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The clinical examination is an important part of any patient consultation. After the primary survey and taking the patient history, a more in-depth examination is sometimes required to aid making a working diagnosis and help negate other differential diagnoses. The extent of this depends on the stability of the patient and may not be possible in time-critical circumstances. However, clinical examination is an increasing part of paramedic practice owing to the continued expansion of the scope of the paramedic role in both urgent and emergency care. Education on clinical examination concerning each of the main body systems is now an integral part of undergraduate paramedic curricula. This clinical examination series provides a step-by-step overview for each of the main body systems. Continuing professional development (CPD) is an essential requirement for all clinicians to maintain and demonstrate they are staying up to date and advancing in their roles. This series gives an overview of each type of examination to support students, newly qualified paramedics and paramedics wishing to use these articles as a CPD development activity and an aide-memoire for clinical practice. This article, which explores the peripheral vascular system, gives an overview of initial examination considerations, including first impressions.

Background: Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy.Methods: RESTART was a prospective, randomised, open-label, blinded-endpoint, parallel-group trial at 122 hospitals in the UK that assessed whether starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. For this prespecified subgroup analysis, consultant neuroradiologists masked to treatment allocation reviewed brain CT or MRI scans performed before randomisation to confirm participant eligibility and rate features of the intracerebral haemorrhage and surrounding brain. We followed participants for primary (recurrent symptomatic intracerebral haemorrhage) and secondary (ischaemic stroke) outcomes for up to 5 years (reported elsewhere). For this report, we analysed eligible participants with intracerebral haemorrhage according to their treatment allocation in primary subgroup analyses of cerebral microbleeds on MRI and in exploratory subgroup analyses of other features on CT or MRI. The trial is registered with the ISRCTN registry, number ISRCTN71907627.Findings: Between May 22, 2013, and May 31, 2018, 537 participants were enrolled, of whom 525 (98%) had intracerebral haemorrhage: 507 (97%) were diagnosed on CT (252 assigned to start antiplatelet therapy and 255 assigned to avoid antiplatelet therapy, of whom one withdrew and was not analysed) and 254 (48%) underwent the required brain MRI protocol (122 in the start antiplatelet therapy group and 132 in the avoid antiplatelet therapy group). There were no clinically or statistically significant hazards of antiplatelet therapy on recurrent intracerebral haemorrhage in primary subgroup analyses of cerebral microbleed presence (2 or more) versus absence (0 or 1) (adjusted hazard ratio [HR] 0·30 [95% CI 0·08–1·13] vs 0·77 [0·13–4·61]; pinteraction=0·41), cerebral microbleed number 0–1 versus 2–4 versus 5 or more (HR 0·77 [0·13–4·62] vs 0·32 [0·03–3·66] vs 0·33 [0·07–1·60]; pinteraction=0·75), or cerebral microbleed strictly lobar versus other location (HR 0·52 [0·004–6·79] vs 0·37 [0·09–1·28]; pinteraction=0·85). There was no evidence of heterogeneity in the effects of antiplatelet therapy in any exploratory subgroup analyses (all pinteraction>0·05).Interpretation: Our findings exclude all but a very modest harmful effect of antiplatelet therapy on recurrent intracerebral haemorrhage in the presence of cerebral microbleeds. Further randomised trials are needed to replicate these findings and investigate them with greater precision.Funding: British Heart Foundation.

Objectives: To perform surgical closure of a clinically significant arterial duct on children in a third world country. Background: An arterial duct is one of the most common congenital cardiac defects. Large arterial ducts can cause significant pulmonary overcirculation, causing symptoms of congestive cardiac failure, ultimately resulting in premature death. Closure of an arterial duct is usually curative, allowing for a normal quality of life and expectancy. In western countries, arterial duct closure in children is usually performed by deployment of a device through a catheter-based approach, replacing previous surgical approaches. In third world countries, there is limited access to the necessary resources for performing catheter-based closure of an arterial duct. Consequently, children with an arterial duct in a third world country may only receive palliative care, can be markedly symptomatic, and often do not survive to adulthood. Methods: We assembled a team of 11 healthcare workers with extensive experience in the medical and surgical management of children with congenital cardiac disease. In all, 21 patients with a history of an arterial duct were screened by performing a comprehensive history, physical, and echocardiogram at the Angkor Hospital for Children in Siem Reap, Cambodia. Results: A total of 18 children (eight male and ten female), ranging in age from 10 months to 14 years, were deemed suitable to undergo surgery. All patients were symptomatic, and the arterial ducts ranged in size from 4 to 15 millimetres. Surgical closure was performed using two clips, and in four cases with the largest arterial duct, sutures were also placed. All patients had successful closure without any significant complications, and were able to be discharged home within 2 days of surgery. Of note, four children with arterial ducts died in the 5 months before our arrival. Conclusion: Surgical closure of an arterial duct can be performed safely and effectively by an experienced paediatric cardiothoracic surgical team on children in a third world country. We hope that our experience will inspire others to perform similar missions throughout the world.

