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Sample records for automatic alarm dosimeter

  1. Development of semiconductor radiation sensors for portable alarm-dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Moon, B. S.; Chung, C. E.; Hong, S. B.; Kim, J. Y.; Kim, J. B.; Han, S. H.; Lee, W. G. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-01-01

    We studied Semiconductor Radiation Sensors for Portable Alarm-Dosimeter. We calculated response functions for gamma energy 0.021, 0.122, 0.662, 0.835, 1.2 MeV using EGS4 codes. When we measured at various distance from source to detector, the detection efficiency of Si semiconductor detector was better than that of GM tube. The linear absorption coefficients of steel and aluminum plate were measured. These experimental results of the response of detector for intensity of radiation field coincide to the theoretical expectation. The count value of Si detector was changed with changing thickness of steel as changing threshold voltage of discriminator, and the linear absorption coefficient increased with increasing threshold voltage. Radiation detection efficiency shows difference at each threshold voltage condition. This results coincided to the theoretical simulation. 33 refs., 27 figs., 8 tabs. (Author)

  2. Aerosol deposition in automatic dosimeter nebulization

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.M.; Lahdensuo, A.; Muittari, A.; Holli, H.; Karvonen, J.

    1987-01-01

    A new dosimeter nebulization method was studied in 10 asthmatics and 8 normal volunteers by delivering fixed doses of /sup 99m/Tc-traced radioaerosol in 0.2 s periods of tidal breathing. Two separate inspiratory phases were studied with the onset of nebulization, when in the earlier phase 15% and in the later phase 60% of tidal volume was inhaled. Further, bronchodilator administration was analogically assessed in the asthmatics. In healthy subjects, the total lung deposition was 17% greater in the earlier phase (P<0.005) than in the later one. In asthmatics, the difference was not significant. The losses of aerosol outside the lower respiratory tract were minimized, in the mouthwashing 0.3% and in the exhaled air 1.4%. The onset of nebulization (early or late) had no significant effect on bronchodilation with salbutamol in asthmatics. We conclude that the present dosimeter method is useful for efficient delivery of radioaerosols and drugs, and for standardization of bronchoprovocation.

  3. An automatic evaluation system for NTA film neutron dosimeters

    CERN Document Server

    Müller, R

    1999-01-01

    At CERN, neutron personal monitoring for over 4000 collaborators is performed with Kodak NTA films, which have been shown to be the most suitable neutron dosimeter in the radiation environment around high-energy accelerators. To overcome the lengthy and strenuous manual scanning process with an optical microscope, an automatic analysis system has been developed. We report on the successful automatic scanning of NTA films irradiated with sup 2 sup 3 sup 8 Pu-Be source neutrons, which results in densely ionised recoil tracks, as well as on the extension of the method to higher energy neutrons causing sparse and fragmentary tracks. The application of the method in routine personal monitoring is discussed. $9 overcome the lengthy and strenuous manual scanning process with an optical microscope, an automatic analysis system has been developed. We report on the successful automatic scanning of NTA films irradiated with /sup 238/Pu-Be source $9 discussed. (10 refs).

  4. Automatic scanning of NTA film neutron dosimeters

    CERN Document Server

    Müller, R

    1999-01-01

    At the European Laboratory for Particle Physics CERN, personal neutron monitoring for over 4000 collaborators is performed with Kodak NTA film, one of the few suitable dosemeters in the stray radiation environment of a high energy accelerator. After development, films are scanned with a projection microscope. To overcome this lengthy and strenuous procedure an automated analysis system for the dosemeters has been developed. General purpose image recognition software, tailored to the specific needs with a macro language, analyses the digitised microscope image. This paper reports on the successful automatic scanning of NTA films irradiated with neutrons from a /sup 238/Pu-Be source (E approximately=4 MeV), as well as on the extension of the method to neutrons of higher energies. The question of detection limits is discussed in the light of an application of the method in routine personal neutron monitoring. (9 refs).

  5. The dosimetric characteristics of personal alarm dosimeter : Dependence of dose rate and photon energy

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Ha-Seok; Lee, Jun Hee; Kim, Jae Min; Song, Gi Chang; Park, Jae Duck [Iljin Radiation Engineering Co. Ltd., Hwaseong (Korea, Republic of)

    2015-10-15

    There is a need to accurately measure the radiation dose. The dosimeters such as TLD(main dosimeter) are cumulative personal dosimeter to be measured after the radiation exposure, not provide information in real-time personal dose. Therefore, active dosimeter such as electronic personal dosimeters have used together as an alternative dosimeter to manage radiation dose of worker in the work place. We have developed and produced electronic personal dosimeters using photo diode as a detector(Model name: CLOVER), have also programmed the dose calculating algorithms to fit this dosimeter. We have developed and produced electronic personal dosimeters using photo diode as a detector, have also programmed the dose calculating algorithms to fit this dosimeter. The result of tests to meet in KS C IEC 61526 requirements for this dosimeter could obtain the following conclusions. 3.1. The relative intrinsic error and the dependence of dose equivalent rate of this electronic dosimeter are not exceed 20%, and meet with requirements. 3.2. The dependence of energy in the low energy region is exceeded 30%.

  6. [Implementation of an automatic alarms system for early detection of patients with severe sepsis].

    Science.gov (United States)

    Ferreras, José María; Judez, Diego; Tirado, Gabriel; Aspiroz, Carmen; Martínez-Álvarez, Rosa; Dorado, Paloma; Ezpeleta, Ana; Marrón, Rafael; Gargallo, Begoña; Herranz, Clara

    2015-10-01

    The objective of this study was to assess the usefulness of a software tool integrated into the medical electronic history at the time of emergency triage. The aim was the early detection of patients with severe sepsis, and the potential impact of this software tool on reducing the mortality rate in patients treated. The study consisted of two comparative samples. Patient selection was performed retrospectively into two groups using ICD-9 codes from the hospital and emergency department discharge reports. The codes were 038.9, 995.9 and 995.92 for sepsis, and 785.52 for severe sepsis and septic shock. The sample called «alarms» consisted of patients studied after implementing the sepsis alarm system in the Emergency Department computer system. There were two types of alarms, a serious one and an alert one depending on the on vital signs defined. The historical sample called «no alarms» consisted of patients seen in the Emergency Department during the year before the introduction of the alarm system. The compliance rate of the sepsis treatment package was higher in the «alarms» sample, compared to the sample without alarms, with blood cultures, 96.3% versus 80.9% (Psepsis allows acting earlier, better compliance with basic measures, and a reduction in hospital stay and mortality. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  7. Application performance evaluation on automatic fire alarm system of metro%地铁火灾自动报警系统使用效能评价

    Institute of Scientific and Technical Information of China (English)

    宋立巍; 宋立丹; 赵海荣

    2009-01-01

    对地铁火灾自动报警系统使用效能评价进行了研究,提出了该系统使用效能的评价要求、评价指标体系、评价流程以及评分模型,为地铁火灾自动报警系统的使用效能评价工作提供了技术参考和指导.%Application performance evaluation on automatic fire alarm system in metro was studied. Requirements, evaluation index system, evaluation process and score model of application performance evaluation on automatic fire alarm system in metro were proposed. And it will provide technical reference and guidance on the application performance evaluation job on automatic fire alarm system in metro.

  8. Multistation alarm system for eruptive activity based on the automatic classification of volcanic tremor: specifications and performance

    Science.gov (United States)

    Langer, Horst; Falsaperla, Susanna; Messina, Alfio; Spampinato, Salvatore

    2015-04-01

    With over fifty eruptive episodes (Strombolian activity, lava fountains, and lava flows) between 2006 and 2013, Mt Etna, Italy, underscored its role as the most active volcano in Europe. Seven paroxysmal lava fountains at the South East Crater occurred in 2007-2008 and 46 at the New South East Crater between 2011 and 2013. Month-lasting lava emissions affected the upper eastern flank of the volcano in 2006 and 2008-2009. On this background, effective monitoring and forecast of volcanic phenomena are a first order issue for their potential socio-economic impact in a densely populated region like the town of Catania and its surroundings. For example, explosive activity has often formed thick ash clouds with widespread tephra fall able to disrupt the air traffic, as well as to cause severe problems at infrastructures, such as highways and roads. For timely information on changes in the state of the volcano and possible onset of dangerous eruptive phenomena, the analysis of the continuous background seismic signal, the so-called volcanic tremor, turned out of paramount importance. Changes in the state of the volcano as well as in its eruptive style are usually concurrent with variations of the spectral characteristics (amplitude and frequency content) of tremor. The huge amount of digital data continuously acquired by INGV's broadband seismic stations every day makes a manual analysis difficult, and techniques of automatic classification of the tremor signal are therefore applied. The application of unsupervised classification techniques to the tremor data revealed significant changes well before the onset of the eruptive episodes. This evidence led to the development of specific software packages related to real-time processing of the tremor data. The operational characteristics of these tools - fail-safe, robustness with respect to noise and data outages, as well as computational efficiency - allowed the identification of criteria for automatic alarm flagging. The

  9. Development and Application of Automatic Transfusion Alarming Device%输液自动报警器的研制与应用

    Institute of Scientific and Technical Information of China (English)

    黄美霞; 严潭

    2013-01-01

    Objective To develop an automatic device which can alarm automatically at the end of medical transfusion. Methods A floating ball was placed in Murphy's tube, and infrared emitter and receiver were put outside of the tube, with alarming circuit mobilized. The liquid level and floating ball fell down at the end of transfusion until the infrared could not be blocked, then infrared receiver receive infrared signals and the device alarmed. Resulte The device gained the advantages of high accuracy and reliability, easy operation and maintenance, and low cost. Conchision The automatic transfusion alarming device can enhance nursing efficiency and has high social & economic benefits.%目的:研制一种在输液终末时可自动报警的输液报警器.方法:在莫菲氏管内增加浮球,管外两侧设置红外发射管及接收管,外联报警线路.输液终末时液面降低,浮球下降不再遮挡红外线,红外线接收管接收红外线继而产生报警.结果:该输液报警器准确可靠,操作简单,成本低廉,维护方便.结论:该输液报警器实用性强,临床应用可明显提高护理工作效率,具有良好的社会和经济效益.

  10. New Neutron Dosimeter

    CERN Multimedia

    2001-01-01

    CERN has been operating an Individual Dosimetry Service for neutrons for about 35 years. The service was based on nuclear emulsions in the form of film packages which were developed and scanned in the Service. In 1999, the supplier of theses packages informed CERN that they will discontinue production of this material. TIS-RP decided to look for an external service provider for individual neutron dosimetry. After an extensive market survey and an invitation for tender, a supplier that met the stringent technical requirements set up by CERN's host states for personal dosimeters was identified. The new dosimeter is based on a track-etching technique. Neutrons have the capability of damaging plastic material. The microscopic damage centres are revealed by etching them in a strong acid. The resulting etch pits can be automatically counted and their density is proportional to dose equivalent from neutrons. On the technical side, the new dosimeter provides an improved independence of its response from energy and th...

  11. Alarm Safety and Alarm Fatigue.

    Science.gov (United States)

    Johnson, Kendall R; Hagadorn, James I; Sink, David W

    2017-09-01

    Clinical alarm systems have received significant attention in recent years following warnings from hospital accrediting and health care technology organizations regarding patient harm caused by unsafe practices. Alarm desensitization or fatigue from frequent, false, or unnecessary alarms, has led to serious events and even patient deaths. Other concerns include settings inappropriate to patient population or condition, inadequate staff training, and improper use or disabling. Research on human factors in alarm response and of functionality of medical devices will help clinicians develop appropriate policies, practices, and device settings for clinical alarms in neonatal intensive care units. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Application of Data Transmission Technology in the Automatic Fire Alarm System%数据通信传输技术在火灾自动报警系统中的运用

    Institute of Scientific and Technical Information of China (English)

    梁鸿

    2011-01-01

    At present the fire damage degree and endanger scope are on the rise. In order to reduce the loss of degree, countnes in the world develop automatic fire alarm system. Data transmission technology is a very important technique in the automatic fire alarm system. Combining with automatic fire alarm system from data transmission mode. string/parallel communication mode. flyers/duplex data transmission. data synchronization method, digital coding method, the article introduced the technology.%目前,火灾损失程度和危害范围呈上升趋势.为了降低火灾损失的程度,世界各国都在积极开发火灾自动报警系统.数据通信传输技术是在火灾自动报警系统中非常重要的一种技术.本文结合火灾自动报警系统从数据通信传输模式,串/并行通信方式、传单/双工数据传输方式、数据同步方式、数字编码方式等方面介绍这一技术.

  13. Alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2014-01-01

    . As a response to this situation, our design artefact, the interactive furniture Kidkit, invites children to become accustomed to the alarming sounds sampled from the ward while they are waiting in the waiting room. Our design acknowledges how atmospheres emerge as temporal negotiations between the rhythms......, a familiar relationship with the alarming sounds in the ward, enabling her to focus later more on the visit with the relative. The article discusses the proposed design strategy behind this solution and the potentiality for its use in hospital environments in general....

  14. Alarm fatigue.

    Science.gov (United States)

    Sendelbach, Sue

    2012-09-01

    The number of false high alarms in the hospital setting remains a serious problem. False alarms have desensitized care providers and, at times, have led to dire consequences for patients. Efforts by both industry and clinicians are beginning to address this situation in collaborative approaches. Research is needed to establish an evidence base around issues such as which patients need to be monitored, and what the threshold settings and delay settings should be on devices. Initial and ongoing education needs to be considered for any new medical device, and be included in the hospital's annual budget. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2014-01-01

    Nurses working in the Neuro-Intensive Care Unit at Aarhus University Hospital lack the tools to prepare children for the alarming atmosphere they will enter when visiting a hospitalised relative. The complex soundscape dominated by alarms and sounds from equipment is mentioned as the main stressor...... of the body and the environment in conjunction with our internalised perception of the habituated background. By actively controlling the sounds built into Kidkit, the child can habituate them through a process of synchronising them with her own bodily rhythms. Hereby the child can establish, in advance...

  16. Micromechanical radiation dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Thundat, T.; Sharp, S.L.; Fisher, W.G.; Warmack, R.J.; Wachter, E.A. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6123 (United States))

    1995-03-20

    We demonstrate the use of microcantilevers coated with ultraviolet cross-linking polymers as optical radiation dosimeters. Upon exposure to radiation, a treated cantilever bends due to stress and its resonance frequency increases due to stiffening. These phenomena can be used to develop sensitive radiation dosimeters which respond to radiation affecting the mechanical properties of the selected coating.

  17. Electronic UV dosimeters.

    Science.gov (United States)

    Wulf, H C; Gniadecka, M

    1996-08-01

    The pathogenic role of ultraviolet (UV) in the development of skin cancer, skin ageing and immunosuppression makes it important to monitor human exposure to UV radiation. In a previous study we constructed UVB and UVC dosimeters based on a thermoluminescent phenomenon induced by UV in CaF2 :Dy and CaF2 crystals. However, these dosimeters were insensitive to UVA radiation and readout was time-consuming. In the present study we aimed to develop an electronic dosimeter suitable for UVA, UVB and UVC. The principle of this dosimeter is a measure of accumulated electric current induced by UV on a photodetector. Electric current induced by UV on a photodetector was accumulated in a Plessey's E-cell coulometer. A special reading device was constructed to quantify total charge of the coulometer. Sensitivity for UVA, UVB and UVC was achieved by the use of appropriate filters in front of the photodetector. The sensitivity of the electronic dosimeter increased with increasing wavelength of UV radiation; therefore, in UVB and UVC dosimeters the use of amplifiers was necessary. A linear response to UVA, UVB and UVC was achieved. Dosimeters with a linear response to increasing doses of UVA, UVB and UVC have been constructed for personal monitoring of UV exposure.

  18. 自动喷水灭火系统湿式报警阀设置问题探讨%On the Fixation of Hydraulic Alarm Valve of Automatic Water-spray Fire System

    Institute of Scientific and Technical Information of China (English)

    许剑方

    2011-01-01

    Wet alarm valve is a crucial part of automatic water-spray fire system.This paper focuses on whether an automatic water-spay fire system needs a wet alarm valve,whether it is in forms of concentration or distribution,and whether its location should be on the top of the building or at the bottom,and the number of sprays needed.%湿式报警阀是自动喷水灭火系统的重要组成部分。针对湿式报警阀的设置问题,重点探讨了自动喷水灭火系统是否都要设置湿式报警阀;湿式报警阀集中设置还是分散设置;湿式报警阀是底层设置还是楼层设置;湿式报警阀后所带喷头数目等几个问题,以真正发挥湿式报警阀的作用和自动喷水灭火系统的灭火效能。

  19. 卷烟生产联合工房火灾自动报警探测器选择%Selection of Automatic Fire Alarm Detector for Cigarette Manufacturing Joint Workshop

    Institute of Scientific and Technical Information of China (English)

    金超

    2015-01-01

    通过分析卷烟生产联合工房内制丝车间、卷接包车间、高架库等不同区域的建筑空间、生产环境以及对火灾自动报警系统的要求,结合工程设计及使用实际情况,探讨不同类型的火灾探测器在各生产区域使用的优劣及适用性,并提出卷烟生产联合工房火灾自动报警探测器选择方案。%By analysis on the architectural spaces, manufacturing environment and requirements for the automatic fire alarm system for the tobacco cutting workshop, fabricating and packing workshop, high-rack warehouse and other areas of the cigarette manufacturing joint workshop, the advantages, disadvantages and suitability of different fire detectors for different manufacturing areas are discussed on the basis of the engineering design and actual utilization conditions, and the selection plan for the automatic fire alarm detector for the cigarette manufacturing joint workshop is proposed.

  20. Smart Home Based SIM900A running water automatic alarm system%基于SIM900A的智能家居跑水自动报警系统设计

    Institute of Scientific and Technical Information of China (English)

    吴翠娟

    2015-01-01

    In this paper, AT89S52 microcontroller and GSM module chip SIM900A, build a home run water system automatic alarms. System consists of evasion detection circuit, microcontroller minimum system and SIM900A SMS modules and other components. Leak detection circuit detection module raindrop raindrop sensor and signal conditioning circuit, as long as the presence of a small amount of running water, rain sensor can be detected and processed by the signal conditioning circuit, to the SCM system, the microcontroller sends SMS module SIM900A command, start module sends alarm messages to family members, and sends an alarm signal to the smart cell property alarm system.%本文采用单片机AT89S52和GSM模块芯片SIM900A,构建一款家庭跑水自动报警的系统.系统由漏税检测电路、单片机最小系统和SIM900A短信模块等组成.漏水检测电路采用雨滴传感器和信号调理电路构成的雨滴检测模块,只要存在少量跑水,雨滴传感器就可检测到,并经信号调理电路处理后,送到单片机控制系统中,单片机向SIM900A短信模块发送指令,启动模块发送报警提示短信给家庭成员,同时向智能小区中的物业报警系统发送报警信号.

  1. A new radiochromic thin-film dosimeter system

    Science.gov (United States)

    Miller, A.; Batsberg, W.; Karman, W.

    A film dosimeter based on pararosaniline cyanide dissolved in polyvinyl butyral (PVB) has been developed and its properties are described. The dosimeter is made in 3 versions: 1) a clear, thin film that requires a thickness measurement for evaluation, 2) a film with a relatively high absorbance for automatic thickness correction, 3) a UV-protected pressure-sensitive adhesive tape. The response of the dosimeter is independent on the dose rate, and it may be used for routine dose measurement of both gamma and electron irradiation. Its high spatial resolution makes it particularly useful for dose distribution measurements.

  2. Spectroscopic Dosimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Analysis of Phase I test data demonstrates that the Photogenics Spectroscopic Dosimeter will detect neutron energies from 0.8 up to 600 MeV. The detector...

  3. 33 CFR 157.440 - Autopilot alarm or indicator.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Autopilot alarm or indicator. 157... § 157.440 Autopilot alarm or indicator. (a) A tankship owner or operator shall ensure that each installed autopilot unit without automatic manual override has an audible and visual alarm, which...

  4. 46 CFR 63.15-7 - Alarms.

    Science.gov (United States)

    2010-10-01

    ... reset. (c) For steam boilers, operation of the lower low water cutoff must automatically sound an..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING AUTOMATIC AUXILIARY BOILERS General... periodically unattended machinery space, the auxiliary boiler trip alarm required by 46 CFR 62.35-50, Table...

  5. Design of an automatic alarm walking stick system based on Internet of things%基于物联网的自动报警智能拐杖系统的设计

    Institute of Scientific and Technical Information of China (English)

    刘元; 吴彦文; 卢佳卉; 熊雅清; 杨凯; 刘沛泽

    2016-01-01

    随着社会事件的发生,老人安全出行再次引发人们的重点关注。一种基于物联网能实现自动报警的智能拐杖能够保障老人安全出行,拐杖系统包括数据采集与数据处理的拐杖终端。该系统利用ADXL345三轴加速度传感器测量倾角精度高,SIM908模块集GPS单元与GSM 单元于一体的特点,可准确获得老人行走状态并进行判断、处理。实验结果证明,该系统可实现定位、摔倒判断、自动报警、通信等功能,克服了目前国内相关产品只能手动报警的缺陷,可为老人安全出行提供保障。%Safety for the old is a matter of considerable interest .It is a design of intelligent walking stick system which can realize automatic alarm based on Internet of things .Data sampling and data processing are included in the walking stick terminal .The system takes good use of which ADXL345 acceleration sensor has the advantage in measuring angles with high precision and SIM 908 integrates GPS and GSM to get accurate condition of the old ,then decide and take actions . It overcomes the shortage that related domestic products currently can only ask for help manually . Experiment proofs the system can get positions ,detect falling down ,communication and alarm automatically .It is a method to providing security for the elderly .

  6. Type testing of the SDM2000 personal dosimeter

    CERN Document Server

    LiuZhengShan; Deng Chang Ming; Guo Zhan Jie; Zhang Zhi Yong

    2001-01-01

    The results of the performance of a new type of personal dosimeter, the SDM2000 Personal Dosimeter made by China Institute for Radiation Protection is presented. Tests were performed on radiological performance including radiation energy, incidence angular, beta radiation, neutron radiation, accuracy of alarm levels, relative intrinsic error, overload, response time, linearity, retention of reading. There are also tests on the effects of a variety of environmental factors, such as temperature, humidity, external magnetic fields, electrostatic discharge, external electromagnetic fields. Other characteristics tested were dropping test, vibration test and battery life. The test results were compared with the relevant requirements of three standards: CIRP standard: Q/DSC1-92, National standard: GB/T 13161-91, IEC standard: IEC1283. In general, the performance of the SDM2000 personal dosimeter was found to be quite acceptable; it meets most of the relevant requirements of the three standards

  7. Dielectric material for dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Moran, P.R.; Podgorsak, E.; Fullerton, G.D.; Fuller, G.E.

    1976-01-27

    A RITAD dosimeter is described having a dielectric material such as sapphire wherein the efficiency as measured by mean drift distance and trapping efficiency is increased by making use of a dielectric material in which the total active impurity does not exceed 50 ppm and in which any one active impurity does not exceed 10 ppm.

  8. Optimal Alarm Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — An optimal alarm system is simply an optimal level-crossing predictor that can be designed to elicit the fewest false alarms for a fixed detection probability. It...

  9. Dosimeter Design Program

    Science.gov (United States)

    2015-01-05

    to measure the radiation at various altitudes and orbital inclinations. By understanding the actual levels, this allows developers of large (and...surface (200km – 400km) from many of the effects of solar radiation . This means that standard commercial electronics (which are much cheaper) can often...applied over each dosimeter to provide an indication of the energy spectrum of the space radiation . The instrument incorporates radiation hardened

  10. Medical device alarms.

    Science.gov (United States)

    Borowski, Matthias; Görges, Matthias; Fried, Roland; Such, Olaf; Wrede, Christian; Imhoff, Michael

    2011-04-01

    The high number of false positive alarms has long been known to be a serious problem in critical care medicine - yet it remains unresolved. At the same time, threats to patient safety due to missing or suppressed alarms are being reported. The purpose of this paper is to present results from a workshop titled "Too many alarms? Too few alarms?" organized by the Section Patient Monitoring and the Workgroup Alarms of the German Association of Biomedical Engineering of the Association for Electrical, Electronic and Information Technologies. The current situation regarding alarms and their problems in intensive care, such as lack of clinical relevance, alarm fatigue, workload increases due to clinically irrelevant alarms, usability problems in alarm systems, problems with manuals and training, and missing alarms due to operator error are outlined, followed by a discussion of solutions and strategies to improve the current situation. Finally, the need for more research and development, focusing on signal quality considerations, networking of medical devices at the bedside, diagnostic alarms and predictive warnings, usability of alarm systems, education of healthcare providers, creation of annotated clinical databases for testing, standardization efforts, and patient monitoring in the regular ward, are called for.

  11. Characteristics of radiophotoluminescent glass dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Masashi; Shiraishi, Akemi; Murakami, Hiroyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-07-01

    In Japan Atomic Energy Research Institute, a film badge is recently replaced by a new type radiophotoluminescent (RPL) glass dosimeter for external personal monitoring. Some fundamental characteristics of this dosimeter, such as dose dependence linearity, energy dependence, angular dependence, dose evaluation accuracy at mixed irradiation conditions, fading, etc., were examined at the Facility of Radiation Standard (FRS), JAERI. The results have proved that the RPL glass dosimeter has sufficient characteristics for practical use as a personal dosimeter for all of the items examined. (author)

  12. Hanford personnel dosimeter supporting studies FY-1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-08-01

    This report examined specific functional components of the routine external personnel dosimeter program at Hanford. Components studied included: dosimeter readout; dosimeter calibration; dosimeter field response; dose calibration algorithm; dosimeter design; and TLD chip acceptance procedures. Additional information is also presented regarding the dosimeter response to light- and medium-filtered x-rays, high energy photons and neutrons. This study was conducted to clarify certain data obtained during the FY-1980 studies.

  13. The Design and Realization of an Automatic Weibo Alarm Monitor System%一种可自动微博报警的监控系统的设计与实现

    Institute of Scientific and Technical Information of China (English)

    苏金池

    2014-01-01

    设计并实现了一种基于ARM嵌入式平台的可自动发送带GIF图片微博报警的智能视频监控系统。系统在原有的智能监控预警系统的基础上,利用PIL图像库及Python脚本,将每次异常事件后保存的多张JPG图片生成一张GIF动画,并利用新浪微博提供的Python SDK发送一条带GIF图片的微博,起到预警的作用。用户可通过多种微博客户端收到提醒信息。%In this paper, design and realize an intelligent monitor early warning system based on ARM embedded platform, which can send a GIF image to Sina weibo automatically. The system is based on the intelligent monitoring early warning system, using python Imaging Library and Python scripts, to detect the abnormal situation. Then, the system will use multiple JPG images to generate a GIF image, and use Python SDK to send a GIF image to Sina weibo,.This function have the effect of alarm. The us-er can receives the reminding information through a variety of Sina weibo client.

  14. Fire detector setting problems discussion of code for design of automatic fire alarm systems%《火灾自动报警系统设计规范》探测器设置问题探讨

    Institute of Scientific and Technical Information of China (English)

    王赞瑞; 门茂琛; 薛原

    2011-01-01

    Based on quantitative and qualitative rules of smoke and temperature spreading along flat or sloping roof, new setting and fitting curve of point type fire detector were proposed, which was different from requirement of current code for design of automatic fire alarm systems. And, correction coefficient of radius of protection was demonstrated , wrong correction was%根据火灾时烟、温气流在平、坡屋顶上运行机理的量变、质变,提出了有别于现行的点型火灾探测器的设置限定、安装曲线及其绘制;论证了曾提出的保护半径修正系数,并分析了所见错误修正的后果和介绍点型探测器在平屋顶上的经济合理快捷设置法.

  15. Understanding Clinical Alarm Safety.

    Science.gov (United States)

    Lukasewicz, Carol L; Mattox, Elizabeth Andersson

    2015-08-01

    Patient safety organizations and health care accreditation agencies recognize the significance of clinical alarm hazards. The Association for the Advancement of Medical Instrumentation, a nonprofit organization focused on development and use of safe and effective medical equipment, identifies alarm management as a major issue for health care organizations. ECRI Institute, a nonprofit organization that researches approaches for improving patient safety and quality of care, identifies alarm hazards as the most significant of the "Top Ten Health Technology Hazards" for 2014. A new Joint Commission National Patient Safety Goal focusing on clinical alarm safety contains new requirements for accredited hospitals to be fully implemented by 2016. Through a fictional unfolding case study, this article reviews selected contributing factors to clinical alarm hazards present in inpatient, high-acuity settings. Understanding these factors improves contributions by nurses to clinical alarm safety practice.

  16. Development of Automatic Monitoring Alarm of Autologous Blood Recoverer Roller Pump Microgap%自体血液回收机滚压泵微量泵距自动监控报警仪的研制

    Institute of Scientific and Technical Information of China (English)

    田勇; 丁巾

    2012-01-01

    Autologous blood recoverer is widely used in surgical operation in recent years. Roller pump is a crucial component of the equipment, and the slot width between rolling axle and pump trough is an important parameter relative to receiving blood quality. In this paper, the automatic monitoring device of rolling and microgap whose processing core was STC12C5A60S2 chip microcomputer was designed by using Flexiforce thin film force transducer as sensing element. In addition, LCD display and alarming functions were provided. With the advantages of small, portable, convenient usage and so on, the instrument is completely suitable for autologous blood recoverer in clinical application process.%自体血液回收机是近年来广泛应用于外科手术的先进仪器.液体滚压泵是自体血液回收机中的关键部件,而其中的滚压轴与泵槽间隙则是关系到血液回收质量等级的重要参数.本文以Flexiforce薄膜压力传感器为感测元件,设计了以STC 12C5A60S2单片机为处理核心的滚压泵微量泵距参数自动监测仪器,并具有液晶显示、超限报警等功能.该仪器体积小、易携带、使用方便,完全适用于自体血液回收机的临床应用.

  17. Medical audible alarms: a review

    Science.gov (United States)

    Edworthy, Judy

    2013-01-01

    Objectives This paper summarizes much of the research that is applicable to the design of auditory alarms in a medical context. It also summarizes research that demonstrates that false alarm rates are unacceptably high, meaning that the proper application of auditory alarm design principles are compromised. Target audience Designers, users, and manufacturers of medical information and monitoring systems that indicate when medical or other parameters are exceeded and that are indicated by an auditory signal or signals. Scope The emergence of alarms as a ‘hot topic’; an outline of the issues and design principles, including IEC 60601-1-8; the high incidence of false alarms and its impact on alarm design and alarm fatigue; approaches to reducing alarm fatigue; alarm philosophy explained; urgency in audible alarms; different classes of sound as alarms; heterogeneity in alarm set design; problems with IEC 60601-1-8 and ways of approaching this design problem. PMID:23100127

  18. Gynecological cancer alarm symptoms:

    DEFF Research Database (Denmark)

    Balasubramaniam, Kirubakaran; Ravn, Pernille; dePont Christensen, René

    2016-01-01

    INTRODUCTION: To determine the proportion of patients who were referred to specialist care after reporting gynecological cancer alarm symptoms to their general practitioner. To investigate whether contact with specialist care was associated with lifestyle factors or socioeconomic status. MATERIAL......: Educational level influence contact with specialist care among patients with gynecological cancer alarm symptoms. Future studies should investigate inequalities in access to the secondary healthcare system. This article is protected by copyright. All rights reserved.......INTRODUCTION: To determine the proportion of patients who were referred to specialist care after reporting gynecological cancer alarm symptoms to their general practitioner. To investigate whether contact with specialist care was associated with lifestyle factors or socioeconomic status. MATERIAL...... and odds ratios (ORs) for associations between specialist care contact, lifestyle factors and socioeconomic status. RESULTS: The study included 25 866 non-pregnant women; 2957 reported the onset of at least one gynecological cancer alarm symptom, and 683 of these (23.1%) reported symptoms to their general...

  19. Smart smoke alarm

    Science.gov (United States)

    Warmack, Robert J. Bruce; Wolf, Dennis A; Frank, Steven Shane

    2015-04-28

    Methods and apparatus for smoke detection are disclosed. In one embodiment, a smoke detector uses linear discriminant analysis (LDA) to determine whether observed conditions indicate that an alarm is warranted.

  20. Study on the angular dependence of personal exposure dosimeter - Focus on thermoluminescent dosimeter and photoluminescent dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kyung-Rae [Department of Radiological Technology, Gwangju Health College University (Korea, Republic of); Department of Nuclear Engineering, Chosun University (Korea, Republic of); Kweon, Dae Cheol [Department of Radiologic Science, Shin Heung College University (Korea, Republic of); Chung, Woon-Kwan, E-mail: wkchung@chosun.ac.kr [Department of Nuclear Engineering, Chosun University (Korea, Republic of); Goo, Eun-Hoe [Department of Diagnostic Radiology, Seoul National University Hospital (Korea, Republic of); Department of Physics, Soonchunhyang University (Korea, Republic of); Dieter, Kevin [Department of Physical Therapy, Gwangju Health College University (Korea, Republic of); Choe, Chong-Hwan [Department of White Memorial Medical Center (United States)

    2011-02-15

    Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of {+-}90{sup o} at an interval scale of 15{sup o} from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0{sup o} to -90{sup o}, respectively. Therefore, PLDs have a lower angular dependence than TLDs.

  1. Miniature spectrally selective dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Adams, R.R.; Macconochie, I.O.; Poole, B.D.

    1983-02-08

    The present invention discloses a miniature spectrally selective dosimeter capable of measuring selected bandwidths of radiation exposure on small mobile areas. This is achieved by the combination of photovoltaic detectors, electrochemical integrators (e-cells) and filters in a small compact case which can be easily attached in close proximity to and substantially parallel to the surface being measured. In one embodiment two photovoltaic detectors, two e-cells and three filters are packaged in a small case with attaching means consisting of a safety pin. In another embodiment, two detectors, one e-cell and three filters are packaged in a small case with attaching means consisting of a clip to clip over a side piece of an eye glass frame in a further embodiment, the electro-optic elements a packaged in a wristwatch case with attaching means being a watchband. The filters in all embodiments allow only selected wavelengths of radiation to be detected by the photovoltaic detectors and then integrated by the e-cells.

  2. A Fiber-Optical Intrusion Alarm System Based on Quasi-Distributed Fiber Bragg Grating Sensors

    Institute of Scientific and Technical Information of China (English)

    Qi Jiang; Yun-Jiang Rao; De-Hong Zeng

    2008-01-01

    A fiber-optical intrusion alarm system based on quasi-distributed fiber Bragg grating (FBG) sensors is demonstrated in this paper. The algorithms of empirical mode decomposition (EMD) and wavelet packet characteristic entropy are adopted to determine the intrusion location. The intrusion alarm software based on the Labview is developed, and it is also proved by the experiments. The results show that such a fiber-optical intrusion alarm system can offer the automatic intrusion alarm in real-time.

  3. Video methods for evaluating physiologic monitor alarms and alarm responses.

    Science.gov (United States)

    Bonafide, Christopher P; Zander, Miriam; Graham, Christian Sarkis; Weirich Paine, Christine M; Rock, Whitney; Rich, Andrew; Roberts, Kathryn E; Fortino, Margaret; Nadkarni, Vinay M; Lin, Richard; Keren, Ron

    2014-01-01

    False physiologic monitor alarms are extremely common in the hospital environment. High false alarm rates have the potential to lead to alarm fatigue, leading nurses to delay their responses to alarms, ignore alarms, or disable them entirely. Recent evidence from the U.S. Food and Drug Administration (FDA) and The Joint Commission has demonstrated a link between alarm fatigue and patient deaths. Yet, very little scientific effort has focused on the rigorous quantitative measurement of alarms and responses in the hospital setting. We developed a system using multiple temporarily mounted, minimally obtrusive video cameras in hospitalized patients' rooms to characterize physiologic monitor alarms and nurse responses as a proxy for alarm fatigue. This allowed us to efficiently categorize each alarm's cause, technical validity, actionable characteristics, and determine the nurse's response time. We describe and illustrate the methods we used to acquire the video, synchronize and process the video, manage the large digital files, integrate the video with data from the physiologic monitor alarm network, archive the video to secure servers, and perform expert review and annotation using alarm "bookmarks." We discuss the technical and logistical challenges we encountered, including the root causes of hardware failures as well as issues with consent, confidentiality, protection of the video from litigation, and Hawthorne-like effects. The description of this video method may be useful to multidisciplinary teams interested in evaluating physiologic monitor alarms and alarm responses to better characterize alarm fatigue and other patient safety issues in clinical settings.

  4. The problem of alarm fatigue.

    Science.gov (United States)

    Tanner, Tanya

    2013-01-01

    Up to 99 percent of alarms sounding on hospital units are false alarms signaling no real danger to patients. These false alarms can lead to alarm fatigue and alarm burden, and may divert health care providers' attention away from significant alarms heralding actual or impending harm. As the health care environment continues to become more dependent upon technological monitoring devices used for patient care, nurses must become aware of the possibility and consequences of alarm fatigue and ways to prevent it from negatively affecting their practice, as well as the possible consequences for patient care. © 2013 AWHONN.

  5. To the attention of all dosimeter users

    CERN Multimedia

    2005-01-01

    Many regular users of CERN personal dosimeters do not respect the safety regulations, which include the compulsory monthly read-out of the dosimeter. Therefore we would like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350.-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short term visitor dosimeter (VCT). This dosimeter has a limited validity period but without for a compulsory periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service Bld 24 E 011 http://cern.ch/rp-dosimetry

  6. To the attention of all dosimeter users

    CERN Multimedia

    Dosimetry Service

    2006-01-01

    Many regular users of CERN personal dosimeters do not respect the safety regulations, which include the compulsory monthly read-out of the dosimeter. We would therefore like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350,-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short-term visitor dosimeter (VCT). This dosimeter has a limited validity period but does not require a periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service - Bldg. 24 E 011 - http://cern.ch/rp-dosimetry

  7. To the attention of all dosimeter users

    CERN Multimedia

    2005-01-01

    Many regular users of CERN personal dosimeters do not respect the safety regulations, which include a compulsory monthly read-out of the dosimeter. Therefore we would like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350.-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short term visitor dosimeter (VCT). This dosimeter has a limited validity period but without for a compulsory periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service Bldg. 24 E 011 http://cern.ch/rp-dosimetry

  8. Reproducibility Experiment of OSL and TL Dosimeter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Reproducibility is an important property of personal dosimeter. It not only can indicate the stability of dosimeter, appraise the precision and accuracy of measured value, but also can evaluate the

  9. Clinical Alarms in Intensive Care Units: Perceived Obstacles of Alarm Management and Alarm Fatigue in Nurses.

    Science.gov (United States)

    Cho, Ok Min; Kim, Hwasoon; Lee, Young Whee; Cho, Insook

    2016-01-01

    The purpose of this descriptive study was to investigate the current situation of clinical alarms in intensive care unit (ICU), nurses' recognition of and fatigue in relation to clinical alarms, and obstacles in alarm management. Subjects were ICU nurses and devices from 48 critically ill patient cases. Data were collected through direct observation of alarm occurrence and questionnaires that were completed by the ICU nurses. The observation time unit was one hour block. One bed out of 56 ICU beds was randomly assigned to each observation time unit. Overall 2,184 clinical alarms were counted for 48 hours of observation, and 45.5 clinical alarms occurred per hour per subject. Of these, 1,394 alarms (63.8%) were categorized as false alarms. The alarm fatigue score was 24.3 ± 4.0 out of 35. The highest scoring item was "always get bothered due to clinical alarms". The highest scoring item in obstacles was "frequent false alarms, which lead to reduced attention or response to alarms". Nurses reported that they felt some fatigue due to clinical alarms, and false alarms were also obstacles to proper management. An appropriate hospital policy should be developed to reduce false alarms and nurses' alarm fatigue.

  10. 消防水泵的联动控制设计--解读《〈火灾自动报警系统设计规范〉图示》%Design of Fire Pump Linkage Control-Interpretation of Graphical Representation of “Code for Design of Automatic Fire Alarm System”

    Institute of Scientific and Technical Information of China (English)

    汪浩

    2014-01-01

    The paper gives an introduction to partial contents related to linkage control in the national building standard disign 14X505-1 Graphical Representation of “Code for Design of Automatic Fire Alarm System”, with the linkage control of the automatic wet pipe sprinkler system and the wet fire hydrant system as examples.%以湿式自动喷水灭火系统和湿式消火栓系统的联动控制为例,介绍国家建筑标准设计14X505-1《〈火灾自动报警系统设计规范〉图示》中关于联动控制的部分内容。

  11. 徐大堡核电站运行和维修技术支持大楼的火灾自动报警系统设计%Automatic Fire Alarm System Design of Operation and Maintenance Technical Support Building of XU Dapu Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    韩圆

    2016-01-01

    Compared with other auxiliary workshops,XU Dapu Nuclear Power Plant has the characteristic of higher personnel density,more fire compartments and more concentrated communication machine rooms, etc. This paper introduced the design of the automatic fire alarm system based on the fire detection requirements,fire-fighting requirements and the characteristics of the building. The design could provide a certain guarantee for the safe operation of the building,and also provide a reference of automatic fire alarm system design for the operation and maintenance technology support building of subsequent AP1000 million kilowatt PWR nuclear power plant.%相比核电站其他辅助厂房,徐大堡核电站运行和维修技术支持大楼具有人员密度高、防火分区多、通信机房集中等特点。根据该建筑物特点、火灾探测和灭火要求对大楼火灾自动报警系统进行设计,为大楼安全运行提供一定保障,也为后续A P1000百万千瓦级压水堆核电站运行和维修技术支持大楼的火灾自动报警系统设计提供参考。

  12. Automated Information System (AIS) Alarm System

    Energy Technology Data Exchange (ETDEWEB)

    Hunteman, W.

    1997-05-01

    The Automated Information Alarm System is a joint effort between Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratory to demonstrate and implement, on a small-to-medium sized local area network, an automated system that detects and automatically responds to attacks that use readily available tools and methodologies. The Alarm System will sense or detect, assess, and respond to suspicious activities that may be detrimental to information on the network or to continued operation of the network. The responses will allow stopping, isolating, or ejecting the suspicious activities. The number of sensors, the sensitivity of the sensors, the assessment criteria, and the desired responses may be set by the using organization to meet their local security policies.

  13. Development of colored alumilite dosimeter

    CERN Document Server

    Obara, K; Yagi, T; Yokoo, N

    2003-01-01

    In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50 approx 100 degC), high gamma-ray radiation (approx 1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10 approx 100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to b...

  14. Visible absorption spectra of radiation exposed SIRAD dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Butson, Martin J [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong (China); Cheung Tsang [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong (China); Yu, Peter K N [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong (China)

    2006-12-07

    SIRAD badge dosimeters are a new type of personal dosimeter designed to measure radiation exposure up to 200 R and give a visual qualitative measurement of exposure. This is performed using the active dosimeter window, which contains a radiochromic material amalgamated in the badge assembly. When irradiated, the badges active window turns blue, which can be matched against the given colour chart for a qualitative assessment of the exposure received. Measurements have been performed to analyse the absorption spectra of the active window, and results show that the window automatically turns a blue colour upon irradiation and produces two peaks in the absorption spectra located at 617 nm and 567 nm. When analysed with a common computer desktop scanner, the optical density response of the film to radiation exposure is non-linear but reproducible. The net OD of the film was 0.21 at 50 R exposure and 0.31 at 200 R exposure when irradiated with a 6 MV x-ray energy beam. When compared to the calibration colour strips at 6 MV x-ray energy the film's OD response matches relatively well within 3.5%. An approximate 8% reduction in measured OD to exposure was seen for 250 kVp x-rays compared to 6 MV x-rays. The film provides an adequate measurement and visually qualitative assessment of radiation exposure for levels in the range of 0 to 200 R. (note)

  15. Dosimeter placement in the Rando phantom

    Energy Technology Data Exchange (ETDEWEB)

    Archer, B.R.; Glaze, S.; North, L.B.; Bushong, S.C.

    1977-07-01

    Each section of the Alderson Rando phantom contains a tissue-equivalent plastic coating layer approximately 2 mm thick, applied to both faces. This compensates for material removed in the sawing process. Conventional use of thermoluminescent dosimeters positions them totally or partially within the coating layer. Analysis shows that, in the lung region, dosimeters placed in this layer received a dose averaging 39% lower than those placed at midsection. Where bony structures interfere, some dosimeters in the coating layer received an 18% higher dose than those at midsection. Therefore, positioning dosimeters at the center of a section is recommended.

  16. Habituating alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie

    functionality for the staff, but are stressful for visitors and patients, as they are designed to demand attention even though they have no direct functional meaning to them. By introducing sounds from the ward, integrated in the furniture as simple sound sample triggers, KidKit invites children to become...... accustomed to the alarming sounds through rhythmic interaction in the waiting room, and bringing the furniture with them afterwards as a secure anchor, when entering the ward. This rhythmic habituation can enable the child to focus her attention on the meeting with the hospitalized relative....

  17. Habituating alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie

    essential dynamic parameters when designing atmospheres. This research is based on the development of the novel research artefact Kidkit, designed for children, who are going to meet a hospitalized relative with fatal injuries in a Neuro–Intensive Care Unit. Sounds from hospital equipment have important...... accustomed to the alarming sounds through rhythmic interaction in the waiting room, and bringing the furniture with them afterwards as a secure anchor, when entering the ward. This rhythmic habituation can enable the child to focus her attention on the meeting with the hospitalized relative....

  18. Distribution of combustible gas alarm based on embedded Ethernet technology

    Institute of Scientific and Technical Information of China (English)

    DING Xi-bo; ZHANG Jun-jie; WANG Yang

    2008-01-01

    One kind of combustible gas alarms based on industrial Ethernet was designed to prevent the gas leakage in industrial production sites. The alarm adopted the high performance microprocessor LPC2214 as the main chip. The embedded operating system μC/OS-Ⅱ and TCP/IP protocol stack ulP running on LPC2214 con-stitute a development platform of application of the combustible gas alarm. The test shows that it can automati-cally and continuously detect combustible gas in industrial production sites in several positions;it can give out sound-light alarm and take protective measures immediately against the gas leakage ; and it can send the detected data to PC through the Etheruet interface to realize the remote detection. The designed project provides a refer-ence to design industrial devices based on industrial Ethernet.

  19. Wireless intelligent alarm technology with pyroelectric infrared sensor

    Science.gov (United States)

    Chen, Xiao

    2009-07-01

    Aiming at the defects of monitoring conducted by man in the conventional practice, we study the passive intelligent automatic alarm technology based on the pyroelectric infrared sensor and wireless communication technology. The designed passive infrared wireless alarm is composed of pyroelectric infrared sensors, infrared special chip BISS0001 and their peripheral circuits. When someone enters into the detecting and monitoring range, the alarm will detect the infrared ray of the human radiation by the contactless form and detect the signals of circuit output. Then it translates them into low frequency signals relative with human sports speed, distance and direction, produce corresponding output signals through amplifying by the back state controller, switch on the work power of the wireless transmitting circuit and make it emit the alarm signals. The system enhances the monitoring level and effects and possesses many advantages such as wide detecting range, long detecting distance and high reliability.

  20. Assessment of Clinical Alarms Influencing Nurses' Perceptions of Alarm Fatigue.

    Science.gov (United States)

    Petersen, Emalie M; Costanzo, Cindy L

    Excessive clinical alarms have inundated health care for years. Multiple governing bodies, organizations, and facilities have deemed alarm management a priority. Alarm management is a multifaceted problem that affects all health care organizations and clinical staff, especially those in critical care units. Ultimately, the lack of knowledge regarding nurses' perceptions to alarm management and alarm fatigue creates patient safety chiasms. The purpose of this quality improvement project was to understand nurses' perceptions of alarm fatigue (utilizing the Healthcare Technology Foundation's Clinical Alarms Committee Survey) while implementing interventions that improve patient safety. The design of this qualitative study is an electronically distributed survey to 31 nurses who work in critical care. The Healthcare Technology Foundation clinical alarms survey has 36 questions with various answering strategies distributed (with permission) via e-mail access by BlueQ through Creighton University. Twenty-six respondents (n = 26) completed the survey, with 42% being intensive care unit nurses and 58% being progressive care unit nurses. The majority of nurses (n = 23, 88%) agreed that nuisance alarms occur frequently and disrupt patient care (n = 25, 96%). A lack of standardized method was noted to alarm management and parameter changes. Multiple patterns emerged that initiated the need for further examination and improvement. Following the survey, themes emerged, and changes were implemented including the following: an alarm management policy was created, tools were provided to staff for easy usage, staff were educated using hands-on practice at an annual training summit, and sustainability was created through continuation of alarm management assessment and improvement.

  1. Development of colored alumilite dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Kenjiro; Shibanuma, Kiyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yagi, Toshiaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yokoo, Noriko [Radiation Application Development Association, Tokai, Ibaraki (Japan)

    2003-03-01

    In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50{approx}100 degC), high gamma-ray radiation ({approx}1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10{approx}100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to be approximately 1MGy which is too low to monitor the RH equipment for the ITER. In addition, these conventional dosimeters do not involve sufficient radiation resistance against the high gamma-ray radiation as well as are not easy handling and low cost. Based on the above backgrounds, a new dosimeter with bleaching of an azo group dye to be applied to a radiation monitor has been developed for high gamma-ray radiation use. The colored alumilite dosimeter is composed of the azo group dye (-N=N-) in an anodic oxidation layer of aluminum alloy (Al{sub 2}O{sub 3}). It can monitor the radiation dose by measuring the change of the bleaching of azo dye in the Al{sub 2}O{sub 3} layer due to gamma-ray irradiation. The degree of bleaching is measured as the change of hue (color) and brightness based on the Munsell's colors with a three dimensional universe using spectrophotometer. In the tests, the dependencies such as colors, anodized layer thickness, type of azo

  2. Alarm management a comprehensive guide

    CERN Document Server

    Hollifield, Bill R

    2011-01-01

    In this second edition, Alarm Management: A Comprehensive Guide, various problems of alarm systems are covered with precise guidance on how they come about and how to effectively correct them. It is written by individuals with vast experience in the different plants, processes, and environments requiring effective alarm management. The second edition is filled with good examples and explanations of procedures, with practical lists and tips on how one should proceed. It is based on hundreds of successful projects.

  3. Alarm Fatigue: A Concept Analysis

    National Research Council Canada - National Science Library

    Patricia West; Patricia Abbott

    2014-01-01

    .... [...]it is the hope of these authors that an enhanced understanding of alarm fatigue can contribute to future collaborative multidisciplinary research efforts and continued policy progression to create...

  4. Fundamental Principles of Alarm Design

    DEFF Research Database (Denmark)

    Us, Tolga; Jensen, Niels; Lind, Morten

    2011-01-01

    Traditionally alarms are designed on the basis of empirical guidelines rather than on a sound scientific framework rooted in a theoretical foundation for process and control system design. This paper proposes scientific principles and a methodology for design of alarms based on a functional...... be applied to any engineering system which can be modeled by MFM. The methodology provides a set of alarms which can facilitate event interpretation and operator support for abnormal situation management. The proposed design methodology provides the information content of the alarms, but does not deal...

  5. A PC based thin film dosimeter system

    DEFF Research Database (Denmark)

    Miller, A.; Hargittai, P.; Kovacs, A.

    2000-01-01

    A dosimeter system based on the Riso B3 dosimeter film, an office scanner for use with PC and the associated software is presented. The scanned image is analyzed either with standard software (Paint Shop Pro 5 or Excel) functions or with the computer code "Scanalizer" that allows presentation...

  6. Alarm Fatigue: Causes and Effects.

    Science.gov (United States)

    Wilken, Marc; Hüske-Kraus, Dirk; Klausen, Andreas; Koch, Christian; Schlauch, Wolfgang; Röhrig, Rainer

    2017-01-01

    The term "Alarm fatigue" is commonly used to describe the effect which a high number of alarms can have on caregivers: Frequent alarms, many of which are avoidable, can lead to inadequate responses, severely impacting patient safety. In the first step of a long-term effort to address this problem, both the direct and indirect impact of alarms, as well as possible causes of unnecessary alarms were focused. Models of these causes and impacts were developed using a scoping review which included guided interviews with experts from medical informatics, clinicians and medical device manufacturers. These models can provide the methodical grounds for the definition of targeted interventions and the assessment of their effects.

  7. Radiation Monitoring Equipment Dosimeter Experiment

    Science.gov (United States)

    Hardy, Kenneth A.; Golightly, Michael J.; Quam, William

    1992-01-01

    Spacecraft crews risk exposure to relatively high levels of ionizing radiation. This radiation may come from charged particles trapped in the Earth's magnetic fields, charged particles released by solar flare activity, galactic cosmic radiation, energetic photons and neutrons generated by interaction of these primary radiations with spacecraft and crew, and man-made sources (e.g., nuclear power generators). As missions are directed to higher radiation level orbits, viz., higher altitudes and inclinations, longer durations, and increased flight frequency, radiation exposure could well become a major factor for crew stay time and career lengths. To more accurately define the radiological exposure and risk to the crew, real-time radiation monitoring instrumentation, which is capable of identifying and measuring the various radiation components, must be flown. This presentation describes a radiation dosimeter instrument which was successfully flown on the Space Shuttle, the RME-3.

  8. Development of an absolute neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, C; Birstein, L; Loyola, H [Section de Desarrollos Innovativos, Comision Chilena de EnergIa Nuclear (CCHEN), Casilla 188-D, Santiago (Chile)], E-mail: lbirstei@cchen.cl

    2008-11-01

    An Absolute Neutron Dosimeter was developed to be used as a calibration standard for the Radiation Metrology Laboratory at CCHEN. The main component of the Dosimeter consists of a Proportional Counter of cylindrical shape, with Polyethylene walls and Ethylene gas in its interior. It includes a cage shaped arrangement of graphite bars that operates like the Proportional Counter cathode and a tungsten wire of 25 {mu}m in diameter {mu}m as the anode. Results of a Montecarlo modeling for the Dosimeter operation and results of tests and measurements performed with a radioactive source are presented.

  9. Monitor alarm fatigue: an integrative review.

    Science.gov (United States)

    Cvach, Maria

    2012-01-01

    Alarm fatigue is a national problem and the number one medical device technology hazard in 2012. The problem of alarm desensitization is multifaceted and related to a high false alarm rate, poor positive predictive value, lack of alarm standardization, and the number of alarming medical devices in hospitals today. This integrative review synthesizes research and non-research findings published between 1/1/2000 and 10/1/2011 using The Johns Hopkins Nursing Evidence-Based Practice model. Seventy-two articles were included. Research evidence was organized into five main themes: excessive alarms and effects on staff; nurse's response to alarms; alarm sounds and audibility; technology to reduce false alarms; and alarm notification systems. Non-research evidence was divided into two main themes: strategies to reduce alarm desensitization, and alarm priority and notification systems. Evidence-based practice recommendations and gaps in research are summarized.

  10. Alarm fatigue: a patient safety concern.

    Science.gov (United States)

    Sendelbach, Sue; Funk, Marjorie

    2013-01-01

    Research has demonstrated that 72% to 99% of clinical alarms are false. The high number of false alarms has led to alarm fatigue. Alarm fatigue is sensory overload when clinicians are exposed to an excessive number of alarms, which can result in desensitization to alarms and missed alarms. Patient deaths have been attributed to alarm fatigue. Patient safety and regulatory agencies have focused on the issue of alarm fatigue, and it is a 2014 Joint Commission National Patient Safety Goal. Quality improvement projects have demonstrated that strategies such as daily electrocardiogram electrode changes, proper skin preparation, education, and customization of alarm parameters have been able to decrease the number of false alarms. These and other strategies need to be tested in rigorous clinical trials to determine whether they reduce alarm burden without compromising patient safety.

  11. Miniature Active Space Radiation Dosimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...

  12. The shelf life of dyed polymethylmethacrylate dosimeters

    Science.gov (United States)

    Bett, R.; Watts, M. F.; Plested, M. E.

    2002-03-01

    The long-term stability of the radiation response of Harwell Red 4034 and Amber 3042 Perspex Dosimeters has been monitored for more than 15 years, and the resulting data used in the justification of their shelf-life specifications.

  13. A fibre optic dosimeter customised for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Suchowerska, N. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia)], E-mail: Natalka@email.cs.nsw.gov.au; Lambert, J.; Nakano, T. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia); Law, S. [School of Physics, University of Sydney, NSW 2006 (Australia); Optical Fibre Technology Centre, University of Sydney, 206 National Innovation Centre, Australian Technology Park, Eveleigh, NSW 1430 (Australia); Elsey, J. [Bandwidth Foundry Pty Ltd, Australian Technology Park, NSW, 1430 (Australia); McKenzie, D.R. [School of Physics, University of Sydney, NSW 2006 (Australia)

    2007-04-15

    In-vivo dosimetry for brachytherapy cancer treatment requires a small dosimeter with a real time readout capability that can be inserted into the patient to determine the dose to critical organs. Fibre optic scintillation dosimeters, consisting of a plastic scintillator coupled to an optical fibre, are a promising dosimeter for this application. We have implemented specific design features to optimise the performance of the dosimeter for specific in-vivo dosimetry during brachytherapy. Two sizes of the BrachyFOD{sup TM} scintillation dosimeter have been developed, with external diameters of approximately 2 and 1 mm. We have determined their important dosimetric characteristics (depth dose relation, angular dependence, energy dependence). We have shown that the background signal created by Cerenkov and fibre fluorescence does not significantly affect the performance in most clinical geometries. The dosimeter design enables readout at less than 0.5 s intervals. The clinical demands of real time in-vivo brachytherapy dosimetry can uniquely be satisfied by the BrachyFOD{sup TM}.

  14. Alarming increase in refugees.

    Science.gov (United States)

    1992-01-01

    Over the past decade and half there has been an alarming worldwide increase in refugees. The total rose form 2.8 million in 1976 to 8.2 million in 1980, to 17.3 million in 1990. Africa's refugees rose from 1.2 million in 1976 to 5.6 million in 1990. Asia's increase over this period was much more rapid--from a mere 180,000 to 8 million. In the Americas the numbers more than trebled, from 770,000 to 2.7 million. Europe was the smallest increase, from 570,000 to 894,000. International law defines a refugee as someone outside of their own country, who has a well-founded fear of persecution because of their political or religious beliefs or ethnic origin, and who cannot turn to their own country for protection. Most refugees are genuine by this definition. The increase reflects, in part, fallout from the cold war. Ethiopia, Mozambique and Angola accounted for almost 1/2 of Africa's refugees; Afghanistan alone for 3/4 of Asia's total. They fled, for the most part, from 1 poor country into another, where they added to shortages of land and fuelwood, and intensified environmental pressure. Malawi, 1 of the poorest countries in the world, is sheltering perhaps as many as 750,000 refugees from the war in Mozambique. But among these refugees--especially among those who turned to the rich countries for asylum--were an increasing number of people who were not suffering political persecution. Driven out of their homes by the collapse of their environment or economic despair, and ready to take any means to get across borders, they are a new category: economic and environmental refugees. The most spectacular attempts hit the television screens: the Vietnamese boat people, ships festooned with Albanians. Behind the headlines there was a growing tide of asylum seekers. The numbers rose 10-fold in Germany from 1983 to 1990. In Switzerland they multiplied by 4 times. In Europe, as a whole, they grew from 71,000 in 1983 to an estimated 550,000 in 1990. In 1990 the numbers threatened to

  15. Alarm Fatigue vs User Expectations Regarding Context-Aware Alarm Handling in Hospital Environments Using CallMeSmart.

