Opportunistic detection of atrial fibrillation using blood pressure monitors: a systematic review

Background: Atrial Fibrillation (AF) affects around 2% of the population and early detection is beneficial, allowing patients to begin potentially life-saving anticoagulant therapies. Blood pressure (BP) monitors may offer an opportunity to screen for AF. Aim: To identify and appraise studies which report the diagnostic accuracy of automated BP monitors used for opportunistic AF detection. Methods: A systematic search was performed of the Medline, Medline-in-process and Embase literature databases. Papers were eligible if they described primary studies of the evaluation of a BP device for AF detection, were published in a peer reviewed journal and reported values for the sensitivity and specificity. Included studies were appraised using the QUADAS-2 tool to assess their risk of bias and applicability to opportunistic AF detection. Values for the sensitivity and specificity of AF detection were extracted from each paper and compared. Results and Conclusion: We identified seven papers evaluating six devices from two manufacturers. Only one study scored low risk in all of the QUADAS-2 domains. All studies reported specificity greater than 85% and six reported sensitivity greater than 90%. The studies showed that blood pressure devices with embedded algorithms for detecting arrhythmias show promise as screening tools for AF, comparing favourably with manual pulse palpation. But the studies used different methodologies and many were subject to potential bias. More studies are needed to more precisely define the sensitivity and specificity of opportunistic screening for AF during blood pressure measurement before its clinical utility in the population of interest can be assessed fully

The Generic Spacecraft Analyst Assistant (gensaa): a Tool for Developing Graphical Expert Systems

During numerous contacts with a satellite each day, spacecraft analysts must closely monitor real-time data. The analysts must watch for combinations of telemetry parameter values, trends, and other indications that may signify a problem or failure. As the satellites become more complex and the number of data items increases, this task is becoming increasingly difficult for humans to perform at acceptable performance levels. At NASA GSFC, fault-isolation expert systems are in operation supporting this data monitoring task. Based on the lessons learned during these initial efforts in expert system automation, a new domain-specific expert system development tool named the Generic Spacecraft Analyst Assistant (GenSAA) is being developed to facilitate the rapid development and reuse of real-time expert systems to serve as fault-isolation assistants for spacecraft analysts. Although initially domain-specific in nature, this powerful tool will readily support the development of highly graphical expert systems for data monitoring purposes throughout the space and commercial industry

Building safe software

Murphy is a set of techniques and tools under investigation for their potential in enhancing the safety of software. This paper describes some of the work which has been done and some which is planned

On Ladder Logic Bombs in Industrial Control Systems

In industrial control systems, devices such as Programmable Logic Controllers (PLCs) are commonly used to directly interact with sensors and actuators, and perform local automatic control. PLCs run software on two different layers: a) firmware (i.e. the OS) and b) control logic (processing sensor readings to determine control actions). In this work, we discuss ladder logic bombs, i.e. malware written in ladder logic (or one of the other IEC 61131-3-compatible languages). Such malware would be inserted by an attacker into existing control logic on a PLC, and either persistently change the behavior, or wait for specific trigger signals to activate malicious behaviour. For example, the LLB could replace legitimate sensor readings with manipulated values. We see the concept of LLBs as a generalization of attacks such as the Stuxnet attack. We introduce LLBs on an abstract level, and then demonstrate several designs based on real PLC devices in our lab. In particular, we also focus on stealthy LLBs, i.e. LLBs that are hard to detect by human operators manually validating the program running in PLCs. In addition to introducing vulnerabilities on the logic layer, we also discuss countermeasures and we propose two detection techniques.Comment: 11 pages, 14 figures, 2 tables, 1 algorith

Teachers guide for building and operating weather satellite ground stations for high school science

A number of colleges and universities are operating APT direct readout stations. However, high school science teachers have often failed to realize the potential of meteorological satellites and their products as unique instructional tools. The ability to receive daily pictures from these satellites offers exciting opportunities for secondary school teachers and students to assemble the electronic hardware and to view real time pictures of Earth from outer space. The station and pictures can be used in the classroom to develop an approach to science teaching that could span many scientific disciplines and offer many opportunities for student research and participation in scientific processes. This can be accomplished with relatively small expenditures of funds for equipment. In most schools some of the equipment may already be available. Others can be constructed by teachers and/or students. Yet another source might be the purchase of used equipment from industry or through the government surplus channels. The information necessary for individuals unfamiliar with these systems to construct a direct readout for receiving real time APT photographs on a daily basis in the classroom is presented

Specifications and programs for computer software validation

Three software products developed during the study are reported and include: (1) FORTRAN Automatic Code Evaluation System, (2) the Specification Language System, and (3) the Array Index Validation System

London Challenge

Report on the London Challenge programme presenting: key findings, recommendations, the national context, leadership and management, teaching and learning, achievement, and standards. "The London Challenge school improvement programme was established in 2003 to improve outcomes in low-performing secondary schools in the capital. Primary schools were included in the scheme from 2008." - Cover