Pedagogical practices in electrical engineering education have been shifting away from teacher-centered learning during the past decade. An innovation that has enabled the adoption of inquiry-based and problem-based learning into the curriculum using experimentation coupled with simulation and analysis has been the development of portable oscilloscopes and other instruments that rely on tablet or laptop computers to perform some of the data processing and to act as the display. Faculty members at six institutions of higher learning have incorporated hands-on experimental activities into existing courses and/or developed new courses that take advantage of these new tools. Assessment data collected by these faculty members have demonstrated that the change towards student-centered learning facilitated by portable electronics increased student interest in electrical engineering, built student confidence in their ability to design circuits and systems, and supported the development of a deeper understanding of the theories that the students investigate or apply in the hands-on activities. A summary of the challenges that are faced in the different implementation models and a discussion of best practices are presented.

In cognitive radio systems, the available frequency bands are usually non-contiguous, which may cause impact on the spectrum utilization efficiency (SUE).When the receiver has a limited sampling capability, the aliasing phenomenon may cause interference among the signals at different frequency points, thus causing the loss of channel capacity. Information theoretic analysis is carried out to quantify the impact of spectrum non-contiguity on the channel capacity by analyzing the SUE. Beginning from the single sampler case, the analysis is also extended to the general case of sampler arrays. Numerical results are provided to answer several important questions on the impact of spectrum non-contiguity.

Small unmanned aerial vehicles (UAVs) have limits on the weight and size of direction finding (DF) systems that can be used. However, by employing multiple sensors that work cooperatively, simple DF systems need only to provide a rough estimate of the signal's angle of arrival (AOA) and received signal strength (RSS). As the UAVs move, a plurality of data points can be obtained from diverse locations. Combining this information from multiple sensor locations can provide a low-cost and effective solution to electronic emitter location problems, using low-accuracy DF technology. In this paper we present an algorithm, based on the compressed sensing technique, that uses AOA and RSS from mobile sensors (UAVs) to geolocate the source of radio signals on the ground.

Unmanned aerial vehicles (UAVs) can be used to chase radio frequency (RF) emitters by sensing the signal sent out by the RF emitters. Meanwhile, the RF emitter can evade from the UAVs, thus forming a pursuit-evasion game. In contrast to traditional pursuit-evasion games, in which the players can always observe each other, the RF emitter can stop transmitting such that the UAVs lose the target. However, stopping the transmission also incurs cost to the RF emitter since it can no longer convey information to destinations. Hence, the RF emitter can take both continuous actions, i.e., the moving direction, and discrete actions, i.e., whether to stop transmission. Meanwhile, there are both discrete states, i.e., whether the RF transmitter is transmitting, and continuous states, i.e., the locations of UAVs and RF emitter, thus forming a hybrid system. We will study the game theoretic properties of this novel game and derive the optimal strategies for both parties under certain assumptions.

We report on a two-week professional development workshop for middle and high school science teachers offered as part of a three-year Indiana Department of Education Math-Science Partnership grant awarded to Rose-Hulman Institute of Technology (RHIT) and Vigo County School Corporation (VCSC).

There is a need at Rose-Hulman Institute of Technology (RHIT) to increase the fundamental design, measurement, and laboratory skills for both Electrical Engineering and Biomedical Engineering students. Our project aims to improve students' design and practical problem solving skills, increase student interest in Electrical and Computer Engineering (ECE), and Biomedical Engineering (BE), and strengthen students' lab skills. In this project, we will be developing a web-based repository of worked circuit design examples; real world application demos of electrical circuits which visualize active, hands-on learning; and video-based tutorials for electrical circuit laboratory exercises.

The Electrical Engineering curriculum is often coupled with extensive laboratory practice. The primary objectives of these laboratory experiences are to develop measurement and testing skills, draw relationships between classroom theory and real world applications and increase students' interest in the practice of the engineering profession. Traditionally, laboratory exercises that instruct students on the operation of instruments and basic measurement techniques are presented in a written format. For a novice student unfamiliar with the equipment, these written instructions can be confusing and frustrating. In this project, we are creating a web-based repository of video tutorials for electrical circuit laboratory exercises in a sophomore-level Introduction to Electrical Circuits class. We will study the effectiveness of the video-based lab tutorials on improving students' lab skills. In addition, this study will examine the students' preference between the video-based lab tutorials and text-based lab tutorials.