    Science.gov (United States)

    Solvoll, Terje; Arntsen, Harald; Hartvigsen, Gunnar

    2017-01-01

    Surveys and research show that mobile communication systems in hospital settings are old and cause frequent interruptions. In the quest to remedy this, an Android based communication system called CallMeSmart tries to encapsulate most of the frequent communication into one hand held device focusing on reducing interruptions and at the same time make the workday easier for healthcare workers. The objective of CallMeSmart is to use context-awareness techniques to automatically monitor the availability of physicians' and nurses', and use this information to prevent or route phone calls, text messages, pages and alarms that would otherwise compromise patient care. In this paper, we present the results from interviewing nurses on alarm fatigue and their expectations regarding context-aware alarm handling using CallMeSmart.

  16. Use of pagers with an alarm escalation system to reduce cardiac monitor alarm signals.

    Science.gov (United States)

    Cvach, Maria M; Frank, Robert J; Doyle, Pete; Stevens, Zeina Khouri

    2014-01-01

    Alarm fatigue desensitizes nurses to alarm signals and presents potential for patient harm. This project describes an innovative method of communicating cardiac monitor alarms to pagers using an alarm escalation algorithm. This innovation was tested on 2 surgical progressive care units over a 6-month period. There was a significant decrease in mean frequency and duration of high-priority monitor alarms and improvement in nurses' perception of alarm response time, using this method of alarm communication.

  17. CERN Alarms Data Management: State And Improvements

    CERN Document Server

    Zaharieva, Z

    2011-01-01

    The CERN Alarms System - LASER is a centralized service ensuring the capturing, storing and notification of anomalies for the whole accelerator chain, including the technical infrastructure at CERN. The underlying database holds the pre-defined configuration data for the alarm definitions, for the Operators alarms consoles as well as the time-stamped, run-time alarm events, propagated through the Alarms Systems. The article will discuss the current state of the Alarms database and recent improvements that have been introduced. It will look into the data management challenges related to the alarms configuration data that is taken from numerous sources. Specially developed Extract-Transform-Load (ETL) processes must be applied to this data in order to transform it into an appropriate format and load it into the Alarms database. The recorded alarms events together with some additional data, necessary for providing events statistics to users, are transferred to the long-term alarms archive.The article will cover...

  18. Alarm fatigue: impacts on patient safety.

    Science.gov (United States)

    Ruskin, Keith J; Hueske-Kraus, Dirk

    2015-12-01

    Electronic medical devices are an integral part of patient care. As new devices are introduced, the number of alarms to which a healthcare professional may be exposed may be as high as 1000 alarms per shift. The US Food and Drug Administration has reported over 500 alarm-related patient deaths in five years. The Joint Commission, recognizing the clinical significance of alarm fatigue, has made clinical alarm management a National Patient Safety Goal. Potential solutions to alarm fatigue include technical, organizational, and educational interventions. Selecting only the right monitors (i.e., avoiding overmonitoring), judicious selection of alarm limits, and multimodal alarms can all reduce the number of nuisance alarms to which a healthcare worker is exposed. Alarm fatigue can jeopardize safety, but some clinical solutions such as setting appropriate thresholds and avoiding overmonitoring are available.

  19. NONLINEAR RESPONSES OF GAMMA —RAY DOSIMETERS

    Institute of Scientific and Technical Information of China (English)

    罗达玲; 杨健明; 等

    1994-01-01

    Either sublinear or supralinear responses of dosimeters to γ-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity,sublinearity and supralinearlty in their responses.The experimental data of gamma dose-responses of alanine ESR dosimeters film dosimeters.LiF(Mg,Cu,P) and LiF(Mg,Ti) thermoluminescence dosimeters are used to test the response function.

  20. Fiber optic dosimeter with silicon photomultipliers

    Science.gov (United States)

    Moutinho, L. M.; Castro, I. F.; Peralta, L.; Abreu, M. C.; Veloso, J. F. C. A.

    2014-08-01

    A small dimension, real-time readout dosimeter is desirable for specific applications in medical physics as for example, dose measurement in prostate brachytherapy. This particular radiotherapy procedure consists in the permanent deposition of low energy, low-dose and low-dose rate small sized radioactive seeds. We developed a scintillating fiber optic based dosimeter suitable for in-vivo, real-time low dose and low dose rate measurements. Due to the low scintillation light produced in the scintillating fiber, a high sensitive and high gain light detector is required. The Silicon Photomultipliers are an interesting option that allowed us to obtain good results in our studies.

  1. Personnel exposure control system with auto thermoluminescence dosimeter in Shimane Nuclear Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Matsubayashi, Hideo; Ochi, Susumu (Chugoku Electric Power Co. Inc., Hiroshima (Japan))

    1982-03-01

    In the past, film badges and pocket dosimeters were put on the persons who entered a controlled area in a nuclear power station to measure the external radiation exposure. For these, read out error or mistake, delay in taking out the result, trouble for monitoring many persons, etc. were problems. To solve these problems, the auto thermoluminescence dosimeter (ATLD) system has been introduced in Shimane Nuclear Power Station in place of pocket dosimeters since the second half of fiscal 1978. The outline of the system and the composition and software of the TLD automatic readout system are described. For the control of access to controlled areas, workers are forced to pass the check point where watchmen check everyone's ID card, and subjected to the check-up with the TLD automatic readout device. The checking items in the case of entering the areas are: (1) confirmation of licensee, (2) confirmation of the term of validity for the medical examination on ionizing radiation, (3) checking for exposure dose compared to the controlled exposure level, (4) confirmation of time limit to stay in controlled areas, and (5) TLD element annealing condition. The checking items in the case of leaving the areas are: (1) checking for identifying the TLD element that the personnel has brought in, (2) exposure dose compared to the controlled exposure level, (3) time for which the personnel stayed in controlled areas.

  2. Estimation of the patient monitor alarm rate for a quantitative analysis of new alarm settings.

    Science.gov (United States)

    de Waele, Stijn; Nielsen, Larry; Frassica, Joseph

    2014-01-01

    In many critical care units, default patient monitor alarm settings are not fine-tuned to the vital signs of the patient population. As a consequence there are many alarms. A large fraction of the alarms are not clinically actionable, thus contributing to alarm fatigue. Recent attention to this phenomenon has resulted in attempts in many institutions to decrease the overall alarm load of clinicians by altering the trigger thresholds for monitored parameters. Typically, new alarm settings are defined based on clinical knowledge and patient population norms and tried empirically on new patients without quantitative knowledge about the potential impact of these new settings. We introduce alarm regeneration as a method to estimate the alarm rate of new alarm settings using recorded patient monitor data. This method enables evaluation of several alarm setting scenarios prior to using these settings in the clinical setting. An expression for the alarm rate variance is derived for the calculation of statistical confidence intervals on the results.

  3. Radiant energy dosimeter for field use

    Science.gov (United States)

    A. Broido; A.W. McMasters

    1967-01-01

    Thermal radiation measurements in Project Flambeau fires involved a limited number of conventional radiometers located outside the fire periphery. A simple, cheap, easily-fabricated, light-weight, self-contained, rugged dosimeter was desired to withstand a hot fire environment, including a specific energy input of 5,000 cal cm -2, and to record...

  4. The framework and the key technology of the alarm embedded in a mobile phone based on automatic photographing and transmitting the photos%基于自动拍照传输图片的手机嵌入式报警器架构及关键技术研究

    Institute of Scientific and Technical Information of China (English)

    陈阵

    2013-01-01

    To design a personal alarm with one by a mobile phone.Based on the ARM11 mobile phone,the mobile phone camera module and MMS module were the main components,at first connected the mobile phone's camera module and the flash circuit module were connected with the mobile phone's camera shortcut key in series,then used the carbide.c+ + language on S60 platform of the Symbian smartphone OS to realize that the MCU interrupted by FIQ,unlocked the keyboard and invoked the JAVA program after that the mobile phone' s camera shortcut key of the hardware bottom was touched,at last use d J2me language on the WTK platform to realize the mobile phone ' s automatic taking pictures and sending pictures by MMS to the designated mobile phone.In case of emergency once the user triggered the mobile phones's camera shortcut key,the mobile phone immediately unlocked the keypad,the light flashed,automatically taked a picture for the scene and sended the picture through mms to the relatives and friends,so that they could take timely measures and provide help to the user,also preserve the information in order to take the evidence.The alarm embedded in the Mobile phone can effectively protect personal safety on body and property.%利用手机设计一种个人随身报警器.基于ARM11手机,以手机照相模块和彩信模块做为主要部件,首先把手机拍照模块和闪光灯电路模块与手机照相机快捷键相串接,然后在Symbian智能手机系统的S60平台上采用carbide.c++语言实现在硬件底层的手机照相机快捷键被触发后MCU进行快速中断启动键盘解锁并调用JAVA程序,最后在WTK平台上采用J2me语言实现手机自动拍照通过彩信传送图片给指定手机.在紧急情况下一旦用户触发手机照相快捷键,手机立刻解开键盘锁,闪光灯亮,并自动对现场情景照相后把图片通过彩信发送给亲友,以便亲友能及时采取措施对用户提供帮助,同时也为事件取证做好信息保存.手机嵌

  5. Systematic Review of Physiologic Monitor Alarm Characteristics and Pragmatic Interventions to Reduce Alarm Frequency.

    Science.gov (United States)

    Paine, Christine Weirich; Goel, Veena V; Ely, Elizabeth; Stave, Christopher D; Stemler, Shannon; Zander, Miriam; Bonafide, Christopher P

    2016-02-01

    Alarm fatigue from frequent nonactionable physiologic monitor alarms is frequently named as a threat to patient safety. To critically examine the available literature relevant to alarm fatigue. Articles published in English, Spanish, or French between January 1980 and April 2015 indexed in PubMed, Cumulative Index to Nursing and Allied Health Literature, Scopus, Cochrane Library, Google Scholar, and ClinicalTrials.gov. Articles focused on hospital physiologic monitor alarms addressing any of the following: (1) the proportion of alarms that are actionable, (2) the relationship between alarm exposure and nurse response time, and (3) the effectiveness of interventions in reducing alarm frequency. We extracted data on setting, collection methods, proportion of alarms determined to be actionable, nurse response time, and associations between interventions and alarm rates. Our search produced 24 observational studies focused on alarm characteristics and response time and 8 studies evaluating interventions. Actionable alarm proportion ranged from alarm exposure and longer nurse response time. Most intervention studies included multiple components implemented simultaneously. Although studies varied widely, and many had high risk of bias, promising but still unproven interventions include widening alarm parameters, instituting alarm delays, and using disposable electrocardiographic wires or frequently changed electrocardiographic electrodes. Physiologic monitor alarms are commonly nonactionable, and evidence supporting the concept of alarm fatigue is emerging. Several interventions have the potential to reduce alarms safely, but more rigorously designed studies with attention to possible unintended consequences are needed. © 2015 Society of Hospital Medicine.

  6. Deficiencies of active electronic radiation protection dosimeters in pulsed fields.

    Science.gov (United States)

    Ankerhold, U; Hupe, O; Ambrosi, P

    2009-07-01

    Nowadays nearly all radiation fields used for X-ray diagnostics are pulsed. These fields are characterised by a high dose rate during the pulse and a short pulse duration in the range of a few milliseconds. The use of active electronic dosimeters has increased in the past few years, but these types of dosimeters might possibly not measure reliably in pulsed radiation fields. Not only personal dosimeters but also area dosimeters that are used mainly for dose rate measurements are concerned. These cannot be substituted by using passive dosimeter types. The characteristics of active electronic dosimeters determined in a continuous radiation field cannot be transferred to those in pulsed fields. Some provisional measurements with typical electronic dosimeters in pulsed radiation fields are presented to reveal this basic problem.

  7. 30 CFR 77.311 - Alarm devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Alarm devices. 77.311 Section 77.311 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY....311 Alarm devices. Thermal dryer systems shall be equipped with both audible and visual alarm...

  8. 21 CFR 876.2040 - Enuresis alarm.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Enuresis alarm. 876.2040 Section 876.2040 Food and... GASTROENTEROLOGY-UROLOGY DEVICES Monitoring Devices § 876.2040 Enuresis alarm. (a) Identification. An enuresis... type of device includes conditioned response enuresis alarms. (b) Classification. Class II...

  9. 10 CFR 74.57 - Alarm resolution.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Alarm resolution. 74.57 Section 74.57 Energy NUCLEAR... Quantities of Strategic Special Nuclear Material § 74.57 Alarm resolution. (a) Licensees subject to § 74.51 shall provide the MC&A alarm resolution capabilities described in paragraphs (b) through (f) of...

  10. Monitor alarm fatigue: standardizing use of physiological monitors and decreasing nuisance alarms.

    Science.gov (United States)

    Graham, Kelly Creighton; Cvach, Maria

    2010-01-01

    Reliance on physiological monitors to continuously "watch" patients and to alert the nurse when a serious rhythm problem occurs is standard practice on monitored units. Alarms are intended to alert clinicians to deviations from a predetermined "normal" status. However, alarm fatigue may occur when the sheer number of monitor alarms overwhelms clinicians, possibly leading to alarms being disabled, silenced, or ignored. Excessive numbers of monitor alarms and fear that nurses have become desensitized to these alarms was the impetus for a unit-based quality improvement project. Small tests of change to improve alarm management were conducted on a medical progressive care unit. The types and frequency of monitor alarms in the unit were assessed. Nurses were trained to individualize patients' alarm parameter limits and levels. Monitor software was modified to promote audibility of critical alarms. Critical monitor alarms were reduced 43% from baseline data. The reduction of alarms could be attributed to adjustment of monitor alarm defaults, careful assessment and customization of monitor alarm parameter limits and levels, and implementation of an interdisciplinary monitor policy. Although alarms are important and sometimes life-saving, they can compromise patients' safety if ignored. This unit-based quality improvement initiative was beneficial as a starting point for revamping alarm management throughout the institution.

  11. HYBRID ALARM SYSTEMS: COMBINING SPATIAL ALARMS AND ALARM LISTS FOR OPTIMIZED CONTROL ROOM OPERATION

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring; J.J. Persensky

    2012-07-01

    The US Department of Energy (DOE) is sponsoring research, development, and deployment on Light Water Reactor Sustainability (LWRS), in which the Idaho National Laboratory (INL) is working closely with nuclear utilities to develop technologies and solutions to help ensure the safe operational life extension of current nuclear power plants. One of the main areas of focus is control room modernization. Within control room modernization, alarm system upgrades present opportunities to meet the broader goals of the LWRS project in demonstrating the use and safety of the advanced instrumentation and control (I&C) technologies and the short-term and longer term objectives of the plant. In this paper, we review approaches for and human factors issues behind upgrading alarms in the main control room of nuclear power plants.

  12. A comparison of the dosimetric characteristics of a glass rod dosimeter and a thermoluminescent dosimeter for mailed dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Rah, Jeong-Eun [Department of Biomedical Engineering, Catholic University of Korea, College of Medicine, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul (Korea, Republic of); Hong, Ju-Young [Department of Radiation Oncology, Kangnam St. Mary' s Hospital, College of Medicine, Catholic University of Korea, Seoul (Korea, Republic of); Kim, Gwe-Ya [Department of Radiation Oncology, Austin Caner Centers, Austin, TX (United States); Kim, Yon-Lae [Department of Radiation Oncology, Konkuk University Hospital, Seoul (Korea, Republic of); Shin, Dong-Oh [Department of Radiation Oncology, Kyung Hee University, School of Medicine, Seoul (Korea, Republic of); Suh, Tae-Suk [Department of Biomedical Engineering, Catholic University of Korea, College of Medicine, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul (Korea, Republic of)], E-mail: suhsanta@catholic.ac.kr

    2009-01-15

    A radiophotoluminescent glass rod dosimeter (RPL-GRD) system has recently become commercially available. The purpose of this study was to investigate the dosimetric characteristics (reproducibility, linearity, fading, energy dependence and angular dependence) of the RPL-GRD for a mailed dosimeter and to compare it with LiF-TLD powder. In this study, the model GD-301 GRD and TLD-700 were powder type used. All measurements with the exception of angular dependence were performed in a water phantom using a holder stand. The RPL-GRD has better reproducibility than the TLD for the Co-60 beam as well as for the clinical photon beam. The RPL-GRD signal was linear as a function of applied dose in the range of 0.5-3 Gy for the Co-60 gamma rays. The fading of the RPL-GRD after a received dose of 2 Gy was initially found to be within 1.7% for five months. The energy dependence of both dosimeters was found to be less than 1.6% for photon beams, but was less than 5.0% for electron beams, which was in agreement with published data. The angular dependence of the RPL-GRD was measured to be approximately 1.4% for angles ranging {+-}90 deg. from the beam axis using a spherical polystyrene phantom. The measurements comparing RPL-GRD and TLD dosimetric characteristics demonstrated that the RPL-GRD is suitable for mailed dosimetry in a quality assurance (QA) audit program.

  13. Optical Fibre Dosimeter for SASE FEL Undulators

    CERN Document Server

    Körfer, M

    2003-01-01

    Single pass Free Electron Lasers (FELs) based on self-amplified spontaneous emission (SASE) are developed for high brightness and short wavelength applications. They use permanent magnet undulators which are radiation sensitive devices. During accelerator commissioning beam losses can appear anywhere along the undulator line. To avoid damage of the permanent magnets due to radiation, an optical fibre dosimeter system can be used. The increase of absorption caused by ionizing radiation is measured in radiation sensitive optical fibers. The dose system enables relatively fast particle loss tuning during accelerator operation and allows the monitoring of the accumulated dose. Dose measurements in narrow gaps which are inaccessible for any other (online) dosimeter type become possible. The electromagnetic insensitivity of optical fibre sensor is an advantage of applications in strong magnetic undulator fields. At each location the light absorption is measured by using an optical power-meter. The dynamic range is ...

  14. Alarming Rise In Birth Defects

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A rapid rise in birth defects has prompted China to look for causes and solutionsEvery 60 seconds two children are born in China with a handicap.It’s an alarming fact,but one that young adults across the country who hope to have children face every day. At a conference on the prevention of birth defects in Chengdu of Sichuan Province in September,Vice Minister of the National Population and Family Planning Commission Jiang Fan revealed this inconvenient truth, supported by shocking statistics.

  15. Video systems for alarm assessment

    Energy Technology Data Exchange (ETDEWEB)

    Greenwoll, D.A.; Matter, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Ebel, P.E. (BE, Inc., Barnwell, SC (United States))

    1991-09-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing closed-circuit television systems for video alarm assessment. There is a section on each of the major components in a video system: camera, lens, lighting, transmission, synchronization, switcher, monitor, and recorder. Each section includes information on component selection, procurement, installation, test, and maintenance. Considerations for system integration of the components are contained in each section. System emphasis is focused on perimeter intrusion detection and assessment systems. A glossary of video terms is included. 13 figs., 9 tabs.

  16. Alarms Remain,Efforts Continue

    Institute of Scientific and Technical Information of China (English)

    Alice

    2007-01-01

    @@ China must come to terms with the fact that it has quality problems in at least 1% of its products.Though there is no country in the world that can completely avoid problems,given the responsible role China plays on the intemational stage,China should stop to take a look at itself and find ways to improve.China must examine herself carefully,when looking at the production chain;we have to keep aware that some alarms still remain.

  17. Real-time Alarm Monitoring System for Detecting Driver Fatigue in Wireless Areas

    Directory of Open Access Journals (Sweden)

    Rongrong Fu

    2017-04-01

    Full Text Available The purpose of this paper was to develop a real-time alarm monitoring system that can detect the fatigue driving state through wireless communication. The drivers’ electroencephalogram (EEG signals were recorded from occipital electrodes. Seven EEG rhythms with different frequency bands as gamma, hbeta, beta, sigma, alpha, theta and delta waves were extracted. They were simultaneously assessed using relative operating characteristic (ROC curves and grey relational analysis to select one as the fatigue feature. The research results showed that the performance of theta wave was the best one. Therefore, theta wave was used as fatigue feature in the following alarm device. The real-time alarm monitoring system based on the result has been developed, once the threshold was settled by using the data of the first ten minutes driving period. The developed system can detect driver fatigue and give alarm to indicate the onset of fatigue automatically.

  18. Measurements of SNAC2 area dosimeters placed in different configurations around the PROSPERO reactor and comparison with TRIPOLI-4 calculations

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, G.; Chambru, L.; Authier, N. [CEA, Centre de Valduc, 21120 Is-sur-Tille, (France)

    2015-07-01

    In the context of criticality accident alarm system tests, several experiments were carried out in 2013 on the PROSPERO reactor to study the response to neutron and gamma of different devices and dosimeters, particularly on the SNAC2 dosimeter. This article presents the results of this criticality dosimeter in different configurations, and compares the experimental measurements with the results of calculation performed with the TRIPOLI-4 Monte-Carlo Neutral Particles transport code. PROSPERO is a metallic critical assembly managed by the Criticality, Neutron Science and Measurement Department located at the French CEA Research Center of Valduc. The core, surrounded by a reflector of depleted uranium, is composed of 2 horizontal cylindrical blocks made of a highly enriched uranium alloy which can be placed in contact, and of 4 depleted uranium control rods which allow the reactor to be driven. This reactor, placed in a cell 10 m x 8 m x 6 m high, with 1.4-meter-thick concrete walls, is used as a fast neutron spectrum source and is operated at stable power level in delayed critical state, which can vary from 3 mW to 3 kW. PROSPERO is extensively used for electronic hardening or to study the effect of the neutrons on various materials. The SNAC2 criticality dosimeter is a zone dosimeter allowing the off line measurement of criticality accident neutron doses. This dosimeter consists of the pile up of seven activation foils embedded into a 23 mm diameter x 21 mm height cadmium container. The activation measurement of each foil, using a gamma spectroscopy technique, gives information about the neutron reaction rates. The SNAC2 software allows the spectrum unfolding from these values, taking into account the hypothesis of a particular spectrum shape, in three components: a Maxwell spectrum component for the thermal range, a 1/E component for the epithermal range, and a Watt spectrum component for the high energy range. Moreover, from the neutron spectrum, the SNAC

  19. Hanford beta-gamma personnel dosimeter prototypes and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Fix, J.J.; Holbrook, K.L.; Soldat, K.L.

    1983-04-01

    Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips.

  20. Standard Procedure for Calibrating an Areal Calorimetry Based Dosimeter

    Science.gov (United States)

    2015-05-01

    2015 AFRL-RH-FS-TR-2015-0013 Standard Procedure for Calibrating an Areal Calorimetry Based Dosimeter Charles W. Beason Devon Ryan...0013 "Standard Procedure for Calibrating an Areal Calorimetry Based Dosimeter" TR LELAND JOHNSON, DR-III, DAF Contract Monitor Radio Frequency...Calibrating an Areal Calorimetry Based Dosimeter 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 62202F 6. AUTHOR(S) 5d. PROJECT NUMBER N/A Charles W

  1. Reactor Gamma Heat Measurements with Calorimeters and Thermoluminescence Dosimeters

    DEFF Research Database (Denmark)

    Haack, Karsten; Majborn, Benny

    1973-01-01

    Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than calorimet...... calorimeters, but possess advantages such as a small probe size and the possibility of making simultaneous measurements at many different positions. Hence, thermoluminescence dosimeters may constitute a valuable supplement to calorimeters for reactor γ-ray heating measurements....

  2. Comparison of the fiber optic dosimeter and semiconductor dosimeter for use in diagnostic radiology

    Science.gov (United States)

    Yoo, W. J.; Shin, S. H.; Sim, H. I.; Hong, S.; Kim, S. G.; Jang, J. S.; Kim, J. S.; Jeon, H. S.; Kwon, G. W.; Jang, K. W.; Cho, S.; Lee, B.

    2014-05-01

    A fiber-optic dosimeter (FOD) was fabricated using a plstic scintillating fiber, a plastic optical fiber, and a multi-pixel photon counter to measure entrance surface dose (ESD) in diagnostic radiology. Under changing tube current and irradition time of the digital radiography (DR) system, we measured the scintillating light and the ESD simultaneously. As experiemtnal results, the total counts of the FOD were changed in a manner similar to the ESDs of the semiconductor dosimeter (SCD). In conclusion, we demonstrated that the proposed FOD minimally affected the diagnostic information of DR image while the SCD caused serious image artifacts.

  3. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    Science.gov (United States)

    Britton, Jr.; Charles L.; Buckner, Mark A.; Hanson, Gregory R.; Bryan, William L.

    2011-04-26

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  4. Alarm system management: evidence-based guidance encouraging direct measurement of informativeness to improve alarm response.

    Science.gov (United States)

    Rayo, Michael F; Moffatt-Bruce, Susan D

    2015-04-01

    Although there are powerful incentives for creating alarm management programmes to reduce 'alarm fatigue', they do not provide guidance on how to reduce the likelihood that clinicians will disregard critical alarms. The literature cites numerous phenomena that contribute to alarm fatigue, although many of these, including total rate of alarms, are not supported in the literature as factors that directly impact alarm response. The contributor that is most frequently associated with alarm response is informativeness, which is defined as the proportion of total alarms that successfully conveys a specific event, and the extent to which it is a hazard. Informativeness is low across all healthcare applications, consistently ranging from 1% to 20%. Because of its likelihood and strong evidential support, informativeness should be evaluated before other contributors are considered. Methods for measuring informativeness and alarm response are discussed. Design directions for potential interventions, as well as design alternatives to traditional alarms, are also discussed. With the increased attention and investment in alarm system management that alarm interventions are currently receiving, initiatives that focus on informativeness and the other evidence-based measures identified will allow us to more effectively, efficiently and reliably redirect clinician attention, ultimately improving alarm response. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. Alarm management for storage and transportation terminals; Gerenciamento de alarmes para terminais de transferencia e estocagem

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Patricia [PETROBRAS, Rio de Janeiro, RJ (Brazil); Feldman, Rafael Noac [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    Recently, in many industrial segments, it has been taken into account the issues related to the high amount of alarms that are announced in the control rooms, even if the industrial process is under normal conditions. Recent studies and surveys have shown that the three major problems related to it are: alarms that remain active during normal operation; alarms that remain chattering during an operational period; the phenomenon called Alarm flood, that occurs when an extensive amount of alarms is announced and the operator does not have enough time to take effective actions. In order to reduce or to eliminate the two above mentioned causes, alarm analysis and housekeeping, called Alarm Rationalization, have been efficient in major cases, because such facts occur mainly due to inadequate limits definition and/or equipment and instruments out of service or in maintenance. Such alarms are called in the literature as bad-actors or villains, and their occurrences may reach up to 50% of the daily total amount of alarms. This paper aims to present the main results of a project named Alarm Management for Transfer and Storage Terminals. The project development is based on two different terminal surveys, in order not only to identify the most frequent causes of undesirable alarms, but also to generate design standards. The main phases of the project are: alarm rationalization based on bad-actors detection; generate a set of design and operation standards; generate an Alarm Philosophy document for the Terminals. (author)

  6. Uncertainties encountered in implementation of adaptive planning with in vivo dosimeters.

    Science.gov (United States)

    Studenski, M T; Gardner, S J; Den, R B

    2015-01-01

    Under a previously approved institutional review board protocol for prostate cancer patients, implanted metal-oxide semiconductor field-effect transistor dosimeters (dose verification system, Sicel Technologies) were used for measurement of the in vivo delivered daily dose. This dosimetric information provided the ability to adapt the plan if the measured doses did not match the dose expected from the planning system. Due to the inherent uncertainty in the dosimeters, the decision to adapt the treatment plan was made only if readings differed by more than 7 % for three consecutive days. To validate this method, we acquired daily cone beam computed tomography images for five patients, and the dose delivered to the dosimeters was calculated by use of (1) an automated procedure (MIM Maestro, MIM Software) and (2) the treatment planning system (XIO, Elekta). 72 % of the doses calculated automatically fell within 1 % of the doses calculated in the planning system, and 99 % agreed within 2 %. When compared to the calculated dose, 53 % of the in vivo measurements fell within 3 % of the calculated dose, 80 % fell within 5 %, and 9.8 % were greater than 7 %, but never on three consecutive days. The measured doses agreed reasonably well with the calculated doses, supporting the decision to adapt the plan only if there were discrepancies of more than 7 % over three consecutive days. Even with the inherent uncertainty in the dosimeters, this adaptive planning method can detect delivery inaccuracies that would not otherwise be caught with the use of only daily image guidance or other dose calculation surrogates.

  7. 33 CFR 127.207 - Warning alarms.

    Science.gov (United States)

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The...

  8. TMACS test procedure TP001: Alarm management. Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    Scanlan, P.K.

    1994-09-01

    The TMACS Software Project Test Procedures translate the project`s acceptance criteria into test steps. Software releases are certified when the affected Test Procedures are successfully performed and the customers authorize installation of these changes. This Test Procedure addresses the Alarm Management requirements of the TMACS. The features to be tested are: real-time alarming on high and low level and discrete alarms, equipment alarms, dead-band filtering, alarm display color coding, alarm acknowledgement, and alarm logging.

  9. Alarm Fatigue: Use of an Evidence-Based Alarm Management Strategy.

    Science.gov (United States)

    Turmell, Jacob W; Coke, Lola; Catinella, Rachel; Hosford, Tracy; Majeski, Amy

    The purpose of this article is to describe the impact of an evidence-based alarm management strategy on patient safety. An alarm management program reduced alarms up to 30%. Evaluation of patients on continuous cardiac monitoring showed a 3.5% decrease in census. This alarm management strategy has the potential to save $136 500 and 841 hours of registered nurses' time per year. No patient harm occurred during the 2-year project.

  10. Positioning of personnel dosimeters - comments on replies

    Energy Technology Data Exchange (ETDEWEB)

    Field, R.W. (Academy of Health Sciences, U.S. Army, Fort Sam Houston, TX); Wiatrowski, W.A. (Audi L. Murphy Memorial Veterans Hospital, San Antonio, TX (USA)); Bushong, S.C. (Baylor Univ., Houston, TX (USA). Coll. of Medicine)

    1982-02-01

    Comments are made on a paper published in 1980 concerning the positioning of personnel dosimeters on individuals wearing protective aprons in diagnostic radiology. The main issue under discussion is whether an additional film badge should be worn on the collar to monitor head and neck exposure while wearing the lead apron over the whole body badge to avoid misinterpretations of reported 'whole body' exposure data. The recommendations on this issue are conflicting in NRCP Reports 57 and 59 and thus clarification is sought.

  11. Phosphate Glass Gamma-Radiation Dosimeter

    Science.gov (United States)

    1952-11-30

    JH Section 3F» 3he PluftXmafoSEP 3 illM^An «ft*i tiöu« Plate 1 Shows the appearance of the !?P-60(XN-»3)/H) dosimeter, or radiac detector...200 r and MB! RESTRICTED FyT^&jw^* ^XJ^ WWW^^S^*^?^^?^’ ’:myv) f’Ol.ArO!»’« rOf.f’. JhV fiOll HI.V-fc "• KCH ÜfPARTMFMT RESTRICTED -56- The

  12. Evaluation of a Colorimetric Personal Dosimeter for Nitrogen Oxide.

    Science.gov (United States)

    Diamond, Philip

    A personal colorimetric dosimeter for nitrogen dioxide was developed. Tests were performed to determine the response of these strips to various concentrations of NO2. The dosimeter strips were satisfactory for approximate determinations of total exposure (concentration + time) of nitrogen dioxide. The total exposure was calculated in terms of time…

  13. Knowledge Discovery from Communication Network Alarm Databases

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The technique of Knowledge Discovery in Databases(KDD) to learn valuable knowledge hidden in network alarm databases is introduced. To get such knowledge, we propose an efficient method based on sliding windows (named as Slidwin) to discover different episode rules from time sequential alarm data. The experimental results show that given different thresholds parameters, large amount of different rules could be discovered quickly.

  14. 46 CFR 130.450 - Machinery alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms....

  15. Light scattering in optical CT scanning of Presage dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y; Adamovics, J; Cheeseborough, J C; Chao, K S; Wuu, C S, E-mail: yx2010@columbia.ed

    2010-11-01

    The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS' optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

  16. SU-E-T-265: Presage Thin Sheet Dosimeter Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, M; Rakowski, J [Wayne State University/Karmanos Cancer Institute, Detroit, MI (United States)

    2014-06-01

    Purpose: To quantify the sensitivity and stability of the Presage dosimeter in sheet form for different concentrations of chemicals and for a diverse range of clinical photon energies. Methods: Presage polymer dosimeters are formulated to investigate and optimize their sensitivity and stability. The dosimeter is composed of clear polyurethane base, leucomalachite green reporting dye, and bromoform radical initiator in 1mm thick sheets. The chemicals are well mixed together, cast in an aluminum mold, and left to cure at 60 psi for a minimum of 2 days. Dosimeter response will be characterized at multiple energies including Co-60, 6 MV, 15 MV, 50 kVp, and 250 kVp. The dosimeters are read by an Epson 10000 XL scanner at 800 dpi, 2{sup 16} bit depth. Red component images are analyzed with ImageJ. Results: Analysis of optical density verse dose for Co-60 energies indicates that the bromoform containing Presage was able to quantify dose from 0 to 300 Gy, with saturation beyond 300 Gy. Initial results show two regions of linear response, 0–100 Gy and 150–300 Gy. The 150–300 Gy region has a sensitivity of 0.0024 net OD/Gy. Further results on other energies are still in progress. Conclusions: This work shows the potential for use of thin sheets of Presage dosimeter as a dosimeter capable of being analyzed with a flatbed scanner.

  17. Novel approach to cardiac alarm management on telemetry units.

    Science.gov (United States)

    Whalen, Deborah A; Covelle, Patricia M; Piepenbrink, James C; Villanova, Karen L; Cuneo, Charlotte L; Awtry, Eric H

    2014-01-01

    General medical-surgical units struggle with how best to use cardiac monitor alarms to alert nursing staff to important abnormal heart rates (HRs) and rhythms while limiting inappropriate and unnecessary alarms that may undermine both patient safety and quality of care. When alarms are more often false than true, the nursing staff's sense of urgency in responding to alarms is diminished. In this syndrome of "clinical alarm fatigue," the simple burden of alarms desensitizes caregivers to alarms. Noise levels associated with frequent alarms may also heighten patient anxiety and disrupt their perception of a healing environment. Alarm fatigue experienced by nurses and patients is a significant problem and innovative solutions are needed. The purpose of this quality improvement study was to determine variables that would safely reduce noncritical telemetry and monitor alarms on a general medical-surgical unit where standard manufacturer defaults contributed to excessive audible alarms. Mining of alarm data and direct observations of staff's response to alarms were used to identify the self-reset warning alarms for bradycardia, tachycardia, and HR limits as the largest contributors of audible alarms. In this quality improvement study, the alarms for bradycardia, tachycardia, and HR limits were changed to "crisis," requiring nursing staff to view and act on the alarm each time it sounded. The limits for HR were HR low 45 bpm and HR high 130 bpm. An overall 89% reduction in total mean weekly audible alarms was achieved on the pilot unit (t = 8.84; P monitoring events, and the incidence of code blues decreased by 50%. Alarms with self-reset capabilities may result in an excess number of audible alarms and clinical alarm fatigue. By eliminating self-resetting alarms, the volume of audible alarms and associated clinical alarm fatigue can be significantly reduced without requiring additional resources or technology or compromising patient safety and lead to improvement in

  18. Personal Active Dosimeter for Space: the Light Observer for Radiation Environment (LORE) project

    Science.gov (United States)

    Narici, Livio

    Long permanence in space outside the protections of the Earth magnetic shield and atmosphere (during long journeys, and on the Moon or/and Mars) requires a careful monitoring of absorbed doses by each astronaut. This is of paramount importance for transient and cumulative effects mostly due to Solar Particle Events. Alarming features and the possibility of monitoring absorbed dose also discriminating the kind of incoming radiation will be needed. Stemming from our large experience in detector building, in modelling, in designing of the supporting electronic, from our payloads flown on satellites, MIR Station and ISS (Nina, Mita, SilEye, SilEye2, Alteino, Pamela, ALTEA) we are developping a personal active dosimeter with alarming and wireless features. The goal is a small object able to measure charged and neutral ionizing radiation (the possibility to insert a miniaturized gamma detector will be investigated) The device will feature portability (cigarette-box dimensions, rechargeable batteries), sensitivity to ions (H to above Fe), to hard X-rays, and possibly to gamma with the ability to detect and count neutrons. Flash memories should contain pre loaded tables and the real Time code to perform the real time operations and risk thresholds so to activate an alarm if/when needed. Whenever in range, the device will connect wirelessly to the main computer and send there the raw and pre-analyzed data for a complete monitoring and possible more sophisticated analyses. The two major novelties and challenges in this project are the miniaturization of the device, including the firmware, and the definition of the transfer function and of its uncertainties, linking measured data with real flux data. This will require the proper balancing among size, radiation discrimination ability and uncertainty minimization.

  19. Personal noise dosimeters: accuracy and reliability in varied settings.

    Science.gov (United States)

    Cook-Cunningham, Sheri Lynn

    2014-01-01

    This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units) in both pink noise (PN) environments and natural environments (NEs) through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3) Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a) All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b) all dosimeters were within the recommended American National Standard Institute (ANSI) SI.25-1991 standard of ±2 dB (A) of a reference measurement; and (c) all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A) when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students). This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D) were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera) while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured during

  20. There Is a Need for Alarm.

    Science.gov (United States)

    Kaufer, Steve

    1994-01-01

    Introduces the alarm system planning process and provides examples of approaches that have worked for school districts. Explains system elements, monitoring, the bidding process, and the importance of staff training. (MLF)

  1. Automatic video surveillance of outdoor scenes using track before detect

    DEFF Research Database (Denmark)

    Hansen, Morten; Sørensen, Helge Bjarup Dissing; Birkemark, Christian M.

    2005-01-01

    This paper concerns automatic video surveillance of outdoor scenes using a single camera. The first step in automatic interpretation of the video stream is activity detection based on background subtraction. Usually, this process will generate a large number of false alarms in outdoor scenes due...

  2. Miniature Space Dosimeter Based on Semiconductor Oxides Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro and Clemson University have teamed for a miniature, ultra low power, space radiation dosimeter. We project this unit, "MicroRad", to be 50X...

  3. Tissue-Equivalent Radiation Dosimeter-On-A-Chip Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Many commercially available digital dosimeters are bulky and are unable to properly measure dose for space radiation. The complexity of space flight design requires...

  4. Antioxidant effect of green tea on polymer gel dosimeter

    Science.gov (United States)

    Samuel, E. J. J.; Sathiyaraj, P.; Deena, T.; Kumar, D. S.

    2015-01-01

    Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer.

  5. Tissue-Equivalent Radiation Dosimeter-On-A-Chip Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Available digital dosimeters are bulky and unable to provide real-time monitoring of dose for space radiation. The complexity of space-flight design requires...

  6. A Medipix-Based Small Personal Space Radiation Dosimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR effort will take the first step in improving the existing Medipix dosimeter technology in terms of advancing the technique now used to couple the actual...

  7. Surface-enhanced Raman scattering (SERS) dosimeter and probe

    Science.gov (United States)

    Vo-Dinh, Tuan

    1995-01-01

    A dosimeter and probe for measuring exposure to chemical and biological compounds is disclosed. The dosimeter or probe includes a collector which may be analyzed by surface-enhanced Raman spectroscopy. The collector comprises a surface-enhanced Raman scattering-active material having a coating applied thereto to improve the adsorption properties of the collector. The collector may also be used in automated sequential devises, in probe array devices.

  8. Overview on conductometric solid-state gas dosimeters

    OpenAIRE

    I. Marr; Groß, A.; Moos, R.

    2014-01-01

    The aim of this article is to introduce the operation principles of conductometric solid-state dosimeter-type gas sensors, which have found increased attention in the past few years, and to give a literature overview on promising materials for this purpose. Contrary to common gas sensors, gas dosimeters are suitable for directly detecting the dose (also called amount or cumulated or integrated exposure of analyte gases) rather than the actual analyte concentration. Therefore...

  9. In vivo clinical dosimetry with LiF: PTFE dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, A. (Junta de Energia Nuclear, Madrid (Spain)); Manzanas, M.J.; Fernandez Leton, P. (Clinica Seg. Soc. 1. Octubre, Madrid (Spain))

    1984-01-01

    The purpose of this report is to describe the implementation of a dosimetric system suitable for ''in vivo'' measurements in some clinical applications. This system is based in re-usable thermoluminiscent dosimeters of Lithium fluoride embebded in teflon (PTFE). The results obtained in the utilization of these dosimeters for the determination of entrance absorbed doses on an antropomorphical phantom and patients are also presented. The irradiations have been made in several anatomical localizations with /sup 60/Co gamma rays. A great number of measurements has been made to determine properly the precision that can be reached with LiF: PTFE dosimeters. A considerable improvement of this precission has been obtained calibrating individually each dosimeter. The effects of the remanent sensibilization of the dosimeters that have received relatively high doses (approx. 1 Gy) are also reported. In order to take into account this unwanted effect it is necessary to calibrate frequently the dosimeters during their useful life, lowering, in this way, the risk of making wrong assignation of absorbed doses. From the results obtained in the measurements of absorbed doses in patients, it is clearly deduced that, even in anatomical localizations without special difficulties, such as the abdominal: flat and without problems to maintain the treatment position, rather high discrepancies can be found between the planned doses and those really imparted in practice. These results confirms the usefulness of making patient dose measurements in order to have effective control of the necessary quality of the therapeutical treatments.

  10. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

  11. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

  12. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

  13. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b) ...

  14. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next to...

  15. 46 CFR 162.050-35 - Bilge alarm: Approval tests.

    Science.gov (United States)

    2010-10-01

    ... mixture causing actuation of the alarm is taken. (2) If the alarm has a positive displacement mixture pump... mixture causing actuation of the alarm is taken. (3) If the alarm has a positive displacement mixture pump... centrifugal mixture pump or is not equipped with a mixture pump, the mixture flow rate is reduced to...

  16. 46 CFR 113.25-12 - Alarm signals.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Alarm signals. 113.25-12 Section 113.25-12 Shipping... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-12 Alarm signals. (a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of...

  17. 47 CFR 80.318 - Use of alarm signals.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Use of alarm signals. 80.318 Section 80.318... § 80.318 Use of alarm signals. (a) The radiotelegraph or radiotelephone alarm signal, as appropriate... transmission of an urgent cyclone warning. In this case the alarm signal may only be used by coast stations...

  18. Potential High Resolution Dosimeters For MRT

    Science.gov (United States)

    Bräuer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

    2010-07-01

    resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic® films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al2O3:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1×1 cm5 field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

  19. Skin autofluorescence as a biological UVR dosimeter.

    Science.gov (United States)

    Sandby-Møller, J; Thieden, E; Philipsen, P A; Heydenreich, J; Wulf, H C

    2004-02-01

    Collagen is one of the major endogenous skin fluorophores. Alteration in the structure of collagen due to chronic ultraviolet radiation (UVR) exposure may influence the intensity of the autofluorescence. The aim of this study was to investigate the relation between collagen-linked autofluorescence and sun exposure to clarify whether the skin can be used as a biological UVR dosimeter. We conducted an in vivo study with 131 healthy volunteers. Fluorescence was measured from sun-exposed (dorsal forearm, forehead and shoulder) and sun-protected (buttock) skin and corrected for the impact of pigmentation and redness. The excitation wavelengths (Ex) and emission wavelengths (Em) were: Ex330:Em370, Ex330:Em455 and Ex370:Em455 nm. Individual UVR exposure data were collected both retrospectively and prospectively using questionnaires and electronic personal UVR dosimeters for a summer period. Age, but not sex, skin type or smoking habits correlated significantly positively with skin autofluorescence at Ex370:Em455 at all body sites (P<0.001, r(2)=0.08-0.26), and at Ex330:Em455 only at the buttock (P=0.001, r(2)=0.08), whereas age was not correlated with Ex330:Em370. Sun-protected buttock skin had significantly higher autofluorescence than sun-exposed skin (P-values<0.0001). Because of great between-subject differences in autofluorescence at different body sites, and because the autofluorescence at the unexposed buttock represents the baseline value, individual correction of skin autofluorescence measurement with that of the buttock was performed. Different measures of individual chronic cumulative UVR doses correlated significantly negatively with the skin autofluorescence ratio (F(ratio)), but the correlations were poor (r(2)=0.03-0.10). The results indicate that the collagen-linked skin F(ratio) might be best to use as a measure of individual photodamage, a UVR dose effect, and that it is also a better marker of individual cumulative UVR dose than the used UVR exposure

  20. Clinical Alarms in intensive care: implications of alarm fatigue for the safety of patients.

    Science.gov (United States)

    Bridi, Adriana Carla; Louro, Thiago Quinellato; da Silva, Roberto Carlos Lyra

    2014-01-01

    to identify the number of electro-medical pieces of equipment in a coronary care unit, characterize their types, and analyze implications for the safety of patients from the perspective of alarm fatigue. this quantitative, observational, descriptive, non-participatory study was conducted in a coronary care unit of a cardiology hospital with 170 beds. a total of 426 alarms were recorded in 40 hours of observation: 227 were triggered by multi-parametric monitors and 199 were triggered by other equipment (infusion pumps, dialysis pumps, mechanical ventilators, and intra-aortic balloons); that is an average of 10.6 alarms per hour. the results reinforce the importance of properly configuring physiological variables, the volume and parameters of alarms of multi-parametric monitors within the routine of intensive care units. The alarms of equipment intended to protect patients have increased noise within the unit, the level of distraction and interruptions in the workflow, leading to a false sense of security.

  1. PDT dose dosimeter for pleural photodynamic therapy

    Science.gov (United States)

    Kim, Michele M.; Darafsheh, Arash; Ahmad, Mahmoud; Finlay, Jarod C.; Zhu, Timothy C.

    2016-03-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in the target tissue. For improved dosimetry during plural photodynamic therapy (PDT), a PDT dose dosimeter was developed to measure both the light fluence and the photosensitizer concentration simultaneously in the same treatment location. Light fluence and spectral data were rigorously compared to other methods of measurement (e.g. photodiode, multi-fiber spectroscopy contact probe) to assess the accuracy of the measurements as well as their uncertainty. Photosensitizer concentration was obtained by measuring the fluorescence of the sensitizer excited by the treatment light. Fluence rate based on the intensity of the laser spectrum was compared to the data obtained by direct measurement of fluence rate by a fiber-coupled photodiode. Phantom studies were done to obtain an optical property correction for the fluorescence signal. Measurements were performed in patients treated Photofrin for different locations in the pleural cavity. Multiple sites were measured to investigate the heterogeneity of the cavity and to provide cross-validation via relative dosimetry. This novel method will allow for accurate real-time determination of delivered PDT dose and improved PDT dosimetry.

  2. System for alarms analysis and optimization in petrochemicals plants; Sistema para analise e otimizacao de alarmes em plantas petroquimicas

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Gustavo; Pifer, Aderson; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Saito, Kaku; Aquino, Leonardo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The present work presents a group of algorithms, techniques and functionalities on alarms management which can be used efficiently on the treatment of 'disturbances' caused by the informal management of the alarm systems. Among the disturbances handled by these techniques, there is the recognition of intermittent alarms and false alarms, location of alarm floods and correlation between alarms, aiming the identification of communal root causes. The results will be presented through a case study on petrochemical alarm plants. At last, the results obtained by the utilization of such functionalities will be presented and discussed. (author)

  3. Behavioral alarm treatment for nocturnal enuresis

    Directory of Open Access Journals (Sweden)

    Rodrigo F. Pereira

    2010-06-01

    Full Text Available PURPOSES: To investigate the efficacy of alarm treatment in a sample of Brazilian children and adolescents with nocturnal enuresis and relate treatment success to age and type of clinical support. MATERIALS AND METHODS: During 32 weeks, 84 children and adolescents received alarm treatment together with weekly psychological support sessions for individual families or groups of 5 to 10 families. RESULTS: 71% of the participants achieved success, defined as 14 consecutive dry nights. The result was similar for children and adolescents and for individual or group support. The time until success was shorter for participants missing fewer support sessions. CONCLUSIONS: Alarm treatment was effective for the present sample, regardless of age or type of support. Missing a higher number of support sessions, which may reflect low motivation for treatment, increased the risk of failure.

  4. Likelihood alarm displays. [for human operator

    Science.gov (United States)

    Sorkin, Robert D.; Kantowitz, Barry H.; Kantowitz, Susan C.

    1988-01-01

    In a likelihood alarm display (LAD) information about event likelihood is computed by an automated monitoring system and encoded into an alerting signal for the human operator. Operator performance within a dual-task paradigm was evaluated with two LADs: a color-coded visual alarm and a linguistically coded synthetic speech alarm. The operator's primary task was one of tracking; the secondary task was to monitor a four-element numerical display and determine whether the data arose from a 'signal' or 'no-signal' condition. A simulated 'intelligent' monitoring system alerted the operator to the likelihood of a signal. The results indicated that (1) automated monitoring systems can improve performance on primary and secondary tasks; (2) LADs can improve the allocation of attention among tasks and provide information integrated into operator decisions; and (3) LADs do not necessarily add to the operator's attentional load.

  5. Description and evaluation of the Hanford personnel dosimeter program from 1944 through 1989. [Contain Glossary

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R.H.; Fix, J.J.; Baumgartner, W.V.; Nichols, L.L.

    1990-09-01

    This report describes the evolution of personnel dosimeter technology at Hanford since the inception of Hanford operations in 1944. Each of the personnel dosimeter systems used by people working or visiting Hanford is described. In addition, the procedures used to calibrate and calculate dose for each of the dosimeter systems are described. The accuracy of the recorded dose, primarily whole body deep dose, for the different dosimeter systems is evaluated. The evaluation is based on an extensive review of historical literature, as well as a 1989 intercomparison study of all film dosimeters and performance testing of the thermoluminescent dosimeter, also conducted during 1989. 73 refs., 40 figs., 41 tabs.

  6. Automatic sequences

    CERN Document Server

    Haeseler, Friedrich

    2003-01-01

    Automatic sequences are sequences which are produced by a finite automaton. Although they are not random they may look as being random. They are complicated, in the sense of not being not ultimately periodic, they may look rather complicated, in the sense that it may not be easy to name the rule by which the sequence is generated, however there exists a rule which generates the sequence. The concept automatic sequences has special applications in algebra, number theory, finite automata and formal languages, combinatorics on words. The text deals with different aspects of automatic sequences, in particular:· a general introduction to automatic sequences· the basic (combinatorial) properties of automatic sequences· the algebraic approach to automatic sequences· geometric objects related to automatic sequences.

  7. Poison and alarm: the Asian hornet Vespa velutina uses sting venom volatiles as an alarm pheromone.

    Science.gov (United States)

    Cheng, Ya-Nan; Wen, Ping; Dong, Shi-Hao; Tan, Ken; Nieh, James C

    2017-02-15

    In colonial organisms, alarm pheromones can provide a key fitness advantage by enhancing colony defence and warning of danger. Learning which species use alarm pheromone and the key compounds involved therefore enhances our understanding of how this important signal has evolved. However, our knowledge of alarm pheromones is more limited in the social wasps and hornets compared with the social bees and ants. Vespa velutina is an economically important and widespread hornet predator that attacks honey bees and humans. This species is native to Asia and has now invaded Europe. Despite growing interest in V. velutina, it was unknown whether it possessed an alarm pheromone. We show that these hornets use sting venom as an alarm pheromone. Sting venom volatiles were strongly attractive to hornet workers and triggered attacks. Two major venom fractions, consisting of monoketones and diketones, also elicited attack. We used gas chromatography coupled to electroantennographic detection (GC-EAD) to isolate 13 known and 3 unknown aliphatic ketones and alcohols in venom that elicited conspicuous hornet antennal activity. Two of the unknown compounds may be an undecen-2-one and an undecene-2,10-dinone. Three major compounds (heptan-2-one, nonan-2-one and undecan-2-one) triggered attacks, but only nonan-2-one did so at biologically relevant levels (10 hornet equivalents). Nonan-2-one thus deserves particular attention. However, the key alarm releasers for V. velutina remain to be identified. Such identification will help to illuminate the evolution and function of alarm compounds in hornets.

  8. A revival of the alarm system: Making the alarm list useful during incidents

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, J. E.; Oehman, B.; Calzada, A. [GoalArt, Scheelevaegen 17, 223 70 Lund (Sweden); Nihlwing, C.; Jokstad, H.; Kristianssen, L. I.; Kvalem, J. [IFE, OS alle 13, 1777 Halden (Norway); Lind, M. [Oested-DTU, Technical Univ. of Denmark, DK-2800, Kongens Lyngby (Denmark)

    2006-07-01

    In control rooms there are often problems with information overload, which means that the operators may receive more information than they are able to interpret. The most serious information overload occurs in two types of situations. The first is when the operating state of the plant changes, which often gives raise to a shower of alarms and events. Such an alarm shower is expected, but can be dangerous, because it may hide other alarms originating from unrelated faults. The second problem occurs when a fault causes several consequential faults, leading to a so-called alarm cascade. Because the alarms seldom arrive in correct time order, it can be very difficult to analyze such a cascade, and the information overload occurs in exactly the moment when a potentially dangerous situation starts. In an ongoing project, GoalArt and IFE are cooperating in testing and evaluating GoalArt's methods for alarm reduction and root cause analysis. The testing comprises two specific algorithms, root cause analysis and state-based alarm priority. The GoalArt system has been integrated with the HAMBO simulator so that operators can evaluate the algorithms on-line. (authors)

  9. ALARM STRATEGY AND COMPLEXITY: PREDICTIONS OF OPERATOR RESPONSE

    Energy Technology Data Exchange (ETDEWEB)

    Austin Ragsdale; Roger Lew; Brian Dyre; Ronald Boring; David Gertman

    2012-07-01

    Decision support for operators is not new, and much has been written regarding the potential usefulness of digital support systems and alarm filtering strategies. However, determining the appropriate characteristics of decision support tools is difficult, especially when alarms can vary in the manner which diagnostic information is formulated and displayed and when event scenario types are complex and numerous. When first reviewed, the advantages or disadvantages of a particular alarm approach may not be apparent to the designer or analyst. The present research focuses on the review of two particular alarm strategies, binary alarm type (BAT) and likelihood alarm type (LAT), and reviews their influence upon accuracy, bias, and trust for tasks performed at a computer workstation capable of replicating a series of control-room-like alarms. The findings are discussed in terms of the of the performance advantages of likelihood alarm technology and related research as an aid to the alarm design process.

  10. PNNL Results from 2010 CALIBAN Criticality Accident Dosimeter Intercomparison Exercise

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Robin L.; Conrady, Matthew M.

    2011-10-28

    This document reports the results of the Hanford personnel nuclear accident dosimeter (PNAD) and fixed nuclear accident dosimeter (FNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on September 20-23, 2010. Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimeter intercomparison exercise at the Commissariat a Energie Atomique (CEA) Valduc Center near Dijon, France on September 20-23, 2010. The intercomparison exercise was funded by the U.S. Department of Energy, Nuclear Criticality Safety Program, with Lawrence Livermore National Laboratory as the lead Laboratory. PNNL was one of six invited DOE Laboratory participants. The other participating Laboratories were: Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Savannah River Site (SRS), the Y-12 National Security Complex at Oak Ridge, and Sandia National Laboratory (SNL). The goals of PNNL's participation in the intercomparison exercise were to test and validate the procedures and algorithm currently used for the Hanford personnel nuclear accident dosimeters (PNADs) on the metallic reactor, CALIBAN, to test exposures to PNADs from the side and from behind a phantom, and to test PNADs that were taken from a historical batch of Hanford PNADs that had varying degrees of degradation of the bare indium foil. Similar testing of the PNADs was done on the Valduc SILENE test reactor in 2009 (Hill and Conrady, 2010). The CALIBAN results are reported here.

  11. A critical assessment of two types of personal UV dosimeters.

    Science.gov (United States)

    Seckmeyer, Gunther; Klingebiel, Marcus; Riechelmann, Stefan; Lohse, Insa; McKenzie, Richard L; Liley, J Ben; Allen, Martin W; Siani, Anna-Maria; Casale, Giuseppe R

    2012-01-01

    Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cut-off filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be over-estimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments. © 2011 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

  12. Photon and neutron kerma coefficients for polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    El-Khayatt, A.M., E-mail: Ahmed_el_khayatt@yahoo.com [Physics Department, College of Science, Al Imam Mohammad Ibn Saud Islamic University (IMSIU) (Saudi Arabia); Reactor Physics Department, Nuclear Research Centre, Atomic Energy Authority, 13759 Cairo (Egypt); Vega-Carrillo, Hector Rene [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, C. Cipres 10, Fracc. La Peñuela, 98068 Zacatecas, Zac. (Mexico)

    2015-08-21

    Neutron and gamma ray kerma coefficients were calculated for 17 3D dosimeters, for the neutron and gamma ray energy ranges extend from 2.53×10{sup −8} to 29 MeV and from 1.0×10{sup −3} to 20 MeV, respectively. The calculated kermas given here for discrete energies and the kerma coefficients are referred to as “point-wise data”. Curves of gamma ray kermas showed slight dips at about 60 keV for most 3D dosimeters. Also, a noticeable departure between thermal and epithermal neutrons kerma sets for water and polymers has been observed. Finally, the obtained results could be useful for dose estimation in the studied 3D dosimeters. - Highlights: • Neutron and gamma ray kerma coefficients were calculated in 17 3D dosimeters. • Curves of gamma-ray kermas showed slight dips at about 60 keV. • Disagreement between neutron kermas for water and polymers has been observed. • The obtained results could be useful for dose estimation in the studied dosimeters.

  13. Mianserin affects alarm reaction to conspecific chemical alarm cues in Nile tilapia.

    Science.gov (United States)

    Barreto, Rodrigo Egydio

    2017-02-01

    In this study, I show that mianserin, a chemical with serotonin and adrenoceptor antagonist activities, increases fish vulnerability to a potential predator threat, when prey fish must deal with this threat based on conspecific chemical alarm cues. For that, I evaluated whether mianserin, diluted in the water, influences the behavioral responses of Nile tilapia (Oreochromis niloticus) to conspecific skin extract (chemical alarm cues). I found that, while mianserin did not abolished antipredator responses, this drug mitigates some components of this defensive reaction. Thus, a potential decrease in serotonin and adrenergic activities reduces the ability of dealing with predators when perceiving conspecific chemical alarm cues.

  14. Stand-alone tsunami alarm equipment

    Science.gov (United States)

    Katsumata, Akio; Hayashi, Yutaka; Miyaoka, Kazuki; Tsushima, Hiroaki; Baba, Toshitaka; Catalán, Patricio A.; Zelaya, Cecilia; Riquelme Vasquez, Felipe; Sanchez-Olavarria, Rodrigo; Barrientos, Sergio

    2017-05-01

    One of the quickest means of tsunami evacuation is transfer to higher ground soon after strong and long ground shaking. Ground shaking itself is a good initiator of the evacuation from disastrous tsunami. Longer period seismic waves are considered to be more correlated with the earthquake magnitude. We investigated the possible application of this to tsunami hazard alarm using single-site ground motion observation. Information from the mass media is sometimes unavailable due to power failure soon after a large earthquake. Even when an official alarm is available, multiple information sources of tsunami alert would help people become aware of the coming risk of a tsunami. Thus, a device that indicates risk of a tsunami without requiring other data would be helpful to those who should evacuate. Since the sensitivity of a low-cost MEMS (microelectromechanical systems) accelerometer is sufficient for this purpose, tsunami alarm equipment for home use may be easily realized. Amplitude of long-period (20 s cutoff) displacement was proposed as the threshold for the alarm based on empirical relationships among magnitude, tsunami height, hypocentral distance, and peak ground displacement of seismic waves. Application of this method to recent major earthquakes indicated that such equipment could effectively alert people to the possibility of tsunami.

