iranian electricity sector using real data. Based on the findings, the efficiencies of power generation and transmission sectors are decreasing while the distribution performance is increasing. The proposed model could be applied to electricity generation systems in other countries as well.Peer reviewe

    Evanescent-Field Excited Surface Plasmon-Enhanced U-Bent Fiber Probes Coated with Au and ZnO Nanoparticles for Humidity Detection

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    We report the design, fabrication, and testing of a humidity sensor based on an optical fiber-based evanescent wave probe. The fiber was bent into a U-shape and de-cladded at the location of the bending. The de-cladded section was coated either with Au or with ZnO nanoparticles. Humidity is detected based on the interaction in the surface plasmon resonance of the Au/ZnO nanoparticles excited by an evanescent wave of light passing through the optical fiber. The response of the U-bent fibers to humidity was investigated using a specifically designed low-voltage portable interrogation box. We found that the fibers coated with ZnO nanoparticles were able to detect a minimum 0.1% change in humidity with an average sensitivity of 143 µV/%RH and 95% linearity over the 10% to 80% humidity range. In comparison, samples coated with Au and Au + ZnO nanoparticles demonstrated a minimum change detection of 0.3% RH and 2% RH respectively. The response and recovery time of the sensor were measured to be 3 s and 4 s, respectively, for a 60% change in humidity from 20% to 80%. The entire measurement system was operated by consuming an electrical power of 1.62 W at an input voltage of 12 Vdc
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