Aircraft electromagnetic compatibility

Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting

Street slang and schizophrenia

We report the case of a 26 year old streetwise young postman who presented with a six month history of reduced occupational and social function, low mood, and lack of motivation. He complained of feeling less sociable and less interested in his friends and of being clumsy and finding it harder to think. He was otherwise fit and healthy, with no physical abnormalities, neurological signs, or objective cognitive impairments. There was no history of a recent stressor that might have precipitated his symptoms. He was referred to a specialist service for patients in the prodromal phase of psychotic illness for further assessment after he had seen his general practitioner and the local community mental health team. The differential diagnosis at this stage was depression, the prodrome of schizophrenia, or no formal clinical disorder. His premorbid occupational and social function had been good. There was no history of abnormal . social, language, and motor development and he left school with two A levels. After three years of service at the post office he had been promoted to a supervisory role. He had a good relationship with his family and had six or so good friends. There has been a number of previous heterosexual relationships, although none in the past year. Aside from smoking cannabis on two occasions when he was 19, there was no history of illicit substance use. Detailed and repeated assessment of his mental state found a normal affect, no delusions, hallucinations, or catatonia, and no cognitive dysfunction. His speech, however, was peppered with what seemed (to his middle class and older psychiatrist) to be an unusual use of words, although he said they were street slang (table).Go It was thus unclear whether he was displaying subtle signs of formal thought disorder (manifest as disorganised speech, including the use of unusual words or phrases, and neologisms) or using a "street" argot. This was a crucial diagnostic distinction as thought disorder is a feature of psychotic illnesses and can indicate a diagnosis of schizophrenia. We sought to verify his explanations using an online dictionary of slang (urbandictionary.com). To our surprise, many of the words he used were listed and the definitions accorded with those he gave (see table). We further investigated whether his speech showed evidence of thought disorder by examining recordings of his speech as he described a series of ambiguous pictures from the thematic apperception test, a procedure that elicits thought disordered speech. His speech was transcribed and rated with the thought and language index, a standardised scale for assessing thought disorder. Slang used in a linguistically appropriate way is not scored as abnormal on this scale. His score was 5.25, primarily reflecting a mild loosening of associations. For example, he described a picture of a boat on a lake thus: "There’s a boat and a tree. There seems to be a reflection. There are no beds, and I wonder why there are no beds. There’s a breeze going through the branches of the tree." His score was outside the normal range (mean for normal controls 0.88, SD 1.15) and indicates subtle thought disorder, equivalent to that evident in remitted patients with schizophrenia (mean in remitted patients 3.89, SD 2.56) but lower than that in patients with formal thought disorder (mean 27.4, SD 8.3). Over the following year his social and occupational functioning deteriorated further, and he developed frank formal thought disorder as well as grandiose and persecutory delusions to the extent that he met DSM-IV criteria for schizophrenia. His speech was assessed as before, and the thought and language index score had increased to 11.75. This mainly reflected abnormalities on items comprising "positive" thought disorder, particularly the use of neologisms such as "chronocolising" and non-sequiturs. To our knowledge this is the first case report to describe difficulties in distinguishing "street" argots from formal thought disorder. It is perhaps not surprising that slang can complicate the assessment of disorganised speech as psychotic illnesses usually develop in young adults, whereas the assessing clinician is often from an older generation (and different sociocultural background) less familiar with contemporary urban slang. Online resources offer a means of distinguishing street argot from neologisms or a peculiar use of words, and linguistic rating scales may be a useful adjunct to clinical assessment when thought disorder is subtle. Differentiating thought disorder from slang can be especially difficult in the context of "prodromal" signs of psychosis, when speech abnormalities, if present, are usually subtle. Nevertheless, accurate speech assessment is important as subtle thought disorder can, as in this case, predate the subsequent onset of schizophrenia, and early detection and treatment of psychosis might be associated with a better long term clinical outcome

Distributed communications and control network for robotic mining

The application of robotics to coal mining machines is one approach pursued to increase productivity while providing enhanced safety for the coal miner. Toward that end, a network composed of microcontrollers, computers, expert systems, real time operating systems, and a variety of program languages are being integrated that will act as the backbone for intelligent machine operation. Actual mining machines, including a few customized ones, have been given telerobotic semiautonomous capabilities by applying the described network. Control devices, intelligent sensors and computers onboard these machines are showing promise of achieving improved mining productivity and safety benefits. Current research using these machines involves navigation, multiple machine interaction, machine diagnostics, mineral detection, and graphical machine representation. Guidance sensors and systems employed include: sonar, laser rangers, gyroscopes, magnetometers, clinometers, and accelerometers. Information on the network of hardware/software and its implementation on mining machines are presented. Anticipated coal production operations using the network are discussed. A parallelism is also drawn between the direction of present day underground coal mining research to how the lunar soil (regolith) may be mined. A conceptual lunar mining operation that employs a distributed communication and control network is detailed