  15. TMACS Test Procedure TP001: Alarm Management

    Energy Technology Data Exchange (ETDEWEB)

    Scanlan, P.K.

    1994-05-31

    The TMACS Software Project Test Procedures translate the project`s acceptance criteria into test steps. Software releases are certified when the affected Test Procedures are successfully performed and the customers authorize installation of these changes. This Test Procedure tests the TMACS Alarm management functions.

  16. Nuclear power plant alarm systems: Problems and issues

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, J.M.; Brown, W.S.

    1991-01-01

    Despite the incorporation of advanced technology into nuclear power plant alarm systems, human factors problems remain. This paper identifies to be addressed in order to allow advanced technology to be used effectively in the design of nuclear power plant alarm systems. The operator's use and processing of alarm system information will be considered. Based upon a review of alarm system research, issues related to general system design, alarm processing, display and control are discussed. It is concluded that the design of effective alarm systems depends on an understanding of the information processing capabilities and limitations of the operator. 39 refs.

  17. Recall of Personal Dosimeters Not Presently in Use

    CERN Multimedia

    SC Unit

    2008-01-01

    The Dosimetry Service requests all persons who do not require access to radiation areas in the foreseeable future to return their personal dosimeter to the Dosimetry Service. This concerns, for example, experimental physicists whose beam time is over until 2009, or persons whose work profile has changed and therefore no longer need regular access to radiation areas. When regular access to radiation areas is needed again at a later date, a new dosimeter can be attributed if the prerequisites (medical fitness certificate, RP course) are met. This recall will allow personal dosimeters to be attributed to personnel who will soon be working in newly created radiation areas at the LHC. Thank you for your understanding and collaboration. Thomas Otto on behalf of the Dosimetry Service Radiation Protection Group

  18. Monitoring of environmental UV radiation by biological dosimeters.

    Science.gov (United States)

    Ronto, G; Berces, A; Grof, P; Fekete, A; Kerekgyarto, T; Gaspar, S; Stick, C

    2000-01-01

    As a consequence of the stratospheric ozone layer depletion biological systems can be damaged due to increased UV-B radiation. The aim of biological dosimetry is to establish a quantitative basis for the risk assessment of the biosphere. DNA is the most important target molecule of biological systems having special sensitivity against short wavelength components of the environmental radiation. Biological dosimeters are usually simple organisms, or components of them, modeling the cellular DNA. Phage T7 and polycrystalline uracil biological dosimeters have been developed and used in our laboratory for monitoring the environmental radiation in different radiation conditions (from the polar to equatorial regions). Comparisons with Robertson-Berger (RB) meter data, as well as with model calculation data weighted by the corresponding spectral sensitivities of the dosimeters are presented. Suggestion is given how to determine the trend of the increase in the biological risk due to ozone depletion. c2001 COSPAR Published by Elsevier Science Ltd. All rights reserved.

  19. Development and evaluation of polycrystalline cadmium telluride dosimeters for accurate quality assurance in radiation therapy

    Science.gov (United States)

    Oh, K.; Han, M.; Kim, K.; Heo, Y.; Moon, C.; Park, S.; Nam, S.

    2016-02-01

    For quality assurance in radiation therapy, several types of dosimeters are used such as ionization chambers, radiographic films, thermo-luminescent dosimeter (TLD), and semiconductor dosimeters. Among them, semiconductor dosimeters are particularly useful for in vivo dosimeters or high dose gradient area such as the penumbra region because they are more sensitive and smaller in size compared to typical dosimeters. In this study, we developed and evaluated Cadmium Telluride (CdTe) dosimeters, one of the most promising semiconductor dosimeters due to their high quantum efficiency and charge collection efficiency. Such CdTe dosimeters include single crystal form and polycrystalline form depending upon the fabrication process. Both types of CdTe dosimeters are commercially available, but only the polycrystalline form is suitable for radiation dosimeters, since it is less affected by volumetric effect and energy dependence. To develop and evaluate polycrystalline CdTe dosimeters, polycrystalline CdTe films were prepared by thermal evaporation. After that, CdTeO3 layer, thin oxide layer, was deposited on top of the CdTe film by RF sputtering to improve charge carrier transport properties and to reduce leakage current. Also, the CdTeO3 layer which acts as a passivation layer help the dosimeter to reduce their sensitivity changes with repeated use due to radiation damage. Finally, the top and bottom electrodes, In/Ti and Pt, were used to have Schottky contact. Subsequently, the electrical properties under high energy photon beams from linear accelerator (LINAC), such as response coincidence, dose linearity, dose rate dependence, reproducibility, and percentage depth dose, were measured to evaluate polycrystalline CdTe dosimeters. In addition, we compared the experimental data of the dosimeter fabricated in this study with those of the silicon diode dosimeter and Thimble ionization chamber which widely used in routine dosimetry system and dose measurements for radiation

  20. Perspectives on use of personal alarms by older fallers

    Directory of Open Access Journals (Sweden)

    Kylie Johnston

    2010-08-01

    Full Text Available Kylie Johnston1, Karen Grimmer-Somers1, Michele Sutherland21International Centre for Allied Health Evidence, University of South Australia, Adelaide; 2Falls Prevention Unit, Department of Health, Government of South Australia, Adelaide, AustraliaBackground: Personal alarms are proposed as a reliable mechanism for older people to obtain assistance after falling. However, little is known about how older people feel about owning and using personal alarms.Aim: This paper reports on experiences of independently living older people, who have recently fallen, regarding alarm use and their independence.Method: Volunteers older than 65 years who had sustained a fall in the previous six months were sought via community invitations. Semistructured telephone interviews were conducted to gain information about their fall and their perspectives on personal alarm use. Interviews were content-analyzed to identify key concepts and themes.Results: Thirty-one interviews were conducted. Twenty callers owned personal alarms. Four subgroups of older fallers were identified; the first group used personal alarms effectively and were advocates for their benefits, the second group owned an alarm but did not use it effectively, the third group did not own alarms mostly because of cost, although were receptive to an alarm should one be provided, and the fourth group did not have an alarm and would not use it even if it was provided.Discussion: Personal alarms produce positive experiences when used effectively by the right people. The cost of personal alarms prohibits some older fallers from being effective alarm users. However, other elderly fallers remain unwilling to consider alarm use even if one was provided. In view of their cost, personal alarms should be targeted to people who will benefit most. ­Alternative strategies should be considered when alarms are unlikely to be used appropriately.Keywords: personal alarm devices, falls, older people, patient perspective

  1. A Community Hospital's Evaluation of Alarm Management Safety Factors.

    Science.gov (United States)

    Kurnat-Thoma, Emma; Shah, Kayuri

    2016-12-01

    The Joint Commission's 2014 National Patient Safety Goals required hospitals to evaluate alarm safety in 2014-2015 and implement alarm safety policies. The aim of this study was to assess common alarm management safety factors in our 187-bed community hospital. Two weeks' worth of IV pump report data was evaluated to characterize 33 IV pump alarm types. Hospital and IV pump noise was measured, and an alarm management nurse survey was conducted. There were 8731 total IV pump alarms/alerts (24-hour mean, 623.6) across 6 units. The 2-minute idle alarm accounted for 32.4% of all total IV alarms/alerts, suggestive of high levels of nurse multitasking and nurse work interruptions. IV pump volumes contributed to overall hospital noise. Survey data identified patient units and alarm safety practices needing additional support. Characterization of IV pump alarms/alerts is an emerging area of scientific inquiry. Findings indicate the need for organizations to evaluate alarm burden and alarm management safety practices to reduce alarm fatigue risks.

  2. Patient characteristics associated with false arrhythmia alarms in intensive care.

    Science.gov (United States)

    Harris, Patricia R; Zègre-Hemsey, Jessica K; Schindler, Daniel; Bai, Yong; Pelter, Michele M; Hu, Xiao

    2017-01-01

    A high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics. A total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients' annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient characteristics were compared in relation to 1) the

  3. Patient characteristics associated with false arrhythmia alarms in intensive care

    Science.gov (United States)

    Harris, Patricia R; Zègre-Hemsey, Jessica K; Schindler, Daniel; Bai, Yong; Pelter, Michele M; Hu, Xiao

    2017-01-01

    Introduction A high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics. Results A total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients’ annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient

  4. Monte Carlo simulation experiments on box-type radon dosimeter

    Science.gov (United States)

    Jamil, Khalid; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-11-01

    Epidemiological studies show that inhalation of radon gas (222Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the 222Rn concentrations (Bq/m3) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter's dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (ηint) and alpha hit efficiency (ηhit). The ηint depends upon only on the dimensions of the dosimeter and ηhit depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper explains that how radon concentration from the

  5. Measurement of a PAGAT gel dosimeter by ultrasound computed tomography

    Science.gov (United States)

    Khoei, S.; Trapp, J. V.; Langton, C. M.

    2013-06-01

    In this work we used a 3D quantitative CT ultrasound imaging system to characterise polymer gel dosimeters. The system comprised of two identical 5 MHz 128 element phased-array ultrasound transducers co-axially aligned and submerged in water as a coupling agent. Rotational and translational movement of the gel dosimeter sample between the transducers were performed using a robotic arm. Ultrasound signals were generated and received using an Olympus Omniscan unit. Dose sensitivity of attenuation and time of flight ultrasonic parameters were assessed using this system.

  6. Mercuric iodide dosimeter response to high energy electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Loewinger, E.; Nissenbaum, J.; Schieber, M.M.

    1988-01-01

    Mercuric iodide solid state dosimeter response to high energy electron beams of up to 35 MeV is reported. High sensitivity of up to 1.5 V/cGy was observed with a 200 V external bias, as well as several mV/cGy, with no external bias for small volume (approx. 10 mm/sup 3/) detectors. The physical characteristics of the detector response are discussed, showing the feasibility of mercuric iodide as a reliable dosimeter for high energy electron beams.

  7. Basic radiological characteristics of a non-scattering gel dosimeter for 3D dosimetry

    Science.gov (United States)

    Chang, Kyung Hwan; Ji, Yunseo; Lee, Suk; Kim, Kwang Hyeon; Yang, Dae Sik; Lee, Jung Ae; Park, Young Je; Yoon, Won Sup; Kim, Chul Yong; Cao, Yuanjie; Cho, Samju

    2016-12-01

    We used a spectrophotometer to compare the dosimetric properties of two non-scattering (radiochromic) gel dosimeters: a non-scattering gel dosimeter developed in-house and a PRESAGE™ gel dosimeter. We evaluated the dosimetric characteristics, including spectral absorption, dose linearity, reproducibility, and dose rate dependency of the two gel dosimeters. The non-scattering gel and the PRESAGE™ gel dosimeters showed peak sensitivity at wavelengths of 600 nm and 630 nm, respectively. Over a range of doses the best dose linearities of the non-scattering and the PRESAGE™ gel dosimeters resulted in R2 values of 0.99 at wavelengths of 600 nm and 630 nm, respectively. The reproducibility and dose-rate dependence of each of the two gel dosimeters were within the range of ±3 %. Our results revealed that the peak sensitivities of the two radiochromic gel dosimeters were significantly different; the in-house non-scattering gel dosimeter demonstrated peak sensitivity at a wavelength of 600 nm while the PRESAGE™ gel dosimeter had peak sensitivity at a wavelength of 630 nm. We confirmed that for 3D gel dosimetry, the in-house non-scattering gel dosimeter had a more stable dose response compared with a commercial non-scattering gel dosimeter.

  8. Sensor fusion methods for reducing false alarms in heart rate monitoring.

    Science.gov (United States)

    Borges, Gabriel; Brusamarello, Valner

    2016-12-01

    Automatic patient monitoring is an essential resource in hospitals for good health care management. While alarms caused by abnormal physiological conditions are important for the delivery of fast treatment, they can be also a source of unnecessary noise because of false alarms caused by electromagnetic interference or motion artifacts. One significant source of false alarms is related to heart rate, which is triggered when the heart rhythm of the patient is too fast or too slow. In this work, the fusion of different physiological sensors is explored in order to create a robust heart rate estimation. A set of algorithms using heart rate variability index, Bayesian inference, neural networks, fuzzy logic and majority voting is proposed to fuse the information from the electrocardiogram, arterial blood pressure and photoplethysmogram. Three kinds of information are extracted from each source, namely, heart rate variability, the heart rate difference between sensors and the spectral analysis of low and high noise of each sensor. This information is used as input to the algorithms. Twenty recordings selected from the MIMIC database were used to validate the system. The results showed that neural networks fusion had the best false alarm reduction of 92.5 %, while the Bayesian technique had a reduction of 84.3 %, fuzzy logic 80.6 %, majority voter 72.5 % and the heart rate variability index 67.5 %. Therefore, the proposed algorithms showed good performance and could be useful in bedside monitors.

  9. Hazard detection and alarm systems of the EMAG Center used in Polish coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Firganek, B.; Mironowicz, W.

    1982-06-01

    This paper presents a review of equipment, measurement and alarm systems for underground mining developed and produced by the EMAG Center for Research and Production of Electrical Engineering and Mine Automation. The following systems for detection and measurement of methane content in mine air are evaluated: the VM-1p methane meter (range from 2 to 10% methane) the MCm-1 methane meter (range from 0 to 3 % methane), the MK-1A methane meter which is mounted on mining machines (it activates an alarm system when methane content in mine air exceeds 1%, 1.5% or 2%), stationary methane measuring systems (MIS-3A, MW-1), automatic methane measuring systems, e.g. the CTT-63/40Up methane station produced on the basis of French licence (Oldham), the CMC-1 methane measuring station developed by EMAG. Systems for detection of underground fires in coal mines are also described: the SATW-4bc carbon monoxide analyzer (used for detecting spontaneous combustion of coal), the SP-24 fire alarm system and the ADD-1 smoke detector used for detecting fires caused by reasons other than spontaneous combustion. Some systems for rock burst forecasting are evaluated: the PRS-4/a computer system, the PRS-4/m microseismologic system, the AUD-80 alarm system for coal mines. Design, specifications and schemes of the safety systems for underground mining are discussed.

  10. A Fault Alarm and Diagnosis Method Based on Sensitive Parameters and Support Vector Machine

    Science.gov (United States)

    Zhang, Jinjie; Yao, Ziyun; Lv, Zhiquan; Zhu, Qunxiong; Xu, Fengtian; Jiang, Zhinong

    2015-08-01

    Study on the extraction of fault feature and the diagnostic technique of reciprocating compressor is one of the hot research topics in the field of reciprocating machinery fault diagnosis at present. A large number of feature extraction and classification methods have been widely applied in the related research, but the practical fault alarm and the accuracy of diagnosis have not been effectively improved. Developing feature extraction and classification methods to meet the requirements of typical fault alarm and automatic diagnosis in practical engineering is urgent task. The typical mechanical faults of reciprocating compressor are presented in the paper, and the existing data of online monitoring system is used to extract fault feature parameters within 15 types in total; the inner sensitive connection between faults and the feature parameters has been made clear by using the distance evaluation technique, also sensitive characteristic parameters of different faults have been obtained. On this basis, a method based on fault feature parameters and support vector machine (SVM) is developed, which will be applied to practical fault diagnosis. A better ability of early fault warning has been proved by the experiment and the practical fault cases. Automatic classification by using the SVM to the data of fault alarm has obtained better diagnostic accuracy.

  11. Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Polyethylene Reflected Pulse of the CEA Valduc SILENE Critical Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McMahan, Kimberly L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Yi-kang [French Atomic Energy Commission (CEA), Saclay (France); Gagnier, Emmanuel [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Authier, Nicolas [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Piot, Jerome [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Jacquet, Xavier [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Rousseau, Guillaume [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-09-01

    This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 19, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube and the Rocky Flats detects neutrons via charged particles produced in a thin 6LiF disc depositing energy in a Si solid state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

  12. Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Polyethylene Reflected Pulse of the CEA Valduc SILENE Critical Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McMahan, Kimberly L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Yi-kang [French Atomic Energy Commission (CEA), Saclay (France); Gagnier, Emmanuel [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Authier, Nicolas [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Piot, Jerome [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Jacquet, Xavier [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Rousseau, Guillaume [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-09-01

    This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 19, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube and the Rocky Flats detects neutrons via charged particles produced in a thin 6LiF disc depositing energy in a Si solid state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

  13. Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Lead Reflected Pulse of the CEA Valduc SILENE Critical Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Isbell, Kimberly McMahan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Yi-kang [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Gagnier, Emmanuel [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Authier, Nicolas [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Piot, Jerome [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Jacquet, Xavier [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Rousseau, Guillaume [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-09-01

    This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 13, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube, and the Rocky Flats detects neutrons via charged particles produced in a thin 6LiF disc, depositing energy in a Si solid-state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

  14. 46 CFR 76.05-5 - Manual alarm system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Manual alarm system. 76.05-5 Section 76.05-5 Shipping... Fire Detecting and Extinguishing Equipment, Where Required § 76.05-5 Manual alarm system. (a) An approved manual alarm system shall be installed in all areas, other than the main machinery spaces,...

  15. 46 CFR 161.002-12 - Manual fire alarm systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Manual fire alarm systems. 161.002-12 Section 161.002-12...: SPECIFICATIONS AND APPROVAL ELECTRICAL EQUIPMENT Fire-Protective Systems § 161.002-12 Manual fire alarm systems. (a) General. A manual fire alarm system shall consist of a power supply, a control unit on which...

  16. Alarm fatigue: a roadmap for mitigating the cacophony of beeps.

    Science.gov (United States)

    Purbaugh, Thomas

    2014-01-01

    The phenomenon known as alarm fatigue is the direct result of excessive alarms in hospitals. This article highlights the effects of alarm fatigue and reviews current clinical recommendations and guidelines to raise nurse awareness and provide tools to combat the problem.

  17. 33 CFR 127.201 - Sensing and alarm systems.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.201 Sensing and alarm systems. (a) Fixed sensors must have audio and visual alarms in the control room and audio alarms...

  18. 21 CFR 870.1100 - Blood pressure alarm.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood...

  19. 46 CFR 130.460 - Placement of machinery alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to...

  20. 46 CFR 169.730 - General alarm bell switch.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false General alarm bell switch. 169.730 Section 169.730... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.730 General alarm bell switch. On vessels of 100 gross tons and over there must be a general alarm bell switch in the pilothouse,...

  1. 46 CFR 108.623 - General alarm bell switch.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false General alarm bell switch. 108.623 Section 108.623... AND EQUIPMENT Equipment Markings and Instructions § 108.623 General alarm bell switch. Each general alarm bell switch must be marked “GENERAL ALARM” on a plate or other firm noncorrosive backing....

  2. Optimal alarm system applied in coffee rust

    Directory of Open Access Journals (Sweden)

    Luciene Resende Gonçalves

    2014-02-01

    Full Text Available Alarm systems have very great utility in detecting and warning of catastrophes. This methodology was applied via TARSO model with Bayesian estimation, serving as a forecasting mechanism for coffee rust disease. The coffee culture is very susceptible to this disease causing several records of incidence in most cultivated crops. Researches involving this limiting factor for production are intense and frequent, indicating environmental factors as responsible for the epidemics spread, which does not occur if these factors are not favorable. The fitting type used by the a posteriori probability, allows the system to be updated each time point. The methodology was applied to the rust index series in the presence of the average temperature series. Thus, it is possible to verify the alarm resulted or in a high catastrophe detection in points at which the catastrophe has not occurred, or in the low detections if the point was already in the catastrophe state.

  3. Alarm annunciation in a graphical environment

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.G.

    1994-08-01

    Well-designed graphical user interfaces, such as Microsoft Windows{trademark} or UNIX{trademark} -- based X-Windows, provide a capability for enhanced display of security alarm information. Conversely, a poorly designed interface can quickly overwhelm an operator. This paper describes types of graphical information that can be displayed and offers guidance on how to best display that information. Limits are proposed for the complexity of the user interface, and guidelines are suggested for the display of maps and sensors.

  4. Research and implementation of intelligent alarm transceiver

    Institute of Scientific and Technical Information of China (English)

    Haobo long; XiaolingTian

    2015-01-01

    To design and implement a inteligent alarm transceiver, the sensor, such as temperature, voltage, video check. is used in transceiver. Then it analyses real-time acquisition data of sensor, if the transceiver is not working normaly, and the results are sent to the host computer. And the latter send fault information to user by mobile phone. During this period, without artificial participation, to achieve the purpose of inteligent warning. it can improve the maintenance efficiency of transceiver.

  5. Comprehensive Angular Response Study of LLNL Panasonic Dosimeter Configurations and Artificial Intelligence Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Stone, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-06-30

    In April of 2016, the Lawrence Livermore National Laboratory External Dosimetry Program underwent a Department of Energy Laboratory Accreditation Program (DOELAP) on-site assessment. The assessment reported a concern that the study performed in 2013 Angular Dependence Study Panasonic UD-802 and UD-810 Dosimeters LLNL Artificial Intelligence Algorithm was incomplete. Only the responses at ±60° and 0° were evaluated and independent data from dosimeters was not used to evaluate the algorithm. Additionally, other configurations of LLNL dosimeters were not considered in this study. This includes nuclear accident dosimeters (NAD) which are placed in the wells surrounding the TLD in the dosimeter holder.

  6. Dose response of thin-film dosimeters irradiated with 80-120 keV electrons

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; Sharpe, P.

    2005-01-01

    Thin-film dosimeters (Riso B3 and alanine films) were irradiated at 10 MeV and 80-120 keV electron accelerators, and it has been shown that the radiation response of the dosimeter materials (the radiation chemical yields) are constant at these irradiation energies. However, dose gradients within...... the dosimeters mean that calibration functions at the lower electron energies will be dependent on both irradiation energy and the required effective point of measurement of the dosimeter. These are general effects that apply to any dosimeters that have non-linear response functions and where dose gradients...

  7. Improvements in opti-chromic dosimeters for radiation processing

    Science.gov (United States)

    Humpherys, K. C.; Kantz, A. D.

    "Opti-Chromic" dosimeters consisting of radiachromic dye in flourinated polymer tubing have been introduced as a dosimetry system in the range from 10 1 to 5 × 10 4 Gy. Batches of "Opti-Chromic" dosimeters have been produced to evaluate performance under large scale industrial conditions. A systematic study was undertaken to determine the effect of various dosimeter parameters on radiation sensitivity, shelf life, and response characteristics at the higher absorbed doses. These parameters were (A) Type of flourinated polymer tubing; (B) Organic solvent used to activate the radiachromic dye; (C) Concentration of radiachromic dye; (D) Additives to provide proper viscosity, color stability, and high-dose response. Prototype batches were produced and experimental dosimeters exposed to a range of absorbed doses and the response measured as a function of shelf life and dose. The results of the study are presented, and an improved formulation recommended for application to Food Processing. Other formulations may be of value in specific requirements of sensitivity or temperature.

  8. Activation of Dosimeters Used in qa of Medical Linear Accelerators

    Science.gov (United States)

    Polaczek-Grelik, Kinga; Nowacka, Magdalena; Raczkowski, Maciej

    2017-09-01

    This paper presents the first results of a project intended to investigate γ-radiation activity induced in dosimeters used in clinical practice during routine quality assurance of high-energy photon beams emitted by electron linear accelerators. Two aspects of the activation via photonuclear reactions (X, n) of therapeutic beam and subsequent capture of secondary neutrons (n,γ) are under considerations: the influence of activation on intrinsic background of the dosimeters and exposure of dosimetrists who operate this equipment. The activation of several types of ionization chambers as well as the silicon diodes was studied after long-time exposure (10 000 MUs) of the 15 MV photon beam (Elekta Synergy). Photon fluxes obtained from spectra of γ-rays registered by HPGe spectrometer were subsequently converted to equivalent doses using appropriate coefficients. The main contribution to the induced activity comes from the neutron capture process on Al, Mn and Cu, therefore it decays quite fast with the half-lives of the order of 15 minutes. Nevertheless, the activation of chlorine was also observed. The estimated equivalent doses to skin and eye lens were in the range 0.19 - 0.62 μSv/min. However, no influence on intrinsic background signal of all studied dosimeters was observed. The preliminary results indicate that induced radioactivity of dosimeters is strongly influenced by therapeutic beam quality and neutron source strength of particular linac. This dependence will be studied deeper in order to quantify it more precisely.

  9. Validation of an Innovative Satellite-Based UV Dosimeter

    Science.gov (United States)

    Morelli, Marco; Masini, Andrea; Simeone, Emilio; Khazova, Marina

    2016-08-01

    We present an innovative satellite-based UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in-vivo assessment of the erythemal effects on some volunteers having a controlled exposure to solar radiation.Both validations showed that the satellite-based UV dosimeter has a good accuracy and reliability needed for health-related applications.The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. This app will be launched on the global market by siHealth Ltd in May 2016 under the name of "HappySun" and available both for Android and for iOS devices (more info on http://www.happysun.co.uk).Extensive R&D activities are on-going for further improvement of the satellite-based UV dosimeter's accuracy.

  10. An assessment of radiotherapy dosimeters based on CVD grown diamond

    CERN Document Server

    Ramkumar, S; Conway, J; Whitehead, A J; Sussman, R S; Hill, G; Walker, S

    2001-01-01

    Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemical inertness are some of the characteristics of diamond, which make it well suited for its application as a dosimeter. Recent advances in the synthesis of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper, the response of prototype dosimeters based on two different types (CVD1 and CVD2) of CVD diamond to X-rays. The diamond devices were assessed for sensitivity, dependence of response on dose and dose rate, and compared with a Scanditronix silicon photon diode and a PTW natural diamond dosimeter. The diamond devices of CVD1 type showed an initial increase in response with dose, which saturates after approx 6 Gy. The diamond devices of CVD2 type had a response at low fields (1162.8 V/cm), the CVD2-type devices show...

  11. Monte Carlo simulation experiments on box-type radon dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, Khalid, E-mail: kjamil@comsats.edu.pk; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-11-11

    Epidemiological studies show that inhalation of radon gas ({sup 222}Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the {sup 222}Rn concentrations (Bq/m{sup 3}) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η{sub int}) and alpha hit efficiency (η{sub hit}). The η{sub int} depends upon only on the dimensions of the dosimeter and η{sub hit} depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper

  12. Automatic recognition of malicious intent indicators.

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, D. J.; Yee, Mark L.; Giron, Casey; Fogler, Robert Joseph; Nguyen, Hung D.; Koch, Mark William

    2010-09-01

    A major goal of next-generation physical protection systems is to extend defenses far beyond the usual outer-perimeter-fence boundaries surrounding protected facilities. Mitigation of nuisance alarms is among the highest priorities. A solution to this problem is to create a robust capability to Automatically Recognize Malicious Indicators of intruders. In extended defense applications, it is not enough to distinguish humans from all other potential alarm sources as human activity can be a common occurrence outside perimeter boundaries. Our approach is unique in that it employs a stimulus to determine a malicious intent indicator for the intruder. The intruder's response to the stimulus can be used in an automatic reasoning system to decide the intruder's intent.

  13. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification.

    Science.gov (United States)

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting; Huang, Yung-Hui; Huang, David Y C

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%.

  14. Smart alarms from medical devices in the OR and ICU.

    Science.gov (United States)

    Imhoff, Michael; Kuhls, Silvia; Gather, Ursula; Fried, Roland

    2009-03-01

    Alarms in medical devices are a matter of concern in critical and perioperative care. The high rate of false alarms is not only a nuisance for patients and caregivers, but can also compromise patient safety and effectiveness of care. The development of alarm systems has lagged behind the technological advances of medical devices over the last 20 years. From a clinical perspective, major improvements in alarm algorithms are urgently needed. This review gives an overview of the current clinical situation and the underlying problems, and discusses different methods from statistics and computational science and their potential for clinical application. Some examples of the application of new alarm algorithms to clinical data are presented.

  15. a Thermally Desorbable Miniature Passive Dosimeter for Organic Vapors

    Science.gov (United States)

    Gonzalez, Jesus Antonio

    A thermally desorbable miniature passive dosimeter (MPD) for organic vapors has been developed in conformity with theoretical and practical aspects of passive dosimeter design. The device was optimized for low sample loadings resulting from short-term and/or low concentration level exposure. This was accomplished by the use of thermal desorption rather than solvent elution, which provided the GC method with significantly higher sensitivity. Laboratory evaluation of this device for factors critical to the performance of passive dosimeters using benzene as the test vapor included: desorption efficiency (97.2%), capacity (1400 ppm-min), sensitivity (7ng/sample or 0.06 ppmv for 15 minutes sampling) accuracy and precision, concentration level, environmental conditions (i.e., air face velocity, relative humidity) and sample stability during short (15 minutes) and long periods of time (15 days). This device has demonstrated that its overall accuracy meets NIOSH and OSHA requirements for a sampling and analytical method for the exposure concentration range of 0.1 to 50 ppm (v/v) and 15 minutes exposures. It was demonstrated that the MPD operates in accordance with theoretically predicted performance and should be adequate for short-term and/or low concentration exposure monitoring of organic vapors in the workplace. In addition a dynamic vapor exposure evaluation system for passive dosimeters have been validated using benzene as the test vapor. The system is capable of generating well defined short-square wave concentration profiles suitable for the evaluation of passive dosimeters for ceiling exposure monitoring.

  16. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  17. Clinical Alarms in intensive care: implications of alarm fatigue for the safety of patients1

    Science.gov (United States)

    Bridi, Adriana Carla; Louro, Thiago Quinellato; da Silva, Roberto Carlos Lyra

    2014-01-01

    OBJECTIVES: to identify the number of electro-medical pieces of equipment in a coronary care unit, characterize their types, and analyze implications for the safety of patients from the perspective of alarm fatigue. METHOD: this quantitative, observational, descriptive, non-participatory study was conducted in a coronary care unit of a cardiology hospital with 170 beds. RESULTS: a total of 426 alarms were recorded in 40 hours of observation: 227 were triggered by multi-parametric monitors and 199 were triggered by other equipment (infusion pumps, dialysis pumps, mechanical ventilators, and intra-aortic balloons); that is an average of 10.6 alarms per hour. CONCLUSION: the results reinforce the importance of properly configuring physiological variables, the volume and parameters of alarms of multi-parametric monitors within the routine of intensive care units. The alarms of equipment intended to protect patients have increased noise within the unit, the level of distraction and interruptions in the workflow, leading to a false sense of security. PMID:25591100

  18. Clinical Alarms in intensive care: implications of alarm fatigue for the safety of patients

    Directory of Open Access Journals (Sweden)

    Adriana Carla Bridi

    2014-12-01

    Full Text Available OBJECTIVES: to identify the number of electro-medical pieces of equipment in a coronary care unit, characterize their types, and analyze implications for the safety of patients from the perspective of alarm fatigue.METHOD: this quantitative, observational, descriptive, non-participatory study was conducted in a coronary care unit of a cardiology hospital with 170 beds.RESULTS: a total of 426 alarms were recorded in 40 hours of observation: 227 were triggered by multi-parametric monitors and 199 were triggered by other equipment (infusion pumps, dialysis pumps, mechanical ventilators, and intra-aortic balloons; that is an average of 10.6 alarms per hour.CONCLUSION: the results reinforce the importance of properly configuring physiological variables, the volume and parameters of alarms of multi-parametric monitors within the routine of intensive care units. The alarms of equipment intended to protect patients have increased noise within the unit, the level of distraction and interruptions in the workflow, leading to a false sense of security.

  19. The implications of probability matching for clinician response to vital sign alarms: a theoretical study of alarm fatigue.

    Science.gov (United States)

    Bailey, James M

    2015-01-01

    Alarm fatigue has been recognised as a significant health technology safety risk. 'Probability matching', in which clinicians respond to the alarm at a rate identical to the perceived reliability of the alarm, has been postulated as a model to explain alarm fatigue. In this article, we quantitatively explore the implications of probability matching for systolic blood pressure alarms. We find that probability matching could have a profound effect on clinician response to the alarm, with a response rate of only 8.6% when the alarm threshold is 90 mm Hg and the optimal threshold for a systolic blood pressure alarm would only be 77 mm Hg. We use the mathematical framework to assess a mitigation strategy when clinicians have a limit to the capacity to respond. We find that a tiered alarm in which clinicians receive information on the severity of vital sign perturbation significantly improves the opportunity to rescue patients. Practitioner Summary: Using a theoretical model, we predict that probability matching, a postulated model of clinician behaviour, can result in a profound decrease in clinician response to alarms for decreased blood pressure. A mitigating strategy is to create alarms that convey information on the degree of vital sign perturbation.

  20. Sunrise alarm clock for the hearing impaired - biomed 2011.

    Science.gov (United States)

    Follum, James D; Catchpole, Jennifer M

    2011-01-01

    The Sunrise Alarm Clock is a device designed to be more effective than standard alarm clocks and more pleasant than specialty devices in waking the hearing impaired. This is accomplished with the inclusion of visual, physical, and audio alarms. The visual alarm stimulus is created by manipulating the light output of a bedside lamp to mimic the sunrise. This is achieved by varying the duty cycle of a pulse width modulated signal supplied through a standard three-prong receptacle located on the side of the alarm clock. Physical alarms are in the form of wristbands containing vibrating motors. Finally, audio alarms are provided with both volume and pitch control to match the user’s specific needs. The entire system is designed with two users in mind by providing two independently controlled receptacles, wristbands, and audio systems. At the conclusion of development, a nearly fully functional prototype has been produced. The prototype’s audio and physical alarm system along with one visual alarm are fully functional. Shortcomings include poor timekeeping accuracy and problems clearly displaying the time. Even so, this development in sleep technology is capable of performing its task and waking its user with all three alarm systems.

  1. Alarm management in gas pipeline plant: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Juliano; Lima, Marcelo; Leitao, Gustavo; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Branco, Nicolau; Coelho, Robson; Elias, Gustavo Passos; Nunes, Marcelo [Transportadora Brasileira Gasoduto Bolivia-Brasil (TBG), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In order to improve the requirements of industrial processes, many decision support systems have been introduced in recent years. In this context, the alarm management systems have great relevance. On the other hand, the informatics revolution allowed a great increase of information concerning the operation of the industrial processes. Currently, process operators handle an excessive number of about 1.500 alarms per day. Thus, this overdose of information implies in the discredit of alarms. Then, in order to improve the operation activities of industrial processes, it is mandatory to incorporate procedures to evaluate and rationalize alarms. Since the EMMUA191 Standard is the reference guide to alarm management, but it does not specify how to execute an alarm management procedure, in this paper, a systematic procedure to evaluate alarms configurations in industrial processes is proposed. This procedure is in line with EMMUA191 and is composed by the following steps: to use statistics analyses to identify problematic alarms, such as occurrence, intermittency, correlation, and flooding calculation; to indicate problematic alarm group; and to propose a set of actions to be implemented. To validate our proposal, we present a case study in a gas pipeline plant using the BR-AlarmExpert software. (author)

  2. Performances of Dose Measurement of Commercial Electronic Dosimeters using Geiger Muller Tube and PIN Diode

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyunjun; Kim, Chankyu; Kim, Yewon; Kim, Giyoon; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    There are two categories in personal dosimeters, one is passive type dosimeter such as TLD (thermoluminescence dosimeter) and the other is active type dosimeter such as electronic dosimeter can show radiation dose immediately while TLD needs long time to readout its data by heating process. For improving the reliability of measuring dose for any energy of radiations, electronic dosimeter uses energy filter by metal packaging its detector using aluminum or copper, but measured dose of electronic dosimeter with energy filter cannot be completely compensated in wide radiation energy region. So, in this paper, we confirmed the accuracy of dose measurement of two types of commercial EPDs using Geiger Muller tube and PIN diode with CsI(Tl) scintillator in three different energy of radiation field. The experiment results for Cs-137 was almost similar with calculation value in the results of both electronic dosimeters, but, the other experiment values with Na-22 and Co-60 had higher error comparing with Cs-137. These results were caused by optimization of their energy filters. The optimization was depending on its thickness of energy filter. So, the electronic dosimeters have to optimizing the energy filter for increasing the accuracy of dose measurement or the electronic dosimeter using PIN diode with CsI(Tl) scintillator uses the multi-channel discriminator for using its energy information.

  3. Modified ferrous ammonium sulfate benzoic acid xyelenol orange (MFBX) and thermoluminescent dosimeters--a comparative study.

    Science.gov (United States)

    Brindha, S; Rose, J V R; Sathyan, S; Singh I, Rabi Raja; Ravindran, B Paul

    2002-06-07

    Radiation dosimetry deals with the determination of absorbed dose to the medium exposed to ionizing radiation. Chemical dosimetry depends on oxidation or reduction of chemicals by ionizing radiation. A ferrous ammonium sulfate benzoic acid xyelenol orange (FBX) dosimeter based on this principle is being used as a clinical dosimeter at present. Certain modifications were carried out in the preparation and storage of the FBX dosimeter to increase its shelf life. The resulting dosimeter was called a modified FBX (MFBX) dosimeter and has been used in our department for the past few years. An extensive study of the dose, dose rate and energy response of the dosimeter was carried out and compared with a thermoluminescent (LiF7) dosimeter. The results obtained were found to be comparable to the thermoluminescent (LiF7) dosimeter. Hence it was concluded that the MFBX dosimeter could be used for phantom dosimetry, data collection and in vivo measurements. Easier preparation and availability of the reagents are added advantages of using MFBX as a clinical dosimeter in small radiotherapy departments.

  4. The Impact of Reduced Pulse Oximetry Use on Alarm Frequency.

    Science.gov (United States)

    Schondelmeyer, Amanda C; Brady, Patrick W; Sucharew, Heidi; Huang, Guixia; Hofacer, Kelsey E; Simmons, Jeffrey M

    2016-04-01

    Concerns about alarm fatigue prompted The Joint Commission to issue a Sentinel Event Alert urging hospitals to minimize alarms. We previously conducted a quality improvement project on a single unit that reduced time on continuous pulse oximetry, a common source of physiologic monitor alarms, for patients with wheezing (ie, asthma and bronchiolitis, wheezing-associated respiratory infections). To study the impact of our improvement work on overall physiologic monitor alarm frequency for these patients. This was a retrospective cohort study at a freestanding children's hospital over an 8-week period. We compared alarm count, including respiratory, cardiac, and pulse oximetry alarms, for patients admitted to the intervention unit with the alarm count for similar patients on a control unit by using the Wilcoxon rank sum test. We used negative binomial regression to evaluate differences in alarm count between the units, adjusting for age, medical comorbidity, and length of stay. There were 101 patients on the intervention unit and 46 patients on the control unit. The percentage of patients with medical comorbidities was significantly higher on the intervention unit (P=.01). Median alarm count per day for patients on the intervention unit was lower; however, this difference was not statistically significant (71 vs 76 alarms per patient-day, P=.29). The multivariable model estimated a nonsignificant 6.4-count decrease in alarms for patients on the intervention unit. Reducing continuous pulse oximetry use alone may not make substantial reductions in overall alarm counts. Even on our intervention unit, alarm burden remained quite high. Copyright © 2016 by the American Academy of Pediatrics.

  5. False alarm reduction during landmine detection

    Science.gov (United States)

    Prado, P. J.; Chongpison, A.; Doraisamy, L.

    2007-04-01

    Quadrupole Resonance sensors have the unique capability of detecting explosives from buried, plastic-cased antipersonnel and antitank landmines. The chemical specificity of this radio-frequency technique provides the potential to deliver remarkably low false alarm rates during landmine detection. This is of particular importance to deminers, who frequently come across numerous clutter items before uncovering a mine. Quadrupole Resonance is typically utilized in a confirmation mode; preceded by rapid primary scans carried out by, for example, metal detectors, ground penetrating radars or a fusion of these. Significant technical and scientific advances have resulted in the fabrication of handheld and vehicle mounted Quadrupole Resonance landmine detectors in compact, power-efficient configurations. The development work is focused on baseline sensitivity increase, as well as the achievement of high detection performance under field conditions. The mine detection capability of Quadrupole Resonance detectors has been evaluated during various blind tests. A modular handheld unit, combining primary and confirmation sensors, was designed to be operated by a single person. A series of field tests demonstrate the unique capability of Quadrupole Resonance for significant false alarm reduction.

  6. Improvement of electronic circuit and performance of electronic dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S. Y.; Lee, B. J.; Kim, B. H.; Kim, J. S.; Lee, K. C. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-03-01

    An electronic personnal dosimeter(EPD) adopting a PIN type Silicon semiconductor as a radiation detector has been designed and manufactured. A hybrid type design of electronic circuit for processing a radiation signal has been adopted not only to improve the EPD response to radiation detection but also to reduce a size as well as a weight. The EPD can be independently used as an individual personal dosimeter for exposure monitoring if necessary after setting some variables by operator. The performance of this EPD has been tested and finally accredited by Korea Testing Laboratory(KTL) through a series of performance test under international criteria given in IEC61526 standard on the mechanical, electronical and radiation performance. The EPD reader which can interface an EPD with entrance door for proper access control has been designed and manufactured. A hangul is supported in this EPD reader in operational display menu for the user convenience. 10 refs., 30 figs., 5 tabs. (Author)

  7. The Response of Alanine Dosimeters in Thermal Neutron Fields

    DEFF Research Database (Denmark)

    Schmitz, T.; Bassler, Niels; Sharpe, P.

    Purpose: Boron Neutron Capture Therapy (BNCT) is a special kind of particle therapy, based on the neutron induced fission of the boron isotope 10B [1]. We have performed dosimetry experiments on the mixed neutron and gamma fields at the TRIGA Mark II research reactor in Mainz. Commonly, dosimetry...... in such fields is realized by foil activation and ion chambers [2]. Here we investigate alanine as an easier and more robust alternative dosimeter. Methods: We have performed four phantom experiments at the TRIGA Mark II research reactor in Mainz [3], in a predominantly thermal neutron field with a strong gamma...... neutron capture of hydrogen. The primary gamma dose deposited originate from the reactor core itself. Conclusion: Alanine dosimeters are suitable of measurements in mixed neutron fields and the alanine response in thermal neutron fields can be fully understood by the used interpretation model. In further...

  8. A new electronic neutron dosimeter (END) for reliable personal dosimetry

    Science.gov (United States)

    Ing, H.; Cousins, T.; Andrews, H. R.; Machrafi, R.; Voevodskiy, A.; Kovaltchouk, V.; Clifford, E. T. H.; Robins, M.; Larsson, C.; Hugron, R.; Brown, J.

    2008-04-01

    Tests of existing electronic neutron dosimeters by military and civilian groups have revealed significant performance limitations. To meet the operational requirements of emergency response personnel to a radiological/nuclear incident as well as those in the nuclear industry, a new END has been developed. It is patterned after a unique commercial neutron spectral dosemeter known as the N-probe. It uses a pair of small special scintillators on tiny photomultiplier tubes. Special electronics were designed to minimize power consumption to allow for weeks of operation on a single charge. The size, performance, and data analysis for the END have been designed to meet/exceed international standards for electronic neutron dosimeters. Results obtained with the END prototype are presented.

  9. General methods for alarm reduction; Larmsanering med generella metoder

    Energy Technology Data Exchange (ETDEWEB)

    Ahnlund, Jonas; Bergquist, Tord; Raaberg, Martin [Lund Univ. (Sweden). Dept. of Information Technology

    2003-10-01

    The information in the control rooms has increased due to the technological advances in process control. Large industries produce large data quantities, where some information is unnecessary or even incorrect. The operator needs support from an advanced and well-adjusted alarm system to be able to separate a real event from a minor disturbance. The alarms must be of assistance and not a nuisance. An enhanced alarm situation qualifies an increased efficiency with fewer production disturbances and an improved safety. Yet, it is still unusual that actions are taken to improve the situation. An alarm cleanup with general methods can shortly be described as taking advantage of the control systems built-in functions, the possibility to modify or create function blocks and fine-tune the settings in the alarm system. In this project, we make use of an intelligent software, Alarm Cleanup Toolbox, that simulate different signal processing methods and tries to find improved settings on all the signals in the process. This is a fast and cost-efficient way to improve the overall alarm situation, and lays a foundation for more advanced alarm systems. An alarm cleanup has been carried out at Flintraennan district heating plant in Malmoe, where various signal processing methods has been implemented in a parallel alarm system. This made it possible to compare the two systems under the same conditions. The result is very promising, and shows that a lot of improvements can be achieved with very little effort. An analysis of the alarm system at Vattenreningen (the water purification process) at Heleneholmsverket in Malmoe has been carried out. Alarm Cleanup Toolbox has, besides suggesting improved settings, also found logical errors in the alarm system. Here, no implementation was carried out and therefore the results are analytical, but they validate the efficiency of the general methods. The project has shown that an alarm cleanup with general methods is cost-efficient, and that the

  10. Classification of alarm processing techniques and human performance issues

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I.S.; O' Hara, J.M.

    1993-01-01

    Human factors reviews indicate that conventional alarm systems based on the one sensor, one alarm approach, have many human engineering deficiencies, a paramount example being too many alarms during major disturbances. As an effort to resolve these deficiencies, various alarm processing systems have been developed using different techniques. To ensure their contribution to operational safety, the impacts of those systems on operating crew performance should be carefully evaluated. This paper briefly reviews some of the human factors research issues associated with alarm processing techniques and then discusses a framework with which to classify the techniques. The dimensions of this framework can be used to explore the effects of alarm processing systems on human performance.

  11. Classification of alarm processing techniques and human performance issues

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I.S.; O`Hara, J.M.

    1993-05-01

    Human factors reviews indicate that conventional alarm systems based on the one sensor, one alarm approach, have many human engineering deficiencies, a paramount example being too many alarms during major disturbances. As an effort to resolve these deficiencies, various alarm processing systems have been developed using different techniques. To ensure their contribution to operational safety, the impacts of those systems on operating crew performance should be carefully evaluated. This paper briefly reviews some of the human factors research issues associated with alarm processing techniques and then discusses a framework with which to classify the techniques. The dimensions of this framework can be used to explore the effects of alarm processing systems on human performance.

  12. An investigation of training strategies to improve alarm reactions.

    Science.gov (United States)

    Bliss, James P; Chancey, Eric T

    2014-09-01

    Researchers have suggested that operator training may improve operator reactions; however, researchers have not documented this for alarm reactions. The goal of this research was to train participants to react to alarms using sensor activity patterns. In Experiment 1, 80 undergraduates monitored a simulated security screen while completing a primary word search task. They received spatial, temporal, single sensor, or no training to respond to alarms of differing reliability levels. Analyses revealed more appropriate and quicker reactions when participants were trained and when the alarms were reliable. In Experiment 2, 56 participants practiced time estimation by simple repetition, performance feedback, or performance feedback and temporal subdivision. They then reacted to alarms based on elapsed time between sensor activity and alarm onset. Surprisingly, results indicated that participants did not benefit differentially from temporal interval training, focusing instead on advertised system reliability. Researchers should replicate these findings with realistic tasks and real-world complex task operators.

  13. Characterization and application of two kinds of ESR dosimeters

    Science.gov (United States)

    Marchioni, Eric; Pabst, Jean-Yves; Kuntz, Florent

    2002-09-01

    Many previous papers described the use of low-concentration alanine pellets, powder or films for industrial high-dose application, but very few authors presented applications of such dosimeters to the low-dose range used for wastewater, flowers or radiotherapy treatment. The present paper describes the large-scale manufacturing process of high-concentration alanine pellets used for radiotherapy dose control in some French hospitals. The fading process due to sunlight exposure has been evaluated by means of direct UV light irradiation. The major disadvantage of alanine is its strong solubility in water (the pellets are completely dissolved when immersed for 10 min in pure water). The use of barium sulphate, not soluble in water, made it possible to carry out dosimetric measurements even when the dosimeter is completely immersed in water or stored after irradiation in high humidity levels. The paper presents manufacturing process of barium sulphate pellets, their dosimetric characteristics and one application of this dosimeter for the control of the absorbed doses during wastewater treatments.

  14. Calcium carbonate as a possible dosimeter for high irradiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Ramos B, S.; Camargo R, C. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M. [Kent State University, College of Technology, Kent OH (United States); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Kobayashi, K., E-mail: negron@nucleares.unam.mx [Yokohama National University (Japan)

    2014-08-15

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  15. Response of ionization chamber based pocket dosimeter to beta radiation.

    Science.gov (United States)

    Kumar, Munish; Gupta, Anil; Pradhan, S M; Bakshi, A K; Chougaonkar, M P; Babu, D A R

    2013-12-01

    Quantitative estimate of the response of ionization chamber based pocket dosimeters (DRDs) to various beta sources was performed. It has been established that the ionization chamber based pocket dosimeters do not respond to beta particles having energy (Emax)1 MeV, the DRDs exhibit measureable response and the values are ~8%, ~14% and ~27% per mSv for natural uranium, (90)Sr/(90)Y and (106)Ru/(106)Rh beta sources respectively. As the energy of the beta particles increases, the response also increases. The response of DRDs to beta particles having energy>1 MeV arises due to the fact that the thickness of the chamber walls is less than the maximum range of beta particles. This may also be one of the reasons for disparity between doses measured with passive/legal dosimeters (TLDs) and DRDs in those situations in which radiation workers are exposed to mixed field of gamma photons and beta particles especially at uranium processing plants, nuclear (power and research) reactors, waste management facilities and fuel reprocessing plants etc. The paper provides the reason (technical) for disparity between the doses recorded by TLDs and DRDs in mixed field of photons and beta particles.

  16. Characterization of a silicate glass as a high dose dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Farah, K., E-mail: k.farah@cnstn.rnrt.t [Laboratoire de Radiotraitement. Centre National des Sciences et Technologie Nucleaires, 2020 Sidi-Thabet (Tunisia); Mejri, A.; Hosni, F. [Laboratoire de Radiotraitement. Centre National des Sciences et Technologie Nucleaires, 2020 Sidi-Thabet (Tunisia); Ben Ouada, H. [Laboratoire de Physique et Chimie des Interfaces, Faculte des Sciences de Monastir, 5000 Monastir (Tunisia); Fuochi, P.G.; Lavalle, M. [ISOF-CNR, Via P. Gobetti 101, 40129 Bologna (Italy); Kovacs, A. [Institute of Isotopes, HAS, P.O. Box 77, H-1525 Budapest (Hungary)

    2010-02-21

    Commercial silicate glass has been investigated as a possible high dose dosimeter using an UV-vis spectrophotometer. Glass samples were irradiated by {sup 60}Co gamma rays and the results compared with those obtained with 3.4 and 8.4 MeV electron beams. The irradiated samples showed rapid fading at room temperature immediately after irradiation. In order to improve the stability of absorbance, glass samples were submitted to post-irradiation thermal treatments (150 deg. C for 20 min). The influences of the dose, type and energy of the ionizing radiation on the fading characteristics and on the response of the irradiated and thermally treated glasses were studied. Dependence of the glass response on the temperature during gamma irradiation in the range -3 to 80 deg. C is reported. The reproducibility to reuse glass dosimeter by thermal bleaching the radiation induced colour centres at 300 deg. C for 30 min was also investigated. Calibration curves in the range 0.1-17 kGy were obtained by using in-plant calibration techniques against transfer standard alanine dosimeters in the Tunisian semi-industrial gamma irradiation facility.

  17. A new 2 methylalanine-PVC ESR dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Bruno T. [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Chen, Felipe [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Department of Radiological Health, Caja de Seguro Social, Panama City (Panama); Department of Physics, Faculty of Natural and Exact Sciences and Technology, University of Panama, Panama City (Panama); Baffa, Oswaldo [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil)

    2005-02-01

    The use of polyvinyl chloride (PVC) as a binder to 2-methylalanine (2MA) dosimeters was investigated. It was recently shown by Olsson et al. (Radiat. Res. 157 (2002) 113), that 2MA is approximately 70% more sensitive than L-alanine which makes this substance a good candidate to replace alanine in ESR dosimetry. PVC is a low yield material for free radical production by ionizing radiation and a good binding material easily processed and widely available. PVC can be prepared at room temperature and mixed up to 50% in weight with 2MA to produce a pellet stable in mass and physical dimensions, in large quantities and with low background signal. Pure PVC pellet irradiated at 50 Gy gave weaker ESR signals compared to 2MA at the region of spectral interest. Spectrometer settings such as microwave power, and modulation amplitude were optimized for the measurements. This dosimeter production scheme allows the addition of Mn{sup 2+} ions for an internal reference signal, leading to a self-calibrated dosimeter (J. Radional. Nucl. Chem. 240 (1999) 215)

  18. 46 CFR 78.47-10 - Manual alarm boxes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Manual alarm boxes. 78.47-10 Section 78.47-10 Shipping... and Emergency Equipment, Etc. § 78.47-10 Manual alarm boxes. (a) In all new installations, manual... at least 1/2 inch letters “IN CASE OF FIRE BREAK GLASS.” All manual alarm boxes shall be numbered...

  19. Standard Guide for Performance Characterization of Dosimeters and Dosimetry Systems for Use in Radiation Processing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This guide provides guidance on determining the performance characteristics of dosimeters and dosimetry systems used in radiation processing. 1.2 This guide describes the influence quantities that might affect the performance of dosimeters and dosimetry systems and that should be considered during dosimeter/dosimetry system characterization. 1.3 Users of this guide are directed to existing standards and literature for procedures to determine the effects from individual influence quantities and from combinations of more than one influence quantity. 1.4 Guidance is provided regarding the roles of the manufacturers, suppliers, and users in the characterization of dosimeters and dosimetry systems. 1.5 This guide does not address how the dosimeter/dosimetry system characterization information is to be used in radiation processing applications or in the calibration of dosimetry systems. Note 1—For guidance on the use of dosimeter/dosimetry system characterization information for the selection and use o...

  20. [How Much Alarm Can the Human Being Tolerate?

    Science.gov (United States)

    Lorenz, Benedikt; Peters, Jürgen; Frey, Ulrich H

    2017-07-01

    Due to growing technisation of intensive care the number of devices with integrated alarm systems is steadily increasing. However, most of the sounding alarms are false alarms causing high levels of frustration, aggression and inappropriate behaviour amongst the medical personnel. All this jeopardises patient care. The high number of alarms also disturb the patients interrupting their sleep and provokes anxiety, and also increases the already high noise level in intensive care units and the operating theatre alike. In the interest of the medical staff and our patients, we should reduce the high frequency of false alarms by using modern alarm algorithms techniques, lower both noise exposure and stress load with the help of modern individualized alarm systems and by increasing awareness on the dangers of alarm fatigue through training and by using individualized patient-related alarm limits. Despite economic challenges hospitals and intensive care units should optimize staffing, thereby lowering the risk to patients and improving employee satisfaction. Georg Thieme Verlag KG Stuttgart · New York.

  1. Fabrication and Optimization of a PAGATA Gel Dosimeter: Increasing the Melting Point of the PAGAT Gel Dosimeter with Agarose Additive

    Directory of Open Access Journals (Sweden)

    Bakhtiar Azadbakht

    2010-12-01

    Full Text Available Introduction: The PAGAT polymer gel dosimeter melts at 30 ˚C and even at room temperature during the summer, so it needs to be kept in a cool place such as a refrigerator. To increase the stability of the PAGAT gel, different amounts of agarose were added to the PAGAT gel composition and the PAGATA gel was manufactured. Material and Methods: The PAGATA gel vials were irradiated using a Co-60 machine. Then, the samples were evaluated using a 1.5 T Siemens MRI scanner. The ingredients of the PAGATA normoxic gel dosimeter were 4.5% N-N' methylen-bis-acrylamide, 4.5% acrylamide, 4.5% gelatine, 5 mM tetrakis (THPC, 0.01 mM hydroquinone (HQ, 0.5% agarose and 86% de-ionized water (HPLC. Results: Melting point and sensitivity of the PAGAT gel dosimeter with addition of 0.0, 0.3, 0.5, 1.0, 1.5 and 2.0% of agarose were measured, in which the melting points were increased to 30, 82, 86, 88, 89 and 90°C and their sensitivities found to be 0.113, 0.1059, 0.125, 0.122, 0.115 and 0.2  respectively. Discussion and Conclusions: Adding agarose increased the sensitivity and background R2 of the evaluated samples. The optimum amount of agarose was found to be 0.5% regarding these parameters and also the melting point of the gel dosimeter. A value of 0.5% agarose was found to be an optimum value considering the increase of sensitivity to 0.125 and melting point to 86°C but at the expense of increasing the background R2 to 4.530.

  2. Personnel Photon Dosimeter on the Base of TLD natLiF

    CERN Document Server

    Kaskanov, G Ya

    2003-01-01

    A personnel photon dosimeter on the base of thermoluminescence detectors (TLD) ^{nat}LiF is described. Experimental responses of the dosimeters in the unit of individual equivalent dose H_p(10) for energy of photons 59.5, 120, 662, and 1250 keV are presented. It is shown that the dosimeter allows one to measure H_p(10) with admissible uncertainty in the energy range from 60 to 1250 keV.

  3. Research of Methodocal Questions of Use of Albedo Personal Neutron Dosi-meter

    CERN Document Server

    Alekseev, A G

    2003-01-01

    In the paper the methods of reception of the correct use of neutron albedo dosimeters are considered. The methods of use such dosimeters in fields with different spectra of neutrons are presented. For testing the experi-mental research of sensitivity DVGN-01and DVN-A-01 dosimeters in reference neutron fields was formed on based of 1-st horizontal research channel of IRT MIPHI reactor.