As digital ink technology continues to make an impact on the technical classroom, faculty members are exploring the different strategies for using this technology to improve student learning. The purpose of this panel is to demonstrate how faculty members are implementing this technology in engineering and science classrooms at three different institutions: Rose-Hulman Institute of Technology, University of Texas at Austin, and University of Vermont. The panel is designed to show both experienced pen computing users and those who are new to the field the different ways this versatile technology may be employed. In addition to the demonstrations, the presenters will discuss the pedagogical implications that result from the implementations. Faculty who are interested in both the pedagogy and assessment of pen-based computing in the classroom should find the session informative and useful.

The material specificity of computed tomography is quantified using an experimental benchtop imaging system and a physics-based system model. The apparatus is operated with different detector and system configurations each giving X-ray energy spectral information but with different overlap among the energy-bin weightings and noise statistics. Multislice, computed tomography sinograms are acquired using dual kVp, sequential source filters or a detector with two scintillator/photodiodes layers. Basis-material and atomic number images are created by first applying a material decomposition algorithm followed by filtered backprojection. CT imaging of phantom materials with known elemental composition and density were used for model validation. X-ray scatter levels are measured with a beam-blocking technique and the impact to material accuracy is quantified. The image noise is related to the intensity and spectral characteristics of the X-ray source. For optimal energy separation adequate image noise is required. The system must be optimized to deliver the appropriate high mA at both energies. The dual kVp method supports the opportunity to separately engineer the photon flux at low and high kvp. As a result, an optimized system can achieve superior material specificity in a system with limited acquisition time or dose. In contrast, the dual-layer and sequential acquisition modes rely on a material absorption mechanism that yields weaker energy separation and lower overall performance.

A convolution model of scatter that is adaptable to rapid simulation and correction algorithms is tested against the measured scatter profiles. In the simple case of a uniform acrylic sheet, the convolution approach yields about 10% absolute agreement with the measured scatter profile. However, significant qualitative differences are demonstrated for phantoms with non-uniform thickness or composition. For example, the scatter profile is dependent on a bone's vertical position in the phantom whereas the primary is unchanged. Similarly, a cusp shape in the scatter profile observed near the abrupt edge of an acrylic sheet is not produced in the convolution model. An alternate approach that calculates the scatter as a 3D integral over the object volume can reproduce this behavior.

The purpose of this paper is to investigate the use of electron-beam Computed Tomography (EBCT) dual energy scanning for improved differentiation of calcified coronary arteries from iodinated-contrasted blood, in fast moving cardiac vessels. The dual energy scanning technique can lead to an improved cardiac examination in a single breath hold with more robust calcium scoring and better vessel characterization. Dual energy can be used for material discrimination in CT imaging to differentiate materials with similar CT number, but different material attenuation properties. Mis-registration is the primary source of error in a dual energy application, since acquisitions have to be made at each energy, and motion between the acquisitions causes inconsistencies in the decomposition algorithm, which may lead to artifacts in the resultant images. Using EBCT to quickly switch x-ray source peak voltage potential (kVp), the mis-registration of patient anatomy is minimized since acquisitions at both energy spectra are completed in one study at the same cardiac phase. Two protocols for scanning the moving heart using EBCT were designed to minimize registration issues. Material basis function decomposition was used to differentiate regions containing calcium and iodine in the image. We find that this protocol is superior to CT imaging at one energy spectrum in discriminating calcium from contrast-enhanced lumen. Using dual energy EBCT scanning can enable accurate calcium scoring, and angiography applications to be performed in one exam.