  4. Investigation of radiological properties and water equivalency of PRESAGE dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Adamovics, John; Bosi, Stephen; Kim, Jung-Ha; Baldock, Clive [Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia) and Department of Radiation Oncology, Royal Prince Alfred Hospital, Sydney, New South Wales 2050 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia); Department of Chemistry and Biology, Rider University, Lawrenceville, New Jersey 08648 (United States); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia) and Department of Radiation Oncology, Prince of Wales Hospital, Randwick, New South Wales 2031 (Australia); Institute of Medical Physics, School of Physics, University of Sydney, New South Wales 2006 (Australia)

    2011-04-15

    Purpose: PRESAGE is a dosimeter made of polyurethane, which is suitable for 3D dosimetry in modern radiation treatment techniques. Since an ideal dosimeter is radiologically water equivalent, the authors investigated water equivalency and the radiological properties of three different PRESAGE formulations that differ primarily in their elemental compositions. Two of the formulations are new and have lower halogen content than the original formulation. Methods: The radiological water equivalence was assessed by comparing the densities, interaction probabilities, and radiation dosimetry properties of the three different PRESAGE formulations to the corresponding values for water. The relative depth doses were calculated using Monte Carlo methods for 50, 100, 200, and 350 kVp and 6 MV x-ray beams. Results: The mass densities of the three PRESAGE formulations varied from 5.3% higher than that of water to as much as 10% higher than that of water for the original formulation. The probability of photoelectric absorption in the three different PRESAGE formulations varied from 2.2 times greater than that of water for the new formulations to 3.5 times greater than that of water for the original formulation. The mass attenuation coefficient for the three formulations is 12%-50% higher than the value for water. These differences occur over an energy range (10-100 keV) in which the photoelectric effect is the dominant interaction. The collision mass stopping powers of the relatively lower halogen-containing PRESAGE formulations also exhibit marginally better water equivalency than the original higher halogen-containing PRESAGE formulation. Furthermore, the depth dose curves for the lower halogen-containing PRESAGE formulations are slightly closer to that of water for a 6 MV beam. In the kilovoltage energy range, the depth dose curves for the lower halogen-containing PRESAGE formulations are in better agreement with water than the original PRESAGE formulation. Conclusions: Based

  5. Aplikasi Sensor Cahaya Untuk Alarm Anti Pencuri

    Directory of Open Access Journals (Sweden)

    Asita Shoman Muzaki

    2011-11-01

    Full Text Available Kasus pencurian di rumah kosong yang ditinggal pergi oleh pemiliknya belakangan ini marak terjadi. Berangkat dari pemikiran ini penulis mencoba merancang alarm yang dapat mendeteksi pergerakan seseorang saat rumah dalam kondisi kosong, ditinggalkan oleh pemiliknya. Alat ini mempunyai prinsip kerja yaitu mendeteksi bayangan seseorang yang melewati titik tertentu. Perancangan dan pembuatan perangkat ini menggunakan sensor cahaya berupa LASER dan LDR yang dirangkai dengan transistor sebagai saklar otomatis serta LED dan telepon rumah untuk melakukan panggilan kepada nomor telepon pemilik rumah. Komponen yang dipakai dalam pembuatan perangkat ini antara lain IC LM7805, LASER pointer, resistor, transistor BC108, LED, relay dan telepon rumah. Perancangan dan pembuatan alat menggunakan software multisim 10.1 sebagai simulator rangkaian, dan software eagle 5.1.1 untuk mendesain jalur rangkaian pada papan PCB. Saat cahaya LASER tidak sampai ke LDR karena terhalang oleh sesuatu, maka rangkaian output yang berupa indikator LED dan panggilan dari telepon rumah akan aktif

  6. Kidkit guides children into alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2013-01-01

    on the development and evaluation of Kidkit, which is interactive furniture designed for young children who are going to visit a hospitalized relative with fatal injuries for the first time. Kidkit empowers the child to engage and be present by shaping Middle Ground Experiences in the hospital ward environment...... that is full of intimidating medical equipment and alarms. The evaluation results indicate collective rewards gained when children succeed in Embodied Habituation. Finally, the paper discusses how Middle Ground Experiences inevitably establish grounds for how we design for spatial experiences within......This paper presents the concept of Embodied Habituation as an architectural approach to designing contextualized technologies. It does so by identifying Middle Ground Experiences acknowledging how spaces are inhabited with ambiguous qualities that affect people emotionally. The research is based...

  7. Clinical application of glass dosimeter for in vivo dose measurements of total body irradiation treatment technique

    Energy Technology Data Exchange (ETDEWEB)

    Rah, Jeong-Eun; Hwang, Ui-Jung; Jeong, Hojin; Lee, Sang-Yeob; Lee, Doo-Hyun; Shin, Dong Ho; Yoon, Myonggeun; Lee, Se Byeong [Proton Therapy Center, National Cancer Center, 809 Madu-dong, Ilsan-gu, Goyang-si, Gyeonggi-do, 410-769 (Korea, Republic of); Lee, Rena [Department of Radiation Oncology, Mokdong Hospital, Ewha Womans University College of Medicine (Korea, Republic of); Park, Sung Yong, E-mail: cool_park@ncc.re.k [Proton Therapy Center, National Cancer Center, 809 Madu-dong, Ilsan-gu, Goyang-si, Gyeonggi-do, 410-769 (Korea, Republic of)

    2011-01-15

    The commercially available glass dosimeter (model GD-301) was investigated for its dosimetric characteristics, in order to evaluate its use for in vivo dosimetry. We specifically assessed overall precision of dosimetric dose data in patients who received treatment with the total body irradiation (TBI). Uniformity obtained in this study was within 1.2% (1 SD). The dose-response was linear in the range of 0.5-10 Gy with R of 0.999. Dose rate, SSD, field size, angular and energy dependence were found to be within 3.0%. In vivo skin dosimetry for TBI was performed for 3 patients. For all patients, the glass dosimeter was exposed and measured dose recorded for one fraction in addition to conventional used TLD and MOSFET. Overall uncertainty of the glass dosimeter for in vivo dose measurement was estimated at 2.4% (68.3% confidence level). The measured doses of the glass dosimeter were well within {+-}5.0% of the prescription dose at all sites expect mediastinum of one patient, for which it is within {+-}5.7%. Agreement of measured doses between glass dosimeter and TLD, MOSFET was within {+-}6.3% and {+-}6.6%, respectively. Results show that the glass dosimeter can be used as an accurate and reproducible dosimeter for TBI treatment skin dose measurements. The glass dosimeter is a practical alternative to TLD or MOSFET as an in vivo dosimeter.

  8. Review of the dose-to-water energy dependence of alanine and lithium formate EPR dosimeters and LiF TL-dosimeters - Comparison with Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Waldeland, Einar, E-mail: einar.waldeland@oslo-universitetssykehus.no [Department of Medical Physics, Oslo University Hospital, Norwegian Radium Hospital, P.O. Box 4953 Nydalen, N-0424 Oslo (Norway); Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Malinen, Eirik [Department of Medical Physics, Oslo University Hospital, The Norwegian Radium Hospital, P.O. Box 4953 Nydalen, N-0424 Oslo (Norway); Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway)

    2011-09-15

    The dose-to-water energy dependence may be defined as the dosimeter reading per absorbed dose to water for a given radiation beam relative to that for {sup 60}Co {gamma} rays. The purpose of this work was to review the literature on the dose-to-water energy dependence of lithium formate and alanine EPR dosimeters and LiF:Mg,Ti TL-dosimeters for clinical beam qualities and to compare the findings with Monte Carlo simulations. Monte Carlo simulations of the energy dependence of lithium formate and alanine EPR dosimeters and LiF:Mg,Ti TL-dosimeters were performed using the EGSnrc code. The following common clinical radiation qualities were applied: 4-24 MV photons, 4-20 MeV electrons, 50-200 kV{sub p} X-rays, {sup 192}Ir {gamma} rays, and {sup 60}Co {gamma} rays as the reference. All dosimeter materials showed measured and Monte Carlo simulated energy responses around unity for MV photons, electrons and {sup 192}Ir {gamma} rays, except LiF TL-dosimeters which showed an average underresponse of approximately 3% for electrons. For medium energy X-rays (50-200 kV{sub p}), LiF displayed an increasing overresponse with decreasing energy to a maximum of about 40% for 50 kV{sub p} X-rays. The two EPR dosimeter materials showed decreasing energy response with decreasing X-ray energy, but lithium formate was less dependent on energy than alanine. Comparisons between Monte Carlo simulations and measurements revealed some deviations for medium energy X-rays, which may be due to LET-effects caused by low energy electrons. In conclusion, lithium formate is the dosimeter material with the lowest energy dependence over a wide range of clinically relevant radiation qualities, which clearly is advantageous for accurate dosimetry.

  9. 46 CFR 111.33-7 - Alarms and shutdowns.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power...

  10. [Citalopram, escitalopram and prolonged QT: warning or alarm?].

    Science.gov (United States)

    Alvarez, Enric; Vieira, Sara; Garcia-Moll, Xavier

    2014-01-01

    The alerts issued by regulatory agencies on the potential cardiac toxicity of citalopram and escitalopram have caused alarm among clinicians. A review of the data concerning this topic shows that the alarm should be limited to patients with a history of syncope or poisoning. As a precautionary measure, an electrocardiogram should be performed on elderly patients.

  11. 46 CFR 28.250 - High water alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a)...

  12. 24 CFR 3280.208 - Smoke alarm requirements.

    Science.gov (United States)

    2010-04-01

    ... locations: (i) To protect both the living area and kitchen space. Manufacturers are encouraged to locate the alarm in the living area remote from the kitchen and cooking appliances. A smoke alarm located within 20... when a home is equipped or designed for future installation of a roof-mounted evaporative cooler...

  13. Successful Use of the Nocturnal Urine Alarm for Diurnal Enuresis.

    Science.gov (United States)

    Friman, Patrick C.; Vollmer, Dennis

    1995-01-01

    A urine alarm, typically used to treat nocturnal enuresis, was effectively used to treat diurnal enuresis in a 15-year-old female with depression, attention deficit hyperactivity disorder, and conduct disorder. The study indicated that the alarm eliminated wetting in both treatment phases and that continence was maintained at three-month and…

  14. Advanced Alarm Systems: Revision of Guidance and Its Technical Basis

    Science.gov (United States)

    2000-11-01

    Pressurized Water Reactor (Westinghouse) APWR Advanced Pressurized Water Reactor (Mitsubishi) ARP alarm response procedure CAMLS CANDU Annunciation Message...List System CANDU Canadian Deuterium Uranium CE Combustion Engineering CPIAS Critical Parameter Indication and Alarm System CRT cathode ray tube ...bulletins and information notices; inspection and investigative reports; licensee event reports; and Commission papers and their attachments. NRC

  15. 46 CFR 131.805 - General alarm bell, switch.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false General alarm bell, switch. 131.805 Section 131.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.805 General alarm bell, switch. The switch in...

  16. Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Lead Reflected Pulse of the CEA Valduc SILENE Critical Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Isbell, Kimberly McMahan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Yi-kang [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Gagnier, Emmanuel [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Authier, Nicolas [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Piot, Jerome [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Jacquet, Xavier [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Rousseau, Guillaume [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-09-01

    This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 13, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube, and the Rocky Flats detects neutrons via charged particles produced in a thin 6LiF disc, depositing energy in a Si solid-state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

  17. A correlation consistency based multivariate alarm thresholds optimization approach.

    Science.gov (United States)

    Gao, Huihui; Liu, Feifei; Zhu, Qunxiong

    2016-11-01

    Different alarm thresholds could generate different alarm data, resulting in different correlations. A new multivariate alarm thresholds optimization methodology based on the correlation consistency between process data and alarm data is proposed in this paper. The interpretative structural modeling is adopted to select the key variables. For the key variables, the correlation coefficients of process data are calculated by the Pearson correlation analysis, while the correlation coefficients of alarm data are calculated by kernel density estimation. To ensure the correlation consistency, the objective function is established as the sum of the absolute differences between these two types of correlations. The optimal thresholds are obtained using particle swarm optimization algorithm. Case study of Tennessee Eastman process is given to demonstrate the effectiveness of proposed method.

  18. Alarm systems a guide to design, management and procurement

    CERN Document Server

    Engineering Equipment and Materials Users' Association. London

    2013-01-01

    Alarm systems form an essential part of the operator interfaces to large modern industrial facilities. They provide vital support to the operators by warning them of situations that need their attention and have an important role in preventing, controlling and mitigating the effects of abnormal situations. Since it was first published in 1999, EEMUA 191 has become the globally accepted and leading guide to good practice for all aspects of alarm systems. The guide, developed by users of alarm systems with input from the GB Health and Safety Executive, gives comprehensive guidance on designing, managing and procuring an effective alarm system. The new Third Edition has been comprehensively updated and includes guidance on implementing the alarm management philosophy in practice; applications in geographically distributed processes; and performance metrics and KPIs.

  19. Automatic Reading

    Institute of Scientific and Technical Information of China (English)

    胡迪

    2007-01-01

    <正>Reading is the key to school success and,like any skill,it takes practice.A child learns to walk by practising until he no longer has to think about how to put one foot in front of the other.The great athlete practises until he can play quickly,accurately and without thinking.Ed- ucators call it automaticity.

  20. Scintillating fiber optic dosimeters for breast and prostate brachytherapy

    Science.gov (United States)

    Moutinho, L. M.; Castro, I. F.; Freitas, H.; Melo, J.; Silva, P.; Gonçalves, A.; Peralta, L.; Rachinhas, P. J.; Simões, P. C. P. S.; Pinto, S.; Pereira, A.; Santos, J. A. M.; Costa, M.; Veloso, J. F. C. A.

    2017-02-01

    Brachytherapy is a radiotherapy modality where the radioactive material is placed close to the tumor, being a common treatment for skin, breast, gynecological and prostate cancers. These treatments can be of low-dose-rate, using isotopes with mean energy of 30 keV, or high-dose-rate, using isotopes such as 192Ir with a mean energy of 380 keV. Currently these treatments are performed in most cases without in-vivo dosimetry for quality control and quality assurance. We developed a dosimeter using small diameter probes that can be inserted into the patient's body using standard brachytherapy needles. By performing real-time dosimetry in breast and prostate brachytherapy it will be possible to perform real-time dose correction when deviations from the treatment plan are observed. The dosimeter presented in this work was evaluated in-vitro. The studies consisted in the characterization of the dosimeter with 500 μm diameter sensitive probes (with a BCF-12 scintillating optical fiber) using an inhouse made gelatin breast phantom with a volume of 566 cm3. A breast brachytherapy treatment was simulated considering a tumor volume of 27 cm3 and a prescribed absolute dose of 5 Gy. The dose distribution was determined by the Inverse Planning Simulated Annealing (IPSA) optimization algorithm (ELEKTA). The dwell times estimated from the experimental measurements are in agreement with the prescribed dwell times, with relative error below 3%. The measured signal-to-noise ratio (SNR) including the stem-effect contribution is below 3%.

  1. Preliminary study of diffusion effects in Fricke gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Quiroga, A. [Centro de Investigacion y Estudios de Matematica de Cordoba, Oficina 318 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Vedelago, J. [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Valente, M., E-mail: aiquiroga@famaf.unc.edu [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Diffusion of ferric ions in ferrous sulfate (Fricke) gels represents one of the main drawbacks of some radiation detectors, like Fricke gel dosimeters. In practice, this disadvantage can be overcome by prompt dosimeter analysis, constraining strongly the time between irradiation and analysis. Due to required integral accuracy levels, special dedicated protocols are implemented with the aim of minimizing signal blurring due to diffusion effects. This work presents dedicated analytic modelling and numerical calculations of diffusion coefficients in Fricke gel radiation sensitive material. Samples are optically analysed by means of visible light transmission measurements capturing images with a Ccd camera provided with a monochromatic 585 nm filter corresponding to the X O-infused Fricke solution absorbance peak. Dose distributions in Fricke gels are suitably delivered in order to assess specific initial conditions further studied by periodical sample image acquisitions. In a first analytic approach, experimental data are fit with linear models in order to achieve a value for the diffusion coefficient. The second approach to the problem consists on a group of computational algorithms based on inverse problem formulation, along with suitable 2D diffusion model capable of estimating diffusion coefficients by fitting the obtained algorithm numerical solutions with the corresponding experimental data. Comparisons are performed by introducing an appropriate functional in order to analyse both experimental and numerical values. Solutions to second order diffusion equation are calculated in the framework of a dedicated method that incorporates Finite Element Method. Moreover, optimised solutions can be attained by gradient type minimisation algorithms. Knowledge about diffusion coefficient for Fricke gel radiation detector might be helpful in accounting for effects regarding elapsed time between dosimeter irradiation and further analysis. Hence, corrections might be included

  2. DNA as a solar dosimeter in the ocean.

    Science.gov (United States)

    Regan, J D; Carrier, W L; Gucinski, H; Olla, B L; Yoshida, H; Fujimura, R K; Wicklund, R I

    1992-07-01

    Stratospheric ozone depletion may result in increased solar UV-B radiation to the ocean's upper layers and may cause deleterious effects on marine organisms. The primary UV-B damage induced in biological systems is to DNA. While physical measurements of solar UV-B penetration into the sea have been made, the effective depth and magnitude of actual DNA damage have not been determined. In the experiments reported here, UV-B-induced photoproducts (cyclobutane pyrimidine dimers) have been quantified in DNA molecules exposed to solar UV at the surface and at various depths in clear, tropical marine waters off Lee Stocking Island (23 degrees 45' N, 76 degrees 0.7' W), Exuma Cays, Bahamas. (14C)thymidine-labeled DNA or unlabeled bacteriophage phi X174 DNA was placed in specially designed quartz tubes at various depths for up to five days. Following exposure, DNA samples were removed to the laboratory where UV-B-induced pyrimidine dimers were quantified using a radiochromatographic assay, and bacteriophage DNA inactivation by solar UV-B was assayed by plaque formation in spheroplasts of Escherichia coli. Pyrimidine dimer induction was linear with time but the accumulation of dimers in DNA with time varied greatly with depth. Attenuation of dimer formation with depth of water was exponential. DNA at 3 m depth had only 17% of the pyrimidine dimers found at the surface. Bacteriophage phi X174 DNA, while reduced 96% in plaque-forming ability by a one day exposure to solar UV at the surface of the water, showed no effect on plaque formation after a similar exposure at 3 m. The data collected at the water's surface showed a "surface-enhanced dose" in that DNA damages at the real surface were greater than at the imaginary surface, which was obtained by extrapolating the data at depth to the surface. These results show the sensitivity of both the biochemical (dimers) and biological (phage plaques) DNA dosimeters. DNA dosimeters offer a sensitive, convenient and relatively

  3. FBX aqueous chemical dosimeter for measurement of dosimetric parameters

    Energy Technology Data Exchange (ETDEWEB)

    Moussous, O., E-mail: o.moussous@crna.d [Centre de Recherche Nucleaire d' Alger (CRNA), 02 Boulevard Frantz Fanon B.P. 399, 16000 Alger (Algeria); Medjadj, T. [Centre de Recherche Nucleaire d' Alger (CRNA), 02 Boulevard Frantz Fanon B.P. 399, 16000 Alger (Algeria); Benguerba, M. [Faculte de Physique, Universite des Sciences et de la Technologie Houari-Boumediene USTHB, Alger (Algeria)

    2011-02-15

    We investigated the ferrous sulphate-benzoic acid-xylenol orange (FBX) aqueous chemical dosimeter for measurement of dosimetric parameters such as the output factor, backscatter factor and lateral beam profiles for different square fields sizes for {sup 60}Co {gamma}-rays. A water phantom was employed to measure these parameters. An ionization chamber (IC) was used for calibration and comparison. A comparison of the resulting measurements with an ionization chamber's measured parameters showed good agreement. We thus believe that the tissue equivalent FBX dosimetry system can measure the dosimetric parameters for {sup 60}Co with reasonable accuracy.

  4. Design of an improved neutron dose equivalent dosimeter

    CERN Document Server

    Brushwood, J M; Spyrou, N M

    2002-01-01

    This paper describes the design and development of a new active area neutron dosimeter. The design incorporates a traditional central detector with a moderator/filter arrangement and a number of outer PIN type photodiodes sensitised to thermal neutrons by the application of a lithium fluoride converter. The outer thermal detectors allow the determination of the neutron radiation field characteristics. The experimental programme has demonstrated that such an arrangement is capable of discriminating between various neutron fields and the usefulness of MCNP4b as a design tool.

  5. Adaptation of a Pocket PC for Use as a Wearable Voice Dosimeter

    Science.gov (United States)

    Popolo, Peter S.; Svec, Jan G.; Titze, Ingo R.

    2005-01-01

    This article deals with the adaptation of a commercially available Pocket PC for use as a voice dosimeter, a wearable device that measures the vocal dose of teachers or other individuals on the job, at home, and elsewhere during the course of an entire day. An engineering approach for designing a voice dosimeter is described, and design data are…

  6. Longevity Tests of High-Sensitivity BD-PND Bubble Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Radev, R; Carlberg, E

    2002-07-09

    Medium- and very-high-sensitivity neutron bubble dosimeters (BD-PNDs) made by Bubble Technology Industries (BTI) were used to study the life span of such dosimeters in a standard setup with a {sup 252}Cf source. Although data on the longevity of bubble dosimeters with low and medium sensitivity exist, such data for dosimeters with high and very high sensitivity are not readily available. The manufacturer guarantees optimum dosimeter performance for 3 months after receipt. However, it is important to know the change in the dosimeters' characteristics with time, especially after the first 3 months. The long-term performance of four sets of very high sensitivity and one set of medium-sensitivity bubble dosimeters was examined for periods of up to 13 months. During that time, the detectors were exposed and reset more than 20 times. Although departures from initial detection sensitivity were observed in several cases, the detectors indicated a significantly longer life span than stated in the manufacturer's warranty. In addition, the change in the number of bubbles and in evaluated neutron dose as a function of the time from the end of exposure until the dosimeters were read was investigated.

  7. Experiences with electronic personal dosimeters at Dukovany Nuclear Power Plant-Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Jurochova, Bozena; Zelenka, Zdenik [Personal Dosimetry Department NPP Dukovany (Czech Republic)

    2004-07-01

    The Dukovany Nuclear Power Plant operates four WWER-440 type reactors. Unit 1 has been operating since 1985, Unit 2 and Unit 3 since 1986, Unit 4 was connected to the grid in 1987. At Dukovany NPP occupational dosimetry is performed by approved Personal Dosimetry Service. The basic facilities for measuring external exposure are film badge (legal dosimeter), electronic personal dosimeter (EPD) and radio-photoluminescent dosimeter (RPL) as operational dosimeter, TLD for measuring doses to the extremities and TLD albedo dosimeter as neutron dosimeter. The presentation is based on the experiences with electronic personal dosimeters gathered at Dukovany NPP for the last three years. Electronic Personal Dosimetry System (EPDS) was developing by Czech company VF, a.s. and from 2002 year is also used at Temelin NPP (Czech Republic), SE VYZ Bohunice (Slovakia) and SE Mochovce NPP (Slovakia) as well. EPDS is designed for Merlin Gerin, Siemens and RADOS electronic dosimeters. Application SW for data analysis is used for daily monitoring of personal doses and for evaluation of collective doses during outages. System gives information about collective doses on devices and collective doses for select work tasks during outages. In addition EPDS allows the calculation of dose indexes I{sub D}. (I{sub D} is the ratio of the relevant collective dose and the number of equivalent working hours). This information is applicable for planning doses on special working activities for next outages and allows a detection radiation sources also.

  8. Evaluation of the effect of temperature variation on response of PRESAGE® dosimeter

    Directory of Open Access Journals (Sweden)

    Bagher Farhood

    2017-01-01

    Conclusion: The finding showed that temperature changes have not impact on the absorption peak. In addition, the results related to the effect of temperature variation on the response of PRESAGE ® dosimeter showed that in the range of clinical applications (temperatures below 75°C, temperature variation has no effect on PRESAGE ® dosimeter response.

  9. [Estimation of personal dose based on the dependent calibration of personal dosimeters in interventional radiology].

    Science.gov (United States)

    Mori, Hiroshige; Koshida, Kichiro; Ichikawa, Katsuhiro

    2007-08-20

    The purpose of present study is, in interventional radiology (IVR), to elucidate the differences between each personal dosimeter, and the dependences and calibrations of area or personal dose by measurement with electronic dosimeters in particular. We compare space dose rate distributions measured by an ionization survey meter with the value measured by personal dosimeter: an optically stimulated luminescence, two fluoroglass, and two electronic dosimeters. Furthermore, with electronic dosimeters, we first measured dose rate, energy, and directional dependences. Secondly, we calibrated the dose rate measured by electronic dosimeters with the results, and estimated these methods with coefficient of determination and Akaike's Information Criterion (AIC). The results, especially in electronic dosimeters, revealed that the dose rate measured fell by energy and directional dependences. In terms of methods of calibration, the method is sufficient for energy dependence, but not for directional dependence, because of the lack of stable calibration. This improvement poses a question for the future. The study suggested that these dependences of the personal dosimeter must be considered when area or personal dose is estimated in IVR.

  10. Ceric and ferrous dosimeters show precision for 50-5000 rad range

    Science.gov (United States)

    Frigerio, N. A.; Henry, V. D.

    1968-01-01

    Ammonium thiocyanate, added to the usual ferrous sulfate dosimeter solution, yielded a very stable, precise and temperature-independent system eight times as sensitive as the classical Fricke system in the 50 to 5000 rad range. The ceric dosimeters, promising for use in mixed radiation fields, respond nearly independently of LET.

  11. Social Odors: Alarm Pheromones and Social Buffering.

    Science.gov (United States)

    Kiyokawa, Yasushi

    2017-01-01

    In this chapter, I describe 2 types of olfactory communication in rats, which appear to arouse anxiety and relief, respectively. In alarm pheromonal communication, rats release 4-methylpentanal and hexanal from their perianal region when they are stressed. These molecules activate the anxiety circuit, including the bed nucleus of the stria terminalis, when 4-methylpentanal and hexanal are simultaneously detected by the vomeronasal system and the main olfactory system, respectively. Consequently, recipient rats show a variety of anxiety responses, depending on the threatening stimuli. In appeasing olfactory communication, non-stressed rats release an appeasing olfactory signal, which is detected by the main olfactory system of other rats. When detected, this olfactory signal suppresses activation of the basolateral complex of the amygdala and, as a result, ameliorates stress responses elicited by an auditory conditioned stimulus during social buffering phenomenon. Because social buffering appears to be based on affinity and attachment to accompanying animals, the appeasing olfactory signal may arouse relief in rats. A definition of social buffering is also proposed as we still have no set definition for the term social buffering yet.

  12. Changes in Default Alarm Settings and Standard In-Service are Insufficient to Improve Alarm Fatigue in an Intensive Care Unit: A Pilot Project.

    Science.gov (United States)

    Sowan, Azizeh Khaled; Gomez, Tiffany Michelle; Tarriela, Albert Fajardo; Reed, Charles Calhoun; Paper, Bruce Michael

    2016-01-11

    Clinical alarm systems safety is a national concern, specifically in intensive care units (ICUs) where alarm rates are known to be the highest. Interventional projects that examined the effect of changing default alarm settings on overall alarm rate and on clinicians' attitudes and practices toward clinical alarms and alarm fatigue are scarce. To examine if (1) a change in default alarm settings of the cardiac monitors and (2) in-service nursing education on cardiac monitor use in an ICU would result in reducing alarm rate and in improving nurses' attitudes and practices toward clinical alarms. This quality improvement project took place in a 20-bed transplant/cardiac ICU with a total of 39 nurses. We implemented a unit-wide change of default alarm settings involving 17 parameters of the cardiac monitors. All nurses received an in-service education on monitor use. Alarm data were collected from the audit log of the cardiac monitors 10 weeks before and 10 weeks after the change in monitors' parameters. Nurses' attitudes and practices toward clinical alarms were measured using the Healthcare Technology Foundation National Clinical Alarms Survey, pre- and postintervention. Alarm rate was 87.86 alarms/patient day (a total of 64,500 alarms) at the preintervention period compared to 59.18 alarms/patient day (49,319 alarms) postintervention (P=.01). At baseline, Arterial Blood Pressure (ABP), Pair Premature Ventricular Contractions (PVCs), and Peripheral Capillary Oxygen Saturation (SpO2) alarms were the highest. ABP and SpO2 alarms remained among the top three at the postproject period. Out of the 39 ICU nurses, 24 (62%) provided complete pre- and postproject survey questionnaires. Compared to the preintervention survey, no remarkable changes in the postproject period were reported in nurses' attitudes. Themes in the narrative data were related to poor usability of cardiac monitors and the frequent alarms. The data showed great variation among nurses in terms of changing

  13. Effects of temperature and humidity during irradiation on the response of a film dosimeter

    Science.gov (United States)

    Khan, Hasan M.; Wahid, Mian S.

    1995-09-01

    A commercially available leuco dye containing polyvinyl butyral based film (FWT-63-02) has been investigated ctrophotometrically for its dosimetric characteristic and for its use as routine dosimeter in radiation processing for the absorbed dose range 0.1 to 10 kGy. The present study was carried out to evaluate the performance of dosimeter under different environmental conditions (i.e. effects of temperature and relative humidity during irradiation). The response was measured at peak wavelength of 600 nm as well as at a number of other wavelengths (550, 625, 640 and 650 nm). The dosimeter was found to show quite stable response up to a radiation chamber temperature of 40°C. The dosimeter also showed stable behavior at low or moderate relative humidity conditions (<76%) in the radiation chamber. The characteristics of the dosimeter are suitable for its possible application in radiation processing, food irradiation and sterilization applications.

  14. Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry

    Directory of Open Access Journals (Sweden)

    Bongsoo Lee

    2015-11-01

    Full Text Available In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter.

  15. Response of the DIS-1 personal dosimeter to neutrons, protons and other hadrons

    CERN Document Server

    Otto, Thomas

    2010-01-01

    The DIS-1 personal dosimeter is approved for assessment of personal dose Hp(10) and Hp(0.07) from γ and β radiation. Dose measurement in the DIS-1 is based on miniaturized ionization chambers. In mixed radiation fields with components other than photons and electrons, the dosimeter will not indicate personal dose, but the ionization chambers will produce a spurious signal that will add to the signal from γ and β radiation. The purpose of this paper is the evaluation of the magnitude of the spurious signal from other radiation types. For this purpose, irradiations of DIS-1 dosimeters were performed in a neutron calibration field and two mixed radiation fields at a particle accelerator. The results show, that the DIS-1 dosimeter indicates absorbed dose in arbitrary radiation fields. This property of the DIS-1 dosimeter can give critical information after accidental exposures or when investigating suspected overexposures.

  16. Perceptual specificity in the alarm calls of Gunnison's prairie dogs.

    Science.gov (United States)

    Kiriazis, Judith; Slobodchikoff, C N

    2006-07-01

    Gunnison's prairie dogs have a complex alarm communication system. We show that the escape responses of prairie dogs to naturally occurring live predators differed depending upon the species of predator. We also show that playbacks of alarm calls that were elicited originally by the live predators produced the same escape responses as the live predators themselves. The escape responses fell into two qualitatively different categories: running to the burrow and diving inside for hawks and humans, and standing upright outside the burrow for coyotes and dogs. Within these two categories there were differences in response. For hawks, only the prairie dogs that were in the direct flight path of a stooping red-tailed hawk ran to their burrows and dove inside, while for humans and human alarm call playbacks there was a colony-wide running to the burrows and diving inside. For coyotes and coyote alarm call playbacks there was a colony-wide running to the burrows and standing alert at the burrow rims, while for domestic dogs and playbacks of alarm calls for domestic dogs the prairie dogs assumed an alert posture wherever they were feeding, but did not run to their burrows. These responses to both the live predators and to predator-elicited alarm calls suggest that the alarm calls of Gunnison's prairie dogs contain meaningful referential information about the categories of predators that approach a colony of prairie dogs.

  17. Acoustic structures in the alarm calls of Gunnison's prairie dogs.

    Science.gov (United States)

    Slobodchikoff, C N; Placer, J

    2006-05-01

    Acoustic structures of sound in Gunnison's prairie dog alarm calls are described, showing how these acoustic structures may encode information about three different predator species (red-tailed hawk-Buteo jamaicensis; domestic dog-Canis familaris; and coyote-Canis latrans). By dividing each alarm call into 25 equal-sized partitions and using resonant frequencies within each partition, commonly occurring acoustic structures were identified as components of alarm calls for the three predators. Although most of the acoustic structures appeared in alarm calls elicited by all three predator species, the frequency of occurrence of these acoustic structures varied among the alarm calls for the different predators, suggesting that these structures encode identifying information for each of the predators. A classification analysis of alarm calls elicited by each of the three predators showed that acoustic structures could correctly classify 67% of the calls elicited by domestic dogs, 73% of the calls elicited by coyotes, and 99% of the calls elicited by red-tailed hawks. The different distributions of acoustic structures associated with alarm calls for the three predator species suggest a duality of function, one of the design elements of language listed by Hockett [in Animal Sounds and Communication, edited by W. E. Lanyon and W. N. Tavolga (American Institute of Biological Sciences, Washington, DC, 1960), pp. 392-430].

  18. Reducing false intracranial pressure alarms using morphological waveform features.

    Science.gov (United States)

    Scalzo, Fabien; Liebeskind, David; Hu, Xiao

    2013-01-01

    False alarms produced by patient monitoring systems in intensive care units are a major issue that causes alarm fatigue, waste of human resources, and increased patient risks. While alarms are typically triggered by manually adjusted thresholds, the trend and patterns observed prior to threshold crossing are generally not used by current systems. This study introduces and evaluates, a smart alarm detection system for intracranial pressure signal (ICP) that is based on advanced pattern recognition methods. Models are trained in a supervised fashion from a comprehensive dataset of 4791 manually labeled alarm episodes extracted from 108 neurosurgical patients. The comparative analysis provided between spectral regression, kernel spectral regression, and support vector machines indicates the significant improvement of the proposed framework in detecting false ICP alarms in comparison to a threshold-based technique that is conventionally used. Another contribution of this work is to exploit an adaptive discretization to reduce the dimensionality of the input features. The resulting features lead to a decrease of 30% of false ICP alarms without compromising sensitivity.

  19. Computational Human Performance Modeling For Alarm System Design

    Energy Technology Data Exchange (ETDEWEB)

    Jacques Hugo

    2012-07-01

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators’ alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  20. Compliance with Washington State's requirement for residential carbon monoxide alarms

    Directory of Open Access Journals (Sweden)

    Neil B. Hampson

    2017-03-01

    Full Text Available Carbon monoxide (CO poisoning is responsible for significant morbidity and mortality in the US. In response, a majority of states have passed legislation in recent years requiring the installation of residential CO alarms. There is, however, no published information evaluating compliance with such laws. Employees of a Seattle medical center were surveyed in 2008 regarding home use of CO and smoke alarms. Washington State enacted legislation requiring residential CO alarms by all residences by January 1, 2013. The survey was repeated in mid-2016 to evaluate compliance. In 2016, a total of 354 employees completed the survey and their responses were compared to an equal number of 2008 survey respondents matched by home ownership and ZIP code. Residential CO alarm use rose from 37% to 78% (p < 0.0001. Among homeowners, 78% had alarms while 80% of renters had them. Homeowners with the highest compliance (96% had purchased their homes since January 1, 2013 while those with the lowest compliance (73% had purchased them earlier. A majority (79% of renters without alarms reported the reason was that their landlord did not provide one, a violation of the law. Only one-half to two-thirds of all equipped homes had the required number of either CO or smoke alarms. Use of residential CO alarms increased significantly in this study population three years after law required them. Areas for further improvement include education of landlords, tenants, and longtime homeowners about the law, as well as public education regarding the number of CO and smoke alarms needed.

  1. A modified Fricke gel dosimeter for fast electron blood dosimetry

    Science.gov (United States)

    Del Lama, L. S.; de Góes, E. G.; Sampaio, F. G. A.; Petchevist, P. C. D.; de Almeida, A.

    2014-12-01

    It has been suggested for more than forty years that blood and blood components be irradiated before allogeneic transfusions for immunosuppressed patients in order to avoid the Transfusion-Associated Graft-versus-Host Disease (TA-GVHD). Whole blood, red blood cells, platelets and granulocytes may have viable T cells and should be irradiated before transfusion for different patient clinical conditions. According to international guides, absorbed doses from 25 up to 50 Gy should be delivered to the central middle plane of each blood bag. Although gamma and X-rays from radiotherapy equipments and dedicated cell irradiators are commonly used for this purpose, electron beams from Linear Accelerators (LINACs) could be used as well. In this work, we developed a methodology able to acquire dosimetric data from blood irradiations, especially after fast electrons exposures. This was achieved using a proposed Fricke Xylenol Gel (FXGp) dosimeter, which presents closer radiological characteristics (attenuation coefficients and stopping-powers) to the whole blood, as well as complete absorbed dose range linearity. The developed methodology and the FXGp dosimeter were also able to provide isodose curves and field profiles for the irradiated samples.

  2. Radiation-induced defects in magnesium lactate as ESR dosimeter

    CERN Document Server

    Hassan, G M; Takaki, S

    1999-01-01

    Magnesium lactate (Mg-lactate: (CH sub 3 CH(OH)COO) sub 2 Mg), magnesium lactate doped with lithium lactate (Mg(Li)-lactate) and nominal pure lithium lactate (CH sub 3 CH(OH)COOLi) doped with Mg-lactate (Li(Mg)-lactate) were irradiated by gamma-rays to study radicals for materials of radiation dosimeter with electron spin resonance (ESR). Quartet spectra were ascribed to lactate radicals in Mg-lactate and Li(Mg)-lactate with the spectroscopic splitting factors (g-factor) of 2.0032+-0.004 and 2.0029+-0.004 and the intensity ratio of 1:3:3:1 due to the hyperfine coupling constants of (A/g beta) of 1.92+-0.06 and 1.82+-0.06 mT, respectively. The response to gamma-ray dose and the thermal stability as well as the effect of UV-illumination have been studied to establish this material as an ESR dosimeter. The number of free radicals per 100 eV (G-value) was obtained to be 1.15+-0.32, 1.35+-0.35, 0.46+-0.14 and 0.78+-0.24 for Mg-lactate, Mg(Li)-lactate, Li-lactate and Lie(Mg)-lactate, respectively. Thermoluminescenc...

  3. Physico-chemical studies for strontium sulfate radiation dosimeter

    Directory of Open Access Journals (Sweden)

    M.A.H. Rushdi

    2015-04-01

    Full Text Available Anhydrous strontium sulfate (SrSO4 has shown a promise candidate as a dosimeter for low dose applications producing unique EPR signals with γ-rays which it has a linear response relationship (r2 = 0.999 in the range of 1–100 Gy. The present study extended to evaluate the properties of strontium sulfate dosimeter in intermediate dose range of technology applications. It was observed that the intensity of the EPR signal at g = 2.01081 increases with a 3rd polynomial function in the range of 0.10–15 kGy. In addition, the radical (SO4− provides a stable signal with a good reproducibility (0.107%. Other physics characteristic including the collision of mass stopping power dependence of the system and the effect of atomic number in different energy regions were investigated. The uncertainty budget for high doses has obtained from the measurement with value of 3.57% at 2σ confidence level.

  4. A modified Fricke gel dosimeter for fast electron blood dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Del Lama, L.S., E-mail: lucasdellama@gmail.com [Departamento de Fsica, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (FFCLRP/USP), Av. Bandeirantes, 3900, CEP 14040-901, Bairro Monte Alegre, Ribeirão Preto, São Paulo (Brazil); Góes, E.G. de [Instituto de Matemática, Estatística e Física, Universidade Federal de Rio Grande (IMEF/FURG), Av. Itália, km 8, CEP 96201-900, Bairro Carreiros, Rio Grande, Rio Grande do Sul (Brazil); Sampaio, F.G.A.; Petchevist, P.C.D.; Almeida, A. de [Departamento de Fsica, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (FFCLRP/USP), Av. Bandeirantes, 3900, CEP 14040-901, Bairro Monte Alegre, Ribeirão Preto, São Paulo (Brazil)

    2014-12-15

    It has been suggested for more than forty years that blood and blood components be irradiated before allogeneic transfusions for immunosuppressed patients in order to avoid the Transfusion-Associated Graft-versus-Host Disease (TA-GVHD). Whole blood, red blood cells, platelets and granulocytes may have viable T cells and should be irradiated before transfusion for different patient clinical conditions. According to international guides, absorbed doses from 25 up to 50 Gy should be delivered to the central middle plane of each blood bag. Although gamma and X-rays from radiotherapy equipments and dedicated cell irradiators are commonly used for this purpose, electron beams from Linear Accelerators (LINACs) could be used as well. In this work, we developed a methodology able to acquire dosimetric data from blood irradiations, especially after fast electrons exposures. This was achieved using a proposed Fricke Xylenol Gel (FXG{sub p}) dosimeter, which presents closer radiological characteristics (attenuation coefficients and stopping-powers) to the whole blood, as well as complete absorbed dose range linearity. The developed methodology and the FXG{sub p} dosimeter were also able to provide isodose curves and field profiles for the irradiated samples.

  5. Early warning, warning or alarm systems for natural hazards? A generic classification.

    Science.gov (United States)

    Sättele, Martina; Bründl, Michael; Straub, Daniel

    2013-04-01

    Early warning, warning and alarm systems have gained popularity in recent years as cost-efficient measures for dangerous natural hazard processes such as floods, storms, rock and snow avalanches, debris flows, rock and ice falls, landslides, flash floods, glacier lake outburst floods, forest fires and even earthquakes. These systems can generate information before an event causes loss of property and life. In this way, they mainly mitigate the overall risk by reducing the presence probability of endangered objects. These systems are typically prototypes tailored to specific project needs. Despite their importance there is no recognised system classification. This contribution classifies warning and alarm systems into three classes: i) threshold systems, ii) expert systems and iii) model-based expert systems. The result is a generic classification, which takes the characteristics of the natural hazard process itself and the related monitoring possibilities into account. The choice of the monitoring parameters directly determines the system's lead time. The classification of 52 active systems moreover revealed typical system characteristics for each system class. i) Threshold systems monitor dynamic process parameters of ongoing events (e.g. water level of a debris flow) and incorporate minor lead times. They have a local geographical coverage and a predefined threshold determines if an alarm is automatically activated to warn endangered objects, authorities and system operators. ii) Expert systems monitor direct changes in the variable disposition (e.g crack opening before a rock avalanche) or trigger events (e.g. heavy rain) at a local scale before the main event starts and thus offer extended lead times. The final alarm decision incorporates human, model and organisational related factors. iii) Model-based expert systems monitor indirect changes in the variable disposition (e.g. snow temperature, height or solar radiation that influence the occurrence probability

  6. Interventions for promoting smoke alarm ownership and function.

    Science.gov (United States)

    DiGuiseppi, C; Higgins, J P

    2001-01-01

    Residential fires caused at least 67 deaths and 2,500 non-fatal injuries to children aged 0-16 in the United Kingdom in 1998. Smoke alarm ownership is associated with a reduced risk of residential fire death. We evaluated interventions to promote residential smoke alarms, to assess their effect on smoke alarm ownership, smoke alarm function, fires and burns and other fire-related injuries. We searched the Cochrane Controlled Trials Register, Cochrane Injuries Group database, MEDLINE, EMBASE, PsycLIT, CINAHL, ERIC, Dissertation Abstracts, International Bibliography of Social Sciences, ISTP, FIREDOC and LRC. Conference proceedings, published case studies, and bibliographies were systematically searched, and investigators and relevant organisations were contacted, to identify trials. Randomised, quasi-randomised or nonrandomised controlled trials completed or published after 1969 evaluating an intervention to promote residential smoke alarms. Two reviewers independently extracted data and assessed trial quality. We identified 26 trials, of which 13 were randomised. Overall, counselling and educational interventions had only a modest effect on the likelihood of owning an alarm (OR=1.26; 95% CI: 0.87 to 1.82) or having a functional alarm (OR=1.19; 0.85 to 1.66). Counselling as part of primary care child health surveillance had greater effects on ownership (OR=1.96; 1.03 to 3.72) and function (OR=1.72; 0.78 to 3.80). Results were sensitive to trial quality, however, and effects on fire-related injuries were not reported. In two non randomised trials, direct provision of free alarms significantly increased functioning alarms and reduced fire-related injuries. Media and community education showed little benefit in non randomised trials. Counselling as part of child health surveillance may increase smoke alarm ownership and function, but its effects on injuries are unevaluated. Community smoke alarm give-away programmes apparently reduce fire-related injuries, but these

  7. ARC Code TI: Optimal Alarm System Design and Implementation

    Data.gov (United States)

    National Aeronautics and Space Administration — An optimal alarm system can robustly predict a level-crossing event that is specified over a fixed prediction horizon. The code contained in this packages provides...

  8. SCADA alarms processing for wind turbine component failure detection

    Science.gov (United States)

    Gonzalez, E.; Reder, M.; Melero, J. J.

    2016-09-01

    Wind turbine failure and downtime can often compromise the profitability of a wind farm due to their high impact on the operation and maintenance (O&M) costs. Early detection of failures can facilitate the changeover from corrective maintenance towards a predictive approach. This paper presents a cost-effective methodology to combine various alarm analysis techniques, using data from the Supervisory Control and Data Acquisition (SCADA) system, in order to detect component failures. The approach categorises the alarms according to a reviewed taxonomy, turning overwhelming data into valuable information to assess component status. Then, different alarms analysis techniques are applied for two purposes: the evaluation of the SCADA alarm system capability to detect failures, and the investigation of the relation between components faults being followed by failure occurrences in others. Various case studies are presented and discussed. The study highlights the relationship between faulty behaviour in different components and between failures and adverse environmental conditions.

  9. Patient characteristics associated with false arrhythmia alarms in intensive care

    Directory of Open Access Journals (Sweden)

    Harris PR

    2017-04-01

    Full Text Available Patricia R Harris,1,2 Jessica K Zègre-Hemsey,3,4 Daniel Schindler,5 Yong Bai,6 Michele M Pelter,2,7 Xiao Hu2,8 1Department of Nursing, School of Health and Natural Sciences, Dominican University of California, San Rafael, 2Department of Physiological Nursing, School of Nursing, University of California, San Francisco, CA, 3School of Nursing, 4Department of Emergency Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, 5Intensive Care Unit, The Neuroscience Center, Sutter Eden Medical Center, Castro Valley, 6Hu Research Laboratory, Department of Physiological Nursing, School of Nursing, University of California, San Francisco, 7ECG Monitoring Research Lab, Department of Physiological Nursing, School of Nursing, 8Physiological Nursing and Neurological Surgery, Affiliate Faculty of Institute for Computational Health Sciences Core Faculty UCB/UCSF Joint Bio-Engineering Graduate Program, University of California, San Francisco, CA, USA Introduction: A high rate of false arrhythmia alarms in the intensive care unit (ICU leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective: The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods: This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and

  10. Male rats respond to their own alarm pheromone.

    Science.gov (United States)

    Inagaki, Hideaki; Kiyokawa, Yasushi; Takeuchi, Yukari; Mori, Yuji

    2012-01-01

    Pheromones are defined as substances released from an individual (donor) that influence a second individual (recipient) of the same species. However, it is unclear whether mammalian pheromones can affect the donor itself. To address this question, the effect of self-exposure to an alarm pheromone was examined. Exposure to the alarm pheromone resulted in an enhanced anxiety response, which was not different between recipients that perceived their own pheromone and those that perceived another individual's pheromone. The present results suggest that the alarm pheromone influences the emotional system of the recipient as well as induces similar anxiogenic effects on the donor rat that released the alarm pheromone. This is the first evidence demonstrating the effectiveness of mammalian pheromone self-exposure.

  11. A distributed approach to alarm management in chronic kidney disease.

    Science.gov (United States)

    Estudillo-Valderrama, Miguel A; Talaminos-Barroso, Alejandro; Roa, Laura M; Naranjo-Hernández, David; Reina-Tosina, Javier; Aresté-Fosalba, Nuria; Milán-Martín, José A

    2014-11-01

    This paper presents the feasibility study of using a distributed approach for the management of alarms from chronic kidney disease patients. In a first place, the key issues regarding alarm definition, classification, and prioritization according to available normalization efforts are analyzed for the main scenarios addressed in hemodialysis. Then, the middleware proposed for alarm management is described, which follows the publish/subscribe pattern, and supports the Object Management Group data distribution service (DDS) standard. This standard facilitates the real-time monitoring of the exchanged information, as well as the scalability and interoperability of the solution developed regarding the different stakeholders and resources involved. Finally, the results section shows, through the proof of concept studied, the viability of DDS for the activation of emergency protocols in terms of alarm prioritization and personalization, as well as some remarks about security, privacy, and real-time communication performance.

  12. A weighted dissimilarity index to isolate faults during alarm floods

    CERN Document Server

    Charbonnier, S; Gayet, P

    2015-01-01

    A fault-isolation method based on pattern matching using the alarm lists raised by the SCADA system during an alarm flood is proposed. A training set composed of faults is used to create fault templates. Alarm vectors generated by unknown faults are classified by comparing them with the fault templates using an original weighted dissimilarity index that increases the influence of the few alarms relevant to diagnose the fault. Different decision strategies are proposed to support the operator in his decision making. The performances are evaluated on two sets of data: an artificial set and a set obtained from a highly realistic simulator of the CERN Large Hadron Collider process connected to the real CERN SCADA system.

  13. Measurement of the Portsmouth Gaseous Diffusion Plant criticality accident alarm

    Energy Technology Data Exchange (ETDEWEB)

    Tayloe, R.W. Jr. (Battelle Columbus (USA)); McGinnis, B. (Martin Marietta Energy Systems, Inc., Piketon, OH (USA))

    1990-08-31

    Measurements of the Portsmouth Gaseous Diffusion Plant's nuclear criticality accident radiation alarm signal response time, sound wave frequency, and sound volume levels were made to demonstrate compliance with ANSI/ANS-8.3-1986. A steady-state alarm signal is produced within one-half second of obtaining a two-out-of-three detector trip. The fundamental alarm sound wave frequency is 440 hertz. The sound volume levels are greater than 10 decibels above background and ranged from 100 to 125 A-weighted decibels. The requirements of the standard were met; however the recommended maximum sound volume level of 115 dBA was exceeded. Emergency procedures require immediate evacuation upon initiation of a facility's radiation alarm. Comparison with standards for allowable time of exposure at different noise levels indicate that the elevated noise level at this location does not represent an occupational injury hazard. 8 refs., 5 figs.

  14. A nurses' alarm fatigue questionnaire: development and psychometric properties.

    Science.gov (United States)

    Torabizadeh, Camellia; Yousefinya, Amirhossein; Zand, Farid; Rakhshan, Mahnaz; Fararooei, Mohammad

    2016-11-15

    Alarm fatigue can adversely affect nurses' efficiency and concentration on their tasks, which is a threat to patients' safety. The purpose of the present study was to develop and test the psychometric accuracy of an alarm fatigue questionnaire for nurses. This study was conducted in two stages: in stage one, in order to establish the different aspects of the concept of alarm fatigue, the researchers reviewed the available literature-articles and books-on alarm fatigue, and then consulted several experts in a meeting to define alarm fatigue and develop statements for the questionnaire. In stage two, after the final draft had been approved, the validity of the instrument was measured using the two methods of face validity (the quantitative and qualitative approaches) and content validity (the qualitative and quantitative approaches). Test-retest, Cronbach's alpha, and Principal Component Analysis were used for item reduction and reliability analysis. Based on the results of stage one, the researchers extracted 30 statements based on a 5-point Likert scale. In stage two, after the face and content validity of the questionnaire had been established, 19 statements were left in the instrument. Based on factor loadings of the items and "alpha if item deleted" and after the second round of consultation with the expert panel, six items were removed from the scale. The test of the reliability of nurses' alarm fatigue questionnaire based on the internal homogeneity and retest methods yielded the following results: test-retest correlation coefficient = 0.99; Guttman split-half correlation coefficient = 0.79; Cronbach's alpha = 0.91. Regarding the importance of recognizing alarm fatigue in nurses, there is need for an instrument to measure the phenomenon. The results of the study show that the developed questionnaire is valid and reliable enough for measuring alarm fatigue in nurses.

  15. CCD imaging for optical tomography of gel radiation dosimeters.

    Science.gov (United States)

    Wolodzko, J G; Marsden, C; Appleby, A

    1999-11-01

    Several investigations have been carried out by a number of researchers over the past few years to evaluate the utility of imaging gel dosimeters for the three-dimensional measurement of radiation fields. These have been proposed to be of particular value in mapping radiation dose distributions associated with emerging and complex approaches to cancer treatment such as conformal (CRT), intensity modulated (IMRT), "gamma knife," and pencil beam radiotherapies. Imaging of the gels has been successfully accomplished with clinical MRI units and via laser-based optical scanning. However, neither of these methods is generally accessible to all potential users, limiting the broader study and implementation of this valuable tool. We report here the design, methodology, and results of a preliminary study carried out to evaluate the utility of a new, inexpensive, and simplified approach to tomographic imaging of gel radiation dosimeters. For the purpose of this initial investigation, an array of liquid scintillation vials was prepared, containing a ferrous sulphate xylenol orange (FSX) gelatin formulation. The FSX formulation undergoes a change in optical absorption characteristics following irradiation, and the resulting color change can be observed visually. The vials were irradiated individually to different doses. Three-dimensional imaging was accomplished by tomographic reconstruction from two-dimensional optical images acquired using a diffuse, fluorescent light source, a digital charge-coupled device camera, single-photon-emission-computed tomography software, and other simple components designed by the authors. The resulting transverse images were evaluated through a region-of-interest (ROI) analysis to obtain the average change in image density in each vial as a function of radiation dose. These measured ROI values were subjected to a linear regression analysis to fit them to a straight line, and to determine the goodness of fit. Results from multiple imaging trials

  16. The responses of three kinds of passive dosimeters to secondary cosmic rays in the lower atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhen; Chen, Bo, E-mail: bochenfys@fudan.edu.cn; Zhuo, Weihai; Fan, Dunhuang; Zhang, Yu [Institute of Radiation Medicine, Fudan University, 2094 Xietu Road, Shanghai 200032 (China); Zhao, Chao [Shanghai Institute of Measurement and Testing Technology, 1500 Zhangheng Road, Shanghai 201203 (China)

    2015-12-15

    For accurate measurements of the secondary cosmic rays by using passive dosimeters, the relative responses of the thermoluminescence dosimeter (TLD), optically stimulated luminescence (OSL) dosimeter, and radiophotoluminescent glass dosimeter (RPLGD) were studied. The cosmic-ray shower generator was used to simulate the secondary cosmic rays at the sea level. Monte Carlo simulations were performed to calculate the air kerma and absorbed doses in each kind of dosimeter. The results showed that compared with their responses to gamma rays of {sup 137}Cs, the relative responses of the TLD, OSL, and RPLGD were 0.786, 0.707, and 0.735 to the hard component of cosmic rays, respectively, and the values were 0.904, 0.838, and 0.857 to the soft component of cosmic rays, respectively. To verify the simulations results, an in situ measurement with the three kinds of dosimeters was performed at the same place. The results indicated that the secondary cosmic rays monitored with the three kinds of dosimeters were well consistent with each other provided their relative responses were taken into account.

  17. Feasibility study of a lead monoxide-based dosimeter for quality assurance in radiotherapy

    Science.gov (United States)

    Kim, K. T.; Han, M. J.; Heo, Y. J.; Park, J. E.; Lee, Y. K.; Kim, J. N.; Oh, K. M.; Cho, H. L.; Choi, Y. S.; Kim, J. Y.; Nam, S. H.; Park, S. K.

    2016-11-01

    Lately, cancer has been treated using high-energy radiation, and this requires highly reliable treatment plans. Therefore, a dosimeter with excellent performance, which is capable of precise dose measurement, is critical. In current clinical practices, an ionization chamber and diode utilizing the ionization reaction mechanism are widely used. Several studies have been carried out to determine optimal materials for the detector in a dosimeter to enable diagnostic imaging. Recently, studies with lead monoxide, which was shown to have low drift current and high resolving power at a high bias, were reported with the dosimeter exhibiting a fast response time against incident photons. This research aims to investigate the feasibility of a lead monoxide-based dosimeter for QA (quality assurance) in radiotherapy. In this paper, we report that the manufactured dosimeter shows similar linearity to a silicon diode and demonstrates similar characteristics in terms of PDD (percent depth dose) results for the thimble ionization chamber. Based on these results, it is demonstrated that the lead monoxide-based dosimeter complies with radiotherapy QA requirements, namely rapid response time, dose linearity, dose rate independence. Thus, we expect the lead monoxide-based dosimeter to be used commercially in the future.

  18. Radiation-induced color bleaching of methyl red in polyvinyl butyral film dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Al Zahrany, Awad A., E-mail: azahrany@kacst.edu.sa [Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, (KACST), P.O. BOX 6086, Riyadh 11442 (Saudi Arabia); Rabaeh, Khalid A. [Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, (KACST), P.O. BOX 6086, Riyadh 11442 (Saudi Arabia); Radiography Department, Faculty of Allied Health Sciences, Hashemite University, Zarqa (Jordan); Basfar, Ahmed A. [Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, (KACST), P.O. BOX 6086, Riyadh 11442 (Saudi Arabia)

    2011-11-15

    Radio-chromic film based on polyvinyl butyral (PVB) containing different concentrations of methyl red (MR) dye for 0.125, 0.25 and 0.5 mM has been introduced as high dose dosimeter. The dosimeters were irradiated with gamma ray from {sup 60}Co source at doses from 5 to 150 kGy. UV/vis spectrophotometry was used to investigate the optical density of unirradiated and irradiated films in terms of absorbance at 497 nm. The dose sensitivity of MR-PVB film dosimeter increases strongly with increase of absorbed dose as well as increase of concentrations of MR dye. The effects of irradiation temperature, relative humidity, dose rate and the stability of the response of the films after irradiation were investigated and found that these films could be used as routine dosimeter in industrial radiation processing. The useful dose range of developed MR-PVB film dosimeters is in the range of 5-100 kGy. - Highlights: > This manuscript relates to radio-chromic dosimeter for used in high dose radiation processing. > Methyl red MR contains azo group which breaking due to gamma radiation, resulting in color bleaching. > Radio-chromic film PVB containing different concentrations of MR dye has been introduced. > The color bleaching of MR-PVB film dosimeter increases gradually with increasing absorbed dose. > Response of MR-PVB films was slightly affected by irradiation temperature and relative humidity.

  19. Procedure for the delivering of personal short-term visitor dosimeters

    CERN Multimedia

    2016-01-01

    Update of the administrative procedure for delivering a personal short-term visitor dosimeter to associated members of CERN’s personnel.   Associated members of the CERN personnel may request a short term visitor dosimeter if working only in Supervised Radiation Areas and for a period of less than two months in a calendar year. Such a dosimeter is delivered without the need to provide the usual regular documents: radiation passport, certificate from the home institute or medical certificate. Periodic verification will ensure that holders of these personal dosimeters do not exceed the maximum allowed personal dose for this type of dosimeter, which is the same as the limit for members of the public at 1 mSv per year. From now on, the two-month period can be spread over a calendar year, offering greater flexibility to users coming to CERN for multiple short periods. Please return unused dosimeters Persons leaving CERN for a period of more than one month should return their dosimeter to the D...

  20. Reproducibility study of TLD-100 dosimeters for {sup 122}I seeds used in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zeituni, Carlos A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil); E-mail: czeituni@ipen.br; Moura, Eduardo S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faculdade Oswaldo Cruz, Sao Paulo, SP (Brazil); Manzoli, Jose E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade Sao Judas Tadeu, Sao Paulo, SP (Brazil); Terremoto, Luis A.A.; Rostelato, Maria Elisa C.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2007-07-01

    In order to provide the dosimetry for {sup 125}I seed production in Brazil, Harshaw thermoluminescent dosimeters (TLD-100) will be used. Even if measurements with TLD-100 of the same batch of fabrication are performed, the precision of the response will not be the same. As a consequence, they must be measured one by one. This paper presents the calculation methodology for selection procedure to TLD-100 dosimeter used, embracing 143 TLD-100 dosimeters prepared by Harshaw Company on December 19th, 2005. These dosimeters are LiF type with a micro-cube (1 mm x 1 mm x 1 mm) shape. The annealing procedure used for these dosimeters consists of annealing the TLD dosimeters at 400 deg C for 65 minutes using a PC controlled annealing oven. This procedure is followed by an oven-typical cooling down profile to about 100 deg C for 127 minutes. The pre-readout thermal stabilization was used and it consists of an annealing at 100 deg C for 15 minutes. Irradiations were performed using 36 {sup 125}I seeds with activity of 0,623 mCi (23,05 MBq) on October 20th, 2006 for approximately 150 minutes, to guarantee a minimum of 5 Gy absorbed dose in each dosimeter. Different evanescence times have been used. These complete procedures were carried out four times in order to compare the data and minimize the systematic error. (author)

  1. [Is it really not possible to use electronic personal dosimeters in clinical exposure situations?].

    Science.gov (United States)

    Borowski, M; Poppe, B; Looe, H K; von Boetticher, H

    2010-09-01

    Due to significant measuring inaccuracies that can occur under certain conditions, the use of electronic personal dosimeters in statutory measurements in X-ray diagnostics is currently legally restricted. The present study investigates the clinically relevant situations in which measurement errors of more then 20 % can be anticipated. Four series of experiments were made, comparing the results of the electronic personal dosimeter EPD Mk2.3 to those of reference dosimeters (TLDs and diagnostic dosimeters). On the one hand, personal doses have been determined in the routine operation of controlled areas in various departments. On the other hand, measurements on phantoms have been conducted in extreme but realistic situations under radiation protection. Experiments were conducted in unweakened scattered radiation as well as in unattenuated and attenuated direct radiation. The tested electronic personal dosimeter type meets the requirements regarding measurement accuracy for "official" personal dosimeters in all of the examined clinically relevant scattered radiation fields. Only if exposed to radiation directly, an underestimation of the dose can occur and can be greater than 90 %. In the range of scattered radiation of diagnostic X-ray equipment, even in pulsed fields, the use of electronic personal dosimeters is reasonable. Considerable measurement errors can only arise in radiation fields that are not realistic under regular conditions and even in connection with most accidents. Georg Thieme Verlag KG Stuttgart, New York.

  2. Development of a GLE Alarm System Based Upon Neutron Monitors

    Science.gov (United States)

    Kuwabara, T.; Bieber, J. W.; Clem, J.; Evenson, P.; Pyle, R.

    2005-12-01

    We have developed a system that watches for count rate increases recorded in real time by eight neutron monitors, and gives an alarm when a Ground Level Enhancement (GLE) is detected. In this work, we determine optimal strategies for detecting the GLE event at a very early stage, while still keeping the false alarm rate from glitches at a very low level. The January 20, 2005 event will be used to illustrate our methods. A reliable system is developed with an algorithm that produces alarms in three levels according to the number of stations showing an increase. We study past events to optimize appropriate intensity threshold values and a baseline to determine the intensity increase. At the highest level alarm produced by the three stations increase, a false alarm rate expected from the observed data during the past five years become zero. Alarm times of GLEs examined from the most recent nine events are compared with satellite proton data. The GLE alert would precede the earliest alert from GOES (100 MeV or 10 MeV protons) by ~10-20 minutes. For the January 20 event, the GLE alert (3 stations) was generated 12 minutes prior to the earliest GOES alert. The realtime GLE data may be viewed at http://neutronm.bartol.udel.edu/spaceweather. An automated e-mail alert system is under development. Supported by NSF grants ATM-0207196 and ATM-0000315.

  3. Oscillometric and conductometric analysis of aqueous and organic dosimeter solutions

    DEFF Research Database (Denmark)

    Kovacs, A.; Slezsak, I.; McLaughlin, W.L.

    1995-01-01

    Conductometric and oscillometric evaluation methods have earlier been developed to determine absorbed dose in the ethanol-monochlorobenzene dosimeter solution. Recent investigations on the same solution as well as on alanine solutions included the study of the possible use of different type...... ''conductometric'' electrodes and the study of the effect of frequency on the sensitivity of the method. On the basis of these investigations an oscillometric reader has been designed and tested. The same evaluation methods have been tested on the irradiated aqueous alanine solutions, aiming also at the study...... of the applicable concentration of the alanine solute and the dose (1 to 50 kGy) and dose-rate range using both electron (2.6 mu s at 13 mu A to 4 mu s at 1.0 A pulse length and beam current) and gamma radiation (0.13 to 30 kGy h(-1))....

  4. Turnbull Blue Gel (TBG) evaluation as optical dosimeter

    Science.gov (United States)

    Borguezan Neto, E.; Batistuti, M. R.; Pavoni, J. F.; Bachmann, L.

    2017-05-01

    The radiochromic Turnbull Blue Gel (TBG) is sensitive to X- and γ-rays. When exposed to high-energy radiation, TBG can simulate biological tissues, so this gel has potential use in ionizing radiation dosimetry. After irradiation, the yellow TBG changes to the blue Turnbull Blue dye. This work aims to evaluate how TBG responds to exposure to ultraviolet, visible, and infrared radiation from the sun. The gel was irradiated with a solar simulator, which sensitized TBG and transformed it into the Turnbull Blue dye; a change in the optical absorption ensued. The fluence values delivered by the source did not provide a linear response, but it was still possible to use TBG as an optical dosimeter. In conclusion, TBG can be applied to detect solar radiation because it is sensitive enough to measure sun exposure values at time intervals of few minutes.

  5. Dual frequency cavitation event sensor with iodide dosimeter.

    Science.gov (United States)

    Ebrahiminia, Ali; Mokhtari-Dizaji, Manijhe; Toliyat, Tayebeh

    2016-01-01

    The inertial cavitation activity depends on the sonication parameters. The purpose of this work is development of dual frequency inertial cavitation meter for therapeutic applications of ultrasound waves. In this study, the chemical effects of sonication parameters in dual frequency sonication (40 kHz and 1 MHz) were investigated in the progressive wave mode using iodide dosimetry. For this purpose, efficacy of different exposure parameters such as intensity, sonication duration, sonication mode, duty factor and net ultrasound energy on the inertial cavitation activity have been studied. To quantify cavitational effects, the KI dosimeter solution was sonicated and its absorbance at a wavelength of 350 nm was measured. The absorbance values in continuous sonication mode was significantly higher than the absorbance corresponding to the pulsed mode having duty factors of 20-80% (plevel intensity (sensor can be useful for ultrasonic treatments.

  6. [AOR characterization and zoning: a dosimeter for blue light].

    Science.gov (United States)

    Dario, R; Uva, J; Di Lecce, V; Quarto, A

    2011-01-01

    The paper presents the results obtained thanks to an innovative experimental device for the assessment of artificial optical radiation (AOR) exposure in workplace. This . device was developed by 'Politecnico di Bari-DIASS'. The wearable personal dosimeter has three sensors: one is used for measuring head position/movement, therefore there is a color light sensor to determine the AOR and finally there is a video camera to localize sources. Our system is connected to a netbook via USB cable that allows one to obtain the real and extimated value of worker's exposure, also with "augmented reality". The aim of this paper is realizing work place safety zoning for the classifacation of not only specific dangerous areas through the analysis of overlapping information from the device.

  7. A BCCD-based dosimeter for mixed radiation fields

    Science.gov (United States)

    Pierschel, M.; Ehwald, K.-E.; Heinemann, B.; Januschewski, F.; Schmitz, T.; Schröder, O.

    1993-03-01

    The development of a personal dosimeter based on a BCCD-detector for mixed neutron and gamma radiation in the energy range from thermal energy to 20 MeV for neutrons respectively 30 keV to a few MeV for gammas will be presented. The detector has to give information on the total radiation dose, D, and on the radiation quality. Both peaces of information are required to determine the directional dose equivalent. The basic radiation physics requirements for the detector as well as a concept of a buried channel CCD-matrix for radiation applications including the technology process will be described. A two dimensional device simulation package was used for both optimization of the charge storage nodes including free charge transfer and the basic electronic processes depending on radiation interaction with silicon.

  8. Applicability of the Sunna dosimeter for food irradiation control

    Science.gov (United States)

    Kovács, A.; Baranyai, M.; Wojnárovits, L.; Miller, S.; Murphy, M.; McLaughlin, W. L.; Slezsák, I.; Kovács, A. I.

    2002-03-01

    The quick development concerning the commercial application of food irradiation in the USA recently resulted in growing marketing of irradiated red meat as well as irradiated fresh and dried fruits. These gamma and electron irradiation technologies require specific dosimetry systems for process control. The new version of the Sunna dosimeter has been characterized in gamma, electron and bremsstrahlung radiation fields by measuring the optically stimulated luminescence (osl) at 530 nm both below and above 1 kGy, i.e. for disinfestation and for meat irradiation purposes. No humidity and no significant dose rate effect on the green osl signal was observed. The temperature coefficient was determined from 0°C up to about 40°C and to stabilize the osl signal after irradiation a heat treatment method was introduced. Based on these investigations the Sunna 'gamma' film is a suitable candidate for dose control below and above 1 kGy for food irradiation technologies.

  9. An evaluation of the BD-100R rechargeable neutron bubble dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Millett, M.; Munno, F.; Ebert, D.; Nelson, M. (Univ. of Maryland, College Park (USA))

    1991-03-01

    The purpose of this paper is to present data gathered in the evaluation of the BD-100R neutron bubble dosimeter done at the University of Maryland and the Naval Research Lab. The performance of 12 dosimeters has been followed over 15 exposure-recharge cycles under a wide range of exposure conditions. Included in this paper are the results from tests on dose rate dependence, neutron energy dependence, beta and gamma exposure, and recharge cycle performance. A statistical analysis of the reusability performance of the dosimeter as a function of dose equivalent is also presented.

  10. Modeling, simulation and measurement of radiation exposure using electronic personal dosimeters on realistic and ICRU phantoms

    CERN Document Server

    Fuelle, D

    2003-01-01

    Exposure studies with voxel phantoms were carried out to understand the new personal dose measurand Hp(10) measured by personal dosimeters under realistic wearing conditions. Two simulated realistic voxel phantoms and the dosimeter assembly are described in a first step. Conditions such as photon fluence, radiation field geometry, and photon energy for simulating the external photon fields at the realistic model are specified. Person-related effective doses are calculated to evaluate the personal dose. The relation between measured deep personal dose and effective dose is demonstrated and discussed by means of the simulated response function of the dosimeters at realistic phantoms.

  11. Chemically tuned linear energy transfer dependent quenching in a deformable, radiochromic 3D dosimeter

    DEFF Research Database (Denmark)

    Høye, Ellen Marie; Skyt, Peter Sandegaard; Balling, Peter

    2017-01-01

    the observed quenching in proton beams. The dependency of dose response on linear energy transfer, as calculated through Monte Carlo simulations of the dosimeter, was investigated in 60 MeV proton beams. We found that the amount of quenching varied with the chemical composition: peak-to-plateau ratios (1cm...... chemical compositions of the dosimeter showed dose-rate dependency; however this was not dependent on the linear energy transfer. Track-structure theory was used to explain the observed quenching effects. In conclusion, this study shows that the silicone-based dosimeter has potential for use in measuring 3...

  12. Calibration factors for the SNOOPY - NP-100 neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Moscu, D.F. [Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, L8S 4L8 (Canada)], E-mail: moscudf@mcmaster.ca; McNeill, F.E. [Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, L8S 4L8 (Canada); Chase, J. [Radiation Protection Division, Ontario Power Generation, Whitby, Ontario, L1N 9E3 (Canada)

    2007-10-15

    Within CANDU nuclear power facilities, only a small fraction of workers are exposed to neutron radiation. For these individuals, roughly 4.5% of the total radiation equivalent dose is the result of exposure to neutrons. When this figure is considered across all workers receiving external exposure of any kind, only 0.25% of the total radiation equivalent dose is the result of exposure to neutrons. At many facilities, the NP-100 neutron dosimeter, manufactured by Canberra Industries Incorporated, is employed in both direct and indirect dosimetry methods. Also known as 'SNOOPY', these detectors undergo calibration, which results in a calibration factor relating the neutron count rate to the ambient dose equivalent rate, using a standard Am-Be neutron source. Using measurements presented in a technical note, readings from the dosimeter for six different neutron fields in six source-detector orientations were used, to determine a calibration factor for each of these sources. The calibration factor depends on the neutron energy spectrum and the radiation weighting factor to link neutron fluence to equivalent dose. Although the neutron energy spectra measured in the CANDU workplace are quite different than that of the Am-Be calibration source, the calibration factor remains constant - within acceptable limits - regardless of the neutron source used in the calibration; for the specified calibration orientation and current radiation weighting factors. However, changing the value of the radiation weighting factors would result in changes to the calibration factor. In the event of changes to the radiation weighting factors, it will be necessary to assess whether a change to the calibration process or resulting calibration factor is warranted.

  13. Characterization of metal oxide semiconductor field effect transistor dosimeters for application in clinical mammography.

    Science.gov (United States)

    Benevides, Luis A; Hintenlang, David E

    2006-02-01

    Five high-sensitivity metal oxide semiconductor field effect transistor dosimeters in the TN-502 and 1002 series (Thomson Nielsen Electronics Ltd., 25B, Northside Road, Ottawa, ON K2H8S1, Canada) were evaluated for use in the mammography x-ray energy range (22-50 kVp) as a tool to assist in the documentation of patient specific average glandular dose. The dosimeters were interfaced with the Patient Dose Verification System, model No. TN-RD 15, which consisted of a dosimeter reader and up to four dual bias power supplies. Two different dual bias power supplies were evaluated in this study, model No. TN-RD 22 in high-sensitivity mode and a very-high sensitivity prototype. Each bias supply accommodates up to five dosimeters for 20 dosimeters per system. Sensitivity of detectors, defined as the mV/C kg(-1), was measured free in air with the bubble side of the dosimeter facing the x-ray field with a constant exposure. All dosimeter models' angular response showed a marked decrease in response when oriented between 120 degrees and 150 degrees and between at 190 degrees and 220 degrees relative to the incident beam. Sensitivity was evaluated for Mo/Mo, Mo/Rh, and Rh/Rh target-filter combinations. The individual dosimeter model sensitiVity was 4.45 x 10(4) mV/C kg(-1) (11.47 mV R(-1)) for TN-502RDS(micro); 5.93 x 10(4) mV per C kg(-1) (15.31 mV R(-1)) for TN-1002RD; 6.06 x 10(4) mV/C kg(-1) (15.63 mV R(-1)) for TN-1002RDI; 9.49 x 10(4) mV per C kg(-1) (24.49 mV R(-1)) for TN-1002RDM (micro); and 11.20 x 10(4) mV/C kg(-1) (28.82 mV R(-1)) for TN-1002RDS (micro). The energy response is presented and is observed to vary with dosimeter model, generally increasing with tube potential through the mammography energy range. An intercomparison of the high-sensitivity mode of TN-RD-22 was made to the very-high sensitivity bias power supply using a Mo/Mo target-filter. The very-high sensitivity-bias power supply increased dosimeter response by 1.45 +/- 0.04 for dosimeter models TN

  14. Data-Driven Implementation of Alarm Reduction Interventions in a Cardiovascular Surgical ICU.

    Science.gov (United States)

    Allan, Sharon H; Doyle, Peter A; Sapirstein, Adam; Cvach, Maria

    2017-02-01

    Alarm fatigue in the ICU setting has been well documented in the literature. The ICU's high-intensity environment requires staff's vigilant attention, and distraction from false and non-actionable alarms pulls staff away from important tasks, creates dissatisfaction, and is a potential patient safety risk if alarms are missed or ignored. This project was intended to improve patient safety by optimizing alarm systems in a cardiovascular surgical intensive care unit (CVSICU). Specific aims were to examine nurses' attitudes toward clinical alarm signals, assess nurses' ability to discriminate audible alarm signals, and implement a bundled set of best practices for monitor alarm reduction without undermining patient safety. CVSICU nurses completed an alarm perception survey and participated in alarm discriminability testing. Nurse survey data and baseline monitor alarm data were used to select targeted alarm reduction interventions, which were progressively phased in. Monitor alarm data and cardiorespiratory event data were trended over one year. Five of the most frequent CVSICU monitor alarm types-pulse oximetry, heart rate, systolic and diastolic blood pressure, pulse oximetry sensor, and ventricular tachycardia > 2-were targeted. After implementation, there was a 61% reduction in average alarms per monitored bed and a downward trend in cardiorespiratory events. To reduce alarm fatigue it is important to decrease alarm burden through targeted interventions. Methods to reduce non-actionable alarms include adding short delays to allow alarm self-correction, adjusting default alarm threshold limits, providing alarm notification through a secondary device, and teaching staff to optimize alarm settings for individual patients. Copyright © 2016 The Joint Commission. Published by Elsevier Inc. All rights reserved.

  15. Alarm pheromone processing in the ant brain: an evolutionary perspective

    Directory of Open Access Journals (Sweden)

    Makoto Mizunami

    2010-06-01

    Full Text Available Social insects exhibit sophisticated communication by means of pheromones, one example of which is the use of alarm pheromones to alert nestmates for colony defense. We review recent advances in the understanding of the processing of alarm pheromone information in the ant brain. We found that information about formic acid and n-undecane, alarm pheromone components, is processed in a set of specific glomeruli in the antennal lobe of the ant Camponotus obscuripes. Alarm pheromone information is then transmitted, via projection neurons, to the lateral horn and the calyces of the mushroom body of the protocerebrum. In the lateral horn, we found a specific area where terminal boutons of alarm pheromone-sensitive projection neurons are more densely distributed than in the rest of the lateral horn. Some neurons in the protocerebrum responded specifically to formic acid or n-undecane and they may participate in the control of behavioral responses to each pheromone component. Other neurons, especially those originating from the mushroom body lobe, responded also to non-pheromonal odors and may play roles in integration of pheromonal and non-pheromonal signals. We found that a class of neurons receive inputs in the lateral horn and the mushroom body lobe and terminate in a variety of premotor areas. These neurons may participate in the control of aggressive behavior, which is sensitized by alarm pheromones and is triggered by non-pheromonal sensory stimuli associated with a potential enemy. We propose that the alarm pheromone processing system has evolved by differentiation of a part of general odor processing system.

  16. Attributions of cancer 'alarm' symptoms in a community sample.

    Directory of Open Access Journals (Sweden)

    Katriina L Whitaker

    Full Text Available BACKGROUND: Attribution of early cancer symptoms to a non-serious cause may lead to longer diagnostic intervals. We investigated attributions of potential cancer 'alarm' and non-alarm symptoms experienced in everyday life in a community sample of adults, without mention of a cancer context. METHODS: A questionnaire was mailed to 4858 adults (≥50 years old, no cancer diagnosis through primary care, asking about symptom experiences in the past 3 months. The word cancer was not mentioned. Target 'alarm' symptoms, publicised by Cancer Research UK, were embedded in a longer symptom list. For each symptom experienced, respondents were asked for their attribution ('what do you think caused it', concern about seriousness ('not at all' to 'extremely', and help-seeking ('did you contact a doctor about it': Yes/No. RESULTS: The response rate was 35% (n = 1724. Over half the respondents (915/1724; 53% had experienced an 'alarm' symptom, and 20 (2% cited cancer as a possible cause. Cancer attributions were highest for 'unexplained lump'; 7% (6/87. Cancer attributions were lowest for 'unexplained weight loss' (0/47. A higher proportion (375/1638; 23% were concerned their symptom might be 'serious', ranging from 12% (13/112 for change in a mole to 41% (100/247 for unexplained pain. Just over half had contacted their doctor about their symptom (59%, although this varied by symptom. Alarm symptoms were appraised as more serious than non-alarm symptoms, and were more likely to trigger help-seeking. CONCLUSIONS: Consistent with retrospective reports from cancer patients, 'alarm' symptoms experienced in daily life were rarely attributed to cancer. These results have implications for understanding how people appraise and act on symptoms that could be early warning signs of cancer.

  17. Automatic Camera Viewfinder Based on TI DaVinci

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-gang; XIAO Zhi-tao; GENG Lei

    2009-01-01

    Presented is an automatic camera viewfinder based on TI DaVinci digital platform and discussed mainly is the scheme of software system based on linux. This system can give an alarm and save the picture when the set features appear in the view, and the saved pictures can be downloaded and zoomed out. All functions are operated in OSD menu. It is well established for its flexible operations, powerful functions, multitasking and stable performance.

  18. Reducing SCADA System Nuisance Alarms in the Water Industry in Northern Ireland.

    Science.gov (United States)

    O'Donoghue, Nigel; Phillips, Debra H; Nicell, Ciaran

    2015-08-01

    The advancement of telemetry control for the water industry has increased the difficulty of managing large volumes of nuisance alarms (i.e., alarms that do not require a response). The aim of this study was to identify and reduce the number of nuisance alarms that occur for Northern Ireland (NI) Water by carrying out alarm duration analysis to determine the appropriate length of persistence (an advanced alarm management tool) that could be applied. All data were extracted from TelemWeb (NI Water's telemetry monitoring system) and analyzed in Excel. Over a 6-week period, an average of 40 000 alarms occurred per week. The alarm duration analysis, which has never been implemented before by NI Water, found that an average of 57% of NI Water alarms had a duration of <5 minutes. Applying 5-minute persistence, therefore, could prevent an average 26 816 nuisance alarms per week. Most of these alarms were from wastewater assets.

  19. FAULT DIAGNOSIS WITH MULTI-STATE ALARMS IN A NUCLEAR POWER CONTROL SIMULATOR

    Energy Technology Data Exchange (ETDEWEB)

    Austin Ragsdale; Roger Lew; Brian P. Dyre; Ronald L. Boring

    2012-10-01

    This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effect of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. We used sensitivity and criterion based on Signal Detection Theory to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

  20. Fault Diagnosis with Multi-State Alarms in a Nuclear Power Control Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Stuart A. Ragsdale; Roger Lew; Ronald L. Boring

    2014-09-01

    This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effects of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized the use of three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. Sensitivity and criterion based on the Signal Detection Theory were used to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

  1. Gel dosimeters as useful dose and thermal-fluence detectors in Boron Neutron Capture Therapy (BNCT)

    Energy Technology Data Exchange (ETDEWEB)

    Gambarini, G.; Valente, M. [Department of Physics of the University and INFN, Via Celoria 16, I-20133 Milan (Italy); Moss, R.L.; Daquino, G.G.; Nievaart, V.A. [Joint Research Centre, Institute for Energy, P.O. Box 2, NL-1755ZG Petten, The Netherlands (Netherlands); Mariani, M.; Vanossi, E. [Department of Nuclear Engineering of Polytechnic, CESNEF, Via Ponzio, 34/3 - I-20133 Milan (Italy); Carrara, M. [Medical Physics Department, National Cancer Institute, Via Venezian 1, I-20131, Milan (Italy)

    2006-07-01

    The dosimetry method based on Fricke-Xylenol-Orange-infused gels in form of layers has shown noticeable potentiality for in-phantom or in-free-beam dose and thermal flux profiling and imaging in the high fluxes of thermal or epithermal neutrons utilised for boron neutron capture therapy (BNCT). Gel-dosimeters in form of layers give the possibility not only of obtaining spatial dose distributions but also of achieving measurements of each dose contribution in neutron fields. The discrimination of the various dose components is achieved by means of pixel-to-pixel manipulations of pairs of images obtained with gel-dosimeters having different isotopic composition. It is possible to place large dosimeters, detecting in such a way large dose images, because the layer geometry of dosimeters avoids sensitive variation of neutron transport due to the gel isotopic composition. Some results obtained after the last improvements of the method are reported. (Author)

  2. New polymer gel dosimeters consisting of less toxic monomers with radiation-crosslinked gel matrix

    Science.gov (United States)

    Hiroki, A.; Yamashita, S.; Sato, Y.; Nagasawa, N.; Taguchi, M.

    2013-06-01

    New polymer gel dosimeters consisting of less toxic methacrylate-type monomers such as 2-hydroxymethyl methacrylate (HEMA) and polyethylene glycol 400 dimethacrylate (9G) with hydroxypropyl cellulose (HPC) gel were prepared. The HPC gels were obtained by using a radiation-induced crosslinking technique to be applied in a matrix instead of a gelatin, which is conventionally used in earlier dosimeters, for the polymer gel dosimeters. The prepared polymer gel dosimeters showed cloudiness by exposing to 60Co γ-ray, in which the cloudiness increased with the dose up to 10 Gy. At the same dose, the increase in the cloudiness appeared with increasing concentration of 9G. As a result of the absorbance measurement, it was found that the dose response depended on the composition ratio between HEMA and 9G.

  3. Novel composition of polymer gel dosimeters based on N-(Hydroxymethyl)acrylamide for radiation therapy

    Science.gov (United States)

    Basfar, Ahmed A.; Moftah, Belal; Rabaeh, Khalid A.; Almousa, Akram A.

    2015-07-01

    A new composition of polymer gel dosimeters is developed based on radiation induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) for radiotherapy treatment planning. The dosimeters were irradiated by 10 MV photon beam of a medical linear accelerator at a constant dose rate of 600 cGy/min with doses up to 20 Gy. The polymerization occurs and increases with increasing absorbed dose. The dose response of polymer gel dosimeters was studied using nuclear magnetic imaging (NMR) for relaxation rate (R2) of water proton. Dose rate, energy of radiation and the stability of the polymerization after irradiation were investigated. No appreciable effects of these parameters on the performance of the novel gel dosimeters were observed.

  4. Performance Testing Of Selected Types of Electronic Personal Dosimeters in X- and Gamma Radiation Fields.

    Science.gov (United States)

    Kržanović, Nikola; Živanović, Miloš; Ciraj-Bjelac, Olivera; Lazarević, Đorđe; Ćeklić, Sandra; Stanković, Srboljub

    2017-10-01

    Electronic personal dosimeters (EPDs) are increasingly being used alongside conventional thermoluminescent dosimeters to measure the dose of legal record in terms of personal dose equivalent. Therefore, it is of great importance to execute performance tests of these dosimeters in photon fields of various energies and at various angles of incidence. This testing is done in order to simulate the behavior of these dosimeters in realistic multidirectional polyenergetic ionizing radiation fields. Tests of accuracy, linearity, energy response, and angular response have been performed on 10 EPDs from multiple manufacturers. Various radiation qualities have been used in the energy range from 33 keV to 1.33 MeV and for angles of incidence 0° to 80°. This research proves that many of the EPDs tested performed according to the manufacturer's specifications and the requirements of the international standards regarding personal dosimetry.

  5. Applications of Neutron Bubble Dosimeters for Neutron Dose Monitoring in Mixed n-γ Fields

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Bubble dosimeter is a promising technology in the field of neutron dosimetry. It provides real-time monitoring of neutron dose, stable energy response over wide range of neutron energy, and a very low

  6. Dose verification to cochlea during gamma knife radiosurgery of acoustic schwannoma using MOSFET dosimeter

    Directory of Open Access Journals (Sweden)

    Sunil D Sharma

    2012-01-01

    Conclusion: The measured dose values were found in good agreement with the dose values calculated using the TPS. The MOSFET dosimeter can be a suitable choice for routine dose verification in the Gamma Knife radiosurgery.

  7. An intercomparison of neutron dosimeters and detectors for in-containment dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Auman, L.E.; Miller, W.H.; Graham, C.C.; Stretch, C.D.; Welty, T.J.; West, L. Jr. (Department of Nuclear Engineering, University of Missouri, Columbia (United States))

    1992-02-01

    To improve the methodology for assessing neutron dose at Union Electric's Callaway Nuclear Power Plant, an intercomparison of neutron detectors and dosimeters was performed. Seven different neutron detectors and dosimeters were tested in four different neutron fields utilizing facilities at the Missouri University Research Reactor and at the Southwest Radiation Calibration Center at the University of Arkansas. In general, all results agree within a factor of 2 in predicting the neutron dose equivalent. It was concluded that measurements of dose in containment should utilize the Tissue-Equivalent Proportional Counter (TEPC), the Bonner-sphere system, and the proton recoil spectrometer to accurately assess the neutron dose. These data can then be used to provide correction factors for more traditionally used dosimeters in containment, such as thermoluminescent dosimeters and survey meters.

  8. Alarm reduction with correlation analysis; Larmsanering genom korrelationsanalys

    Energy Technology Data Exchange (ETDEWEB)

    Bergquist, Tord; Ahnlund, Jonas; Johansson, Bjoern; Gaardman, Lennart; Raaberg, Martin [Lund Univ. (Sweden). Dept. of Information Technology

    2004-09-01

    This project's main interest is to improve the overall alarm situation in the control rooms. By doing so, the operators working environment is less overstrained, which simplifies the decision-making. According to a study of the British refinery industry, the operators make wrong decisions in four times out of ten due to badly tuned alarm systems, with heavy expenses as a result. Furthermore, a more efficiently alarm handling is estimated to decrease the production loss with between three and eight percent. This sounds, according to Swedish standards, maybe a bit extreme, but there is no doubt about the benefits of having a well-tuned alarm system. This project can be seen as an extension of 'General Methods for Alarm Reduction' (VARMEFORSK--835), where the process improvements were the result of suggestions tailored for every signal. Here, instead causal dependences in the process are examined. A method for this, specially designed to fit process signals, has been developed. It is called MLPC (Multiple Local Property Correlation) and could be seen as an unprejudiced way of increase the information value in the process. There are a number of ways to make use of the additional process understanding a correlation analysis provides. In the report some are mentioned, foremost aiming to improve the alarm situation for operators. Signals from two heating plants have been analyzed with MLPC. In simulations, with the use of the result from these analyses as a base, a large number of alarms have been successfully suppressed. The results have been studied by personal with process knowledge, and they are very positive to the use of MLPC and they express many benefits by the clarification of process relations. It was established in 'General Methods for Alarm Reduction' that low pass filter are superior to mean value filter and time delay when trying to suppress alarms. As a result, a module for signal processing has been developed. The main purpose is

  9. Wild birds learn to eavesdrop on heterospecific alarm calls.

    Science.gov (United States)

    Magrath, Robert D; Haff, Tonya M; McLachlan, Jessica R; Igic, Branislav

    2015-08-01

    Many vertebrates gain critical information about danger by eavesdropping on other species' alarm calls [1], providing an excellent context in which to study information flow among species in animal communities [2-4]. A fundamental but unresolved question is how individuals recognize other species' alarm calls. Although individuals respond to heterospecific calls that are acoustically similar to their own, alarms vary greatly among species, and eavesdropping probably also requires learning [1]. Surprisingly, however, we lack studies demonstrating such learning. Here, we show experimentally that individual wild superb fairy-wrens, Malurus cyaneus, can learn to recognize previously unfamiliar alarm calls. We trained individuals by broadcasting unfamiliar sounds while simultaneously presenting gliding predatory birds. Fairy-wrens in the experiment originally ignored these sounds, but most fled in response to the sounds after two days' training. The learned response was not due to increased responsiveness in general or to sensitization following repeated exposure and was independent of sound structure. Learning can therefore help explain the taxonomic diversity of eavesdropping and the refining of behavior to suit the local community. In combination with previous work on unfamiliar predator recognition (e.g., [5]), our results imply rapid spread of anti-predator behavior within wild populations and suggest methods for training captive-bred animals before release into the wild [6]. A remaining challenge is to assess the importance and consequences of direct association of unfamiliar sounds with predators, compared with social learning-such as associating unfamiliar sounds with conspecific alarms.

  10. Nuclear-power-plant perimeter-intrusion alarm systems

    Energy Technology Data Exchange (ETDEWEB)

    Halsey, D.J.

    1982-04-01

    Timely intercept of an intruder requires the examination of perimeter barriers and sensors in terms of reliable detection, immediate assessment and prompt response provisions. Perimeter security equipment and operations must at the same time meet the requirements of the Code of Federal Regulations, 10 CFR 73.55 with some attention to the performance and testing figures of Nuclear Regulatory Guide 5.44, Revision 2, May 1980. A baseline system is defined which recommends a general approach to implementing perimeter security elements: barriers, lighting, intrusion detection, alarm assessment. The baseline approach emphasizes cost/effectiveness achieved by detector layering and logic processing of alarm signals to produce reliable alarms and low nuisance alarm rates. A cost benefit of layering along with video assessment is reduction in operating expense. The concept of layering is also shown to minimize testing costs where detectability performance as suggested by Regulatory Guide 5.44 is to be performed. Synthesis of the perimeter intrusion alarm system and limited testing of CCTV and Video Motion Detectors (VMD), were performed at E-Systems, Greenville Division, Greenville, Texas during 1981.

  11. Calculation of the Energy Dependence of Dosimeter Response to Ionizing Photons

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1982-01-01

    Using a program in BASIC applied to a desk-top calculator, simplified calculations provide approximate energy dependence correction factors of dosimeter readings of absorbed dose according to Bragg-Gray cavity theories. Burlin's general cavity theory is applied in the present calculations, and ce...... as given here are available for certain dosimeter probe materials and combinations used with intermediate energy photon spectra (0.01–100 MeV)....

  12. FlexyDos3D: a deformable anthropomorphic 3D radiation dosimeter: radiation properties

    DEFF Research Database (Denmark)

    De Deene, Yves; Skyt, Peter Sandegaard; Hill, Robin

    2015-01-01

    Three dimensional radiation dosimetry has received growing interest with the implementation of highly conformal radiotherapy treatments. The radiotherapy community faces new challenges with the commissioning of image guided and image gated radiotherapy treatments (IGRT) and deformable image...... and oxygen concentration has also been investigated. The radiophysical properties of this new dosimeter are discussed including stability, spatial integrity, temperature dependence of the dosimeter during radiation, readout and storage, dose rate dependence and tissue equivalence....

  13. Effects from Spatial Cues on Detectability of Alarm Signals in Car Environments

    OpenAIRE

    Kuroda, Naoki; Li, Junfeng; Iwaya, Yukio; Unoki, Masashi; Akagi, Masato

    2009-01-01

    It is crucial to correctly detect alarm signals in noise conditions, for instance, especially in car environments. However, alarm signals are possibly masked by noises from engine, friction between tires and road, etc., in car environments. To design the alarm signals that can be easily detected,it is necessary to first understand the perceptual characteristics of alarm signals in noisy environments. In this paper, the masked thresholds of alarm signals in the presence of car noise were measu...

  14. Characterization of a water-equivalent fiber-optic coupled dosimeter for use in diagnostic radiology.

    Science.gov (United States)

    Hyer, Daniel E; Fisher, Ryan F; Hintenlang, David E

    2009-05-01

    This work reports on the characterization of a new fiber-optic coupled (FOC) dosimeter for use in the diagnostic radiology energy range. The FOC dosimeter was constructed by coupling a small cylindrical plastic scintillator, 500 microm in diameter and 2 mm in length, to a 2 m long optical fiber, which acts as a light guide to transmit scintillation photons from the sensitive element to a photo-multiplier tube (PMT). A serial port interface on the PMT permits real-time monitoring of light output from the dosimeter via a custom computer program. The FOC dosimeter offered excellent sensitivity and reproducibility, allowing doses as low as 0.16 mGy to be measured with a coefficient of variation of only 3.64%. Dose linearity was also excellent with a correlation coefficient of 1.000 over exposures ranging from 0.16 to 57.29 mGy. The FOC dosimeter exhibited little angular dependence from axial irradiation, varying by less than 5% over an entire revolution. A positive energy dependence was observed and measurements performed within a scatter medium yielded a 10% variation in sensitivity as beam quality changed due to hardening and scatter across a 16 cm depth range. The current dosimetry system features an array of five PMTs to allow multiple FOC dosimeters to be monitored simultaneously. Overall, the system allows for rapid and accurate dose measurements relevant to a range of diagnostic imaging applications.

  15. An investigation into the sensitivity of various albedo neutron dosimeters aimed at correcting the readings

    Science.gov (United States)

    Alekseev, A. G.; Mokrov, Yu. V.; Morozova, S. V.

    2012-03-01

    The results of an experimental determination of the sensitivity of three types of individual neutron albedo dosimeters in neutron reference fields on the basis of radionuclide sources and at the top concrete shielding of the U-70 accelerator are presented. The results show that the ratios between the responses of the albedo dosimeters designed earlier at the Joint Institute for Nuclear Research (the albedo dosimeter (AD) and the multicomponent dosimeter (MD)) and the currently used DVGN-01 dosimeter are constant within 25% in a wide range of neutron energy. This fact makes it possible to use the results of measuring the AD and MD responses obtained earlier in neutron fields of nuclear-physical installations at the Joint Institute for Nuclear Research (JINR) for the correction of DVGN-01 dosimeter measurement results to apply it to personal radiation monitoring (PRM) at these installations. The correction factors for DVGN-01 measurement results are found and recommended to be used in PRM for most JINR installations.

  16. Compliance and data reliability in sun exposure studies with diaries and personal, electronic UV dosimeters.

    Science.gov (United States)

    Thieden, Elisabeth; Philipsen, Peter A; Wulf, Hans Christian

    2006-04-01

    Skin cancer risk estimations are based on sun exposure data. However, the reliability of collected data in personal ultraviolet (UV) dosimeters studies has not previously been validated. We aimed at investigating the data reliability and subject compliance in a study of sun exposure behaviour among 407 subjects (age range, 4-68 years) during 54 943 days based on time-stamped personal UV dosimeter readings and diary records. By comparing diary records and UV dosimeter readings on a daily basis, we investigated subject compliance, total sun exposure record, reasons for non-responding along with rates of diary completing errors. Efforts to improve compliance were described. The subject compliance rate was median 93.5% (percent days where the diary was completed and the UV dosimeter was worn). The total sun exposure record rate was median 84.1% (percent of participation days with both UV dosimeter and diary records and where the UV dosimeter was worn). Children, adolescents and golfers had lower sun exposure record rates than the rest of the groups (Pdosimeter maintenance service within 24 h and scrutinized data for errors and mistakes.

  17. UV dosimeter based on polyamide woven fabric and nitro blue tetrazolium chloride as an active compound

    Energy Technology Data Exchange (ETDEWEB)

    Kozicki, Marek, E-mail: mkozicki@mitr.p.lodz.pl [Institute of Architecture of Textiles, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); European Centre of Bio- and Nano-Technology (ECBNT), Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); Sasiadek, Elzbieta [Institute of Architecture of Textiles, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); European Centre of Bio- and Nano-Technology (ECBNT), Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland)

    2011-10-15

    This paper reports on the preparation and features of a UV light dosimeter composed of nitro blue tetrazolium chloride (NBT) and polyamide woven fabric. This textile dosimeter is based on the conversion reaction of NBT into formazan, which was initially examined in aerated aqueous solutions through steady state UV irradiation. Irradiated solutions change their colour as a consequence of the formation of polydisperse NBT formazan particles. This was analysed in relation to the absorbed dose of UV light through UV-VIS spectrophotometry and dynamic laser light scattering measurements. When NBT substrate molecules are embedded in polyamide textile, UV irradiation leads to similar effects as in solution. However, the tinge intensity changes at much lower absorbed doses. The dependence of the tinge intensity on the absorbed dose was followed by measurements of the remission of light from the NBT-polyamide samples. Consequently, the calibration parameters were calculated such as the dose sensitivity, dose range, and quasi-linear dose range. An improvement of the NBT-polyamide samples by application of a colour levelling agent and improvement of their resistance to humidity is presented. Finally, the samples were used for estimation of absorbed UV energy distribution showing their capability as new dosimeters for in-plane high resolution radiation dose measurements. - Highlights: > Preparation of a textile dosimeter with nitro blue tetrazolium chloride is shown. > The dosimeter responds to UV light by a colour change. > 2D radiation dose measurements are possible. > PC scanners can be employed for measurements of the dosimeter.

  18. Statistical Study of False Alarms of Geomagnetic Storms

    DEFF Research Database (Denmark)

    Leer, Kristoffer; Vennerstrøm, Susanne; Veronig, A.

    Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue....... A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs. The ability to identify potential false...... alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates...

  19. Statistical Study of False Alarms of Geomagnetic Storms

    DEFF Research Database (Denmark)

    Leer, Kristoffer; Vennerstrøm, Susanne; Veronig, A.;

    Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue....... A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs. The ability to identify potential false...... alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates...

  20. Implementation of alarm system for vibration monitoring of KOMAC facility

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Ha; Ahn, Tae-Sung; Song, Young-Gi; Kwon, Hyeok-Jung; Cho, Yong-Sub [KOMAC, Gyeongju (Korea, Republic of)

    2015-05-15

    For operating 100 MeV linac, Devices have to be operated in certain order. Thus malfunction of a device cause damage to linac and related devices. To protect linac, machine protect system (MPS) has been developed. The MPS protects the components by monitoring hardwired signals. When values of operating parameters go beyond or below limit, alarm will be generated and interlock system which stops related devices in certain sequence will run. Other factor, giving damage to linac is disaster. A strong vibration such as earthquake causes malfunction of devices and damage to linac. Against disaster, the monitoring system based on Experimental Physics and Industrial Control System (EPICS) was implemented. Configuration and Implementation of the monitoring system are presented and some preliminary results are reported. KOMAC implemented alarm system for a strong vibration and fire. Alarm is generated in unusual situation. Coping rapidly with situation, damages for Linac and related devices can be reduced.

  1. Type tests to the automatic system of thermoluminescent dosimetry acquired by the CPHR for personnel dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Pernas S, R. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Calle 20, No. 4113 e/ 41 y 47, Miramar, Ciudad de la Habana (Cuba)]. e-mail: daniel@cphr.edu.cu

    2005-07-01

    The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF: Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

  2. Type tests to the automatic thermoluminescent dosimetry system acquired by the CPHR for personal dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Pernas S, R.; Martinez G, A. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Calle 20 No. 4113 e/41 y 47. Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba)

    2006-07-01

    The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF:Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

  3. Nurses' Perceptions and Practices Toward Clinical Alarms in a Transplant Cardiac Intensive Care Unit: Exploring Key Issues Leading to Alarm Fatigue.

    Science.gov (United States)

    Sowan, Azizeh Khaled; Tarriela, Albert Fajardo; Gomez, Tiffany Michelle; Reed, Charles Calhoun; Rapp, Kami Marie

    2015-03-16

    Intensive care units (ICUs) are complex work environments where false alarms occur more frequently than on non-critical care units. The Joint Commission National Patient Safety Goal .06.01.01 targeted improving the safety of clinical alarm systems and required health care facilities to establish alarm systems safety as a hospital priority by July 2014. An important initial step toward this requirement is identifying ICU nurses' perceptions and common clinical practices toward clinical alarms, where little information is available. Our aim was to determine perceptions and practices of transplant/cardiac ICU (TCICU) nurses toward clinical alarms and benchmark the results against the 2011 Healthcare Technology Foundation's (HTF) Clinical Alarms Committee Survey. A quality improvement project was conducted on a 20-bed TCICU with 39 full- and part-time nurses. Nurses were surveyed about their perceptions and attitudes toward and practices on clinical alarms using an adapted HTF clinical alarms survey. Results were compared to the 2011 HTF data. Correlations among variables were examined. All TCICU nurses provided usable responses (N=39, 100%). Almost all nurses (95%-98%) believed that false alarms are frequent, disrupt care, and reduce trust in alarm systems, causing nurses to inappropriately disable them. Unlike the 2011 HTF clinical alarms survey results, a significantly higher percentage of our TCICU nurses believed that existing devices are complex, questioned the ability and adequacy of the new monitoring systems to solve alarm management issues, pointed to the lack of prompt response to alarms, and indicated the lack of clinical policy on alarm management (Palarms and poor usability of the cardiac monitors. A lack of standardized approaches exists in changing patients' electrodes and individualizing parameters. Around 60% of nurses indicated they received insufficient training on bedside and central cardiac monitors. A correlation also showed the need for training

  4. Pulse register phonation in Diana monkey alarm calls

    Science.gov (United States)

    Riede, Tobias; Zuberbühler, Klaus

    2003-05-01

    The adult male Diana monkeys (Cercopithecus diana) produce predator-specific alarm calls in response to two of their predators, the crowned eagles and the leopards. The acoustic structure of these alarm calls is remarkable for a number of theoretical and empirical reasons. First, although pulsed phonation has been described in a variety of mammalian vocalizations, very little is known about the underlying production mechanism. Second, Diana monkey alarm calls are based almost exclusively on this vocal production mechanism to an extent that has never been documented in mammalian vocal behavior. Finally, the Diana monkeys' pulsed phonation strongly resembles the pulse register in human speech, where fundamental frequency is mainly controlled by subglottal pressure. Here, we report the results of a detailed acoustic analysis to investigate the production mechanism of Diana monkey alarm calls. Within calls, we found a positive correlation between the fundamental frequency and the pulse amplitude, suggesting that both humans and monkeys control fundamental frequency by subglottal pressure. While in humans pulsed phonation is usually considered pathological or artificial, male Diana monkeys rely exclusively on pulsed phonation, suggesting a functional adaptation. Moreover, we were unable to document any nonlinear phenomena, despite the fact that they occur frequently in the vocal repertoire of humans and nonhumans, further suggesting that the very robust Diana monkey pulse production mechanism has evolved for a particular functional purpose. We discuss the implications of these findings for the structural evolution of Diana monkey alarm calls and suggest that the restricted variability in fundamental frequency and robustness of the source signal gave rise to the formant patterns observed in Diana monkey alarm calls, used to convey predator information.

  5. Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect.

    Science.gov (United States)

    Ishikawa, Masayori; Nagase, Naomi; Matsuura, Taeko; Hiratsuka, Junichi; Suzuki, Ryusuke; Miyamoto, Naoki; Sutherland, Kenneth Lee; Fujita, Katsuhisa; Shirato, Hiroki

    2015-03-01

    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter.

  6. An ESR study on biological dosimeters: Human hair

    Energy Technology Data Exchange (ETDEWEB)

    Colak, Seyda, E-mail: seyda@hacettepe.edu.t [Hacettepe University, Physics Engineering Department, 06800 Ankara (Turkey); Ozbey, Turan [Hacettepe University, Physics Engineering Department, 06800 Ankara (Turkey)

    2011-05-15

    In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with {Delta}Hpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (G{sub mean}) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

  7. Radiochromic dye dosimeter solutions as reference measurement systems

    Science.gov (United States)

    Farahani, Mahnaz; McLaughlin, William L.

    Solutions of leucocyanides of triphenylmethane dyes in organic solvents are designed as stable reference dosimeters for large radiation doses, with useful characteristics, both for steady-state and pulsed radiation fields. These radiochromic solutions may be used in conventional glass ampoules to cover the absorbed dose range 10 2-10 4kGy, when analyzed spectrophotometrically at visible wavelengths at the maxima of radiation-induced absorption bands. The radiation chemical yields of dye formation ( G-values) and molar linear absorption coefficients (ɛ m) of the dyes in several formulations, with and without dissolved polymer and weak oxidizing agents, are established. The most stable formulation before and after irradiation consists of new fuchsin cyanide in a mixture of dimethyl sulfoxide and triethyl phosphate containing small amounts of acetic acid, p-nitrobenzoic acid and polyvinyl butyral. The useful range of doses for this solution is 10 2-4 x 10 3 Gy when measured at 557 nm wavelength. The radiation chemical yield, G-value for dye production, is 3.35 x 10 15 molec J -1 (0.0055 μmol J -1) and the value of ɛ m at this wavelength is 1.32 x 10 5 M -1 cm -1.

  8. Aqueous solution of basic fuchsin as food irradiation dosimeter

    Institute of Scientific and Technical Information of China (English)

    Hasan M. KHAN; Shagufta NAZ

    2007-01-01

    Dosimetric characterization of aqueous solution of basic fuchsin was studied spectrophotometrically for possible application in the low-dose food irradiation dosimetry. Absorption spectra of unirradiated and irradiated solutions were determined and the decrease in absorbance with the dose was noted down. Radiation-induced bleaching of the dye was measured at wavelengths of maximum absorption λmax (540nm) as well as 510nm and 460 nm. At all these wavelengths, the decrease in absorbance of the dosimeter was linear with respect to the absorbed dose from 50 Gy to 600 Gy. The stability of dosimetric solution during post-irradiation storage in the dark at room temperature showed that after initial bleaching during first ten to twenty days, the response was almost stable for about 34 days. The study on the effect of different light and temperature conditions also showed that the response gradually decreased during the storage period of 34 days, which shows that basic fuchsin dye is photosensitive as well as thermally sensitive.

  9. Quality control for X-ray dosimetry with Fricke dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vivianne Lucia Bormann de [Centro Regional de Cincias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)]. E-mail: lsouza@cnen.gov.br; Austerlitz, C. [East Carolina University, NC (United States)]. E-mail: camposc@ecu.edu

    2007-07-01

    It is a well-established fact that the success of radiation therapy is dependent on the accurate dosimetry of the radiation beam used. This dosimetry must include equipment performance as well. A system for Fricke dosimetry was used for this purpose. The Fricke solution and a parallel ionization chamber (used for comparison) were irradiated with an X-ray beam from a Pantak X-ray equipment. The ionization chamber was positioned at a distance of 500 mm of the focal point, in the central axis of the X-ray field which is defined as 100x100 mm{sup 2} at the calibration distance. A plexiglas phantom appropriate to hold the polypropylene tube was used to irradiate the vials with the Fricke solution. The irradiated solutions were transferred directly from the polypropylene vials to 10 mm length cuvettes and the optical densities were measured in 304 nm using a Beckman Counter Model DU 640 spectrophotometer. Three institutions were visited to verify their procedures and two were in accordance with the lAEA recommended procedures for soft X-ray dosimetry. The results of the measurements performed in the institutions visited show that the Fricke dosimeter system developed can be used for quality control for soft X-ray equipment. (author)

  10. Study of Fricke gel dosimeter response for different gel quality

    Science.gov (United States)

    Cavinato, C. C.; Campos, L. L.

    2010-11-01

    The Fricke xylenol gel (FXG) dosimeter has been studied for application in radiotherapy because it is capable of to measure the spatial distribution of radiation doses. The dosimetry is based on the oxidation of ferrous (Fe2+) to ferric (Fe3+) ions radiation induced, related to the radiation dose. The gel material usually employed is the 300 Bloom gelatin, which is imported and very expensive in Brazil. Aiming to analyze the viability of to use a locally produced and low cost gel material, in this work the spectrophotometric responses of FXG solutions prepared using 270 Bloom gelatin commercially available and 300 Bloom gelatin imported were compared. The absorption spectra of solutions prepared with 5% by weight 270 and 300 Bloom gelatins non-irradiated and irradiated with 60Co gamma radiation in the dose range between 0.5 and 100 Gy were analysed, the dose-response curves were evaluated and the useful dose range was established. The obtained results indicate that the FXG solution prepared with 270 Bloom gelatin presents good performance, similar to that presented by the FXG solution prepared with 300 Bloom gelatin and its use can be recommended owing to the low cost and the availability in local market.

  11. Association between exposure to nonactionable physiologic monitor alarms and response time in a children's hospital.

    Science.gov (United States)

    Bonafide, Christopher P; Lin, Richard; Zander, Miriam; Graham, Christian Sarkis; Paine, Christine W; Rock, Whitney; Rich, Andrew; Roberts, Kathryn E; Fortino, Margaret; Nadkarni, Vinay M; Localio, A Russell; Keren, Ron

    2015-06-01

    Alarm fatigue is reported to be a major threat to patient safety, yet little empirical data support its existence in the hospital. To determine if nurses exposed to high rates of nonactionable physiologic monitor alarms respond more slowly to subsequent alarms that could represent life-threatening conditions. Observational study using video. Freestanding children's hospital. Pediatric intensive care unit (PICU) patients requiring inotropic support and/or mechanical ventilation, and medical ward patients. None. Actionable alarms were defined as correctly identifying physiologic status and warranting clinical intervention or consultation. We measured response time to alarms occurring while there were no clinicians in the patient's room. We evaluated the association between the number of nonactionable alarms the patient had in the preceding 120 minutes (categorized as 0-29, 30-79, or 80+ alarms) and response time to subsequent alarms in the same patient using a log-rank test that accounts for within-nurse clustering. We observed 36 nurses for 210 hours with 5070 alarms; 87.1% of PICU and 99.0% of ward clinical alarms were nonactionable. Kaplan-Meier plots showed incremental increases in response time as the number of nonactionable alarms in the preceding 120 minutes increased (log-rank test stratified by nurse P alarms were nonactionable, and response time increased as nonactionable alarm exposure increased. Alarm fatigue could explain these findings. Future studies should evaluate the simultaneous influence of workload and other factors that can impact response time. © 2015 Society of Hospital Medicine.

  12. Balancing the Tension Between Hyperoxia Prevention and Alarm Fatigue in the NICU.

    Science.gov (United States)

    Ketko, Anastasia K; Martin, Craig M; Nemshak, Michelle A; Niedner, Matthew; Vartanian, Rebecca J

    2015-08-01

    After the implementation of narrowed oxygen saturation alarms, alarm frequency increased in the C.S. Mott Children's Hospital NICU which could have a negative impact on patient safety. The Joint Commission on the Accreditation of Healthcare Organizations issued a Sentinel Event Alert for hospitals in 2013 to improve alarm safety, resulting in a 2014 National Patient Safety Goal requiring institutional policies and procedures to be in place to manage alarms. A multidisciplinary improvement team developed an alarm management bundle applying strategies to decrease alarm frequency, which included evaluating existing strategies and developing patient care-based and systems-based interventions. The total number of delivered and detected saturation alarms and high saturation alarms and the total time spent within a targeted saturation range were quantitatively tracked. Nursing morale was assessed qualitatively. SpO2 alarms per monitored patient-day increased from 78 to 105 after the narrowing of alarm limits. Modification of the high saturation alarm algorithm substantially decreased the delivery and escalation of high pulse oxygen saturation (SpO2) alarms. During a pilot period, using histogram technology to individually customize alarm limits resulted in increased time spent within the targeted saturation range and fewer alarms per day. Qualitatively, nurses reported improved satisfaction when not assigned >1 infant with frequent alarms, as identified by an alarm frequency tool. Alarm fatigue may detrimentally affect patient care and safety. Alarm management strategies should coincide with oxygen management within a NICU, especially in single-patient-bed units. Copyright © 2015 by the American Academy of Pediatrics.

  13. Entrance surface dose measurements using a small OSL dosimeter with a computed tomography scanner having 320 rows of detectors.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Yamada, Kenji; Mihara, Yoshiki; Kimoto, Natsumi; Kanazawa, Yuki; Higashino, Kousaku; Yamashita, Kazuta; Hayashi, Fumio; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2017-03-01

    Entrance surface dose (ESD) measurements are important in X-ray computed tomography (CT) for examination, but in clinical settings it is difficult to measure ESDs because of a lack of suitable dosimeters. We focus on the capability of a small optically stimulated luminescence (OSL) dosimeter. The aim of this study is to propose a practical method for using an OSL dosimeter to measure the ESD when performing a CT examination. The small OSL dosimeter has an outer width of 10 mm; it is assumed that a partial dose may be measured because the slice thickness and helical pitch can be set to various values. To verify our method, we used a CT scanner having 320 rows of detectors and checked the consistencies of the ESDs measured using OSL dosimeters by comparing them with those measured using Gafchromic™ films. The films were calibrated using an ionization chamber on the basis of half-value layer estimation. On the other hand, the OSL dosimeter was appropriately calibrated using a practical calibration curve previously proposed by our group. The ESDs measured using the OSL dosimeters were in good agreement with the reference ESDs from the Gafchromic™ films. Using these data, we also estimated the uncertainty of ESDs measured with small OSL dosimeters. We concluded that a small OSL dosimeter can be considered suitable for measuring the ESD with an uncertainty of 30 % during CT examinations in which pitch factors below 1.000 are applied.

  14. Early development and characterization of a DNA-based radiation dosimeter

    Science.gov (United States)

    Avarmaa, Kirsten A.

    It is the priority of first responders to minimize damage to persons and infrastructure in the case of a nuclear emergency due to an accident or deliberate terrorist attack -- if this emergency includes a radioactive hazard, first responders require a simple-to-use, accurate and complete dosimeter for radiation protection purposes in order to minimize the health risk to these individuals and the general population at large. This work consists of the early evaluation of the design and performance of a biologically relevant dosimeter which uses DNA material that can respond to the radiation of any particle type. The construct consists of fluorescently tagged strands of DNA. The signalling components of this dosimeter are also investigated for their sensitivity to radiation damage and light exposure. The dual-labelled dosimeter that is evaluated in this work gave a measurable response to gamma radiation at dose levels of 10 Gy for the given detector design and experimental setup. Further testing outside of this work confirmed this finding and indicated a working range of 100 mGy to 10 Gy using a custom-built fluorimeter as part of a larger CRTI initiative. Characterization of the chromatic components of the dosimeter showed that photobleaching is not expected to have an effect on dosimeter performance, but that radiation can damage the non-DNA signalling components at higher dose levels, although this damage is minimal at lower doses over the expected operating ranges. This work therefore describes the early steps in the quantification of the behaviour of the DNA dosimeter as a potential biologically-based device to measure radiation dose.

  15. SU-E-T-368: Effect of a Strong Magnetic Field On Select Radiation Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Mathis, M; Wen, Z; Tailor, R; Sawakuchi, G; Flint, D; Beddar, S; Ibbott, G [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: To determine the effect of a strong magnetic field on TLD-100, OSLD (Al{sub 2}O{sub 2}:C), and PRESAGE dosimetry devices. This study will help to determine which types of dosimeters can be used for quality assurance and in-vivo dosimetry measurements in a magnetic resonance imaginglinear accelerator (MRI-linac) system. Methods: The dosimeters were separated into two categories which were either exposed or not exposed to a strong magnetic field. In each category a set of dosimeters was irradiated with 0, 2, or 6 Gy. To expose the dosimeters to a magnetic field the samples in that category were place in a Bruker small animal magnetic resonance scanner at a field strength slightly greater than 2.5 T for at least 1 hour preirradiation and at least 1 hour post-irradiation. Irradiations were performed with a 6 MV x-ray beam from a Varian TrueBeam linac with 10×10 cm{sup 2} field at a 600 MU/min dose rate. The samples that received no radiation dose were used as control detectors. Results: The readouts of the dosimeters which were not exposed to a strong magnetic field were compared with the measurements of the dosimetry devices which were exposed to a magnetic field. No significant differences (less than 2% difference) in the performance of TLD, OSLD, or PRESAGE dosimeters due to exposure to a strong magnetic field were observed. Conclusion: Exposure to a strong magnetic field before and after irradiation does not appear to change the dosimetric properties of TLD, OSLD, or PRESAGE which indicates that these dosimeters have potential for use in quality assurance and in-vivo dosimetry in a MRI-linac. We plan to further test the effect of magnetic fields on these devices by irradiating them in the presence of a magnetic fields similar to those produced by a MRI-linac system. Elekta-MD Anderson Cancer Center Research Agreement.

  16. Study of a non-diffusing radiochromic gel dosimeter for 3D radiation dose imaging

    Science.gov (United States)

    Marsden, Craig Michael

    2000-12-01

    This thesis investigates the potential of a new radiation gel dosimeter, based on nitro-blue tetrazolium (NBTZ) suspended in a gelatin mold. Unlike all Fricke based gel dosimeters this dosimeter does not suffer from diffusive loss of image stability. Images are obtained by an optical tomography method. Nitro blue tetrazolium is a common biological indicator that when irradiated in an aqueous medium undergoes reduction to a highly colored formazan, which has an absorbance maximum at 525nm. Tetrazolium is water soluble while the formazan product is insoluble. The formazan product sticks to the gelatin matrix and the dose image is maintained for three months. Methods to maximize the sensitivity of the system were evaluated. It was found that a chemical detergent, Triton X-100, in combination with sodium formate, increased the dosimeter sensitivity significantly. An initial G-value of formazan production for a dosimeter composed of 1mM NBTZ, gelatin, and water was on the order of 0.2. The addition of Triton and formate produced a G-value in excess of 5.0. The effects of NBTZ, triton, formate, and gel concentration were all investigated. All the gels provided linear dose vs. absorbance plots for doses from 0 to >100 Gy. It was determined that gel concentration had minimal if any effect on sensitivity. Sensitivity increased slightly with increasing NBTZ concentration. Triton and formate individually and together provided moderate to large increases in dosimeter sensitivity. The dosimeter described in this work can provide stable 3D radiation dose images for all modalities of radiation therapy equipment. Methods to increase sensitivity are developed and discussed.