Since the 1970s CT has been used to generatecross-sectional images of human anatomy from x-rayprojection data acquired at many angular positionsaround the body. The development of the first CTscanner is credited to Hounsfield [1], using recon-struction methods developed by Cormack [2]. Sincethen several key technological advancements haveincreased the usefulness of CT to the point where ithas become an essential tool in the clinical evaluationof patients, with most hospitals having CT scannersavailable 24 hours a day, 7 days a week. First-generation CT systems, which used a single, thinx-ray beam and a single detector element to acquirethe x-ray projection data necessary for image recon-struction, quickly evolved into third-generation sys-tems, which use a fan-shaped x-ray beam combinedwith a rotating x-ray tube and detector to acquire thex-ray projection data needed for image reconstruc-tion. With the development of helical CT systems inthe late 1980s [3–6], large sections of anatomy couldbe scanned quickly using linear, continuous table mo-tion, enabling faster throughput and better registrationbetween adjacent slices of the body. Electron beamCT (EBCT) technology, incorporating a stationarydetector and using an x-ray tube comprised of astationary target ring and a swept electron beam,was developed in 1983 to scan the heart and coronaryarteries at subsecond scan times, thereby reducingmotion artifacts resulting from the beating of the heartduring data acquisition [7]. Recently, CT has furtherevolved from single-slice scanners to systems incor-porating multiple detector rows with improved reso-lution, with the introduction of multislice CT (MSCT)in 1998, enabling high-resolution, thin-slice scanningof large sections of human anatomy.Over the years CTscanning has found widespreaduse in imaging applications for trauma assessment,thoracicandvascularstudies,andstrokeassessment,aswellasemergingapplicationsincardiacimaging,lungcancer detection, colonoscopy, and brain and myo-cardial perfusion. The goal of this article is to outlinesome of the recent technological advances that willdrive future CTevolution and to describe the recentlyenabled applications and trends in chest imaging.Image acquisition aspectsImage acquisition with today’s multislice scanneris more flexible when compared with a single-slicescanner because many scanning modes are madeavailable to the clinician. For example, several com-binations of slice thickness and helical pitch can nowbe used to scan the full thorax within a single breath-hold, giving clinicians many options to maximize theclinical value of the acquired images. Because moreprotocol options are available to the clinician, it is im-portanttounderstandtherelationshipbetweenscannerparameters and resulting image quality so that theacquisition can be tailored to meet the particularimaging need. Some of the key geometric parametersare identified in Fig. 1, a third-generation CTsystem.Two important characteristics to consider whenthinking about CT image quality are spatial resolu-tion and image noise. The key imaging parameters

In addition to a conventional Computed Tomography (CT) image, dual energy (dual kVp) imaging can be used to generate an image of the same anatomy that represents the equivalent density of a particular material, for example, calcium, iodine, water, etc. This image can be used to improve the differentiation of materials as well as improve the accuracy of absolute density measurements in a cross-sectional image. It is important to understand the certainty of the estimation of the density of the material. Both simulations and measurements are used to quantify these errors. Data are acquired using a flat-panel based volumetric CT system, by taking two scans and adjusting the maximum energy of the source spectrum (kVp). Physics based simulations are used to compare with the measurements. After validating the simulation algorithms, the accuracy of the dual kVp method is determined using the simulations in a perturbation study.

Dose is becoming increasingly important for computed tomography clinical practice. It is of general interest to understand the impact that system design can have on dose and image quality. This study addresses the effect of bowtie shape on the dose and contrast-to-noise across the field of view. Simulation of the CT acquisition is used to calculate the energy deposition throughout a numerical phantom for a set of relevant system operating parameters and bowtie shapes. Mean absorbed dose is calculated by summing over the phantom volume and is compared with other typical dose specifications. A more aggressive attenuation profile of the bowtie which offers higher attenuation in the periphery of the field of view can offer the benefit of lower dose but at the expense of reduced contrast-to-noise at the edge of the cross-sectional image.

A framework for rapid and reliable design of Volumetric Computed Tomography (VCT) systems is presented. This work uses detailed system simulation tools to model standard and anthropomorphic phantoms in order to simulate the CT image and choose optimal system specifications. CT systems using small-pitch, 2-D flat area detectors, initially developed for x-ray projection imaging, have been proposed to implement Volume CT for clinical applications. Such systems offer many advantages, but there are also many trade-offs not fully understood that affect image quality. Although many of these effects have been studied in the literature for traditional CT applications, there are unique interactions for very high-resolution flat-panel detectors that are proposed for volumetric CT. To demonstrate the process we describe an example that optimizes the parameters to achieve high detectability for thin slices. The VCT system was modeled over a range of operating parameters, including: tube voltage, tube current, tube focal spot size, detector cell size, number of views, and scintillator thickness. The response surface, which captures the effects of system components on image quality, was calculated. Optimal and robust designs can be achieved by determining an operating point from the response equations, given the constraints. We verify the system design with images from standard and low contrast phantoms. Eventually this design tool could be used, in conjunction with clinical researchers, to specify VCT scanner designs, optimize imaging protocols, and quantify image accuracy and repeatability.