  17. Mouse alarm pheromone shares structural similarity with predator scents

    Science.gov (United States)

    Brechbühl, Julien; Moine, Fabian; Klaey, Magali; Nenniger-Tosato, Monique; Hurni, Nicolas; Sporkert, Frank; Giroud, Christian; Broillet, Marie-Christine

    2013-01-01

    Sensing the chemical warnings present in the environment is essential for species survival. In mammals, this form of danger communication occurs via the release of natural predator scents that can involuntarily warn the prey or by the production of alarm pheromones by the stressed prey alerting its conspecifics. Although we previously identified the olfactory Grueneberg ganglion as the sensory organ through which mammalian alarm pheromones signal a threatening situation, the chemical nature of these cues remains elusive. We here identify, through chemical analysis in combination with a series of physiological and behavioral tests, the chemical structure of a mouse alarm pheromone. To successfully recognize the volatile cues that signal danger, we based our selection on their activation of the mouse olfactory Grueneberg ganglion and the concomitant display of innate fear reactions. Interestingly, we found that the chemical structure of the identified mouse alarm pheromone has similar features as the sulfur-containing volatiles that are released by predating carnivores. Our findings thus not only reveal a chemical Leitmotiv that underlies signaling of fear, but also point to a double role for the olfactory Grueneberg ganglion in intraspecies as well as interspecies communication of danger. PMID:23487748

  18. Cost-Effective School Alarm Systems. Security Topics Series.

    Science.gov (United States)

    Kaufer, Steve

    This document outlines considerations in the selection of a cost-effective school-alarm system. Steps in the planning process include: conducting a district needs assessment; gathering input from all staff levels; consulting technical expertise; and selecting a security system that can be integrated with other site needs. It further describes the…

  19. False Alarm Probability Estimation for Compressive Sensing Radar

    NARCIS (Netherlands)

    Anitori, L.; Otten, M.P.G.; Hoogeboom, P.

    2011-01-01

    In this paper false alarm probability (FAP) estimation of a radar using Compressive Sensing (CS) in the frequency domain is investigated. Compressive Sensing is a recently proposed technique which allows reconstruction of sparse signal from sub-Nyquist rate measurements. The estimation of the FAP is

  20. Integrated alarm annunciation and entry control systems -- Survey results

    Energy Technology Data Exchange (ETDEWEB)

    Clever, J.J.; Arakaki, L.H.; Monaco, F.M.; Juarros, L.E.; Quintana, G.R.

    1993-10-01

    This report provides the results and analyses of a detailed survey undertaken in Summer 1993 to address integrated intrusion detection alarm annunciation and entry control system issues. This survey was undertaken as a first attempt toward beginning to answer questions about integrated systems and commercial capabilities to meet or partially meet US Department of Energy (DOE) site needs.

  1. Alarm management in TRANSPETRO National Oil Control Center

    Energy Technology Data Exchange (ETDEWEB)

    Amado, Helio; Costa, Luciano [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    For sure Alarm Management is not a new issue. EEMUA 191 has been around since 1999 and everyone has received visits from consultants in this area. Besides this regulators have requested that operators have a policy for it. However there are few papers showing actual pipeline operator experience in alarm management. In this paper we present the work developed in TRANSPETRO National Oil Control Center since 2006, where we operate 5509 km of crude oil and refined products pipelines. Since the beginning of the centralized operation in 2002, alarm management has been a concern but a systematic approach has been taken since 2006. Initially we will make a brief revision of the literature and show trends for regulations. Then we will show the tools and the approach we have taken. Finally, the further developments we see. The point that we want to discuss is that, it has been very difficult to implement the system in a linear way and we believe that companies that have huge legacy systems, the same probably will occur. Putting in simple words, our main conclusion is: Implementing an Alarm Management policy produces good results however probably sometimes is better not to follow strictly the traditional steps. (author)

  2. Studies on dosimetric tests applying source irradiation force of Cs-137 for using in chambers for calibration and TLD type dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Laila Lorena X. [Pontificia Univ. Catolica de Goias (PUC-GO), Goiania, GO (Brazil). Dept. de Matematica, Fisica, Quimica e Engenharia de Alimentos; Barbosa, Rugles Cesar, E-mail: rbarbosa@cnen.gov.br [Centro Regional de Ciencias Nucleares do Centro Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil). Laboratorio de Radioprotecao; Correa, Rosangela S., E-mail: rcorrea@cnen.gov.br [Centro Regional de Ciencias Nucleares do Centro Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil). Laboratorio de Imagens e Dosimetria

    2011-07-01

    The West Central region of Brazil does not have a basic infrastructure for research, development, training programs, and personnel dosimetry education. All of them applied to environmental, industrial and medical uses. Service deployment for irradiance of TLD, via {sup 137}Cs irradiator J. L. SHEPHERD model 28-8A (444 activity GBq) in CRCN-CO, it is necessary to introduce procedures for calibration of the radiator and other procedures related to dosimetry and calibration. Such procedures should be repeated periodically, as necessary to introduce techniques that make the service of the CRCN-CO a template, and that meet all standards requirements for radioprotection and operation of dosimetry and calibration. The objective of this work was to evaluate the radiation field of Cs-137, and the automatic system which systematizes the calibration procedures attached to a system control target for the radiator/calibration of monitors, and portable dosimeters. (author)

  3. A team-based approach to reducing cardiac monitor alarms.

    Science.gov (United States)

    Dandoy, Christopher E; Davies, Stella M; Flesch, Laura; Hayward, Melissa; Koons, Connie; Coleman, Kristen; Jacobs, Jodi; McKenna, Lori Ann; Olomajeye, Alero; Olson, Chad; Powers, Jessica; Shoemaker, Kimberly; Jodele, Sonata; Alessandrini, Evaline; Weiss, Brian

    2014-12-01

    Excessive cardiac monitor alarms lead to desensitization and alarm fatigue. We created and implemented a standardized cardiac monitor care process (CMCP) on a 24-bed pediatric bone marrow transplant unit. The aim of this project was to decrease monitor alarms through the use of team-based standardized care and processes. Using small tests of change, we developed and implemented a standardized CMCP that included: (1) a process for initial ordering of monitor parameters based on age-appropriate standards; (2) pain-free daily replacement of electrodes; (3) daily individualized assessment of cardiac monitor parameters; and (4) a reliable method for appropriate discontinuation of monitor. The Model for Improvement was used to design, test, and implement changes. The changes that were implemented after testing and adaptation were: family/patient engagement in the CMCP; creation of a monitor care log to address parameters, lead changes, and discontinuation; development of a pain-free process for electrode removal; and customized monitor delay and customized threshold parameters. From January to November 2013, percent compliance with each of the 4 components of the CMCP increased. Overall compliance with the CMCP increased from a median of 38% to 95%. During this time, the median number of alarms per patient-day decreased from 180 to 40. Implementation of the standardized CMCP resulted in a significant decrease in cardiac monitor alarms per patient day. We recommend a team-based approach to monitor care, including individualized assessment of monitor parameters, daily lead change, and proper discontinuation of the monitors. Copyright © 2014 by the American Academy of Pediatrics.

  4. Economic evaluation of smoke alarm distribution methods in Baltimore, Maryland.

    Science.gov (United States)

    Diamond-Smith, Nadia; Bishai, David; Perry, Elise; Shields, Wendy; Gielen, Andrea

    2014-08-01

    This paper analyses costs and potential lives saved from a door-to-door smoke alarm distribution programme using data from a programme run by the Baltimore City Fire Department in 2010-2011. We evaluate the impact of a standard home visit programme and an enhanced home visit programme that includes having community health workers provide advance notice, promote the programme, and accompany fire department personnel on the day of the home visit, compared with each other and with an option of not having a home visit programme (control). Study data show that the home visit programme increased by 10% the number of homes that went from having no working alarm to having any working alarm, and the enhanced programme added an additional 1% to the number of homes protected. We use published reports on the relative risk of death in homes with and without a working smoke alarm to show that the standard programme would save an additional 0.24 lives per 10,000 homes over 10 years, compared with control areas and the enhanced home visit programme saved an additional 0.07 lives compared with the standard programme. The incremental cost of each life saved for the standard programme compared with control was $28,252 per death averted and $284,501per additional death averted for the enhanced compared with the standard. Following the US guidelines for the value of a life, both programmes are cost effective, however, the standard programme may offer a better value in terms of dollars per death averted. The study also highlights the need for better data on the benefits of current smoke alarm recommendations and their impact on injury, death and property damage. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. The development of new generation electronic personal dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Kei; Nagase, Yoshiyuki; Suzuki, T. [Fuji Electric Co., Ltd., Tokyo (Japan); Watanabe, Shinichi; Taniguchi, Kazufumi; Muramatsu, Kunihiro; Fujita, Mikio; Fujii, Yutaka [Japan Atomic Power Company, Tokyo (Japan)

    2000-05-01

    We have developed two types of new small, light, electronic personal dosemeters (EPDs) which can be used for dose management of workers at nuclear power plants without additional dosemeters. The one is a card size dosemeter to measure gamma exposure dose and the other is a multi sensor dosemeter to measure gamma, beta and neutron dose respectively. With direct reading, alarm and instant readout, these EPDs have ruggedness and if failure happens, memory readout facility can read dose data in the dosemeter. These dosemeters have enough performance characteristics and reliability for use as a dose record dosemeter. The gamma dosemeter has a lightweight credit card size body to reduce workers' burden of wearing it. The multi sensor dosemeter has four hetero junction silicon detectors that detect gamma, beta, thermal and fast neutron respectively and it is smaller and lighter than conventional alarm dosemeters presently used at nuclear power plant. Thermal neutron detector has thin Boron layer deposited on silicon surface and fast neutron detector has polyethylene radiator in front of silicon wafer. These dosemeters with a rechargeable battery can operate more than 15 hours continuously. The data transmission can be made with radiofrequency wave in area smaller than 30 cm distance between dosemeter and readout system. These dosemeters were introduced into Tokai nuclear power plant on October 1997, Tsuruga nuclear power plant on December 1997 of Japan Atomic Power Company and have been operating satisfactorily. At now these EPD have been used as secondary dosemeters. The performance characteristics comparison between EPD and film badge(FB) have been continuing to assure EPD suitable for use as a primary dosemeter. Near future Japco will abolish FB and establish the radiation control system based on the electronic personal dosemeters as a dose record dosemeter. (author)

  6. TH-C-19A-05: Evaluation of a New Reusable 3D Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Juang, T [Medical Physics Graduate Program, Duke University Medical Center, Durham, NC (United States); Adamovics, J [Rider University, Skillman, NJ (United States); Oldham, M [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Purpose: PRESAGE is a radiochromic plastic which has demonstrated strong potential for high resolution single-use 3D dosimetry. This study evaluates a new PRESAGE formulation (Presage-RU) in which the radiochromic response is reversible (the dosimeter optically clears after irradiation), enabling the potential for reusability. Methods: Presage-RU dose response and optical-clearing rates were evaluated in both small volume dosimeters (1×1×4.5cm) and a larger cylindrical dosimeter (8cm diameter, 4.5cm length). All dosimeters were allowed to fully optically clear in dark, room temperature conditions between irradiations. Dose response was determined by irradiating small volume samples from 0–8.0Gy and measuring change in optical density. The cylindrical dosimeter was irradiated with a simple 4-field box plan (parallel opposed pairs of 4cm×4cm AP-PA beams and 2cm×4cm lateral beams) to 20Gy. High resolution 3D dosimetry was achieved utilizing optical-CT readout. Readings were tracked up to 14 days to characterize optical clearing. Results: Initial irradiation yielded a response of 0.0119△OD/(Gy*cm) while two subsequent reirradiations yielded a lower but consistent response of 0.0087△OD/(Gy*cm). Strong linearity of dose response was observed for all irradiations. In the large cylindrical dosimeter, the integral dose within the high dose region exhibited an exponential decay in signal over time (halflife= 23.9 hours), with the dosimeter effectively cleared (0.04% of the initial signal) after 10 days. Subsequent irradiation resulted in 19.5% lower initial signal but demonstrated that the exponential clearing rate remained consistent. Results of additional subsequent irradiations will also be presented. Conclusion: This work introduces a new re-usable radiochromic dosimeter (Presage-RU) compatible with high resolution (sub-millimeter) 3D dosimetry. Sensitivity of the initial radiation was observed to be slightly higher than subsequent irradiations, but the

  7. Telemetry Monitor Watchers Reduce Bedside Nurses' Exposure to Alarms by Intercepting a High Number of Nonactionable Alarms.

    Science.gov (United States)

    Palchaudhuri, Sonali; Chen, Stephanie; Clayton, Elaine; Accurso, Anthony; Zakaria, Sammy

    2017-06-01

    Cardiac telemetry, designed to monitor hospitalized patients with active cardiac conditions, is highly utilized outside the intensive care unit but is also resource-intensive and produces many nonactionable alarms. In a hospital setting in which dedicated monitor watchers are set up to be the first responders to system-generated alerts, we conducted a retrospective study of the alerts produced over a continuous 2-month period to evaluate how many were intercepted before nurse notification for being nonactionable, and how many resulted in code team activations. Over the 2-month period, the system generated 20,775 alerts (5.1/patient-day, on average), of which 87% were intercepted by monitor watchers. None of the alerts for asystole, ventricular fibrillation, or ventricular tachycardia resulted in a code team activation. Our results highlight the high burden of alerts, the large majority of which are nonactionable, as well as the role of monitor watchers in decreasing the alarm burden on nurses. Measures are needed to decrease telemetry-related alerts in order to reduce alarm-related harms, such as alarm fatigue. Journal of Hospital Medicine 2017;12:447-449. © 2017 Society of Hospital Medicine.

  8. Biological and physical dosimeters for monitoring solar UV-B light.

    Science.gov (United States)

    Furusawa, Y; Suzuki, K; Sasaki, M

    1990-06-01

    A biological dosimetry system for measuring solar UV-B light was established using bacteriophage T1 with E. coli Bs-1 as the host cell. Also a new physical UV-B dosimeter was developed which can specifically detect the UV spectral region related to inactivation of phage T1. Phage T1 is very stable in liquid suspension and it has adequate sensitivity to measure the intensity of solar UV-B. In addition, the survival of phage T1 responded linearly to UV fluences when plotted semi-logarithmic ally. Thus T1 seemed to have characteristic features making it suitable material as a biological dosimeter for sunlight. Outdoor experiments throughout one year showed that the mean amount of solar UV light in summer was about 6 fold larger than that in winter at Isehara (139.5 degrees E, 35.5 degrees N), Japan. A novel physical dosimeter which responds faithfully to UV-B light under atmospheric conditions on the ground was developed as well. The spectral response was very close to that of biological materials. Readings of this UV-B dosimeter could be converted into the efficiency of sunlight upon biological materials. This instrument is compact; it can also be used as an erythemal dosimeter.

  9. A study on Fricke-PVA-xylenol orange hydrogel dosimeter for E-beam radiotherapy

    Institute of Scientific and Technical Information of China (English)

    CAO Fangqi; YANG Liming; CHEN Jie; LIN Han; FAN Jinchen; RONG Liang; LUO Wenyun; ZHA Yuanzi; WU Guohua

    2009-01-01

    A Fricke-PVA-xylenol orange (FPX) hydrogel dosimeter, in good transparency, was prepared by physical crosslinking for three-dimensional dose measurements. The process of mixing the chemical dosimeter with the PVA solution was carried out at room temperature, which reduced the influence of auto-oxidation rate. Gradation in color was obviously observed with different distance from the radiation source after 6 MeV electron beam irradiation for radiotherapy. The effects of irradiation dose and three components of the FPX gel dosimeter, i.e. ferrous ions, xylenol orange (XO) and sulphuric acid on sensitivity and stability of dose response were investigated by UV-vis spectropho-tometric measurement. The dose response of the FPX gel dosimeter was linear in the range 0~2.0 Gy. The orthogonal test was employed to find the optimal composition of the gel dosimeter with a sensitivity of about 0.095 cm-1·Gy-1. It was found that XO concentration greatly affected the sensitivity of dose response and lower concentrations of the fer-rous ion and XO gave higher sensitivity within the range 0~2.0 Gy.

  10. Single and multichannel scintillating fiber dosimeter for radiotherapic beams with SiPM readout

    Science.gov (United States)

    Berra, A.; Ferri, A.; Novati, C.; Ostinelli, A.; Paternoster, G.; Piemonte, C.; Prest, M.; Vallazza, E.

    2016-12-01

    The treatment of many neoplastic diseases requires the use of radiotherapy, which consists in the irradiation of the tumor, identified as the target volume, with ionizing radiations generated both by administered radiopharmaceuticals or by linear particle accelerators (LINACs). The radiotherapy beam delivered to the patient must be regularly checked to assure the best tumor control probability: this task is performed with dosimeters, i.e. devices able to provide a measurement of the dose deposited in their sensitive volume. This paper describes the development of two scintillator dosimeter prototypes for radiotherapic applications based on plastic scintillating fibers read out by high dynamic range Silicon PhotoMultipliers. The first dosimeter, consisting of a single-channel prototype with a pair of optical fibers, a scintillating and a white one, read out by two SiPMs, has been fully characterized and led to the development of a second multi-channel dosimeter based on an array of scintillating fibers: this device represents the first step towards the assembly of a "one-shot" device, capable to perform some of the daily quality controls in a few seconds. The dosimeters characterization was performed with a Varian Clinac iX linear accelerator at the Radiotherapy Department of the St. Anna Hospital in Como (IT).

  11. Radiation-induced color bleaching of methyl red in polyvinyl butyral film dosimeter

    Science.gov (United States)

    Al Zahrany, Awad A.; Rabaeh, Khalid A.; Basfar, Ahmed A.

    2011-11-01

    Radio-chromic film based on polyvinyl butyral (PVB) containing different concentrations of methyl red (MR) dye for 0.125, 0.25 and 0.5 mM has been introduced as high dose dosimeter. The dosimeters were irradiated with gamma ray from 60Co source at doses from 5 to 150 kGy. UV/vis spectrophotometry was used to investigate the optical density of unirradiated and irradiated films in terms of absorbance at 497 nm. The dose sensitivity of MR-PVB film dosimeter increases strongly with increase of absorbed dose as well as increase of concentrations of MR dye. The effects of irradiation temperature, relative humidity, dose rate and the stability of the response of the films after irradiation were investigated and found that these films could be used as routine dosimeter in industrial radiation processing. The useful dose range of developed MR-PVB film dosimeters is in the range of 5-100 kGy.

  12. SU-D-213-07: Initial Characterization of a Gel Patch Dosimeter for in Vivo Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Matrosic, C; Culberson, W; Rosen, B; Madsen, E; Frank, G; Bednarz, B [Univ of Wisc Madison, Madison, WI (United States)

    2015-06-15

    Purpose: In vivo dosimetry, despite being the most direct method for monitoring the dose delivered during radiation therapy and being recommended by several national and international organizations (AAPM, ICRU, NACP), is underutilized in the clinic due to issues associated with dose sensitivity, feasibility, and cost. Given the increasing complexity of radiation therapy modern treatments, there is a compelling need for a robust, affordable in vivo dosimetry option. In this work we present the initial characterization of a novel gel patch in vivo dosimeter. Methods: DEFGEL (6%T) was used to make 1-cm thick small cylindrical patch dosimeters. The optical density of each dosimeter was read before and after irradiation by an in-house laser densitometer. The dosimeters were irradiated using a Varian Clinac EX linac. Three separate batches of gel patches were used to create dose response curves and evaluate repeatability. The development time of the dosimeter was also evaluated. Results: The dose response of the dosimeter was found to be linear from a range of approximately 1-Gy to 20-Gy, which is a larger window of linearity compared to other in vivo dosimeters. At doses below 1-Gy, the cumulative uncertainties were on the order of the measured data. When compared, the three batches demonstrated repeatability from 1-Gy to approximately 13-Gy, with some variation at higher doses. For doses of >8-Gy, the dosimeter reached full optical density after 4-hours, whereas low doses developed within an hour. Conclusion: Initial results indicate that the gel patch dosimeter is a reliable and simple way to measure a large range of doses, including high doses such as those delivered during hypofractionated treatments (e.g. SBRT or MR-guided radiotherapy). The simple fabrication method for the dosimeter and the use of a laser densitometer would allow for the dosimeter to used and read in-house, cheaply and easily.

  13. 128 slice computed tomography dose profile measurement using thermoluminescent dosimeter

    Science.gov (United States)

    Salehhon, N.; Hashim, S.; Karim, M. K. A.; Ang, W. C.; Musa, Y.; Bahruddin, N. A.

    2017-05-01

    The increasing use of computed tomography (CT) in clinical practice marks the needs to understand the dose descriptor and dose profile. The purposes of the current study were to determine the CT dose index free-in-air (CTDIair) in 128 slice CT scanner and to evaluate the single scan dose profile (SSDP). Thermoluminescent dosimeters (TLD-100) were used to measure the dose profile of the scanner. There were three sets of CT protocols where the tube potential (kV) setting was manipulated for each protocol while the rest of parameters were kept constant. These protocols were based from routine CT abdominal examinations for male adult abdomen. It was found that the increase of kV settings made the values of CTDIair increased as well. When the kV setting was changed from 80 kV to 120 kV and from 120 kV to 140 kV, the CTDIair values were increased as much as 147.9% and 53.9% respectively. The highest kV setting (140 kV) led to the highest CTDIair value (13.585 mGy). The p-value of less than 0.05 indicated that the results were statistically different. The SSDP showed that when the kV settings were varied, the peak sharpness and height of Gaussian function profiles were affected. The full width at half maximum (FWHM) of dose profiles for all protocols were coincided with the nominal beam width set for the measurements. The findings of the study revealed much information on the characterization and performance of 128 slice CT scanner.

  14. Intravenous infusion alarm device level signal detection principle%静脉输液报警装置中液位信号的检测原理

    Institute of Scientific and Technical Information of China (English)

    李文静

    2013-01-01

    To reduce the labor intensity of nurses,the burden on the families of patients,to ensure the safety of the infusion,the level detection method using optical,capacitive,ultrasonic,mechanical,images,design an infusion monitoring alarm device changes by monitoring physical quantities.Monitoring liquid level information in real time,then the relevant signal sent to the follow-up alarm circuit,in order to achieve the automatic alarm.Experiments show that the design can be an effective solution liquid level monitoring,alarm display functions.%为减轻护士的劳动强度、患者家属负担、保证输液安全,文中通过采用光电式、电容式、超声、力学、图像等液位检测方法,设计了一种输液监视报警装置.通过监视物理量的变化,以实时监控液位信息,再将相关信号传送到后续报警电路,从而实现自动报警.实验证明,该设计可以有效实现对药液液位的监测、报警、显示等功能.

  15. "Turn it off!": diabetes device alarm fatigue considerations for the present and the future.

    Science.gov (United States)

    Shivers, Joseph P; Mackowiak, Linda; Anhalt, Henry; Zisser, Howard

    2013-05-01

    Safe and widespread use of diabetes technology is constrained by alarm fatigue: when someone receives so many alarms that he or she becomes less likely to respond appropriately. Alarm fatigue and related usability issues deserve consideration at every stage of alarm system design, especially as new technologies expand the potential number and complexity of alarms. The guiding principle should be patient wellbeing, while taking into consideration the regulatory and liability issues that sometimes contribute to building excessive alarms. With examples from diabetes devices, we illustrate two complementary frameworks for alarm design: a "patient safety first" perspective and a focus on human factors. We also describe opportunities and challenges that will come with new technologies such as remote monitoring, adaptive alarms, and ever-closer integration of glucose sensing with insulin delivery. © 2013 Diabetes Technology Society.

  16. Integrating monitor alarms with laboratory test results to enhance patient deterioration prediction.

    Science.gov (United States)

    Bai, Yong; Do, Duc H; Harris, Patricia Rae Eileen; Schindler, Daniel; Boyle, Noel G; Drew, Barbara J; Hu, Xiao

    2015-02-01

    Patient monitors in modern hospitals have become ubiquitous but they generate an excessive number of false alarms causing alarm fatigue. Our previous work showed that combinations of frequently co-occurring monitor alarms, called SuperAlarm patterns, were capable of predicting in-hospital code blue events at a lower alarm frequency. In the present study, we extend the conceptual domain of a SuperAlarm to incorporate laboratory test results along with monitor alarms so as to build an integrated data set to mine SuperAlarm patterns. We propose two approaches to integrate monitor alarms with laboratory test results and use a maximal frequent itemsets mining algorithm to find SuperAlarm patterns. Under an acceptable false positive rate FPRmax, optimal parameters including the minimum support threshold and the length of time window for the algorithm to find the combinations of monitor alarms and laboratory test results are determined based on a 10-fold cross-validation set. SuperAlarm candidates are generated under these optimal parameters. The final SuperAlarm patterns are obtained by further removing the candidates with false positive rate>FPRmax. The performance of SuperAlarm patterns are assessed using an independent test data set. First, we calculate the sensitivity with respect to prediction window and the sensitivity with respect to lead time. Second, we calculate the false SuperAlarm ratio (ratio of the hourly number of SuperAlarm triggers for control patients to that of the monitor alarms, or that of regular monitor alarms plus laboratory test results if the SuperAlarm patterns contain laboratory test results) and the work-up to detection ratio, WDR (ratio of the number of patients triggering any SuperAlarm patterns to that of code blue patients triggering any SuperAlarm patterns). The experiment results demonstrate that when varying FPRmax between 0.02 and 0.15, the SuperAlarm patterns composed of monitor alarms along with the last two laboratory test results

  17. PT-SAFE: a software tool for development and annunciation of medical audible alarms.

    Science.gov (United States)

    Bennett, Christopher L; McNeer, Richard R

    2012-03-01

    Recent reports by The Joint Commission as well as the Anesthesia Patient Safety Foundation have indicated that medical audible alarm effectiveness needs to be improved. Several recent studies have explored various approaches to improving the audible alarms, motivating the authors to develop real-time software capable of comparing such alarms. We sought to devise software that would allow for the development of a variety of audible alarm designs that could also integrate into existing operating room equipment configurations. The software is meant to be used as a tool for alarm researchers to quickly evaluate novel alarm designs. A software tool was developed for the purpose of creating and annunciating audible alarms. The alarms consisted of annunciators that were mapped to vital sign data received from a patient monitor. An object-oriented approach to software design was used to create a tool that is flexible and modular at run-time, can annunciate wave-files from disk, and can be programmed with MATLAB by the user to create custom alarm algorithms. The software was tested in a simulated operating room to measure technical performance and to validate the time-to-annunciation against existing equipment alarms. The software tool showed efficacy in a simulated operating room environment by providing alarm annunciation in response to physiologic and ventilator signals generated by a human patient simulator, on average 6.2 seconds faster than existing equipment alarms. Performance analysis showed that the software was capable of supporting up to 15 audible alarms on a mid-grade laptop computer before audio dropouts occurred. These results suggest that this software tool provides a foundation for rapidly staging multiple audible alarm sets from the laboratory to a simulation environment for the purpose of evaluating novel alarm designs, thus producing valuable findings for medical audible alarm standardization.

  18. A Scintillating Fiber Dosimeter for Radiology and Brachytherapy with photodiode readout

    CERN Document Server

    Rêgo, Florbela; Abreu, Maria da Conceição

    2011-01-01

    Purpose: For more than a decade that plastic optical fiber based dosimeters have been developed for medical applications. The feasibility of dosimeters using optical fibers that are almost Cherenkov light free has been demonstrated in some prototypes, particularly suitable for photon high-energy beams. In the energy range up to a few hundred keV, where the production of Cherenkov light by secondary electrons is negligible or small, the largest source of background are the fluorescence mechanisms. Methods: In recent years our group has developed an optical fiber dosimeter with photodiode readout named DosFib, which has small energy dependence in the range below 100 keV relevant for radiology. Photodiodes are robust photodetectors, presenting good stability over time and enough sensitivity to allow the use of an electrometer as a measuring device without extra electronics. Results: In-vitro tests using a High Dose Rate 192Ir source have demonstrated its suitability for brachytherapy applications using this impo...

  19. Investigation of nanoscale structures by small-angle X-ray scattering in a radiochromic dosimeter

    DEFF Research Database (Denmark)

    Skyt, Peter Sandegaard; Jensen, Grethe Vestergaard; Wahlstedt, Isak Hannes

    2014-01-01

    This study examines the nanoscale structures in a radiochromic dosimeter that was based on leuco-malachite-green dye and the surfactant sodium dodecyl sulfate (SDS) suspended in a gelatin matrix. Small-angle X-ray scattering was used to investigate the structures of a range of compositions...... of the dosimeter. When omitting gelatin, ellipsoidal micelles of SDS were formed with a core radius near 15 Å, an eccentricity of 1.6, and a head-group shell thickness near 7 Å. Gelatin significantly changed the micelles to a cylindrical shape with around three times lower core radius and four times larger shell...... thickness, which shows that the gelatin is present in the shell and the outer part of the core. Insight into the detailed structure might help to improve the dosimeter performance and increase the dose response to clinically relevant dose levels....

  20. Considerations concerning the use of counting active personal dosimeters in pulsed fields of ionising radiation.

    Science.gov (United States)

    Ambrosi, Peter; Borowski, Markus; Iwatschenko, Michael

    2010-06-01

    Active personal electronic dosimeters (APDs) exhibit limitations in pulsed radiation fields, which cannot be overcome without the use of new detection technology. As an interim solution, this paper proposes a method by which some conventional dosimeters can be operated in a way such that, based on the basic knowledge about the pulsed radiation field, any dosimetric failure of the dosimeter is signalised by the instrument itself. This method is not applicable to all combinations of APD and pulsed radiation field. The necessary requirements for the APD and for the parameters of the pulsed radiation field are given in the paper. Up to now, all such requirements for APDs have not been tested or verified in a type test. The suitability of the method is verified for the use of one APD used in two clinical pulsed fields.

  1. Dependence of alanine gel dosimeter response as a function of photon clinical beams dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo, E-mail: cleber.feijo@famesp.com.br [Faculdade Metodo de Sao Paulo (FAMESP), SP (Brazil); Campos, Leticia Lucente, E-mail: Icrodri@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-11-01

    Gel dosimetry is a new area developed by Gore, it is ery useful for application in radiotherapy because using NMR imaging as evaluation technique is possible to evaluate three dimensional absorbed dose distribution. The measure technique is based on difference of ferrous (Fe{sup 2+}) and ferric (Fe{sup 3+}) ) ions concentration that can be measured also by spectrophotometry technique. The Alanine gel dosimeter was developed at IPEN. The alanine is an amino acid and tissue equivalent material that presents significant improvement on previous alanine dosimetry systems. The addition of Alanine increases the production of ferric ions in the solution. This work aims to study the dose rate dependence of photon clinical beams radiation on the alanine gel dosimeter optical response, as well as the response repeatability and gel production reproducibility, since this property is very important for characterization and standardization of any dosimeter. (author)

  2. A passive radon dosimeter based on the combination of a track etch detector and activated charcoal

    CERN Document Server

    Deynse, A V; Poffijn, A

    1999-01-01

    The aim of this work is to test a combination of a Makrofol track detector with a new type of charcoal (Carboxen-564) to design a personal radon dosimeter. The intention is to use this dosimeter as a personal radon dosimeter to measure the monthly radon exposure in workplaces, especially when the occupancy is not exactly known. The proposed combination was exposed to low and high concentrations of radon in a large range of relative humidity (RH). For the optimal layer thickness, a charcoal bed of 2.2 mm, a specific track density of 5.1 tracks cm sup - sup 2 /kBq h m sup - sup 3 was obtained. For a monthly working exposure (170 h) at an average radon concentration of 100 Bq/m sup 3 , this means 87 tracks/cm sup 2 or 10 times the background of the Makrofol detector, with a statistical uncertainty of 15%.

  3. Calibration of thin-film dosimeters irradiated with 80-120 kev electrons

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; McEwen, M.

    2004-01-01

    A method for calibration of thin-film dosimeters irradiated with 80-120keV electrons has been developed. The method is based on measurement of dose with a totally absorbing graphite calorimeter, and conversion of dose in the graphite calorimeter to dose in the film dosimeter by Monte Carlo...... calculations. A thermal model was developed to estimate the temperature contributions from the air above the calorimeter that is heated by the electron beam. As an example, Riso B3 thin-film dosimeters were calibrated by 80-120 keV electron irradiation and compared with a calibration carried out at 10 Me......V electron irradiation. The two calibrations were found to be equal within the estimated uncertainties of +/-10% at 1 s.d. (C) 2004 Elsevier Ltd. All rights reserved....

  4. FXG dosimeter response for three-dimensional conformal radiotherapy using different evaluation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B., E-mail: bhsouza@unifesp.b, E-mail: daros.kellen@unifesp.b, E-mail: rbitel-li.ddi@epm.b [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Servico de Radioterapia

    2011-07-01

    This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)

  5. Temperature response of a number of plastic dosimeters for radiation processing

    Science.gov (United States)

    Sohrabpour, M.; Kazemi, A. A.; Mousavi, H.; Solati, K.

    1993-10-01

    Various plastic dosemeters are employed for dosimetry control of radiation processing within gamma and electron irradiation facilities. The temperature response of a dosimeter is important when the dose to such a dosimeter is accumulated under varying irradiation temperatures. Such measurements would be significant for proper assessment of the dose for better process control, as well as, performance evaluation of dosimetry systems. In this work we have developed a high current peltier junction temperature controller system for our Gammacell-220. This system has been designed to regulate the operating temperature of the irradiation chamber in the range of 0 to 80 C this system has been applied to measure the temperature response of the red perspex, a local clear PMMA, Gammex, Gammachrome, and Gafchromic dosimeters. The curves of relative performance or variation of the induced optical densities of the above dosemeters versus the irradiation temperature at fixed dose values are obtained.

  6. Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).

    Science.gov (United States)

    Amar, Abdurazaq; Parisi, Alfio V

    2013-11-01

    The dosimetric properties of the recently introduced UV dosimeter based on 16 μm PVC film have been fully characterised. Drying the thin film in air at 50 °C for at least 28 days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3 weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies.

  7. SU-E-T-643: Pure Alanine Dosimeter for Verification Dosimetry in IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Al-Karmi, Anan M.; Zraiqat, Fadi [Physics Department, King Fahd University of Petroleum & Minerals, Dhahran 31261 (Saudi Arabia)

    2015-06-15

    Purpose: The objective of this study was evaluation of accuracy of pure alanine dosimeters measuring intensity-modulated radiation therapy (IMRT) dose distributions in a thorax phantom. Methods: Alanine dosimeters were prepared in the form of 110 mg pure L-α-alanine powder filled into clear tissue-equivalent polymethylmethacrylate (PMMA) plastic tubes with the dimensions 25 mm length, 3 mm inner diameter, and 1 mm wall thickness. A dose-response calibration curve was established for the alanine by placing the dosimeters at 1.5 cm depth in a 30×30×30 cm{sup 3} solid water phantom and then irradiating on a linac with 6 MV photon beam at 10×10 cm{sup 2} field size to doses ranging from 1 to 5 Gy. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the absorbed dose in alanine. An IMRT treatment plan was designed for a commercial heterogeneous CIRS thorax phantom and the dose values were calculated at three different points located in tissue, lung, and bone equivalent materials. A set of dose measurements was carried out to compare measured and calculated dose values by placing the alanine dosimeters at those selected locations inside the thorax phantom and delivering the IMRT to the phantom. Results: The alanine dose measurements and the IMRT plan dose calculations were found to be in agreement within ±2%. Specifically, the deviations were −0.5%, 1.3%, and −1.7% for tissue, lung, and bone; respectively. The slightly large deviations observed for lung and bone may be attributed to tissue inhomogeneity, steep dose gradients in these regions, and uncontrollable changes in spectrometer conditions. Conclusion: The results described herein confirmed that pure alanine dosimeter was suitable for in-phantom dosimetry of IMRT beams because of its high sensitivity and acceptable accuracy. This makes the dosimeter a promising option for quality control of the therapeutic beams, complementing the commonly used ionization chambers, TLDs, and films.

  8. Miniature personal electronic UVR dosimeter with erythema response and time-stamped readings in a wristwatch.

    Science.gov (United States)

    Heydenreich, Jakob; Wulf, Hans Christian

    2005-01-01

    Personal ultraviolet radiation (UVR) dosimetry is important because sunlight is the most important risk factor for skin cancer and a risk factor for some eye diseases and immunosuppression and related disorders. Integrating devices, such as polysulphone film dosimeters, are generally used. To measure the exact dose at specific times, we have developed a personal electronic UVR dosimeter that makes time-stamped measurements. It has a sensor with an erythema action spectrum response and a linear sensitivity (dose-response) with no offset. The sensor has cosine response, and the dosimeter can cope with environmental conditions such as rain, temperature and dirt. It can be programmed to measure with different time intervals and save the average of a specified number of measurements in the memory that can store 32 000 time-stamped measurements. It is small (36 x 28 x 13 mm), weighs 14 g and can work for 4 months without maintenance. It is worn on the wrist, is equipped with a watch showing the time and may thus be used in large-scale studies. The sensitivity can change by 10% due to temperature changes from -5 to 40 degrees C. The UVR dosimeter sensitivity is 0.09 standard erythema doses (SED)/h and the difference in total received dose during 7 days between a Solar Light 501 UV-Biometer (186 SED) and our UVR dosimeter was 3% and the median difference in daily total dose was 2.2%. The dosimeter provides unique possibilities. Examples of personal UVR measurements, data calculations and how they can be interpreted are given.

  9. SU-D-213-06: Dosimetry of Modulated Electron Radiation Therapy Using Fricke Gel Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Gawad, M Abdel; Elgohary, M; Hassaan, M; Emam, M [Al Azhar University, Cairo Egypt (Egypt); Desouky, O [National center for radiation research and technology-Egyptian atomic energy, Cairo (Egypt); Eldib, A [Al Azhar University, Cairo Egypt (Egypt); Fox Chase Cancer Center, Philadelphia, PA (United States); Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2015-06-15

    Purpose: Modulated electron radiation therapy (MERT) has been proposed as an effective modality for treatment of superficial targets. MERT utilizes multiple beams of different energies which are intensity modulated to deliver optimized dose distribution. Energy independent dosimeters are thus needed for quantitative evaluations of MERT dose distributions and measurements of absolute doses delivered to patients. Thus in the current work we study the feasibility of Fricke gel dosimeters in MERT dosimetry. Methods: Batches of radiation sensitive Fricke gel is fabricated and poured into polymethyl methacrylate cuvettes. The samples were irradiated in solid water phantom and a thick layer of bolus was used as a buildup. A spectrophotometer system was used for measuring the color changes (the absorbance) before and after irradiation and then we calculate net absorbance. We constructed calibration curves to relate the measured absorbance in terms of absorbed dose for all available electron energies. Dosimetric measurements were performed for mixed electron beam delivery and we also performed measurement for segmented field delivery with the dosimeter placed at the junction of two adjacent electron beams of different energies. Dose measured by our gel dosimetry is compared to that calculation from our precise treatment planning system. We also initiated a Monte Carlo study to evaluate the water equivalence of our dosimeters. MCBEAM and MCSIM codes were used for treatment head simulation and phantom dose calculation. PDDs and profiles were calculated for electron beams incident on a phantom designed with 1cm slab of Fricke gel. Results: The calibration curves showed no observed energy dependence with all studied electron beam energies. Good agreement was obtained between dose calculated and that obtained by gel dosimetry. Monte Carlo results illustrated the tissue equivalency of our Gel dosimeters. Conclusion: Fricke Gel dosimeters represent a good option for the dosimetric

  10. K-band EPR dosimetry: small-field beam profile determination with miniature alanine dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Felipe [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Department of Radiological Health, Caja de Seguro Social, Panama City (Panama); Department of Physics, Faculty of Natural and Exact Sciences and Technology, University of Panama, Panama City (Panama); Graeff, Carlos F.O. [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Baffa, Oswaldo [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil)

    2005-02-01

    The use of small-size alanine dosimeters presents a challenge because the signal intensity is less than the spectrometer sensitivity. K-band (24 GHz) EPR spectrometer seems to be a good compromise between size and sensitivity of the sample. Miniature alanine pellets were evaluated for small-field radiation dosimetry. Dosimeters of DL-alanine/PVC with dimensions of 1.5 mm diameter and 2.5 mm length with 5 mg mass were developed. These dosimeters were irradiated with 10 MV X-rays in the dose range 0.05-60 Gy and the first harmonic (1 h) spectra were recorded. Microwave power, frequency and amplitude of modulation were optimized to obtain the best signal-to-noise ratio (S/N). For beam profile determination, a group of 25 dosimeters were placed in an acrylic device with dimensions of (7.5x2.5x1) cm{sup 3} and irradiated with a (3x3) cm{sup 2} 10 MV X-rays beam field size. The dose at the central region of the beam was 20 Gy at a depth of 2.2 cm (build up for acrylic). The acrylic device was oriented perpendicular to the beam axis and to the gantry rotation axis. For the purposes of comparison of the spatial resolution, the beam profile was also determined with a radiographic film and 2 mm aperture optical densitometer; in this case the dose was 1 cGy. The results showed a similar spatial resolution for both types of dosimeters. The dispersion in dose reading was larger for alanine in comparison with the film, but alanine dosimeters can be read faster and more directly than film over a wide dose range.

  11. SU-E-T-274: Does Atmospheric Oxygen Affect the PRESAGE Dosimeter?

    Energy Technology Data Exchange (ETDEWEB)

    Alqathami, M; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States); Blencowe, A [The University of South Australia, South Australia, SA (Australia)

    2015-06-15

    Purpose: To experimentally determine the influence of atmospheric oxygen on the efficiency of the PRESAGE dosimeter and its reporting system. Methods: Batches of the reporting system – a mixture of chloroform and leuchomalachite green dye – and PRESAGE were prepared in aerobic and anaerobic conditions. For anaerobic batches, samples were deoxygenated by bubbling nitrogen through the dosimeter precursors or reporting system for 10 min. The dosimeters and reporting systems were prepared in spectrophotometric cuvettes and glass vials, respectively, and were irradiated with 6 MV photons to various radiation doses using a clinical linear accelerator. Changes in optical density of the dosimeters and reporting system before and after irradiation were measured using a spectrophotometer. In addition, the concentrations of dissolved oxygen were measured using a dissolved oxygen meter. Results: The experiments revealed that oxygen has little influence on the characteristics of PRESAGE, with the radical initiator oxidizing the leucomalachite green even in the presence of oxygen. However, deoxygenation of the reporting system leads to an increase in sensitivity to radiation dose by ∼ 30% when compared to the non-deoxygenated system. A slight improvement in sensitivity (∼ 5%) was also achieved by deoxygenating the PRESAGE precursor prior to casting. Measurement of the dissolved oxygen revealed low levels (0.4 ppm) in the polyurethane precursor used to fabricate the dosimeters, as compared to water (8.6 ppm). In addition, deoxygenation had no effect on the retention of the post-response absorption value of the PRESAGE dosimeter. Conclusion: The results suggest that the presence of oxygen does not inhibit the radiochromic properties of the PRESAGE system. In addition, there were no observed changes in the dose linearity, absorption spectrum and post-response photofading characteristics of the PRESAGE under the conditions investigated.

  12. 46 CFR 62.25-20 - Instrumentation, alarms, and centralized stations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Instrumentation, alarms, and centralized stations. 62.25... Instrumentation, alarms, and centralized stations. (a) General. Minimum instrumentation and alarms required for specific types of automated vital systems are listed in Table 62.35-50. (b) Instrumentation Location....

  13. 47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...

  14. 46 CFR 113.25-8 - Distribution of general emergency alarm system feeders and branch circuits.

    Science.gov (United States)

    2010-10-01

    ... Systems § 113.25-8 Distribution of general emergency alarm system feeders and branch circuits. (a) Each... alarm signal. (e) Each system must have one or more branch circuit distribution panels for each zone... 46 Shipping 4 2010-10-01 2010-10-01 false Distribution of general emergency alarm system...

  15. 33 CFR 149.135 - What should be marked on the cargo transfer system alarm switch?

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What should be marked on the cargo transfer system alarm switch? 149.135 Section 149.135 Navigation and Navigable Waters COAST GUARD... switch? Each switch for activating an alarm, and each audio or visual device for signaling an alarm,...

  16. Potential Nematode Alarm Pheromone Induces Acute Avoidance in Caenorhabditis elegans.

    Science.gov (United States)

    Zhou, Ying; Loeza-Cabrera, Mario; Liu, Zheng; Aleman-Meza, Boanerges; Nguyen, Julie K; Jung, Sang-Kyu; Choi, Yuna; Shou, Qingyao; Butcher, Rebecca A; Zhong, Weiwei

    2017-07-01

    It is crucial for animal survival to detect dangers such as predators. A good indicator of dangers is injury of conspecifics. Here we show that fluids released from injured conspecifics invoke acute avoidance in both free-living and parasitic nematodes. Caenorhabditis elegans avoids extracts from closely related nematode species but not fruit fly larvae. The worm extracts have no impact on animal lifespan, suggesting that the worm extract may function as an alarm instead of inflicting physical harm. Avoidance of the worm extract requires the function of a cGMP signaling pathway that includes the cGMP-gated channel TAX-2/TAX-4 in the amphid sensory neurons ASI and ASK. Genetic evidence indicates that the avoidance behavior is modulated by the neurotransmitters GABA and serotonin, two common targets of anxiolytic drugs. Together, these data support a model that nematodes use a nematode-specific alarm pheromone to detect conspecific injury. Copyright © 2017 by the Genetics Society of America.

  17. Optimal go/no-go ratios to maximize false alarms.

    Science.gov (United States)

    Young, Michael E; Sutherland, Steven C; McCoy, Anthony W

    2017-06-29

    Despite the ubiquity of go/no-go tasks in the study of behavioral inhibition, there is a lack of evidence regarding the impact of key design characteristics, including the go/no-go ratio, intertrial interval, and number of types of go stimuli, on the production of different response classes of central interest. In the present study we sought to empirically determine the optimal conditions to maximize the production of a rare outcome of considerable interest to researchers: false alarms. As predicted, the shortest intertrial intervals (450 ms), intermediate go/no-go ratios (2:1 to 4:1), and the use of multiple types of go stimuli produced the greatest numbers of false alarms. These results are placed within the context of behavioral changes during learning.

  18. In vivo dosimetry thermoluminescence dosimeters during brachytherapy with a 370 GBq {sup 192}Ir source

    Energy Technology Data Exchange (ETDEWEB)

    Cuepers, S.; Piessens, M.; Verbeke, L.; Roelstraete, A. [Onze-Lieve-Vrouw Hospitaal, Aalst (Belgium). Dept. of Radiotherapy and Oncology

    1995-12-01

    When using LiF thermoluminescence dosimeters in brachytherapy, we have to take into account the properties of a high dose rate {sup 192}Ir source (energy spectrum ranging form 9 to 885 keV, steep dose gradient in the vicinity of the source) and these of the dosimeters themselves (supralinearity, reproducibility, size). All these characteristics combine into a set of correction factors which have been determined during in phantom measurements. These results have then been used to measure the dose delivered to organs at risk (e.g. rectum, bladder, etc.) during high dose rate brachytherapy with a 370 GBq {sup 192}Ir source for patients with gynaecological tumors.

  19. Initial characterization of a gel patch dosimeter for in vivo dosimetry

    Science.gov (United States)

    Matrosic, C.; Culberson, W.; Rosen, B.; Madsen, E.; Frank, G.; Bednarz, B.

    2016-05-01

    In vivo dosimetry is a greatly underutilized tool for patient safety in clinical external beam radiotherapy treatments, despite being recommended by several national and international organizations (AAPM, ICRU, IAEA, NACP). The reasons for this underutilization mostly relate to the feasibility and cost of in vivo dosimetry methods. Due to the increase in the number of beam angles and dose per fraction in modern treatments, there is a compelling need for a novel dosimeter that is robust and affordable while able to operate properly in these complex conditions. This work presents a gel patch dosimeter as a novel method of in vivo dosimetry. DEFGEL, a 6% T normoxic polyacrylamide gel, was injected into 1 cm thick acrylic molds to create 1 cm thick small cylindrical patch dosimeters. To evaluate the change in optical density due to radiation induced polymerization, dosimeters were scanned before and after irradiation using an in-house developed laser densitometer. The dose-responses of three separate batches of gel were evaluated and compared to check for linearity and repeatability. The response development time was evaluated to ensure that the patch dosimeter could be high throughput. Additionally, the potential of this system to be used as an in vivo dosimeter was tested with a clinically relevant end-to-end in vivo phantom test. All irradiations were performed with a Varian Clinac 21EX at the University of Wisconsin Medical Radiation Research Center (UWMRRC). The dose-response of all three batches of gel was found to be linear within the range of 2-20 Gy. At doses below 0.5 Gy the statistical uncertainties were prohibitively large to make quantitative assessments of the results. The three batches demonstrated good repeatability in the range of 2 Gy to up to 10 Gy, with only slight variations in response at higher doses. For low doses the dosimeter fully developed within an hour while at higher doses they fully developed within four hours. During the in vivo

  20. Calibration of dosimeters at 80-120 keV electron irradiation

    DEFF Research Database (Denmark)

    Miller, A.; Helt-Hansen, J.

    We describe calorimeters for dose measurement at low-energy electron accelerator energies (80–120 keV). Three calorimeters with different characteristics were designed and their dose response and measurement uncertainties were characterized. The heatedair between the electron beam exit window...... to calibrate thin-film dosimeters (Risø B3 and alanine films) by irradiation at the 80–120 keV electron accelerators. This calibration was compared to a 10MeV calibration, and we show that the radiation response of the dosimeter materials (the radiation chemical yield) is constant at these irradiation energies...

  1. On the response of electronic personal dosimeters in constant potential and pulsed X-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Margarete C.; Silva, Teogenes; Silva, Claudete R.E., E-mail: margaretecristinag@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Paulo Marcio C. de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem

    2015-07-01

    Electronic personal dosimeters (EPDs) based on solid state detectors have widely been used but some deficiencies in their response in pulsed radiation beams have been reported. Nowadays, there is not an international standard for pulsed X-ray beams for calibration or type testing of dosimeters. Irradiation conditions for testing the response of EPDs in both the constant potential and pulsed X-ray beams were established in CDTN. Three different types of EPDs were tested in different conditions in similar ISO and IEC X-ray qualities. Results stressed the need of performing additional checks before using EPDs in constant potential or pulsed X-rays. (author)

  2. On the response of electronic personal dosimeters in constant potential and pulsed x- ray beams

    Science.gov (United States)

    Guimarães, M. C.; Silva, C. R. E.; Oliveira, P. M. C.; da Silva, T. A.

    2016-07-01

    Electronic personal dosimeters (EPDs) based on solid state detectors have widely been used but some deficiencies in their response in pulsed radiation beams have been reported. Nowadays, there is not an international standard for pulsed x-ray beams for calibration or type testing of dosimeters. Irradiation conditions for testing the response of EPDs in both the constant potential and pulsed x-ray beams were established in CDTN. Three different types of EPDs were tested in different conditions in similar ISO and IEC x-ray qualities. Results stressed the need of performing additional checks before using EPDs in constant potential or pulsed x-rays.

  3. Iron salts in solid state and in frozen solutions as dosimeters for low irradiation temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, T. [Facultad de Quimica UNAM, Ciudad Universitaria, D.F. Mexico (Mexico); Lartigue, J. [Facultad de Quimica UNAM, Ciudad Universitaria, D.F. Mexico (Mexico); Ramos-Bernal, S. [Instituto de Ciencias Nucleares, UNAM, A.P. 70-543 C.P.4510, Ciudad Universitaria, D.F. Mexico (Mexico); Ramos, A. [Instituto de Ciencias Nucleares, UNAM, A.P. 70-543 C.P.4510, Ciudad Universitaria, D.F. Mexico (Mexico); Mosqueira, G.F. [Direccion General de Divulgacion de la Ciencia de la UNAM, A.P. 70-487, C:P, D.F. Mexico 04510 (Mexico); Negron-Mendoza, A. [Instituto de Ciencias Nucleares, UNAM, A.P. 70-543 C.P.4510, Ciudad Universitaria, D.F. Mexico (Mexico)]. E-mail: negron@nuclecu.unam.mx

    2005-12-01

    The aim of this work is to study the irradiation of iron salts in solid state (heptahydrated ferrous sulfate) and in frozen acid solutions. The study is focused on finding their possible use as dosimeters for low temperature irradiations and high doses. The analysis of the samples was made by UV-visible and Moessbauer spectroscopies. The output signal was linear from 0 to 10 MGy for the solid samples, and 0-600 Gy for the frozen solutions. The obtained data is reproducible and easy to handle. For these reasons, heptahydrate iron sulfate is a suitable dosimeter for low temperature and high irradiation doses, in solid state, and in frozen solution.

  4. Enhancement in dose sensitivity of polymer gel dosimeters composed of radiation-crosslinked gel matrix and less toxic monomers

    Science.gov (United States)

    Hiroki, A.; Yamashita, S.; Taguchi, M.

    2015-01-01

    Polymer gel dosimeters based on radiation-crosslinked hydroxypropyl cellulose gel were prepared, which comprised 2-hydroxyethyl methacrylate (HEMA) and polyethylene glycol #400 dimethacrylate (9G) as less toxic monomers and tetrakis (hydroxymethyl) phosphonium chloride (THPC) as an antioxidant. The dosimeters exposed to 60Co γ-rays became cloudy at only 1 Gy. The irradiated dosimeters were optically analyzed by using a UV- vis spectrophotometer to evaluate dose response. Absorbance of the dosimeters linearly increased in the dose range from 0 to 10 Gy, in which dose sensitivity increased with increasing 9G concentration. The dose sensitivity of the dosimeters with 2 wt% HEMA and 3 wt% 9G was also enhanced by increment in THPC.

  5. Effect of D-(+-Glucose on the Stability of Polyvinyl Alcohol Fricke Hydrogel Three-Dimensional Dosimeter for Radiotherapy

    Directory of Open Access Journals (Sweden)

    Yuejiao Yang

    2016-06-01

    Full Text Available D-(+-glucose (Glc was added to the original Fricke polyvinyl alcohol–glutaraldehyde–xylenol orange (FPGX hydrogel dosimeter system to make a more stable FPGX hydrogel three-dimensional dosimeter in this paper. Polyvinyl alcohol was used as a substrate, which was combined with Fricke solution. Various concentrations of Glc were tested with linear relevant fitting for optimal hydrogel production conditions. The effects of various formulations on the stability and sensitivity of dosimeters were evaluated. The results indicated that D-(+-Glc, as a free radical scavenger, had a great effect on stabilizing the dose response related to absorbency and reducing the auto-oxidization of ferrous ions. A careful doping with Glc could slow down the color change of the dosimeter before and after radiation without any effect on the sensitivity of the dosimeter.

  6. Effect of D-(+)-glucose on the stability of polyvinyl alcohol fricke hydrogel three dimensional dosimeter for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yue Jiao; Chen, Jie; Yang, Liming; Chen, Bin; Sheng, Zhenmei; Luo, Wen Yun [School of Environmental and Chemical Engineering, Shanghai University, Shanghai (China); Chen, Jian Xin; Lu, Xun; Sui, Guo Ping [Chemical and Ionizing Radiation Metrology Institute, Shanghai Institute of Measurement and Testing Technology, Shanghai (China)

    2016-06-15

    D-(+)-glucose (Glc) was added to the original Fricke polyvinyl alcohol-glutaraldehyde-xylenol orange (FPGX) hydrogel dosimeter system to make a more stable FPGX hydrogel three-dimensional dosimeter in this paper. Polyvinyl alcohol was used as a substrate, which was combined with Fricke solution. Various concentrations of Glc were tested with linear relevant fitting for optimal hydrogel production conditions. The effects of various formulations on the stability and sensitivity of dosimeters were evaluated. The results indicated that D-(+)-Glc, as a free radical scavenger, had a great effect on stabilizing the dose response related to absorbency and reducing the auto-oxidization of ferrous ions. A careful doping with Glc could slow down the color change of the dosimeter before and after radiation without any effect on the sensitivity of the dosimeter.

  7. Feasibility of smartphone diaries and personal dosimeters to quantitatively study exposure to ultraviolet radiation in a small national sample

    DEFF Research Database (Denmark)

    Køster, Brian; Søndergaard, Jens; Nielsen, Jesper B

    2015-01-01

    studies and of smartphones as a data collection tool. MATERIALS AND METHODS: Participants were sent a dosimeter which they wore for 7 days, received a short diary questionnaire by text message each day and subsequently a longer questionnaire. Correlation between responses from questionnaire, smartphone...... diaries and dosimeters were examined. RESULTS: This study shows a 99.5% return rate (n = 205) of the dosimeters by ordinary mail and high response-rates for a smartphone questionnaire dairy. Correlation coefficients for outdoor-time reported through smartphones and dosimeters as average by week 0.62 (0...... that dosimeter studies are feasible in national settings and that smartphones are a useful tool for monitoring and collecting UV behavior data. CONCLUSION: We found diary data reported on a daily basis through smartphones more strongly associated with actual outdoor time than questionnaire data. Our results...

  8. On preserving robustness-false alarm tradeoff in media hashing

    Science.gov (United States)

    Roy, S.; Zhu, X.; Yuan, J.; Chang, E.-C.

    2007-01-01

    This paper discusses one of the important issues in generating a robust media hash. Robustness of a media hashing algorithm is primarily determined by three factors, (1) robustness-false alarm tradeoff achieved by the chosen feature representation, (2) accuracy of the bit extraction step and (3) the distance measure used to measure similarity (dissimilarity) between two hashes. The robustness-false alarm tradeoff in feature space is measured by a similarity (dissimilarity) measure and it defines a limit on the performance of the hashing algorithm. The distance measure used to compute the distance between the hashes determines how far this tradeoff in the feature space is preserved through the bit extraction step. Hence the bit extraction step is crucial, in defining the robustness of a hashing algorithm. Although this is recognized as an important requirement by all, to our knowledge there is no work in the existing literature that elucidates the effcacy of their algorithm based on their effectiveness in improving this tradeoff compared to other methods. This paper specifically demonstrates the kind of robustness false alarm tradeoff achieved by existing methods and proposes a method for hashing that clearly improves this tradeoff.

  9. User image mismatch in anaesthesia alarms: a cognitive systems analysis.

    Science.gov (United States)

    Raymer, Karen E; Bergström, Johan

    2013-01-01

    In this study, principles of Cognitive Systems Engineering are used to better understand the human-machine interaction manifesting in the use of anaesthesia alarms. The hypothesis is that the design of the machine incorporates built-in assumptions of the user that are discrepant with the anaesthesiologist's self-assessment, creating 'user image mismatch'. Mismatch was interpreted by focusing on the 'user image' as described from the perspectives of both machine and user. The machine-embedded image was interpreted through document analysis. The user-described image was interpreted through user (anaesthesiologist) interviews. Finally, an analysis was conducted in which the machine-embedded and user-described images were contrasted to identify user image mismatch. It is concluded that analysing user image mismatch expands the focus of attention towards macro-elements in the interaction between man and machine. User image mismatch is interpreted to arise from complexity of algorithm design and incongruity between alarm design and tenets of anaesthesia practice. Cognitive system engineering principles are applied to enhance the understanding of the interaction between anaesthesiologist and alarm. The 'user image' is interpreted and contrasted from the perspectives of machine as well as the user. Apparent machine-user mismatch is explored pertaining to specific design features.

  10. Nano-barium–strontium sulfate as a new thermoluminescence dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Aboelezz, E., E-mail: eslam_genius@hotmail.com [Department of Ionizing Radiation, National Institute for Standards, El-Giza (Egypt); Sharaf, M.A.; Hassan, G.M. [Department of Ionizing Radiation, National Institute for Standards, El-Giza (Egypt); El-Khodary, A. [Department of Physics, Faculty of Science, Mansoura University (Egypt)

    2015-10-15

    A sensitive thermoluminescence (Ba{sub 0.88}Sr{sub 0.12}SO{sub 4}){sub 99.8%}:Eu{sub 0.2%} (B88) nano-phosphor has been prepared using the chemical co-precipitation method. A comparative study of B88 nanophosphor with its corresponding prepared micro-crystalline form has been made. The dose response of nano-B88, to γ-ray in low and intermediate ranges, was studied in comparison with micro-phase and reference material (TL-700H). The supralinearity factors for nano/micro-B88 and TL-700H are calculated and compared between them along both low and intermediate dose ranges. The lower detection limit of dose calculation (D{sub LDL}) method is compared with the detection limit (D{sub DL}) and critical level (D{sub CL}) of dose calculation algorithm. According to B88 energy dependence study, it is energy dependent for all photon energies except from 0.8 to 4 MeV due to their high value of effective atomic number (Z{sub eff}=43.5). Nano-B88 is sensitive to light, so the nano-B88 should be stored in dark region away from any source of visible and UV-light. The fading and reusability studies of both nano/micro-B88 samples are also included. The combined and expanded uncertainties that accompanied the radiation dose measurements are calculated. - Highlights: • A comparative study of nano/micro-B88 form has been made. • The sensitivity of both phases for B88 in low range of dose is ≈50 times TL-700H. • The lower detection limit of dose calculation was found to be ≈135 μGy for nano-B88. • B88 is energy independent for photon energies ranging from 0.8 to 4 MeV. • Nano-B88 can be used as a good TL dosimeter in radiation dosimetry.

  11. Reduction of clinically irrelevant alarms in patient monitoring by adaptive time delays.

    Science.gov (United States)

    Schmid, Felix; Goepfert, Matthias S; Franz, Frank; Laule, David; Reiter, Beate; Goetz, Alwin E; Reuter, Daniel A

    2017-02-01

    The problem of high rates of false alarms in patient monitoring in anesthesiology and intensive care medicine is well known but remains unsolved. False alarms desensitize the medical staff, leading to ignored true alarms and reduced quality of patient care. A database of intra-operative monitoring data was analyzed to find characteristic alarm patterns. The original data were re-evaluated to find relevant events and to rate the severity of these events. Based on this analysis an adaptive time delay was developed that individually delays the alarms depending on the grade of threshold deviation. The conventional threshold algorithm led to 4893 alarms. 3515 (71.84 %) of these alarms were annotated as clinically irrelevant. In total 81.0 % of all clinically irrelevant alarms were caused by only mild and/or brief threshold violations. We implemented the new algorithm for selected parameters. These parameters equipped with adaptive validation delays led to 1729 alarms. 931 (53.85 %) alarms were annotated as clinically irrelevant. 632 alarms indicated the 645 clinically relevant events. The positive predictive value of occurring alarms improved from 28.16 % (conventional algorithm) to 46.15 % (new algorithm). 13 events were missed. The false positive alarm reduction rate of the algorithm ranged from 33 to 86.75 %. The overall reduction was 73.51 %. The implementation of this algorithm may be able to suppress a large percentage of false alarms. The effect of this approach has not been demonstrated but shows promise for reducing alarm fatigue. Its safety needs to be proven in a prospective study.

  12. Increasing smoke alarm operability through theory-based health education: a randomised trial

    Science.gov (United States)

    Miller, Ted R; Bergen, Gwen; Ballesteros, Michael F; Bhattacharya, Soma; Gielen, Andrea Carlson; Sheppard, Monique S

    2015-01-01

    Background Although working smoke alarms halve deaths in residential fires, many households do not keep alarms operational. We tested whether theory-based education increases alarm operability. Methods Randomised multiarm trial, with a single arm randomly selected for use each day, in low-income neighbourhoods in Maryland, USA. Intervention arms: (1) Full Education combining a health belief module with a social-cognitive theory module that provided hands-on practice installing alarm batteries and using the alarm’s hush button; (2) Hands-on Practice social-cognitive module supplemented by typical fire department education; (3) Current Norm receiving typical fire department education only. Four hundred and thirty-six homes recruited through churches or by knocking on doors in 2005–2008. Followup visits checked alarm operability in 370 homes (85%) 1–3.5 years after installation. Main outcome measures: number of homes with working alarms defined as alarms with working batteries or hard-wired and number of working alarms per home. Regressions controlled for alarm status preintervention; demographics and beliefs about fire risks and alarm effectiveness. Results Homes in the Full Education and Practice arms were more likely to have a functioning smoke alarm at follow-up (OR=2.77, 95% CI 1.09 to 7.03) and had an average of 0.32 more working alarms per home (95% CI 0.09 to 0.56). Working alarms per home rose 16%. Full Education and Practice had similar effectiveness (p=0.97 on both outcome measures). Conclusions Without exceeding typical fire department installation time, installers can achieve greater smoke alarm operability. Hands-on practice is key. Two years after installation, for every three homes that received hands-on practice, one had an additional working alarm. Trial registration number http://www.clinicaltrials.gov number NCT00139126. PMID:25165090

  13. An Evidence-Based Approach to Reducing Cardiac Telemetry Alarm Fatigue.

    Science.gov (United States)

    Srinivasa, Ekta; Mankoo, Jaspreet; Kerr, Charles

    2017-08-01

    It is estimated that between 80% and 99% of alarms in the clinical areas are in actionable alarms (Gross, Dahl, & Nielson). Alarm management is one of the Joint Commission's National Patient Safety Goals (2014) because sentinel events have directly been linked to the devices generating these alarms. At an acute care facility in Boston, a multidisciplinary team consisting of Nursing, Biomedical Engineers, Patient Safety and Providers was formed to conduct a pilot study on the state of telemetry alarms on a surgical floor. An evidence-based approach was taken utilizing Philips Real-time data exporter alarms tracking software to capture all telemetry alarms during a 43-day time span. Likewise, noise meters were placed near telemetry alarm speakers to track decibel levels within the aforementioned timeframe for 21 days. Analysis of the data showed that clinically insignificant Premature Ventricular Contractions (PVC) alarms accounted for more than 40% of all alarms in the unit within the time span, while also contributing to an average noise level of 58.49 dB. In response to the data, the interdisciplinary team approved to permanently default the settings for PAIR PVC, MULTIFORM PVC, and RUN PVC alarms to off. The results showed a 54% decrease in the rate of alarms per bed per day, and an average noise reduction of 2.3 dB between the two selected noise measurement areas. Organizing a multidisciplinary team provides an effective framework toward analyzing and addressing cardiac telemetry alarm fatigue. Looking at quantitative datasets for clinical care areas through various lenses helps identify opportunities for improvement in regards to highlighting alarms that are not actionable. Pilot changes to alarm parameters can be tested for their environmental impact in the care area. © 2017 Sigma Theta Tau International.

  14. DLR-Biofilm - a biological weighting UV-dosimeter in medical application; Der DLR-Biofilm - ein biologisch wichtendes UV-Dosimeter in der medizinischen Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, K.; Rettberg, P.; Horneck, G.J [Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln (Germany). Inst. fuer Luft- und Raumfahrtmedizin; Schneider, L.; Wlaschek, M.; Scharffetter-Kochanek, K. [Universitaetsklinikum Koeln, Klinik und Poliklinik fuer Dermatologie und Venerologie, Koeln (Germany)

    2004-07-01

    A prototype of an optoelectronic-biological UV dosimeter was developed as a combination of DLR-Biofilm and the optoelectronic UV sensor X20001. The device was used to quantify the individual exposure during UV therapy. The obtained biologically weighted doses were compared to the UV dose given by the manufacturer of the UV therapy lamp. The endogenous parameter 8-Isoprostan obtained directly from the skin of probands showed good correlation with the measured biologically weighted dose. (orig.)

  15. Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Bryce A. [Univ. of New Mexico, Albuquerque, NM (United States)

    2009-12-01

    A detailed instructional manual was created to guide criticality safety engineers through the process of designing a criticality alarm system (CAS) for Department of Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements were both addressed. A list of design tasks and technical subtasks are thoroughly analyzed to provide concise direction for how to complete the analysis. An example of the application of the design methodology, the Criticality Alarm System developed for the Radioisotope Production Laboratory (RPL) of Richland, Washington is also included. The analysis for RPL utilizes the Monte Carlo code MCNP5 for establishing detector coverage in the facility. Significant improvements to the existing CAS were made that increase the reliability, transparency, and coverage of the system.

  16. Health and environment in Eastern Europe: an alarming diagnosis. Sante et environnement a l'Est: un diagnostic alarmant

    Energy Technology Data Exchange (ETDEWEB)

    Bonnefoy, X.

    1993-05-01

    Life-expectancy, infant and maternal mortality rates... the distance between East and West in increasing. Among the explanations: ways of life, systems of health care, socioeconomic situations or even historical fatality. But other factors can be pointed out: polluted air, water and soil - an environment whose deterioration is reason for alarm. International organizations have the job of making a diagnosis prior to any treatment.

  17. Production dosimeter LiF: Mg, Ti and comparison its responses with dosimeter LiF: Mg, Ti (TLD-100 in Harshaw company against of gamma rays

    Directory of Open Access Journals (Sweden)

    KH Mohammadi

    2010-03-01

    Full Text Available Thermoluminescence dosimeters are small tablets used with 3. 2*3. 2*0. 9mm^3 for measurement of received dose from radioactive various beams. The most common dosimeter is TLD-100 which is lithium-fluoride family and this dosimeter contain magnesium impurities. In this study, first lithium-flouride powder was mixed with titanium and controlled atmosphere samples were heated. After measuring of samples density and hardness, their glow curves were drawn and microscopic pictures of producted samples were provided. Of course, the reader should know that the best press pressure, the best range of temperature heating and the best range of samples heating were determined in 6-8 (ton/cm2, 775-800 ° C and 15-20 h, respectively [1]. Then, the response of producted TLD-100 under radiation of gamma sources, 60Co, was measured in 500 mSv rate and obtained values were compared with obtained values by Harshaw producted samples. Dosimetry characteristics of producted samples was evaluated according to ASTM E 668-00, IEC-ISO 1066 standards. The results of comparisions indicate good agreements between producted sample and Harshaw sample.

  18. A High-confidence Cyber-Physical Alarm System: Design and Implementation

    CERN Document Server

    Ma, Longhua; Xia, Feng; Xu, Ming; Yao, Jun; Shao, Meng

    2010-01-01

    Most traditional alarm systems cannot address security threats in a satisfactory manner. To alleviate this problem, we developed a high-confidence cyber-physical alarm system (CPAS), a new kind of alarm systems. This system establishes the connection of the Internet (i.e. TCP/IP) through GPRS/CDMA/3G. It achieves mutual communication control among terminal equipments, human machine interfaces and users by using the existing mobile communication network. The CPAS will enable the transformation in alarm mode from traditional one-way alarm to two-way alarm. The system has been successfully applied in practice. The results show that the CPAS could avoid false alarms and satisfy residents' security needs.

  19. Human factors engineering guidance for the review of advanced alarm systems

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.M.; Brown, W.S.; Higgins, J.C.; Stubler, W.F. [Brookhaven National Lab., Upton, NY (United States)

    1994-09-01

    This report provides guidance to support the review of the human factors aspects of advanced alarm system designs in nuclear power plants. The report is organized into three major sections. The first section describes the methodology and criteria that were used to develop the design review guidelines. Also included is a description of the scope, organization, and format of the guidelines. The second section provides a systematic review procedure in which important characteristics of the alarm system are identified, described, and evaluated. The third section provides the detailed review guidelines. The review guidelines are organized according to important characteristics of the alarm system including: alarm definition; alarm processing and reduction; alarm prioritization and availability; display; control; automated; dynamic, and modifiable characteristics; reliability, test, maintenance, and failure indication; alarm response procedures; and control-display integration and layout.

  20. Semi-supervised detection of intracranial pressure alarms using waveform dynamics.

    Science.gov (United States)

    Scalzo, Fabien; Hu, Xiao

    2013-04-01

    Patient monitoring systems in intensive care units (ICU) are usually set to trigger alarms when abnormal values are detected. Alarms are generated by threshold-crossing rules that lead to high false alarm rates. This is a recognized issue that causes alarm fatigue, waste of human resources, and increased patient risks. Recently developed smart alarm models require alarms to be validated by experts during the training phase. The manual annotation process involved is time-consuming and virtually impossible to achieve for the thousands of alarms recorded in the ICU every week. To tackle this problem, we investigate in this study if the use of semi-supervised learning methods, that can naturally integrate unlabeled data samples in the model, can be used to improve the accuracy of the alarm detection. As a proof of concept, the detection system is evaluated on intracranial pressure (ICP) signal alarms. Specific morphological and trending features are extracted from the ICP signal waveform to capture the dynamic of the signal prior to alarms. This study is based on a comprehensive dataset of 4791 manually labeled alarms recorded from 108 neurosurgical patients. A comparative analysis is provided between kernel spectral regression (SR-KDA) and support vector machine (SVM) both modified for the semi-supervised setting. Results obtained during the experimental evaluations indicate that the two models can significantly reduce false alarms using unlabeled samples; especially in the presence of a restrained number of labeled examples. At a true alarm recognition rate of 99%, the false alarm reduction rates improved from 9% (supervised) to 27% (semi-supervised) for SR-KDA, and from 3% (supervised) to 16% (semi-supervised) for SVM.

  1. An experimental investigation of the effects of alarm processing and display on operator performance

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.; Brown, W. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology; Hallbert, B.; Skraaning, G. [Halden Reactor Project (Norway); Wachtel, J.; Persensky, J. [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research

    1998-03-01

    This paper describes a research program sponsored by the US Nuclear Regulatory Commission to address the human factors engineering (HFE) aspects of nuclear power plant alarm systems. The overall objective of the program is to develop HFE review guidance for advanced alarm systems. As part of this program, guidance has been developed based on a broad base of technical and research literature. In the course of guidance development, aspects of alarm system design for which the technical basis was insufficient to support complete guidance development were identified. The primary purpose of the research reported in this paper was to evaluate the effects of three of these alarm system design characteristics on operator performance in order to contribute to the understanding of potential safety issues and to provide data to support the development of design review guidance in these areas. Three alarm system design characteristics studied were (1) alarm processing (degree of alarm reduction), (2) alarm availability (dynamic prioritization and suppression), and (3) alarm display (a dedicated tile format, a mixed tile and message list format, and a format in which alarm information is integrated into the process displays). A secondary purpose was to provide confirmatory evidence of selected alarm system guidance developed in an earlier phase of the project. The alarm characteristics were combined into eight separate experimental conditions. Six, two-person crews of professional nuclear power plant operators participated in the study. Following training, each crew completed 16 test trials which consisted of two trials in each of the eight experimental conditions (one with a low-complexity scenario and one with a high-complexity scenario). Measures of process performance, operator task performance, situation awareness, and workload were obtained. In addition, operator opinions and evaluations of the alarm processing and display conditions were collected. No deficient

  2. Characterization of MOSFET dosimeters for low-dose measurements in maxillofacial anthropomorphic phantoms

    NARCIS (Netherlands)

    Koivisto, J.H.; Wolff, J.E.; Kiljunen, T.; Schulze, D.; Kortesniemi, M.

    2015-01-01

    The aims of this study were to characterize reinforced metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to assess the measurement uncertainty, single exposure low-dose limit with acceptable accuracy, and the number of exposures required to attain the corresponding limit of the t

  3. Design and fabrication of an optical dosimeter for UV and gamma irradiation

    CERN Document Server

    Ramirez-Nino, J; Castano, V M

    1999-01-01

    A simple UV and gamma radiation optical dosimeter is presented. The organic dye degradation with radiation absorption is used to measure the radiation dose. The design, the electronic circuit, the calibration and the operation procedure are also described in detail. Finally, the results of actual applications are shown with beta-carotene in an acetone/ethanol solution utilised as an optical probe.

  4. Investigation of nanoscale structures by small-angle X-ray scattering in a radiochromic dosimeter

    DEFF Research Database (Denmark)

    Skyt, Peter Sandegaard; Jensen, Grethe Vestergaard; Wahlstedt, Isak Hannes

    2014-01-01

    of the dosimeter. When omitting gelatin, ellipsoidal micelles of SDS were formed with a core radius near 15 Å, an eccentricity of 1.6, and a head-group shell thickness near 7 Å. Gelatin significantly changed the micelles to a cylindrical shape with around three times lower core radius and four times larger shell...

  5. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 1998

    Energy Technology Data Exchange (ETDEWEB)

    SR Bivins; GA Stoetzel

    1999-06-17

    In January 1993, Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM). The purpose of the program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the RCM, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-1997 confirmed that personnel dosimetry was not needed for individuals located in areas monitored by the program. A total of 97 area thermoluminescent dosimeters (TLDs) were placed in PNNL facilities during calendar year 1998. The TLDs were exchanged and analyzed quarterly. All routine area monitoring TLD results were less than 50 mrem annually after correcting for worker occupancy. The results support the conclusion that personnel dosimeters are not necessary for staff, declared pregnant workers, minors, or members of the public in these monitored areas.

  6. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 1999

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Steven R.; Stoetzel, Gregory A.

    2000-09-19

    In January 1993, PNNL established an area monitoring dosimeter program in accordance with Article 514 of the DOE Radiological Control Manual. This program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-1998 confirmed that personnel dosimetry was not needed for individuals located in areas monitored by the program. A total of 123 area thermoluminescent dosimeters (TLDs) were placed in PNNL facilities during calendar year 1999. The TLDs were exchanged and analyzed quarterly. All routine area monitoring TLD results were less than 50 mrem annually after correcting for worker occupancy. The results support the conclusion that personnel dosimeters are not necessary for staff, declared pregnant workers, minors, or members of the public in these monitored areas.

  7. Film dosimeters based on methylene blue and methyl orange in polyvinyl alcohol

    DEFF Research Database (Denmark)

    Chung, W.H.; Miller, A.

    1994-01-01

    Polyvinyl alcohol (PVA) films containing methylene blue and methyl orange are useful as gamma and electron radiation dosimeters. Absorbed doses should not exceed 40 kGy for methylene blue and 500 kGy for methyl orange. Because PVA is water-soluble, the films may be made without toxic solvents. Th...

  8. Characteristics of polyacrylamide gel with THPC and Turnbull Blue gel dosimeters evaluated using optical tomography

    Science.gov (United States)

    Pilařová (Vávrů), Kateřina; Kozubíková, Petra; Šolc, Jaroslav; Spěváček, Václav

    2014-11-01

    The purpose of this study was to compare characteristics of radiochromic gel - Turnbull Blue gel (TB gel) with polymer gel - polyacrylamide gel and tetrakis hydroxymethyl phosphonium chloride (PAGAT) using optical tomography. Both types of gels were examined in terms of dose sensitivity, dose response linearity and background value of spectrophotometric absorbance. The calibration curve was obtained for 60Co irradiation performed on Gammacell 220 at predefined gamma dose levels between 0 and 140 Gy for TBG and 0-15 Gy for PAGAT. To measure relative dose distributions from stereotactic irradiation, dosimeters were irradiated on Leksell Gamma Knife Perfexion. The cylindrical glass housings filled with gel were attached to the stereotactic frame. They were exposed with single shot and 16 mm collimator by 65 Gy to a 50% prescription isodose for TB gel and 4 Gy to a 50% prescription isodose for PAGAT. Evaluations of dosimeters were performed on an UV-vis Spectrophotometer Helios β and an optical cone beam homemade tomography scanner with a 16-bit astronomy CCD camera with a set of color filters. The advantages and potential disadvantages for both types of gel dosimeters were summarized. Dose distribution in central slice and measured profiles of 16 mm shot shows excellent correspondence with treatment planning system Leksell GammaPlan® for both PAGAT and Turnbull Blue gels. Gel dosimeters are suitable for steep dose gradient verification. An optical tomography evaluation method is successful. Dose response characteristics of TB gel and PAGAT gel are presented.

  9. Area monitoring dosimeter program for the Pacific Northwest National Laboratory: Results for CY 1997

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, S.R.; Stoetzel, G.A.

    1998-07-01

    In January 1993, Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the US Department of Energy (DOE) Radiological Control Manual (RCM). The purpose of the program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)--(3) and Article 511.1 of the RCM, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years (CY) 1993--1996 confirmed that personnel dosimetry was not needed for individuals located in areas monitored by the program. A total of 93 area thermoluminescent dosimeters (TLDs) were placed in PNNL facilities during CY 1997. The TLDs were exchanged and analyzed quarterly. All routine area monitoring TLD results were less than 50 mrem annually after correcting for worker occupancy. The results support the conclusions that personnel dosimeters are not necessary for staff, declared pregnant workers, minors, or members of the public in these monitored areas.

  10. Automatic Fiscal Stabilizers

    Directory of Open Access Journals (Sweden)

    Narcis Eduard Mitu

    2013-11-01

    Full Text Available Policies or institutions (built into an economic system that automatically tend to dampen economic cycle fluctuations in income, employment, etc., without direct government intervention. For example, in boom times, progressive income tax automatically reduces money supply as incomes and spendings rise. Similarly, in recessionary times, payment of unemployment benefits injects more money in the system and stimulates demand. Also called automatic stabilizers or built-in stabilizers.

  11. Solid-state dosimeters: A new approach for mammography measurements

    Energy Technology Data Exchange (ETDEWEB)

    Brateman, Libby F., E-mail: bratel@radiology.ufl.edu [Department of Radiology, University of Florida College of Medicine Box 100374, Gainesville, Florida 32610-0374 (United States); Heintz, Philip H. [Department of Radiology, University of New Mexico, MSC10 5530, Albuquerque, New Mexico 87131 (United States)

    2015-02-15

    Purpose: To compare responses of modern commercially available solid-state dosimeters (SStDs) used in mammography medical physics surveys for two major vendors of current digital mammography units. To compare differences in dose estimates among SStD responses with ionization chamber (IC) measurements for several target/filter (TF) combinations and report their characteristics. To review scientific bases for measurements of quantities required for mammography for traditional measurement procedures and SStDs. Methods: SStDs designed for use with modern digital mammography units were acquired for evaluation from four manufacturers. Each instrument was evaluated under similar conditions with the available mammography beams provided by two modern full-field digital mammography units in clinical use: a GE Healthcare Senographe Essential (Essential) and a Hologic Selenia Dimensions 5000 (Dimensions), with TFs of Mo/Mo, Mo/Rh; and Rh/Rh and W/Rh, W/Ag, and W/Al, respectively. Measurements were compared among the instruments for the TFs over their respective clinical ranges of peak tube potentials for kVp and half-value layer (HVL) measurements. Comparisons for air kerma (AK) and their associated relative calculated average glandular doses (AGDs), i.e., using fixed mAs, were evaluated over the limited range of 28–30 kVp. Measurements were compared with reference IC measurements for AK, reference HVLs and calculated AGD, for two compression paddle heights for AK, to evaluate scatter effects from compression paddles. SStDs may require different positioning from current mammography measurement protocols. Results: Measurements of kVp were accurate in general for the SStDs (within −1.2 and +1.1 kVp) for all instruments over a wide range of set kVp’s and TFs and most accurate for Mo/Mo and W/Rh. Discrepancies between measurements and reference values were greater for HVL and AK. Measured HVL values differed from reference values by −6.5% to +3.5% depending on the SStD and

  12. Characteristics of a novel polymer gel dosimeter formula for MRI scanning: Dosimetry, toxicity and temporal stability of response.

    Science.gov (United States)

    Abtahi, S M

    2016-09-01

    The present study intended to investigate the composition of a new polymer gel dosimeter. The new composition would be more suitable for a wide range of applications in comparison to polyacrylamide gel dosimeter since its extremely toxic acrylamide has been replaced with less harmful monomer i.e. 2-Acrylamido-2-MethylPropane Sulfonic acid (AMPS). To this end, the PAGAT gel dosimeter formula was used as a basis to test the new formulation of polymer gel dosimeter with a different monomer (AMPS) instead of acrylamide by using the %6T and %50C to the formula. The new formulation was named PAMPSGAT (Poly AMPS, Gelatin and THPC) polymer gel dosimeter. Moreover, the MRI response (R2) of dosimeters was analyzed in terms of different dose range as well as post-irradiation time. The results indicated that the dose-response (R2) of AMPS/Bis had a linear trend over a wide dose range. Furthermore, the results showed an acceptable temporal stability for the new polymer gel dosimeter.

  13. Determining the applicability of the Landauer nanoDot as a general public dosimeter in a research imaging facility.

    Science.gov (United States)

    Charlton, Michael A; Thoreson, Kelly F; Cerecero, Jennifer A

    2012-11-01

    The Research Imaging Institute (RII) building at the University of Texas Health Science Center at San Antonio (UTHSCSA) houses two cyclotron particle accelerators, positron emission tomography (PET) machines, and a fluoroscopic unit. As part of the radiation protection program (RPP) and meeting the standard for achieving ALARA (as low as reasonably achievable), it is essential to minimize the ionizing radiation exposure to the general public through the use of controlled areas and area dose monitoring. Currently, thirty-four whole body Luxel+ dosimeters, manufactured by Landauer, are being used in various locations within the RII to monitor dose to the general public. The intent of this research was to determine if the nanoDot, a single point dosimeter, can be used as a general public dosimeter in a diagnostic facility. This was tested by first verifying characteristics of the nanoDot dosimeter including dose linearity, dose rate dependence, angular dependence, and energy dependence. Then, the response of the nanoDot dosimeter to the Luxel+ dosimeter when placed in a continuous, low dose environment was investigated. Finally, the nanoDot was checked for appropriate response in an acute, high dose environment. Based on the results, the current recommendation is that the nanoDot should not replace the Luxel+ dosimeter without further work to determine the energy spectra in the RII building and without considering the limitation of the microStar reader, portable on-site OSL reader, at doses below 0.1 mGy (10 mrad).

  14. Automatic differentiation bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, G.F. (comp.)

    1992-07-01

    This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.

  15. 基于ATmega16的GSM家居安防报警器%GSM Home Alarm System based on ATmega16

    Institute of Scientific and Technical Information of China (English)

    卞建勇; 杨润丰; 杨洋; 朱彩莲

    2011-01-01

    The demand of home alarm systems, including remote control for fire alarm, theft alarm and home appliances, is growing increasingly. As mobile phone is a popular and portable communication tool for residents, an automatic SMS home alarm system based on GSM technology was designed, which offer a remote control service via mobile phone for fire, intruder alarm and home appliance. The host controller is a microcontroller (AVR ATmega16) connecting with an external GSM module. SMS operation with password request can set eight mobile phone numbers for authorized users and the alarm message in Chinese. Wireless communication interface is used for infrared and microwave sensors for fire and intruder monitoring. In addition, wireless controlled relay with two output ends for linkage power, video recording, etc. Finally, experimental results demonstrate the effectiveness of the home alarm system.%当前人们对家居防火、防盗以及对家用电器远程控制的需求日益提升,同时手机已经成为居民随身携带的通信工具,基于此设计了一种基于GSM模块的能够通过手机对家用电器进行远程控制的集火灾、入侵报警于一体的自动短信安防报警系统.该系统由AVR ATmega16单片机外接GSM模块作为控制主机,由短信带密码操作,可设定8组用户电话号码,可中文短信报警,带有红外微波双鉴防盗和火灾检测无线通信接口,有2路无线控制继电器输出端,可联动电源,录像等工作.最后经实测表明系统具有很好的检测效果.

  16. Molecular structure effects on the post irradiation diffusion in polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Mattea, F.; Romero, M.; Strumia, M. [Instituto Multidisciplinario de Biologia Vegetal / CONICET, Universidad Nacional de Cordoba, Departamento de Quimica Organica, Ciudad Universitaria, 5000 Cordoba (Argentina); Vedelago, J. [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Quiroga, A. [Centro de Investigacion y Estudios de Matematica / CONICET, Oficina 318 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Valente, M., E-mail: fmattea@gmail.com [Instituto de Fisica E. Gaviola / CONICET, LIIFAMIRx, Oficina 102 FaMAF - UNC, 5000 Cordoba (Argentina)

    2014-08-15

    Polymer gel dosimeters have specific advantages for recording 3D radiation dose distribution representing a key factor for most of the therapeutic and diagnostic radiation techniques. Radiation-induced polymerization and crosslinking reactions that take place in the dosimeter have been studied for different monomers like acrylamide and N,N-methylene-bis acrylamide (Bis) and most recently for less toxic monomers like N-isopropylacrylamide and Bis. In this work a novel system based on itaconic acid and Bis is proposed, the radical polymerization or gel formation of these monomers has been already studied for the formation of an hydrogel for non dosimetric applications and their reactivity are comparable with the already mentioned systems. Although the 3D structure is maintained after the dosimeter has been irradiated, it is not possible to eliminate the diffusion of the reacted and monomer species in regions of dose gradients within the gel after irradiation. As a consequence the dose information of the dosimeters loose quality over time. The mobility within the gelatin structure of the already mentioned species is related to their chemical structure, and nature. In this work the effect of changes in the chemical structure of the monomers over the dosimetric sensitivity and over the post-irradiation diffusion of species is studied. One of the acrylic acid groups of the itaconic acid molecule is modified to obtain molecules with similar reactivity but different molecular sizes. Dosimetric systems with these modified species, Bis, an antioxidant to avoid oxygen polymerization inhibition, water and gelatin are irradiated in an X-ray tomography at different doses, and the resulting dosimeters are characterized by Raman spectroscopy and optical absorbance to study their feasibility and capabilities as dosimetric systems, and by optical-CT to analyze the diffusion degree after being irradiated. (Author)

  17. Development of a high efficiency personal/environmental radon dosimeter using polycarbonate detectors.

    Science.gov (United States)

    Taheri, M; Jafarizadeh, M; Baradaran, S; Zainali, Gh

    2006-12-01

    Passive radon dosimeters, based on alpha particle etched track detectors, are widely used for the assessment of radon exposure. These methods are often applied in radon dosimetry for long periods of time. In this research work, we have developed a highly efficient method of personal/environmental radon dosimetry that is based upon the detection of alpha particles from radon daughters, (218)Po and (214)Po, using a polycarbonate detector (PC). The radon daughters are collected on the filter surface by passing a fixed flow of air through it and the PC detector, placed at a specified distance from the filter, is simultaneously exposed to alpha particles. After exposure, the latent tracks on the detector are made to appear by means of an electrochemical etching process; these are proportional to the radon dose. The air flow rate and the detector-filter distance are the major factors that can affect the performance of the dosimeter. The results obtained in our experimental investigations have shown that a distance of 1.5 cm between the detector and the filter, an absorber layer of Al with a thickness of 12 microm and an air flow rate of 4 l min(-1) offer the best design parameters for a high efficiency radon dosimeter. Then, the designed dosimeter was calibrated against different values of radon exposures and the obtained sensitivity was found to be 2.1 (tracks cm(-2)) (kBq h m(-3))(-1). The most important advantages of this method are that it is reliable, fast and convenient when used for radon dose assessment. In this paper, the optimized parameters of the dosimeter structure and its calibration procedure are presented and discussed.

  18. Integration of criticality alarm system at a fuel manufacturing facility

    Energy Technology Data Exchange (ETDEWEB)

    Longinov, M.; Pant, A. [Zircatec Precision Industries, Port Hope, Ontario (Canada)

    2005-07-01

    In response to the Power Uprate program at Bruce Power, Zircatec has committed to introduce, by Spring 2006 a new manufacturing line for the production of 43 element CANFLEX bundles containing Slightly Enriched Uranium (SEU) with a centre pin of blended dysprosia/urania (BDU). This is a new fuel design and is the first change in fuel design since the introduction of the current 37 element fuel over 20 years ago. As the primary fuel supplier to the reactor site that has chosen to utilize this new fuel design, Zircatec has agreed to manufacture and supply this new fuel at their facility in Port Hope, Ontario. Under this agreement, Zircatec is challenged with converting a fuel manufacturing facility to include the processing of enriched uranium. The challenge is to introduce the new concept of criticality control to a facility that traditionally does not have to deal with such a concept. One of the elements of the implementation is the criticality detection and alarm system - CIDAS. Since a criticality could go undetected by human senses, one of the methods of ensuring safety from radiation exposure in the event of a criticality is the installation of a criticality incident detection and alarm system. This early warning device could be the difference between low dose exposure and lethal exposure. This paper describes the challenges that Zircatec has faced with the installation of a criticality incident detection and alarm system. These challenges include determining the needs and requirements, determining appropriate specifications, selecting the right equipment, installing the equipment and training personnel in the operation of the new equipment. (author)

  19. Reverse-engineering a detector with false alarms

    Science.gov (United States)

    Craver, Scott; Yu, Jun

    2007-02-01

    Inspired by results from the Break Our Watermarking System (BOWS) contest, we explored techniques to reverse-engineer watermarking algorithms via oracle attacks. We exploit a principle called "superrobustness," which allows a watermarking algorithm to be characterized by its resistance to specific distortions. The generic application of this principle to an oracle attack seeks to find a severe false alarm, or a point on the watermark detection region as far as possible from the watermarked image. For specific types of detection regions, these severe false positives can leak information about the feature space as well as detector parameters. We explore the specific case of detectors using normalized correlation, or correlation coefficient.

  20. Detecting outliers in multivariate data while controlling false alarm rate

    Directory of Open Access Journals (Sweden)

    André Achim

    2012-06-01

    Full Text Available Outlier identification often implies inspecting each z-transformed variable and adding a Mahalanobis D^2. Multiple outliers may mask each other by increasing variance estimates. Caroni and Prescott (1992 proposed a multivariate extension of Rosner’s (1983 technique to circumvent masking, taking sample size into account to keep the false alarm risk below, say, alpha = .05. Simulations studies here compare the single multivariate approach to "multiple-univariate plus multivariate" tests, each at a Bonferroni corrected alpha level, in terms of power at detecting outliers. Results suggest the former is better only up to about 12 variables. Macros in an Excel spreadsheet implement these techniques.

  1. Miniaturized, low power FGMOSFET radiation sensor and wireless dosimeter system

    KAUST Repository

    Arsalan, Muhammad

    2013-08-27

    A miniaturized floating gate (FG) MOSFET radiation sensor system is disclosed, The sensor preferably comprises a matched pair of sensor and reference FGMOSFETs wherein the sensor FGMOSFET has a larger area floating gate with an extension over a field oxide layer, for accumulation of charge and increased sensitivity. Elimination of a conventional control gate and injector gate reduces capacitance, and increases sensitivity, and allows for fabrication using standard low cost CMOS technology. A sensor system may be provided with integrated signal processing electronics, for monitoring a change in differential channel current I.sub.D, indicative of radiation dose, and an integrated negative bias generator for automatic pre-charging from a low voltage power source. Optionally, the system may be coupled to a wireless transmitter. A compact wireless sensor System on Package solution is presented, suitable for dosimetry for radiotherapy or other biomedical applications.

  2. An evaluation of Genipin gel as a water equivalent dosimeter for megavoltage electron beams and kilovoltage x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Bosi, Stephen; Baldock, Clive, E-mail: clive.baldock@sydney.edu.a

    2010-11-01

    Genipin gel is a radiochromic gel with the potential to be used as a three dimensional (3D) dosimeter. An ideal dosimeter should present radiologically water equivalent properties. In this work, we have evaluated the water equivalency of genipin gel by calculating its radiological properties, such as mass and electron density, effective atomic number, fractional interaction probabilities, mass energy absorption coefficient and mass stopping powers as well as depth doses for kilovoltage x-ray and megavoltage electron beams. Based on the results of this study, we conclude that genipin gel is a water equivalent dosimeter.

  3. Behavioural implications of alarm mistrust as a function of task workload.

    Science.gov (United States)

    Bliss, J P; Dunn, M C

    2000-09-01

    The research was conducted to investigate the effect of increasing primary task and alarm workload on alarm mistrust as reflected by alarm and primary task performances. A total of 126 undergraduate students performed a complex psychomotor task battery three times, with the number of concurrent tasks increasing each time. During their performance, the students were required to react to an alarm system (including visual and auditory components) of questionable reliability. Depending on the group to which participants were assigned, the alarm presentation rate constituted a low-, medium- or high-workload condition. Alarm response data (times, frequencies, accuracies) and primary task data (tracking error) were analyzed to assess performance differences as a function of primary and secondary task workload levels. Results generally supported the hypotheses: increasing primary task and alarm task workload degraded alarm response performance. Also, response frequencies supported earlier research suggesting that participants 'probability match' their response rates to alarm system reliability. The results are discussed with regard to the cry-wolf effect, attention theory and alarm system design.

  4. Isolation of a pyrazine alarm pheromone component from the fire ant, Solenopsis invicta.

    Science.gov (United States)

    Vander Meer, Robert K; Preston, Catherine A; Choi, Man-Yeon

    2010-02-01

    Alarm pheromones in social insects are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality. The alarm pheromones of ants were among the first examples of animal pheromones identified, primarily because of the large amount of chemical produced and the distinctive responses of ants to the pheromone. However, the alarm pheromone of the fire ant, Solenopsis invicta, eluded identification for over four decades. We identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of S. invicta. Worker fire ants detect the pyrazine alarm pheromone at 30 pg/ml, which is comparable to alarm pheromone sensitivities reported for other ant species. The source of this alarm pheromone are the mandibular glands, which, in fire ants, are not well developed and contain only about 300 pg of the compound, much less than the microgram quantities of alarm pheromones reported for several other ant species. Female and male sexuals and workers produce the pyrazine, which suggests that it may be involved in fire ant mating flight initiation, as well as the typical worker alarm response. This is the first report of 2-ethyl-3,6-dimethylpyrazine from a Solenopsis species and the first example of this alkaloid functioning as an alarm pheromone.

  5. Alarm Pheromone Composition and Behavioral Activity in Fungus-Growing Ants.

    Science.gov (United States)

    Norman, Victoria C; Butterfield, Thomas; Drijfhout, Falko; Tasman, Kiah; Hughes, William O H

    2017-03-01

    Chemical communication is a dominant method of communication throughout the animal kingdom and can be especially important in group-living animals in which communicating threats, either from predation or other dangers, can have large impacts on group survival. Social insects, in particular, have evolved a number of pheromonal compounds specifically to signal alarm. There is predicted to be little selection for interspecific variation in alarm cues because individuals may benefit from recognizing interspecific as well as conspecific cues and, consequently, alarm cues are not normally thought to be used for species or nestmate recognition. Here, we examine the composition of the alarm pheromones of seven species of fungus-growing ants (Attini), including both basal and derived species and examine the behavioral responses to alarm pheromone of Acromyrmex leaf-cutting ants, the sister genus to the highly studied Atta leaf-cutting ants. We find surprisingly high interspecific variation in alarm pheromone composition across the attine phylogeny. Interestingly, the active component of the alarm pheromone was different between the two leaf-cutting ant genera. Furthermore, in contrast to previous studies on Atta, we found no differences among morphological castes in their responses to alarm pheromone in Acromyrmex but we did find differences in responses among putative age classes. The results suggest that the evolution of alarm communication and signaling within social insect clades can be unexpectedly complex and that further work is warranted to understand whether the evolution of different alarm pheromone compounds is adaptive.

  6. Signal Quality Analysis of Ambulatory Electrocardiograms to Gate False Myocardial Ischemia Alarms.

    Science.gov (United States)

    Abdelazez, Mohamed; Quesnel, Patrick X; Chan, Adrian D C; Yang, Homer

    2017-06-01

    The objective of this study is to propose and validate an alarm gating system for a myocardial ischemia monitoring system that uses ambulatory electrocardiogram. The PeriOperative ISchemic Evaluation study recommended the selective administration of β blockers to patients at risk of cardiac events following noncardiac surgery. Patients at risk are identified by monitoring ST segment deviations in the electrocardiogram (ECG); however, patients are encouraged to ambulate to improve recovery, which deteriorates the signal quality of the ECG leading to false alarms. The proposed alarm gating system computes a signal quality index (SQI) to quantify the ECG signal quality and rejects alarms with a low SQI. The system was validated by artificially contaminating ECG records with motion artifact records obtained from the long-term ST database and MIT-BIH noise stress test database, respectively. Without alarm gating, the myocardial ischemia monitoring system attained a Precision of 0.31 and a Recall of 0.78. The alarm gating improved the Precision to 0.58 with a reduction of Recall to 0.77. The proposed system successfully gated false alarms with future work exploring the misidentification of fiducial points by myocardial ischemia monitoring systems. The reduction of false alarms due to the proposed system will decrease the incidence of the alarm fatigue condition typically found in clinicians. Alarm fatigue condition was rated as the top patient safety hazard from 2012 to 2015 by the Emergency Care Research Institute.

  7. Correlating data from different sensors to increase the positive predictive value of alarms: an empiric assessment.

    Science.gov (United States)

    Bitan, Yuval; O'Connor, Michael F

    2012-01-01

    Alarm fatigue from high false alarm rate is a well described phenomenon in the intensive care unit (ICU). Progress to further reduce false alarms must employ a new strategy. Highly sensitive alarms invariably have a very high false alarm rate. Clinically useful alarms have a high Positive-Predictive Value. Our goal is to demonstrate one approach to suppressing false alarms using an algorithm that correlates information across sensors and replicates the ways that human evaluators discriminate artifact from real signal. After obtaining IRB approval and waiver of informed consent, a set of definitions, (hypovolemia, left ventricular shock, tamponade, hemodynamically significant ventricular tachycardia, and hemodynamically significant supraventricular tachycardia), were installed in the monitors in a 10 bed cardiothoracic ICU and evaluated over an 85 day study period. The logic of the algorithms was intended to replicate the logic of practitioners, and correlated information across sensors in a way similar to that used by practitioners. The performance of the alarms was evaluated via a daily interview with the ICU attending and review of the tracings recorded over the previous 24 hours in the monitor. True alarms and false alarms were identified by an expert clinician, and the performance of the algorithms evaluated using the standard definitions of sensitivity, specificity, positive predictive value, and negative predictive value. Between 1 and 221 instances of defined events occurred over the duration of the study, and the positive predictive value of the definitions varied between 4.1% and 84%. Correlation of information across alarms can suppress artifact, increase the positive predictive value of alarms, and can employ more sophisticated definitions of alarm events than present single-sensor based systems.

  8. Mediation and Automatization.

    Science.gov (United States)

    Hutchins, Edwin

    This paper discusses the relationship between the mediation of task performance by some structure that is not inherent in the task domain itself and the phenomenon of automatization, in which skilled performance becomes effortless or phenomenologically "automatic" after extensive practice. The use of a common simple explicit mediating…

  9. Automatic Differentiation Package

    Energy Technology Data Exchange (ETDEWEB)

    2007-03-01

    Sacado is an automatic differentiation package for C++ codes using operator overloading and C++ templating. Sacado provide forward, reverse, and Taylor polynomial automatic differentiation classes and utilities for incorporating these classes into C++ codes. Users can compute derivatives of computations arising in engineering and scientific applications, including nonlinear equation solving, time integration, sensitivity analysis, stability analysis, optimization and uncertainity quantification.

  10. Digital automatic gain control

    Science.gov (United States)

    Uzdy, Z.

    1980-01-01

    Performance analysis, used to evaluated fitness of several circuits to digital automatic gain control (AGC), indicates that digital integrator employing coherent amplitude detector (CAD) is best device suited for application. Circuit reduces gain error to half that of conventional analog AGC while making it possible to automatically modify response of receiver to match incoming signal conditions.

  11. Focusing Automatic Code Inspections

    NARCIS (Netherlands)

    Boogerd, C.J.

    2010-01-01

    Automatic Code Inspection tools help developers in early detection of defects in software. A well-known drawback of many automatic inspection approaches is that they yield too many warnings and require a clearer focus. In this thesis, we provide such focus by proposing two methods to prioritize

  12. A NEW INVENTION OF ALARM REMINDER LOCKING (ARL SECURITY SYSTEM

    Directory of Open Access Journals (Sweden)

    M.S.M. Effendi

    2016-02-01

    Full Text Available Alarm Reminder Locking (ARL Security System mainly focuses on a door security system, which can install in the door area to increase the security level for home, office room, hostel or other places. This system used Arduino Controller and Global System for Mobile Communication (GSM technology, which is the cheapest source to embed the security system to transmit the Short Message Service (SMS alert data. This device integrates three functions that are alarming, reminder and locked for a purpose of safety and connecting via mobile phone to remind the users through SMS. This device has a 3 modes of operation which is the system will be functional when the door is not improperly closed for the first reminder with the buzzer alert. The second mode is automated locked will be activated when users closed the door, but did not lock manually. Intrusion mode will activate while auto locked modes are interrupted without proper access. All this integrated system will provide high security access against intrusion occurrence. This security device will bring a new benefit to the user to consider about the userfriendly application, low power consumption and reasonable cost to install.

  13. Elevated Carbon Dioxide Concentration Reduces Alarm Signaling in Aphids.

    Science.gov (United States)

    Boullis, Antoine; Fassotte, Bérénice; Sarles, Landry; Lognay, Georges; Heuskin, Stéphanie; Vanderplanck, Maryse; Bartram, Stefan; Haubruge, Eric; Francis, Frédéric; Verheggen, François J

    2017-02-01

    Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO2 concentrations over several generations. We found that an increase in CO2 concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO2 strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels.

  14. Evaluation of LLNL's Nuclear Accident Dosimeters at the CALIBAN Reactor September 2010

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, D P; Wysong, A R; Heinrichs, D P; Wong, C T; Merritt, M J; Topper, J D; Gressmann, F A; Madden, D J

    2011-06-21

    The Lawrence Livermore National Laboratory uses neutron activation elements in a Panasonic TLD holder as a personnel nuclear accident dosimeter (PNAD). The LLNL PNAD has periodically been tested using a Cf-252 neutron source, however until 2009, it was more than 25 years since the PNAD has been tested against a source of neutrons that arise from a reactor generated neutron spectrum that simulates a criticality. In October 2009, LLNL participated in an intercomparison of nuclear accident dosimeters at the CEA Valduc Silene reactor (Hickman, et.al. 2010). In September 2010, LLNL participated in a second intercomparison of nuclear accident dosimeters at CEA Valduc. The reactor generated neutron irradiations for the 2010 exercise were performed at the Caliban reactor. The Caliban results are described in this report. The procedure for measuring the nuclear accident dosimeters in the event of an accident has a solid foundation based on many experimental results and comparisons. The entire process, from receiving the activated NADs to collecting and storing them after counting was executed successfully in a field based operation. Under normal conditions at LLNL, detectors are ready and available 24/7 to perform the necessary measurement of nuclear accident components. Likewise LLNL maintains processing laboratories that are separated from the areas where measurements occur, but contained within the same facility for easy movement from processing area to measurement area. In the event of a loss of LLNL permanent facilities, the Caliban and previous Silene exercises have demonstrated that LLNL can establish field operations that will very good nuclear accident dosimetry results. There are still several aspects of LLNL's nuclear accident dosimetry program that have not been tested or confirmed. For instance, LLNL's method for using of biological samples (blood and hair) has not been verified since the method was first developed in the 1980's. Because LLNL and

  15. Driver behavior following an automatic steering intervention.

    Science.gov (United States)

    Fricke, Nicola; Griesche, Stefan; Schieben, Anna; Hesse, Tobias; Baumann, Martin

    2015-10-01

    The study investigated driver behavior toward an automatic steering intervention of a collision mitigation system. Forty participants were tested in a driving simulator and confronted with an inevitable collision. They performed a naïve drive and afterwards a repeated exposure in which they were told to hold the steering wheel loosely. In a third drive they experienced a false alarm situation. Data on driving behavior, i.e. steering and braking behavior as well as subjective data was assessed in the scenarios. Results showed that most participants held on to the steering wheel strongly or counter-steered during the system intervention during the first encounter. Moreover, subjective data collected after the first drive showed that the majority of drivers was not aware of the system intervention. Data from the repeated drive in which participants were instructed to hold the steering wheel loosely, led to significantly more participants holding the steering wheel loosely and thus complying with the instruction. This study seems to imply that without knowledge and information of the system about an upcoming intervention, the most prevalent driving behavior is a strong reaction with the steering wheel similar to an automatic steering reflex which decreases the system's effectiveness. Results of the second drive show some potential for countermeasures, such as informing drivers shortly before a system intervention in order to prevent inhibiting reactions.

  16. Fully automatic CNC machining production system

    Directory of Open Access Journals (Sweden)

    Lee Jeng-Dao

    2017-01-01

    Full Text Available Customized manufacturing is increasing years by years. The consumption habits change has been cause the shorter of product life cycle. Therefore, many countries view industry 4.0 as a target to achieve more efficient and more flexible automated production. To develop an automatic loading and unloading CNC machining system via vision inspection is the first step in industrial upgrading. CNC controller is adopted as the main controller to command to the robot, conveyor, and other equipment in this study. Moreover, machine vision systems are used to detect position of material on the conveyor and the edge of the machining material. In addition, Open CNC and SCADA software will be utilized to make real-time monitor, remote system of control, alarm email notification, and parameters collection. Furthermore, RFID has been added to employee classification and management. The machine handshaking has been successfully proposed to achieve automatic vision detect, edge tracing measurement, machining and system parameters collection for data analysis to accomplish industrial automation system integration with real-time monitor.

  17. Multifactorial study and kinetics of signal development in ferrous-methylthymol blue-gelatin gel dosimeters.

    Science.gov (United States)

    Penev, Kalin I; Mequanint, Kibret

    2017-05-01

    To develop and characterize a ferrous-methylthymol blue-gelatin gel dosimeter with low optical background and appropriate additives for reduced rate of auto-oxidation and diffusion. A mixed-level multifactorial design of experiments was used to test the effects of the concentrations of sulfuric acid, 5-nitro-1,10-phenanthroline (Nn), and glyoxal (Gx) on the background absorbance, dose sensitivity, and auto-oxidation of the tested gel dosimeter. The dosimetric properties of the proposed ferrous-methylthymol blue-gelatin dosimeter, doped with Nn and Gx, were compared with the undoped formulation and with ferrous-xylenol orange-gelatin gel dosimeters. Irradiations were performed in both small-scale cuvette samples and large 400-mL bulk samples. In addition to that, a new kinetic model for the signal development postirradiation was derived based on chemical principles and used for comparison of the different formulations. The new formulation showed a reduced auto-oxidation rate, while maintaining low background absorbance relative to the common ferrous-xylenol orange-gelatin gel dosimeter. Compared with undoped ferrous-xylenol orange or ferrous-methylthymol blue gels, the dose sensitivity of the new formulation is approximately 2 to 3 times lower, but remains clinically adequate. A previously unreported dose rate dependence of the dose sensitivity was observed, and a new kinetic model for the signal development postirradiation was used to investigate this effect. Similar dose rate dependences in gels containing either methylthymol blue or xylenol orange, with or without doping with Nn and Gx, were observed, suggesting that the low ferrous ammonium sulfate concentrations used in studied formulations were responsible for this effect. A multifactorial design of experiments and a new kinetic model for the signal development postirradiation were successfully employed to optimize the composition and characterize the properties of a new ferrous-methylthymol blue-gelatin gel

  18. Automatic Epileptic Seizure Onset Detection Using Matching Pursuit

    DEFF Research Database (Denmark)

    Sorensen, Thomas Lynggaard; Olsen, Ulrich L.; Conradsen, Isa

    2010-01-01

    An automatic alarm system for detecting epileptic seizure onsets could be of great assistance to patients and medical staff. A novel approach is proposed using the Matching Pursuit algorithm as a feature extractor combined with the Support Vector Machine (SVM) as a classifier for this purpose....... The combination of Matching Pursuit and SVM for automatic seizure detection has never been tested before, making this a pilot study. Data from red different patients with 6 to 49 seizures are used to test our model. Three patients are recorded with scalp electroencephalography (sEEG) and three with intracranial...... electroencephalography (iEEG). A sensitivity of 78-100% and a detection latency of 5-18s has been achieved, while holding the false detection at 0.16-5.31/h. Our results show the potential of Matching Pursuit as a feature xtractor for detection of epileptic seizures....

  19. Development of Alarm System link Drawing for Operation Support for APR1400 Digital Main Control Room

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki-Hwan [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    Digitalized MMI(Man-Machine Interface) including Digital Main Control Room(MCR) and digital I and C system was being applied for SKN 3 and 4 Nuclear Power Plant(NPP) and subsequent APR1400 NPP type. But, operators can not easily find instrument for alarm immediately. Therefore, Alarm system is required to easily find instrument for Alarm. For this implementation, we will plan system design considering design feature without affecting network load and CPU load. We have developed Alarm system link drawing for digital MCR. Operators of the digitalized MCR navigates from their consoles to the drawings related to the plant alarms and their instruments or the operation status. Such method gives cognitive load to the operators having to travel to different locations in finding the related information. Screen Sharing System, which is the fundamental technique for Drawing Interconnection Alarm System is close to completion, and it should be functionally tested and verified by the human factor engineering. For the actual application to the operating plants, the drawings to be interconnected to the alarms and the opinions from the operators/maintenance departments for designating alarm number should be surveyed, Also, another function that allows the access to the alarm related drawings not only from the MCR but also from the other offices.

  20. False alarm rates of three third-generation pulse oximeters in PACU, ICU and IABP patients.

    Science.gov (United States)

    Lutter, Norbert O; Urankar, Sabine; Kroeber, Steffi

    2002-01-01

    The objective of this clinical study was to determine alarm rates--in particular the frequency of false positive alarms--of three third-generation pulse oximeters in the postanesthesia care unit (PACU), the intensive care unit (ICU), and in patients with an intra-aortic balloon pump (IABP): Nellcor Symphony N-3000, a Masimo IVY 2000, and Agilent Viridia CMS 2000. All alarms were classified into technical/physiological and false/correct. 235 consecutive ASA physical status I-IV patients after surgery were included into the study. In the PACU false positive alarms were rare: CMS n = 60, N-3000 n = 60, Masimo n = 87. Bland-Altman testing discovered only negligible differences of alarm rates and dropout times. Out of a total of 728 alarms 67.3% were classified as false positive in ICU-patients: 97 alarms by CMS, 176 by N-3000 and 218 by Masimo SET. If IABP was present, CMS indicated a significant smaller number of false positive alarms (n = 35, 7.2%) when compared to Masimo SET (n = 188, 38.9%) and N-3000 (n = 229, 47.4%), consecutively the majority of false positive alarms (76.2%) can be rated as a result of the interference of IABP. Unless IABP (and to a considerably smaller extent cardiac arrhythmia) is present the pulse oximeters do not differ significantly regarding sensitivity and specificity.

  1. Study on the principle of intelligent helmet's electric alarm device in transmission line

    Science.gov (United States)

    Zhang, Zehao; Peng, Lin; Bao, Xingchuan; Zhu, Liang; Wang, He; Zhou, Qiang

    2017-08-01

    This thesis made study on the Principle of Intelligent Helmet's Electric Alarm Device in Transmission Line. Based on the simulation analysis of the electric field strength and electric field characteristics of three-phase 10kV transmission line, this thesis put forward the calculation method of the electric alarm distance by developing a calculation model, and then explains proof of the accuracy of intelligent helmet's electric alarm and discusses its theoretical basis. At last, the theoretical analysis' correctness and the measurement's accuracy of the intelligent helmet's electric alarm device is proved by tests.

  2. A novel algorithm for reducing false arrhythmia alarms in intensive care units.

    Science.gov (United States)

    Srivastava, Chandan; Sharma, Sonal; Jalali, Ali

    2016-08-01

    Alarm fatigue in intensive care units (ICU) is one of the top healthcare issues in the US. False alarms in ICU will decrease the quality of care and staff response time over the alarms. Normally, false alarm will cause desensitization of the clinical staff which leads to warnings and misleading, if the triggered alarm is true. In this study, we have proposed a multi-model ensemble approach to reduce the false alarm rate in monitoring systems. We have used 750 patient records from PhysioNet database. At First arrhythmia based features from electrocardiogram (ECG), arterial blood pressure (ABP) and photoplethysmogram (PPG) features were extracted from the records. Next, the dataset has been separated into two subsets on the basis of available features information. The first dataset (DS1) is the combination of ECG physiological, ABP and PPG features. Their correlation coefficient and p-values criteria have been applied for relevant alarm-wise feature-set selection, and random forest classifier was used for model development and validation. The threshold based approach was used on second dataset (DS2) which is the combination of arrhythmia, ABP and PPG features. The developed ensemble model is able to achieve sensitivity 83.33-100 % (average 95.56 %) being true alarms and suppress false alarms rate 66.67-89% (average 77.25%). The predictability of classifier shows the advantage to deal with unbalanced set of information, therefore overall model performance has reached to 83.96% accuracy.

  3. Predictive combinations of monitor alarms preceding in-hospital code blue events.

    Science.gov (United States)

    Hu, Xiao; Sapo, Monica; Nenov, Val; Barry, Tod; Kim, Sunghan; Do, Duc H; Boyle, Noel; Martin, Neil

    2012-10-01

    Bedside monitors are ubiquitous in acute care units of modern healthcare enterprises. However, they have been criticized for generating an excessive number of false positive alarms causing alarm fatigue among care givers and potentially compromising patient safety. We hypothesize that combinations of regular monitor alarms denoted as SuperAlarm set may be more indicative of ongoing patient deteriorations and hence predictive of in-hospital code blue events. The present work develops and assesses an alarm mining approach based on finding frequent combinations of single alarms that are also specific to code blue events to compose a SuperAlarm set. We use 4-way analysis of variance (ANOVA) to investigate the influence of four algorithm parameters on the performance of the data mining approach. The results are obtained from millions of monitor alarms from a cohort of 223 adult code blue and 1768 control patients using a multiple 10-fold cross-validation experiment setup. Using the optimal setting of parameters determined in the cross-validation experiment, final SuperAlarm sets are mined from the training data and used on an independent test data set to simulate running a SuperAlarm set against live regular monitor alarms. The ANOVA shows that the content of a SuperAlarm set is influenced by a subset of key algorithm parameters. Simulation of the extracted SuperAlarm set shows that it can predict code blue events one hour ahead with sensitivity between 66.7% and 90.9% while producing false SuperAlarms for control patients that account for between 2.2% and 11.2% of regular monitor alarms depending on user-supplied acceptable false positive rate. We conclude that even though the present work is still preliminary due to the usage of a moderately-sized database to test our hypothesis it represents an effort to develop algorithms to alleviate the alarm fatigue issue in a unique way. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Multi-parameter vital sign database to assist in alarm optimization for general care units.

    Science.gov (United States)

    Welch, James; Kanter, Benjamin; Skora, Brooke; McCombie, Scott; Henry, Isaac; McCombie, Devin; Kennedy, Rosemary; Soller, Babs

    2016-12-01

    Continual vital sign assessment on the general care, medical-surgical floor is expected to provide early indication of patient deterioration and increase the effectiveness of rapid response teams. However, there is concern that continual, multi-parameter vital sign monitoring will produce alarm fatigue. The objective of this study was the development of a methodology to help care teams optimize alarm settings. An on-body wireless monitoring system was used to continually assess heart rate, respiratory rate, SpO2 and noninvasive blood pressure in the general ward of ten hospitals between April 1, 2014 and January 19, 2015. These data, 94,575 h for 3430 patients are contained in a large database, accessible with cloud computing tools. Simulation scenarios assessed the total alarm rate as a function of threshold and annunciation delay (s). The total alarm rate of ten alarms/patient/day predicted from the cloud-hosted database was the same as the total alarm rate for a 10 day evaluation (1550 h for 36 patients) in an independent hospital. Plots of vital sign distributions in the cloud-hosted database were similar to other large databases published by different authors. The cloud-hosted database can be used to run simulations for various alarm thresholds and annunciation delays to predict the total alarm burden experienced by nursing staff. This methodology might, in the future, be used to help reduce alarm fatigue without sacrificing the ability to continually monitor all vital signs.

  5. Clinical Trial of an Educational Program to Decrease Monitor Alarms in a Medical Intensive Care Unit.

    Science.gov (United States)

    Brantley, Arian; Collins-Brown, Sandra; Kirkland, Jasmine; Knapp, Meghan; Pressley, Jackie; Higgins, Melinda; McMurtry, James P

    2016-07-01

    Clinical research to identify effective interventions for decreasing nonactionable alarms has been limited. The objective of this study was to determine if a staff educational program on customizing alarm settings on bedside monitors decreased alarms in a medical intensive care unit (MICU). A preintervention, postintervention, nonequivalent group design was used to evaluate an educational program on alarm management in a convenience sample of MICU nurses. A 15-minute session was provided in a 1-week period. The outcome variable (number of alarms for low oxygen saturation via pulse oximetry [SpO2]) was determined from monitor log files adjusted by patient census. Data were collected for 15 days before and after the intervention. χ(2) analysis was used, with P less than .05 considered significant. After 1 week of education, low SpO2 alarms decreased from 502 to 306 alarms per patient monitored per day, a 39% reduction (P alarm settings to patients' clinical condition decreased common monitor alarms by 39%. ©2016 American Association of Critical-Care Nurses.

  6. Non-specific alarm calls trigger mobbing behavior in Hainan gibbons (Nomascus hainanus).

    Science.gov (United States)

    Deng, Huaiqing; Gao, Kai; Zhou, Jiang

    2016-09-30

    Alarm calls are important defensive behaviors. Here, we report the acoustic spectrum characteristics of alarm calls produced by Hainan gibbons (Nomascus hainanus) inhabiting Bawangling National Nature Reserve in Hainan, China. Analysis of call data collected from 2002-2014 shows that alarm calls are emitted by all family group members, except infants. Alarm behavior included simple short alarming calls (7-10 min) followed by longer variable-frequency mobbing calls lasting 5-12 min. The duration of individual alarming and mobbing calls was 0.078 ± 0.014 s and 0.154 ± 0.041 s at frequency ranges of 520-1000 Hz and 690-3920 Hz, respectively. Alarming call duration was positively associated with group size. The alarm calls can trigger mobbing behavior in Hainan gibbons; this is a defense way of social animals, and first report among the primates' species. The system of vocal alarm behavior described in this critically endangered species is simple and effective.

  7. A Human Factors Perspective on Alarm System Research and Development 2000 to 2010

    Energy Technology Data Exchange (ETDEWEB)

    Curt Braun; John Grimes; Eric Shaver; Ronald Boring (Principal Investigator)

    2011-09-01

    By definition, alarms serve to notify human operators of out-of-parameter conditions that could threaten equipment, the environment, product quality and, of course, human life. Given the complexities of industrial systems, human machine interfaces, and the human operator, the understanding of how alarms and humans can best work together to prevent disaster is continually developing. This review examines advances in alarm research and development from 2000 to 2010 and includes the writings of trade professionals, engineering and human factors researchers, and standards organizations with the goal of documenting advances in alarms system design, research, and implementation.

  8. The Response of an Albedo Neutron Dosimeter to Moderated AmBe and 252(Cf) Neutron Sources.

    Science.gov (United States)

    2014-09-26

    neutrons is deter- mined by making multiple integrations on the glow curves from the detectors [41, or by computer analysis of the glow curves [5-61...Falk, "A Personnel Neutron Dosimeter Using Lithium Fluoride Thermoluminescent Dosim- eters," Report No. RFP-1581, Dow Chemical Co., Golden CO (1971...Addison Wesley, Reading, MA, 1953). 18. D.E. Hankins, "Factors Affecting the Design of Albedo Neutron Dosimeters Containing Lithium Fluoride

  9. Physiologic monitoring alarm load on medical/surgical floors of a community hospital.

    Science.gov (United States)

    Gross, Brian; Dahl, Deborah; Nielsen, Larry

    2011-01-01

    It has been known to the public that high frequency of false and/or unnecessary alarms from patient monitoring devices causes "alarm fatigue" in critical care. But little is known about the impact to care on the less acute patients located outside the critical care areas, such as the traditional medical/surgical (med/surg) floor. As part of a larger population management study, we initiated continuous physiological monitoring to 79 beds of floor patients in a community hospital. In order to qualify the patient monitoring alarm load for subacute medical and surgical floor patients, we assessed alarm data from April 2009 to January 2010. A standard critical care monitoring system (Philips IntelliVue MP-5 and Telemetry) was installed and set to the default alarm limits. All waveform data available for the patient (typically ECG, RESP, PPG at 125hz 8 bit), all alarm conditions declared by the monitoring system, and 1 minute parameter trend data were saved to disk every 8 hours for all patients. A monitoring care protocol was created to determine whether the patient was monitored via the hardwired bedside or wirelessly via telemetry. Alarms were not announced on the care unit but instead notifications were the responsibility of remote telehealth center personnel. We retrospectively evaluated the frequency of alarms over specific physiologic thresholds (n= 4104 patients) and conducted adjudication of all alarms based on a smaller sampling (n=30 patients). For all patients, the average hours of monitoring per patient were 16.5 hours with a standard deviation (s) of 8.3 hours and a median of 22 hours. The average number of alarms (all severities) per patient was 69.7 (s =90.3, median =28) alarms. When this is adjusted to the duration of monitoring, the average per patient, per day rate was 95.6 (s =124.2, median =34.2) alarms. The adjudicated sample (n=30 patients) resulted in 34% of critical alarms (lethal arrhythmias, extreme high or low heart rate [HR], extreme

  10. In situ ion-beam-induced luminescence analysis for evaluating a micrometer-scale radio-photoluminescence glass dosimeter

    Science.gov (United States)

    Kawabata, Shunsuke; Kada, Wataru; Parajuli, Raj Kumar; Matsubara, Yoshinori; Sakai, Makoto; Miura, Kenta; Satoh, Takahiro; Koka, Masashi; Yamada, Naoto; Kamiya, Tomihiro; Hanaizumi, Osamu

    2016-06-01

    Micrometer-scale responses of radio-photoluminescence (RPL) glass dosimeters to focused ionized particle radiation were evaluated by combining ion-beam-induced luminescence (IBIL) and proton beam writing (PBW) using a 3 MeV focused proton microbeam. RPL phosphate glass dosimeters doped with ionic Ag or Cu activators at concentrations of 0.2 and 0.1% were fabricated, and their scintillation intensities were evaluated by IBIL spectroscopy under a PBW micropatterning condition. Compared with the Ag-doped dosimeter, the Cu-doped dosimeter was more tolerant of the radiation, while the peak intensity of its luminescence was lower, under the precise dose control of the proton microprobe. Proton-irradiated areas were successfully recorded using these dosimeters and their RPL centers were visualized under 375 nm ultraviolet light. The reproduction of the irradiated region by post-RPL imaging suggests that precise estimation of irradiation dose using microdosimeters can be accomplished by optimizing RPL glass dosimeters for various proton microprobe applications in organic material analysis and in micrometer-scale material modifications.

  11. Design and construct optimum dosimeter to detect airborne radon and thoron gas: Experimental study

    Science.gov (United States)

    Ismail, Asaad H.; Jaafar, Mohamad S.

    2011-02-01

    Aim of this work is to design and select optimum dimension of a radon and thoron dosimeter within the measure optimum value of the calibration factor, using CR-39 Nuclear Track Detectors (NTDs). The results show that the best dimension to detect and measure real values of airborne radon and thoron concentrations is 6 cm and 7 cm for diameter and height, respectively. Calibration factors (K) for radon and thoron at this dimension were 2.68 ± 0.03 cm and 0.83 ± 0.01 cm, respectively, and these factors relatively depend on the detector efficiency. Therefore, the efficiency of CR-39NTDs to register alpha particles and their effects on the calibration factor estimated. It is found that the calibration factor increased exponentially with detector efficiency. Moreover, detector efficiency was equal to 80.3 ± 1.23% at the optimum dosimeter.

  12. Cyanocobalamin solutions as potential dosimeters in low-dose food irradiations.

    Science.gov (United States)

    Prakasan, Velayudhan; Sanyal, Bhaskar; Pritamdas Chawla, Surinder; Chander, Ramesh; Sharma, Arun

    2014-04-01

    Potential of aqueous solutions of cyanocobalamin in gamma radiation dosimetry was investigated. The solutions are inexpensive, nontoxic and easy-to-prepare dosimeters, which could be useful for measuring gamma radiation doses in various applications, such as quarantine treatment of fruit or insect disinfestation of grains and pulses. The optical absorbance of cyanocobalamin solutions of the optimal concentration 0.08 mM decreases with increasing radiation dose. The reproducible dependence of the absorbance decrease on the dose can be described with a polynomial. Pre- and post-irradiation stability of the solution absorbance, as well as effects of the irradiation temperature and dose rate, were studied. The response is not significantly affected by storage of the irradiated dosimeters under ambient conditions for 20 days. The performance characteristics of this chemical dosimetry system suggest that it can be useful to measure doses in irradiations of food. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. OSL and TL dosimeter characterization of boron doped CVD diamond films

    Science.gov (United States)

    Gonçalves, J. A. N.; Sandonato, G. M.; Meléndrez, R.; Chernov, V.; Pedroza-Montero, M.; De la Rosa, E.; Rodríguez, R. A.; Salas, P.; Barboza-Flores, M.

    2005-04-01

    Natural diamond is an exceptional prospect for clinical radiation dosimetry due to its tissue-equivalence properties and being chemically inert. The use of diamond in radiation dosimetry has been halted by the high market price; although recently the capability of growing high quality CVD diamond has renewed the interest in using diamond films as radiation dosimeters. In the present work we have characterized the dosimetric properties of diamond films synthesized by the HFCVD method. The thermoluminescence and the optically stimulated luminescence of beta exposed diamond sample containing a B/C 4000 ppm doping presents excellent properties suitable for dosimetric applications with β-ray doses up to 3.0 kGy. The observed OSL and TL performance is reasonable appropriate to justify further investigation of diamond films as dosimeters for ionizing radiation, specially in the radiotherapy field where very well localized and in vivo and real time radiation dose applications are essential.

  14. The 'push-pull' dosimeter: When two pigments are better than one

    Energy Technology Data Exchange (ETDEWEB)

    Bosi, Stephen G; Baldock, Clive; Smee, Robert, E-mail: s.bosi@physics.usyd.edu.a

    2010-11-01

    A new kind of gel dosimeter (the 'push-pull' dosimeter) is proposed which would contain two spectrally complementary pigments, one which darkens with increasing dose and another which bleaches. The bleaching pigment would be optimised for high sensitivity and the darkening pigment for low sensitivity. By employing dual pigments optimised independently, the usual requisite compromises between sensitivity at low dose and accuracy at high dose would be relaxed. Such a gel, after exposure would be read using two successive optical CT scans employing two different scan wavelengths. The use of dual pigments could also reduce the occurrence of regions of high optical attenuation which generate artefacts in optical CT. This paper also presents results of simulations of the behaviour of such a gel when scanned using optical cone beam CT.

  15. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2005

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Steven R.; Stoetzel, Gregory A.

    2006-06-21

    Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the PNNL Radiological Control Program Description, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2005 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program

  16. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2001

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Steven R.; Stoetzel, Gregory A.

    2002-07-08

    Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the U.S. Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the PNNL Radiological Control Program Description, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually, and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2001 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.

  17. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2006

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Steven R.; Stoetzel, Gregory A.

    2007-07-19

    Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the PNNL Radiological Control Program Description, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually, and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2005 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.

  18. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Steven R.; Stoetzel, Gregory A.

    2001-07-05

    Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually, and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2000 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.

  19. The behaviour of alanine dosimeters at temperatures between 100 and 300 K

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, P.H.G. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom)], E-mail: peter.sharpe@npl.co.uk; Sephton, J.P.; Gouldstone, C.A. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom)

    2009-07-15

    A cryostat has been constructed to enable irradiations in a MDS Nordion Gammacell 220 irradiator to be carried out at selected temperatures between 100 and 300 K. The principle of operation and the performance of this cryostat are described and results are given of a study into the behaviour of alanine dosimeters at cryogenic temperatures. This work extends previously published data to the region between solid CO{sub 2} and liquid N{sub 2} temperatures and has demonstrated complex dose-dependent behaviour. A sharp discontinuity in the effect of temperature on alanine dosimeter response has been found in the region between 150 and 180 K, with no further influence of irradiation temperature on response observed below this point.

  20. The behaviour of alanine dosimeters at temperatures between 100 and 300 K

    Science.gov (United States)

    Sharpe, P. H. G.; Sephton, J. P.; Gouldstone, C. A.

    2009-07-01

    A cryostat has been constructed to enable irradiations in a MDS Nordion Gammacell 220 irradiator to be carried out at selected temperatures between 100 and 300 K. The principle of operation and the performance of this cryostat are described and results are given of a study into the behaviour of alanine dosimeters at cryogenic temperatures. This work extends previously published data to the region between solid CO 2 and liquid N 2 temperatures and has demonstrated complex dose-dependent behaviour. A sharp discontinuity in the effect of temperature on alanine dosimeter response has been found in the region between 150 and 180 K, with no further influence of irradiation temperature on response observed below this point.

  1. Development of methods and means to improve a performance of microprocessor shock sensors for car alarms

    Directory of Open Access Journals (Sweden)

    S. A. Vasyukov

    2014-01-01

    Full Text Available Existing shock sensors for car protection using the sensitive elements (SE of piezoelectric, microphone and electromagnetic types and the analogue circuitry of signal processing, have a number of essential shortcomings:- piezoelectric sensitive elements have no characteristics repeatability that complicates their use in mass production;- microphone sensors are structurally complicated and demand difficult information signal processing;- sensitive elements of electromagnetic sensors demand individual control (a specified clearance to be set between a magnet and the coil.Use of analogue elements (resistors, capacitors in the amplifier and filter circuits reduces temporary and temperature stability of characteristics. An adjustment of the sensor operating zones via variable resistors on a printed circuit is extremely inconvenient and doesn't allow to change quickly the sensor sensitivity depending on an external situation (for example, to increase quickly an operating zone of the sensor with an alarm system of a key fob when securing a car in the country or in the woods, or to reduce it in the street with heavy traffic streams.An analogue circuit–based sensor design disables its automatic adaptation to such external impacts as a rain, a stream passing by cars, etc.The article considers how to solve some of above problems while designing the two-zone digital shock sensors with a SE of electromagnetic type. It shows the SE design developed by the authors as a module containing the coil and a magnet, secured on the coil axis in a silicone extension. The circuitry solution and algorithms of signals processing allowed authors to realize a remote control of the prevention and alarm zones (with 16 gradation of sensitivity. The algorithm of self-adaptation to the repeating external impacts is proposed. The developed method to form the basic levels of digital comparators for each gradation of sensitivity enables the sensor to have the straight

  2. Expected Detection and False Alarm Rates for Transiting Jovian Planets

    CERN Document Server

    Brown, T M

    2003-01-01

    Ground-based searches for transiting Jupiter-sized planets have so far produced few detections of planets, but many of stellar systems with eclipse depths, durations, and orbital periods that resemble those expected from planets. I show that these detection rates are consistent with our present knowledge of binary and multiple-star systems, and of Jovian-mass extrasolar planets. Upcoming space-based searches for transiting Earth-sized planets will be largely unaffected by the sources of false alarms that afflict current ground-based searches, with one exception, namely distant eclipsing binaries whose light is strongly diluted by that of a foreground star. A byproduct of the rate estimation is evidence that the period distribution of extrasolar planets is depressed for periods between 5 and 200 days.

  3. False alarm recognition in hyperspectral gas plume identification

    Science.gov (United States)

    Conger, James L [San Ramon, CA; Lawson, Janice K [Tracy, CA; Aimonetti, William D [Livermore, CA

    2011-03-29

    According to one embodiment, a method for analyzing hyperspectral data includes collecting first hyperspectral data of a scene using a hyperspectral imager during a no-gas period and analyzing the first hyperspectral data using one or more gas plume detection logics. The gas plume detection logic is executed using a low detection threshold, and detects each occurrence of an observed hyperspectral signature. The method also includes generating a histogram for all occurrences of each observed hyperspectral signature which is detected using the gas plume detection logic, and determining a probability of false alarm (PFA) for all occurrences of each observed hyperspectral signature based on the histogram. Possibly at some other time, the method includes collecting second hyperspectral data, and analyzing the second hyperspectral data using the one or more gas plume detection logics and the PFA to determine if any gas is present. Other systems and methods are also included.

  4. False alarm recognition in hyperspectral gas plume identification

    Energy Technology Data Exchange (ETDEWEB)

    Conger, James L. (San Ramon, CA); Lawson, Janice K. (Tracy, CA); Aimonetti, William D. (Livermore, CA)

    2011-03-29

    According to one embodiment, a method for analyzing hyperspectral data includes collecting first hyperspectral data of a scene using a hyperspectral imager during a no-gas period and analyzing the first hyperspectral data using one or more gas plume detection logics. The gas plume detection logic is executed using a low detection threshold, and detects each occurrence of an observed hyperspectral signature. The method also includes generating a histogram for all occurrences of each observed hyperspectral signature which is detected using the gas plume detection logic, and determining a probability of false alarm (PFA) for all occurrences of each observed hyperspectral signature based on the histogram. Possibly at some other time, the method includes collecting second hyperspectral data, and analyzing the second hyperspectral data using the one or more gas plume detection logics and the PFA to determine if any gas is present. Other systems and methods are also included.

  5. A new fire alarm system for electrical installations

    CERN Document Server

    Pietersen, A H

    1978-01-01

    Fires in electrical installations are considered to develop in four phases - initiation, smouldering, flame formation and heat development. Cables are among the more sensitive components, with working temperatures around 50 degrees C and fire detection at 70 degrees C. Conventional alarms include smoke detectors. The new technique described uses microcapsules containing powder forming a gas of the Freon type after diffusion. A typical microcapsule loses 4% per year and has a natural life of 10 years. Fabrication methods are described. Detection is by gas concentration, with a sensitivity of 1 to 10 ppm, or by acoustic methods with microphones to pick up the sound of fractures. Pressure/temperature characteristics of various types of Freon mixtures commercially available are given in graphical form.

  6. Online measurement of the BEPC Ⅱ background using RadFET dosimeters

    Institute of Scientific and Technical Information of China (English)

    GONG Hui; LI Jin; GONG Guang-Hua; LI Yu-Xiong; HOU Lei; SHAO Bei-Bei

    2009-01-01

    To monitor the integral dose deposited in the BESⅢ electromagnetic calorimeter whose perfor-mance degrades due to exposure to the BEPCⅡ background, a 400 nm IMPL RadFET dosimeter-based integral dose online monitor system is built. After calibration with the 60Co source and verification with TLD in the pulse radiation fields, an experiment was arranged to measure the BEPC Ⅱ background online. The results are presented.

  7. Assessment of radiation exposure of nuclear medicine staff using personal TLD dosimeters and charcoal detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, F.; Garcia-Talavera, M.; Pardo, R.; Deban, L. [Valladolid Univ., Dept. de Quimica Analitica, Facultad de Ciencias (Spain); Garcia-Talavera, P.; Singi, G.M.; Martin, E. [Hospital Clinico Univ., Servicio de Medicina Nuclear, Salamanca (Spain)

    2006-07-01

    Although the main concern regarding exposure to ionizing radiation for nuclear medicine workers is external radiation, inhalation of radionuclides can significantly contribute to the imparted doses. We propose a new approach to assess exposure to inhalation of {sup 131}I based on passive monitoring using activated charcoal detectors. We compared the inhalation doses to the staff of a nuclear medicine department, based on the measurements derived from charcoal detectors placed at various locations, and the external doses monitored using personal TLD dosimeters. (authors)

  8. Polyvinyl butyral films containing leuco-malachite green as low-dose dosimeters

    Science.gov (United States)

    Mai, Hoang Hoa; Solomon, H. M.; Taguchi, M.; Kojima, T.

    2008-04-01

    Thin films containing leuco-malachite green (LMG) dye in polyvinyl butyral (PVB) have been developed for dose measurements of a few hundreds Gy level. The film shows significant color change in the visible range, and the sensitivity of the film to absorbed dose was enhanced by addition of chloride-containing compounds, such as chloral hydrate or 2,2,2-trichloroethanol. The film is suitable as dosimeters for dose measurements, e.g. in food irradiation and environmental protection.

  9. Polyvinyl butyral films containing leuco-malachite green as low-dose dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Hoang Hoa Mai [Institute for Nuclear Science Technique, Vietnam Atomic Energy Commission (VAEC), 59 Ly Thuong Kiet, Hanoi (Viet Nam); Solomon, H.M. [Philippine Nuclear Research Institute (PNRI), Commonwealth Avenue, Diliman Quezon City (Philippines); Taguchi, M. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki-shi. Gunma 370-1292 (Japan); Kojima, T. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki-shi. Gunma 370-1292 (Japan)], E-mail: kojima.takuji@jaea.go.jp

    2008-04-15

    Thin films containing leuco-malachite green (LMG) dye in polyvinyl butyral (PVB) have been developed for dose measurements of a few hundreds Gy level. The film shows significant color change in the visible range, and the sensitivity of the film to absorbed dose was enhanced by addition of chloride-containing compounds, such as chloral hydrate or 2,2,2-trichloroethanol. The film is suitable as dosimeters for dose measurements, e.g. in food irradiation and environmental protection.

  10. Thermoluminescent Dosimeter Use for Environmental Surveillance at the Hanford Site, 1971–2005

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, Ernest J.; Poston, Ted M.; Rathbone, Bruce A.

    2010-03-01

    This report describes the use of thermo luminescent dosimeters for environmental surveillance of external radiation on and around the Hanford Site for the period of 1970 to 2005. It addresses changes in the technology and associated quality control and assurance used in this work and summarizes the results of the 35 year period of external radiation surveillance. The appendices to this report provide trend plots for each location that comprised the shoreline, onsite, perimeter, and offsite sample design.

  11. ESR dosimeter material properties of phenols compound exposed to radiotherapeutic electron beams

    Science.gov (United States)

    Gallo, Salvatore; Iacoviello, Giuseppina; Bartolotta, Antonio; Dondi, Daniele; Panzeca, Salvatore; Marrale, Maurizio

    2017-09-01

    There is a need for a sensitive dosimeter using Electron Spin Resonance spectroscopy for use in medical applications, since non-destructive read-out and dose archival could be achieved with this method. This work reports a systematic ESR investigation of IRGANOX ® 1076 exposed to clinical electron beams produced by a LINAC used for radiation therapy treatments. Recently, dosimetric features of this material were investigated for irradiation with 60Co γ -photons and neutrons in both pellet and film shape and have been found promising thanks to their high efficiency of radiation-matter energy transfer and radical stability at room temperature. Here the analysis of the dosimetric features of these ESR dosimeters exposed to clinical electron beams at energies of 7, 10 and 14 MeV, is described in terms of dependence on microwave power and modulation amplitude, response on dose, dependence on beam type, detection limits, and signal stability after irradiation. The analysis of the ESR signal as function of absorbed dose highlights that the response of this material is linear in the dose range investigated (1-13 Gy) and is independent of the beam energy. The minimum detectable dose is found to be smaller than 1 Gy. Comparison of electron stopping power values of these dosimeters with those of water and soft tissue highlights equivalence of the response to electron beams in the energy range considered. The signal intensity was monitored for 40 days after irradiation and for all energies considered and it shows negligible variations in the first 500 h after irradiation whereas after 1100 h the signal decay is only of about 4%. In conclusion, it is found that phenolic compounds possess good dosimetric features which make it useful as a sensitive dosimeter for medical applications.

  12. Performance characteristics of mobile MOSFET dosimeter for kilovoltage X-rays used in image guided radiotherapy

    Directory of Open Access Journals (Sweden)

    A Sathish Kumar

    2015-01-01

    Full Text Available The main objective of this study was to investigate the characteristics of metal oxide semiconductor field effect transistor (MOSFET dosimeter for kilovoltage (kV X-ray beams in order to perform the in vivo dosimetry during image guidance in radiotherapy. The performance characteristics of high sensitivity MOSFET dosimeters were investigated for 80, 90, 100, 110, 120, and 125 kV X-ray beams used for imaging in radiotherapy. This study was performed using Clinac 2100 C/D medical electron linear accelerator with on-board imaging and kV cone beam computed tomography system. The characteristics studied in this work include energy dependence, angular dependence, and linearity. The X-ray beam outputs were measured as per American Association of Physicists in Medicine (AAPM TG 61 recommendations using PTW parallel plate (PP ionization chamber, which was calibrated in terms of air kerma (Nk by the National Standard Laboratory. The MOSFET dosimeters were calibrated against the PP ionization chamber for all the kV X-ray beams and the calibration coefficient was found to be 0.11 cGy/mV with a standard deviation of about ±1%. The response of MOSFET was found to be energy independent for the kV X-ray energies used in this study. The response of the MOSFET dosimeter was also found independent of angle of incidence for the gantry angles in the range of 0° to 360° in-air as well as at 3 cm depth in tissue equivalent phantom.

  13. Dose rate measurement of a cobalt source 'Issledovatel' by means of Fricke dosimeter

    CERN Document Server

    Peimel-Stuglik, Z

    2001-01-01

    The results of measurements leading to the elaboration of a reliable and accurate dose rate determination for a cobalt irradiator 'Issledovatel' were presented. The dose measurements were done by means of classic Fricke dosimeter. The conclusions from measurements can be useful also for the dosimetry of other kinds of cobalt irradiators. The measurements were performed by a newly employed Laboratory for Measurements of Technological Doses staff and were a practical test of their proficiency in gamma ray dosimetry.

  14. Soft real-time alarm messages for ATLAS TDAQ

    Science.gov (United States)

    Darlea, G.; Al Shabibi, A.; Martin, B.; Lehmann Miotto, G.

    2010-05-01

    The ATLAS TDAQ network consists of three separate Ethernet-based networks (Data, Control and Management) with over 2000 end-nodes. The TDAQ system has to be aware of the meaningful network failures and events in order for it to take effective recovery actions. The first stage of the process is implemented with Spectrum, a commercial network management tool. Spectrum detects and registers all network events, then it publishes the information via a CORBA programming interface. A gateway program (called NSG—Network Service Gateway) connects to Spectrum through CORBA and exposes to its clients a Java RMI interface. This interface implements a callback mechanism that allows the clients to subscribe for monitoring "interesting" parts of the network. The last stage of the TDAQ network monitoring tool is implemented in a module named DNC (DAQ to Network Connection), which filters the events that are to be reported to the TDAQ system: it subscribes to the gateway only for the machines that are currently active in the system and it forwards only the alarms that are considered important for the current TDAQ data taking session. The network information is then synthesized and presented in a human-readable format. These messages can be further processed either by the shifter who is in charge, the network expert or the Online Expert System. This article aims to describe the different mechanisms of the chain that transports the network events to the front-end user, as well as the constraints and rules that govern the filtering and the final format of the alarm messages.

  15. Soft real-time alarm messages for ATLAS TDAQ

    Energy Technology Data Exchange (ETDEWEB)

    Darlea, G., E-mail: georgiana.lavinia.darlea@cern.c [CERN, Geneva (Switzerland); Al Shabibi, A.; Martin, B.; Lehmann Miotto, G. [CERN, Geneva (Switzerland)

    2010-05-21

    The ATLAS TDAQ network consists of three separate Ethernet-based networks (Data, Control and Management) with over 2000 end-nodes. The TDAQ system has to be aware of the meaningful network failures and events in order for it to take effective recovery actions. The first stage of the process is implemented with Spectrum, a commercial network management tool. Spectrum detects and registers all network events, then it publishes the information via a CORBA programming interface. A gateway program (called NSG-Network Service Gateway) connects to Spectrum through CORBA and exposes to its clients a Java RMI interface. This interface implements a callback mechanism that allows the clients to subscribe for monitoring 'interesting' parts of the network. The last stage of the TDAQ network monitoring tool is implemented in a module named DNC (DAQ to Network Connection), which filters the events that are to be reported to the TDAQ system: it subscribes to the gateway only for the machines that are currently active in the system and it forwards only the alarms that are considered important for the current TDAQ data taking session. The network information is then synthesized and presented in a human-readable format. These messages can be further processed either by the shifter who is in charge, the network expert or the Online Expert System. This article aims to describe the different mechanisms of the chain that transports the network events to the front-end user, as well as the constraints and rules that govern the filtering and the final format of the alarm messages.

  16. A small animal image guided irradiation system study using 3D dosimeters

    Science.gov (United States)

    Qian, Xin; Admovics, John; Wuu, Cheng-Shie

    2015-01-01

    In a high resolution image-guided small animal irradiation platform, a cone beam computed tomography (CBCT) is integrated with an irradiation unit for precise targeting. Precise quality assurance is essential for both imaging and irradiation components. The conventional commissioning techniques with films face major challenges due to alignment uncertainty and labour intensive film preparation and scanning. In addition, due to the novel design of this platform the mouse stage rotation for CBCT imaging is perpendicular to the gantry rotation for irradiation. Because these two rotations are associated with different mechanical systems, discrepancy between rotation isocenters exists. In order to deliver x-ray precisely, it is essential to verify coincidence of the imaging and the irradiation isocenters. A 3D PRESAGE dosimeter can provide an excellent tool for checking dosimetry and verifying coincidence of irradiation and imaging coordinates in one system. Dosimetric measurements were performed to obtain beam profiles and percent depth dose (PDD). Isocentricity and coincidence of the mouse stage and gantry rotations were evaluated with starshots acquired using PRESAGE dosimeters. A single PRESAGE dosimeter can provide 3 -D information in both geometric and dosimetric uncertainty, which is crucial for translational studies.

  17. Real time radiation dosimeters based on vertically aligned multiwall carbon nanotubes and graphene

    Science.gov (United States)

    Funaro, Maria; Sarno, Maria; Ciambelli, Paolo; Altavilla, Claudia; Proto, Antonio

    2013-02-01

    Measurements of the absorbed dose and quality assurance programs play an important role in radiotherapy. Ionization chambers (CIs) are considered the most important dosimeters for their high accuracy, practicality and reliability, allowing absolute dose measurements. However, they have a relative large physical size, which limits their spatial resolution, and require a high bias voltage to achieve an acceptable collection of charges, excluding their use for in vivo dosimetry. In this paper, we propose new real time radiation detectors with electrodes based on graphene or vertically aligned multiwall carbon nanotubes (MWCNTs). We have investigated their charge collection efficiency and compared their performance with electrodes made of a conventional material. Moreover, in order to highlight the effect of nanocarbons, reference radiation detectors were also tested. The proposed dosimeters display an excellent linear response to dose and collect more charge than reference ones at a standard bias voltage, permitting the construction of miniaturized CIs. Moreover, an MWCNT based CI gives the best charge collection efficiency and it enables working also to lower bias voltages and zero volts, allowing in vivo applications. Graphene based CIs show better performance with respect to reference dosimeters at a standard bias voltage. However, at decreasing bias voltage the charge collection efficiency becomes worse if compared to a reference detector, likely due to graphene’s semiconducting behavior.

  18. Improving the Success Rate of Delivering Annual Occupational Dosimetry Reports to Persons Issued Temporary External Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Mallett, Michael Wesley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-09

    Workers who are not routinely monitored for occupational radiation exposure at LANL may be issued temporary dosimeters in the field. Per 10CFR835 and DOE O 231.1A, the Laboratory's radiation protection program is responsible for reporting these results to the worker at the end of the year. To do so, the identity of the worker and their mailing address must be recorded by the delegated person at the time the dosimeter is issued. Historically, this data has not been consistently captured. A new online application was developed to record the issue of temporary dosimeters. The process flow of the application was structured such that: 1) the worker must be uniquely identified in the Lab's HR database, and 2) the mailing address of record is verified live time via a commercial web service, for the transaction to be completed. A COPQ savings (Type B1) of $96K/year is demonstrated for the new application.

  19. Response of thermoluminescent dosimeters to photons simulated with the Monte Carlo method

    Science.gov (United States)

    Moralles, M.; Guimarães, C. C.; Okuno, E.

    2005-06-01

    Personal monitors composed of thermoluminescent dosimeters (TLDs) made of natural fluorite (CaF 2:NaCl) and lithium fluoride (Harshaw TLD-100) were exposed to gamma and X rays of different qualities. The GEANT4 radiation transport Monte Carlo toolkit was employed to calculate the energy depth deposition profile in the TLDs. X-ray spectra of the ISO/4037-1 narrow-spectrum series, with peak voltage (kVp) values in the range 20-300 kV, were obtained by simulating a X-ray Philips MG-450 tube associated with the recommended filters. A realistic photon distribution of a 60Co radiotherapy source was taken from results of Monte Carlo simulations found in the literature. Comparison between simulated and experimental results revealed that the attenuation of emitted light in the readout process of the fluorite dosimeter must be taken into account, while this effect is negligible for lithium fluoride. Differences between results obtained by heating the dosimeter from the irradiated side and from the opposite side allowed the determination of the light attenuation coefficient for CaF 2:NaCl (mass proportion 60:40) as 2.2 mm -1.

  20. Evaluation of a multi-guard ring (MGR) structure diode as diagnostic X-ray dosimeter

    Science.gov (United States)

    Camargo, F.; Khoury, H. J.; Nascimento, C. R.; Asfora, V. K.; Bueno, C. C.

    2007-09-01

    In this paper, we describe the results obtained for the evaluation of a multi-guard ring (MGR) structure diode as diagnostic X-ray dosimeter. This device was developed in the framework of R&D programs for the future CMS experiment at the Large Hadron Collider (LHC) with high radiation hardness to fulfill the requirements from this accelerator environment. In order to use the MGR diode as a dosimeter, it was connected in the photovoltaic mode to the input of an integrating electrometer and positioned at the center of an X-ray beam, beside a previously calibrated ionization chamber. The dependence of the diode response on the X-ray beam doses was evaluated for 35-90 kV X-ray generator bias supply, with doses in the range of 50 μGy-5 mGy. The good linearity of the dose-response curve obtained showed the MGR diode dosimeter to be a reliable alternative method for diagnostic X-ray dosimetry.

  1. Calibration of routine dosimeters in radiation processing: Validation procedure for in-plant calibration

    Directory of Open Access Journals (Sweden)

    Šećerov Bojana Lj.

    2011-01-01

    Full Text Available The essential prerequisite of radiation dosimetry is to provide quality assurance and documentation that the irradiation procedure has been carried out according to the specification requirement of correct calibration of the chosen dosimetry system. At the Radiation Plant of the Vinča Institute of Nuclear Sciences we compared two recommended protocols of irradiation procedures in the calibration of dosimetry systems in radiation processing: (1 by irradiation of routine dosimeters (ethanol-chlorobenzene - ECB at the calibration laboratory and (2, by in-plant calibration with alanine transfer - dosimeters. The critical point for in-plant calibration is irradiation geometry, so we carefully positioned the phantom carrying both dosimeters in order to minimize dose gradients across the sample. The analysis of results obtained showed that the difference among determined absorbed doses for the construction of calibration curves between these two methods, (alanine vs. ECB, is less than 1%. The difference in combined standard uncertainty for each calibration procedure is 0.1%. These results demonstrate that our in-plant calibration is as good as calibration by irradiation at the calibration laboratory and validates our placement of the irradiation phantom during irradiation.

  2. Area monitoring dosimeter program for the Pacific Northwest National Laboratory: Results for CY 1996

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, S R; Stoetzel, G A

    1997-06-01

    In January 1993, Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM). The purpose of the program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(3) and Article 511.1 of the RCM, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993, 1994, and 1995 confirmed that personnel dosimetry was not needed for individuals located in areas monitored by the program. A total of 108 area TLDs were placed in PNNL facilities during CY 1996. The TLDs were exchanged and analyzed quarterly. All routine area monitoring TLD results were less than 50 mrem annually after correcting for worker occupancy. The results support the conclusion that personnel dosimeters are not necessary for staff, declared pregnant workers, minors, or members of the public in these monitored areas.

  3. SINGLE ANODE TRIPLE GEM TISSUE EQUIVALENT PROPORTIONAL COUNTER AS THE BASIS FOR A PERSONAL NEUTRON DOSIMETER.

    Science.gov (United States)

    Seydaliev, M; Dubeau, J; Ali, F

    2017-04-28

    This paper reports on a tissue-equivalent proportional counter (TEPC) based on a triple gas electron multiplier structure, with a single pad readout, as a basis for a personal neutron dosimeter. Its dosimetric response was studied using the 252Cf neutron source at the Health Physics Generator Facility of the Canadian Nuclear Laboratories. Measured lineal energy spectra were found to be in agreement with numerical simulations performed with Monte Carlo N-Particle eXtended (MCNPX). Both simulations and measurements showed that the mean pathlength of secondary charged particles in the TEPC gas was best represented by the thickness of the drift region of the device. It was determined that the Cauchy Theorem, used to calculate the mean chord length in spherical and cylindrical TEPCs, overestimated the simulated mean chord length by nearly a factor of two. Important operational characteristics of the device were investigated, including gas gain, sensitivity and dosimetric response, as functions of tissue-equivalent gas pressure. This work demonstrates that the proposed design can serve as the basis for a personal neutron dosimeter device, which would satisfy the angular dosimetric response criteria of the personal dosimeter standard IEC61526. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Word Automaticity of Tree Automatic Scattered Linear Orderings Is Decidable

    CERN Document Server

    Huschenbett, Martin

    2012-01-01

    A tree automatic structure is a structure whose domain can be encoded by a regular tree language such that each relation is recognisable by a finite automaton processing tuples of trees synchronously. Words can be regarded as specific simple trees and a structure is word automatic if it is encodable using only these trees. The question naturally arises whether a given tree automatic structure is already word automatic. We prove that this problem is decidable for tree automatic scattered linear orderings. Moreover, we show that in case of a positive answer a word automatic presentation is computable from the tree automatic presentation.

  5. SU-F-BRF-13: Investigating the Feasibility of Accurate Dose Measurement in a Deforming Radiochromic Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Juang, T [Medical Physics Graduate Program, Duke University Medical Center, Durham, NC (United States); Adamovics, J [Rider University, Skillman, NJ (United States); Oldham, M [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Purpose: Presage-Def, a deformable radiochromic 3D dosimeter, has been previously shown to have potential for validating deformable image registration algorithms. This work extends this effort to investigate the feasibility of using Presage-Def to validate dose-accumulation algorithms in deforming structures. Methods: Two cylindrical Presage-Def dosimeters (8cm diameter, 4.5cm length) were irradiated in a water-bath with a simple 4-field box treatment. Isocentric dose was 20Gy. One dosimeter served as control (no deformation) while the other was laterally compressed during irradiation by 21%. Both dosimeters were imaged before and after irradiation with a fast (∼10 minutes for 1mm isotropic resolution), broad beam, high resolution optical-CT scanner. Measured dose distributions were compared to corresponding distributions calculated by a commissioned Eclipse planning system. Accuracy in the control was evaluated with 3D gamma (3%/3mm). The dose distribution calculated for the compressed dosimeter in the irradiation geometry cannot be directly compared via profiles or 3D gamma to the measured distribution, which deforms with release from compression. Thus, accuracy under deformation was determined by comparing integral dose within the high dose region of the deformed dosimeter distribution versus calculated dose. Dose profiles were used to study temporal stability of measured dose distributions. Results: Good dose agreement was demonstrated in the control with a 3D gamma passing rate of 96.6%. For the dosimeter irradiated under compression, the measured integral dose in the high dose region (518.0Gy*cm3) was within 6% of the Eclipse-calculated integral dose (549.4Gy*cm3). Elevated signal was noted on the dosimeter edge in the direction of compression. Change in dosimeter signal over 1.5 hours was ≤2.7%, and the relative dose distribution remained stable over this period of time. Conclusion: Presage-Def is promising as a 3D dosimeter capable of accurately

  6. SU-E-T-171: Characterization of the New Xoft Axxent Electronic Brachytherapy Source Using PRESAGE Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, A; Followill, D; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States); Adamovics, J [John Adamovics, Skillman, NJ (United States)

    2015-06-15

    Purpose: To characterize the Xoft Axxent electronic brachytherapy source using PRESAGE™ dosimeters to obtain independent confirmation of TG-43U1 dosimetry values from previous studies and ascertain its reproducibility in HDR brachytherapy. Methods: PRESAGE™ dosimeters are solid, polyurethane-based dosimeters doped with radiochromic leucodyes that produce a linear optical-density response when exposed to radiation. Eight 1-kg dosimeters were scanned prior to irradiation on an optical-CT scanner to eliminate background signal and any optical imperfections from each dosimeter. To quantify potential imaging artifacts due to oversaturated responses in the immediate range of the source, half of the eight dosimeters were cast with a smaller channel diameter of 5.4 mm, and the other half were cast with a larger channel diameter of 15mm. During irradiation, the catheters were placed in the center of each channel. Catheters fit the 5.4mm diameters channels whereas polyurethane plugs were inserted into the larger channels to create a sturdy, immobile catheter which allowed uniform dose distributions. Two dosimeters of each 5.4mm and 15mm were irradiated at either 1517.3 cGy or 2017.5 cGy. Post-irradiation scans were performed within 48 hours of irradiation. A 3D reconstruction based on subtraction of these two images and the relative dose measurements were made using in-house software. Results: Comparing measured radial dose rates with previous results revealed smaller percent errors when PRESAGE™ irradiations were at lower maximum dose. The dosimeters showed small deviations in radial dose function, g{sub p} (r), from previous studies. Among the dosimeters irradiated at 1517.3 cGy, the g{sub p}(r) compared to previous studies fluctuated from 0.0043 to 0.3922. This suggests small fluctuations can drastically change radial dose calculations. Conclusion: The subtraction of pre-irradiation and post-irradiation scans of PRESAGE™ dosimeters using an optical-CT scanner

  7. Sensitivity and variability of Presage dosimeter formulations in sheet form with application to SBRT and SRS QA

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, Michael, E-mail: mdumas1127@gmail.com [Department of Radiation Oncology, Wayne State University School of Medicine and Karmanos Cancer Institute Detroit, Detroit, Michigan 48201 and Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan 48202 (United States); Rakowski, Joseph T. [Department of Radiation Oncology, Wayne State University School of Medicine and Karmanos Cancer Institute Detroit, Detroit, Michigan 48201 (United States)

    2015-12-15

    Purpose: To measure sensitivity and stability of the Presage dosimeter in sheet form for various chemical concentrations over a range of clinical photon energies and examine its use for stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) QA. Methods: Presage polymer dosimeters were formulated to investigate and optimize their sensitivity and stability. The dosimeter is composed of clear polyurethane base, leucomalachite green (LMG) reporting dye, and bromoform radical initiator in 0.9–1.0 mm thick sheets. The chemicals are mixed together for 2 min, cast in an aluminum mold, and left to cure at 60 psi for a minimum of two days. Dosimeter response was characterized at energies Co-60, 6 MV, 10 MV flattening-filter free, 15 MV, 50 kVp (mean 19.2 keV), and Ir-192. The dosimeters were scanned by a Microtek Scanmaker i800 at 300 dpi, 2{sup 16} bit depth per color channel. Red component images were analyzed with ImageJ and RIT. SBRT QA was done with gamma analysis tolerances of 2% and 2 mm DTA. Results: The sensitivity of the Presage dosimeter increased with increasing concentration of bromoform. Addition of tin catalyst decreased curing time and had negligible effect on sensitivity. LMG concentration should be at least as high as the bromoform, with ideal concentration being 2% wt. Gamma Knife SRS QA measurements of relative output and profile widths were within 2% of manufacturer’s values validated at commissioning, except the 4 mm collimator relative output which was within 3%. The gamma pass rate of Presage with SBRT was 73.7%, compared to 93.1% for EBT2 Gafchromic film. Conclusions: The Presage dosimeter in sheet form was capable of detecting radiation over all tested photon energies and chemical concentrations. The best sensitivity and photostability of the dosimeter were achieved with 2.5% wt. LMG and 8.2% wt. bromoform. Scanner used should not emit any UV radiation as it will expose the dosimeter, as with the Epson 10000 XL scanner

  8. Fricke gel dosimeter with improved sensitivity for low-dose-level measurements.

    Science.gov (United States)

    Vaiente, Mauro; Molina, Wladimir; Silva, Lila Carrizales; Figueroa, Rodolfo; Malano, Francisco; Pérez, Pedro; Santibañez, Mauricio; Vedelago, José

    2016-07-01

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue-equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, independence of dose rate and incident direction, as well as linear dose response. This work presents the development and characterization of an improved Fricke gel system, based on modified chemical compositions, making possible its application in clinical radiology due to its improved sensitivity. Properties of standard Fricke gel dosimeter for high-dose levels are used as a starting point, and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low-dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose-dependency, showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain an adequate dosimeter response for low-dose levels. A suitable composition from among those studied is selected as a good candidate for low-dose-level radiation dosimetry consisting of a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, Xylenol orange, and tridistilled water. Dosimeter samples are prepared in standard vials for in-phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated using typical X-ray tubes for radiology and calibrated Farmer-type ionization chamber is used as reference to measure dose rates inside phantoms at vial locations. Once sensitive material composition is optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels

  9. Red emission phosphor for real-time skin dosimeter for fluoroscopy and interventional radiology

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masaaki, E-mail: QYJ05476@nifty.com; Chida, Koichi; Zuguchi, Masayuki [Department of Radiological Technology, Faculty of Medicine, School of Health Sciences, Tohoku University, 2-1 Seiryou-machi, Aoba-ku, Sendai 980-8575 (Japan)

    2014-10-15

    Purpose: There are no effective real-time direct skin dosimeters for interventional radiology. Such a scintillation dosimeter would be available if there was a suitable red emission phosphor in the medical x-ray range, since the silicon photodiode is a highly efficient device for red light. However, it is unknown whether there is a suitable red emission phosphor. The purpose of this study is to find a suitable red emission phosphor that can be used in x-ray dosimeters. Methods: Five kinds of phosphors which emit red light when irradiated with electron beams or ultraviolet rays in practical devices were chosen. For the brightness measurement, phosphor was put into transparent plastic cells or coated onto plastic sheets. The phosphors were irradiated with medical range x-rays [60–120 kV(peak), maximum dose rate of 160 mGy min{sup −1}], and the emission was measured by a luminance meter. Several characteristics, such as brightness, dose rate dependence, tube voltage dependence, and brightness stability, were investigated. Results: The luminescence of Y V O{sub 4}:Eu, (Y,Gd,Eu) BO{sub 3}, and Y{sub 2}O{sub 3}:Eu significantly deteriorated by 5%–10% when irradiated with continuous 2 Gy x-rays. The 0.5MgF{sub 2}⋅3.5MgO⋅GeO{sub 2}:Mn phosphor did not emit enough. Only the Y{sub 2}O{sub 2}S:Eu,Sm phosphor had hardly any brightness deterioration, and it had a linear relationship so that the x-ray dose rate could be determined from the brightness with sufficient accuracy. For the tube voltage dependence of the Y{sub 2}O{sub 2}S:Eu,Sm phosphor, the brightness per unit dose rate with 120 kV(peak) x-rays was 30% higher than that with 60 kV(peak) x-rays. Conclusions: Five kinds of phosphors were chosen as an x-ray scintillator for a real-time direct skin dosimeter. The Y V O{sub 4}:Eu, (Y,Gd,Eu)BO{sub 3}, and Y{sub 2}O{sub 3}:Eu phosphors had brightness deterioration caused by the x-rays. Only the Y{sub 2}O{sub 2}S:Eu,Sm phosphor had hardly any brightness deterioration

  10. Dosimetric comparison among different head and neck radiotherapy techniques using PRESAGE® dosimeter

    Directory of Open Access Journals (Sweden)

    Jalil Rehman

    2015-12-01

    Full Text Available Purpose: The purpose of this analysis was to investigate dose distribution of Three Dimensional Conformal Radiation Therapy (3DCRT, Intensity Modulated Radiation Therapy (IMRT and Volumetric Modulated Arc Therapy (VMAT for Head and Neck cancer using 3-dimensional PRESAGE® dosimeter. Method: Computer Tomography (CT scans of Radiological Physics Center (RPC Head and Neck anthropomorphic phantom with both RPC standard insert and PRESAGE® insert were acquired separated with Philipp’s CT scanner and both CT scans were exported via DICOM to the pinnacle treatment planning system (TPS. Each plan was delivered twice to the RPC phantom first containing the RPC standard insert having Thermoluminescent detectors (TLD and film dosimeters and then again containing the PRESAGE® insert having three dimensional dosimeter (PRESAGE® by using a Varian True beam linear accelerator. After irradiation, the standard insert including point dose measurement (TLD and planner GafChromic® EBT film measurement was read using RPC standard procedure. The 3D dose distribution from PRESAGE® was read out with the Duke Midsized optical scanner dedicated to RPC (DMOS-RPC. Dose volume histogram (DVH, mean and maximal doses for organ-at-risk (OARs were calculated and compared among each Head and Neck technique. The prescription dose was same for all Head and Neck radiotherapy techniques which was 6.60 Gy per friction. Beam profile comparison and gamma analysis were used to quantify agreement among film measurement, PRESAGE® measurement and calculated dose distribution. Quality assurances of all plans were performed by using ArcCHECK method. Results: VMAT delivered the lowest mean and maximal doses to organ at risk (spinal cord and parotid than IMRT and 3DCRT. Such dose distribution was verified by absolute dose distribution using TLD system. 2D gamma 5%/3 mm criteria of Pinnacle vs. EBT2 film 3DCRT (92.34%, IMRT (92.3% and VMAT (96.63% in axial plan respectively. It was

  11. Characterization of ferric ions diffusion in Fricke gel dosimeters by using inverse problem techniques

    Science.gov (United States)

    Vedelago, J.; Quiroga, A.; Valente, M.

    2014-10-01

    Diffusion of ferric ions in ferrous sulfate (Fricke) gels represents one of the main drawbacks of some radiation detectors, such as Fricke gel dosimeters. In practice, this disadvantage can be overcome by prompt dosimeter analysis, and constraining strongly the time between irradiation and analysis, implementing special dedicated protocols aimed at minimizing signal blurring due to diffusion effects. This work presents a novel analytic modeling and numerical calculation approach of diffusion coefficients in Fricke gel radiation sensitive materials. Samples are optically analyzed by means of visible light transmission measurements by capturing images with a charge-coupled device camera provided with a monochromatic filter corresponding to the XO-infused Fricke solution absorbance peak. Dose distributions in Fricke gels are suitably delivered by assessing specific initial conditions further studied by periodical sample image acquisitions. Diffusion coefficient calculations were performed using a set of computational algorithms based on inverse problem formulation. Although 1D approaches to the diffusion equation might provide estimations of the diffusion coefficient, it should be calculated in the 2D framework due to the intrinsic bi-dimensional characteristics of Fricke gel layers here considered as radiation dosimeters. Thus a suitable 2D diffusion model capable of determining diffusion coefficients was developed by fitting the obtained algorithm numerical solutions with the corresponding experimental data. Comparisons were performed by introducing an appropriate functional in order to analyze both experimental and numerical values. Solutions to the second-order diffusion equation are calculated in the framework of a dedicated method that incorporates finite element method. Moreover, optimized solutions can be attained by gradient-type minimization algorithms. Knowledge about diffusion coefficient for a Fricke gel radiation detector is helpful in accounting for

  12. Use of alarm features in referral of febrile children to the emergency department : an observational study

    NARCIS (Netherlands)

    van Ierland, Yvette; Elshout, Gijs; Moll, Henritte A.; Nijman, Ruud G.; Vergouwe, Yvonne; van der Lei, Johan; Berger, Marjolein Y.; Oostenbrink, Rianne

    2014-01-01

    Background The diagnostic value of alarm features of serious infections in low prevalence settings is unclear. Aim To explore to what extent alarm features play a role in referral to the emergency department (ED) by GPs who face a febrile child during out-of-hours care. Design and setting Observatio

  13. Design for safety: A new service for alarming and informing the population in case of emergency

    NARCIS (Netherlands)

    Jagtman, H.M.

    2012-01-01

    In case of emergencies the population in danger should be alarmed so individuals can take action to get or remain out of danger. For alarming the population the means available are limited. Many countries have outdoor sirens. They operability however is limited since the siren has only one implicit

  14. Ontogeny of Alarm pheromone production in the fire ant, Solenopsis invicta

    Science.gov (United States)

    Alarm pheromones are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality in social insects. Recently, we identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of the fire ant, Solenopsis invicta. We continued...

  15. A Computational Pipeline to Improve Clinical Alarms Using a Parallel Computing Infrastructure

    Science.gov (United States)

    Nguyen, Andrew V.

    2013-01-01

    Physicians, nurses, and other clinical staff rely on alarms from various bedside monitors and sensors to alert when there is a change in the patient's clinical status, typically when urgent intervention is necessary. These alarms are usually embedded directly within the sensor or monitor and lacks the context of the patient's medical history and…

  16. ED accreditation update. Hospitals put on notice: alarm management is a top priority for 2014.

    Science.gov (United States)

    2013-09-01

    Establishing alarm management as a new National Patient Safety Goal (NPSG), The Joint Commission (TJC) is calling on hospitals to make the issue a safety priority, and to begin establishing policies and procedures designed to minimize alarm fatigue among clinical staff. Beginning on January 1,2014, hospitals need to begin identifying the most important alarm signals to manage based on input from staff as well as factors such as patient risk, and the potential for harm as demonstrated by the device's history. By January 1,2016, hospitals need to have policies and procedures in place for managing alarms identified in the first phase of the NPSG's requirements. Also, staff and independent licensed practitioners need to be educated about the purpose and proper operation of alarm systems that they are responsible for.

  17. Systematic review of controlled trials of interventions to promote smoke alarms.

    Science.gov (United States)

    DiGuiseppi, C; Higgins, J P

    2000-05-01

    To evaluate the effects of promotion of residential smoke alarms. Electronic databases, conference proceedings, and bibliographies were systematically searched, and investigators and organisations were contacted, in order to identify controlled trials evaluating interventions designed to promote residential smoke alarms. The following were assessed: smoke alarm acquisition, ownership, and function; fires; burns; and fire related injuries. Odds ratios (OR) were estimated by meta analysis of randomised trials. A total of 26 trials were identified, of which 13 were randomised. Overall, counselling and educational interventions had only a modest effect on the likelihood of owning an alarm (OR = 1.26; 95% confidence interval (CI): 0.87 to 1.81) or having a functional alarm (OR = 1.19; 95% CI: 0.85 to 1.66). Counselling as part of primary care child health surveillance had greater effects on ownership (OR = 1.93; 95% CI: 1.04 to 3.58) and function (OR = 1. 72; 95% CI: 0.78 to 3.78). Results were sensitive to trial quality, however, and effects on fire related injuries were not reported. In two non-randomised trials, direct provision of free alarms significantly increased functioning alarms and reduced fire related injuries. Media and community education showed little benefit in non-randomised trials. Counselling as part of child health surveillance may increase smoke alarm ownership and function, but its effects on injuries are unevaluated. Community smoke alarm give away programmes apparently reduce fire related injuries, but these trials were not randomised and results must be interpreted cautiously. Further efforts to promote smoke alarms in primary care or through give away programmes should be evaluated by adequately designed randomised controlled trials measuring injury outcomes.

  18. A description of nurses' decision-making in managing electrocardiographic monitor alarms.

    Science.gov (United States)

    Gazarian, Priscilla K; Carrier, Natalie; Cohen, Rachel; Schram, Haley; Shiromani, Samara

    2015-01-01

    To describe the cues and factors that nurses use in their decision-making when responding to clinical alarms. Alarms are designed to be very sensitive, and as a result, they are not very specific. Lack of adherence to the practice standards for electrocardiographic monitoring in hospital settings has been observed, resulting in overuse of the electrocardiographic monitoring. Monitoring without consideration of clinical indicators uses scarce healthcare resources and may even produce untoward circumstances because of alarm fatigue. With so many false alarms, alarm fatigue represents a symptom of a larger problem. It cannot be fixed until all of the factors that contribute to its existence have been examined. This was a qualitative descriptive study. This study was conducted at an academic medical centre located in the Northeast United States. Eight participants were enrolled using purposive sampling. Nurses were observed for two three-hour periods. Following each observation, the nurse was interviewed using the critical decision method to describe the cognitive processes related to the alarm activities. Qualitative data from the conducted interviews were analysed via an a priori framework founded in the critical decision method. This study reveals information, experience, guidance and decision-making as the four prominent categories contributing to nurses' decision-making in relation to alarm management. Managing technology was a category not identified a priori that emerged in the data analysis. Nurses revealed a breadth of information needed to adequately identify and interpret monitor alarms, and how they used that information to put the alarms into the particular context of an individual patient's situations. Understanding the cues and factors nurses use when responding to cardiac alarms will guide the development of learning experiences and inform policies to guide practice. © 2014 John Wiley & Sons Ltd.

  19. Differences in alarm events between disposable and reusable electrocardiography lead wires.

    Science.gov (United States)

    Albert, Nancy M; Murray, Terri; Bena, James F; Slifcak, Ellen; Roach, Joel D; Spence, Jackie; Burkle, Alicia

    2015-01-01

    Disposable electrocardiographic lead wires (ECG-LWs) may not be as durable as reusable ones. To examine differences in alarm events between disposable and reusable ECG-LWs. Two cardiac telemetry units were randomized to reusable ECG-LWs, and 2 units alternated between disposable and reusable ECG-LWs for 4 months. A remote monitoring team, blinded to ECG-LW type, assessed frequency and type of alarm events by using total counts and rates per 100 patient days. Event rates were compared by using generalized linear mixed-effect models for differences and noninferiority between wire types. In 1611 patients and 9385.5 patient days of ECG monitoring, patient characteristics were similar between groups. Rates of alarms for no telemetry, leads fail, or leads off were lower in disposable ECG-LWs (adjusted relative risk [95% CI], 0.71 [0.53-0.96]; noninferiority P monitoring (artifact) alarms were significantly noninferior (adjusted relative risk [95% CI]: 0.88, [0.62-1.24], P = .02; superiority P = .44). No between-group differences existed in false or true crisis alarms. Disposable ECG-LWs were noninferior to reusable ECG-LWs for all false-alarm events (N [rate per 100 patient days], disposable 2029 [79.1] vs reusable 6673 [97.9]; adjusted relative risk [95% CI]: 0.81 [0.63-1.06], P = .002; superiority P = .12.) Disposable ECG-LWs with patented push-button design had superior performance in reducing alarms created by no telemetry, leads fail, or leads off and significant noninferiority in all false-alarm rates compared with reusable ECG-LWs. Fewer ECG alarms may save nurses time, decrease alarm fatigue, and improve patient safety. ©2015 American Association of Critical-Care Nurses.

  20. Automatic Program Development

    DEFF Research Database (Denmark)

    by members of the IFIP Working Group 2.1 of which Bob was an active member. All papers are related to some of the research interests of Bob and, in particular, to the transformational development of programs and their algorithmic derivation from formal specifications. Automatic Program Development offers......Automatic Program Development is a tribute to Robert Paige (1947-1999), our accomplished and respected colleague, and moreover our good friend, whose untimely passing was a loss to our academic and research community. We have collected the revised, updated versions of the papers published in his...... honor in the Higher-Order and Symbolic Computation Journal in the years 2003 and 2005. Among them there are two papers by Bob: (i) a retrospective view of his research lines, and (ii) a proposal for future studies in the area of the automatic program derivation. The book also includes some papers...