Debatable issues in automated ECG reporting

Although automated ECG analysis has been available for many years, there are some aspects which require to be re-assessed with respect to their value while newer techniques which are worthy of review are beginning to find their way into routine use. At the annual International Society of Computerized Electrocardiology conference held in April 2017, four areas in particular were debated. These were a) automated 12 lead resting ECG analysis; b) real time out of hospital ECG monitoring; c) ECG imaging; and d) single channel ECG rhythm interpretation. One speaker presented the positive aspects of each technique and another outlined the more negative aspects. Debate ensued. There were many positives set out for each technique but equally, more negative features were not in short supply, particularly for out of hospital ECG monitoring

Heart Rate Variability Measurement and Clinical Depression in Acute Coronary Syndrome Patients: Narrative Review of Recent Literature

Aim: We aimed to explore links between heart rate variability (HRV) and clinical depression in patients with acute coronary syndrome (ACS), through a review of recent clinical research literature. Background: Patients with ACS are at risk for both cardiac autonomic dysfunction and clinical depression. Both conditions can negatively impact the ability to recover from an acute physiological insult, such as unstable angina or myocardial infarction, increasing the risk for adverse cardiovascular outcomes. HRV is recognized as a reflection of autonomic function. Methods: A narrative review was undertaken to evaluate state-of-the-art clinical research, using the PubMed database, January 2013. The search terms “heart rate variability” and “depression” were used in conjunction with “acute coronary syndrome”, “unstable angina”, or “myocardial infarction” to find clinical studies published within the past 10 years related to HRV and clinical depression, in patients with an ACS episode. Studies were included if HRV measurement and depression screening were undertaken during an ACS hospitalization or within 2 months of hospital discharge. Results: Nine clinical studies met the inclusion criteria. The studies’ results indicate that there may be a relationship between abnormal HRV and clinical depression when assessed early after an ACS event, offering the possibility that these risk factors play a modest role in patient outcomes. Conclusion: While a definitive conclusion about the relevance of HRV and clinical depression measurement in ACS patients would be premature, the literature suggests that these measures may provide additional information in risk assessment. Potential avenues for further research are proposed

Stroke saturation on a MEMS deformable mirror for woofer-tweeter adaptive optics

High-contrast imaging of extrasolar planet candidates around a main-sequence star has recently been realized from the ground using current adaptive optics (AO) systems. Advancing such observations will be a task for the Gemini Planet Imager, an upcoming "extreme" AO instrument. High-order "tweeter" and low-order "woofer" deformable mirrors (DMs) will supply a >90%-Strehl correction, a specialized coronagraph will suppress the stellar flux, and any planets can then be imaged in the "dark hole" region. Residual wavefront error scatters light into the DM-controlled dark hole, making planets difficult to image above the noise. It is crucial in this regard that the high-density tweeter, a micro-electrical mechanical systems (MEMS) DM, have sufficient stroke to deform to the shapes required by atmospheric turbulence. Laboratory experiments were conducted to determine the rate and circumstance of saturation, i.e. stroke insufficiency. A 1024-actuator 1.5-um-stroke MEMS device was empirically tested with software Kolmogorov-turbulence screens of r_0=10-15cm. The MEMS when solitary suffered saturation ~4% of the time. Simulating a woofer DM with ~5-10 actuators across a 5-m primary mitigated MEMS saturation occurrence to a fraction of a percent. While no adjacent actuators were saturated at opposing positions, mid-to-high-spatial-frequency stroke did saturate more frequently than expected, implying that correlations through the influence functions are important. Analytical models underpredict the stroke requirements, so empirical studies are important.Comment: 16 pages, 10 figure

Effect of Wavefront Error on 10^-7 Contrast Measurements

We have measured a contrast of 6.5 {center_dot} 10{sup -8} from 10-25{lambda}/D in visible light on the Extreme Adaptive Optics testbed using a shaped pupil for diffraction suppression. The testbed was designed with a minimal number of high-quality optics to ensure low wavefront error and uses a phase shifting diffraction interferometer for metrology. This level of contrast is within the regime needed for imaging young Jupiter-like planets, a primary application of high-contrast imaging. We have concluded that wavefront error, not pupil quality, is the limiting error source for improved contrast in our system

Fabrication and testing of optics for EUV projection lithography

Extreme Ultraviolet Lithography (EUVL) is a leading candidate as a stepper technology for fabricating the next generation of microelectronic circuits. EUVL is an optical printing technique qualitatively similar to Deep UV Lithography (DUVL), except that 11-13nm wavelength light is used instead of 193-248nm. The feasibility of creating 0.1µm features has been well-established using small- field EUVL printing tools, and development efforts are currently underway to demonstrate that cost- effective production equipment can be engineered to perform full-width ring-field imaging consistent with high wafer throughput rates. Ensuring that an industrial supplier base will be available for key components and subsystems is crucial to the success of EUVL. In particular, the projection optics are the heart of the EUVL imaging system, yet they have figure and finish specifications that are beyond the state-of-the-art in optics manufacturing. Thus it is important to demonstrate that industry will be able to fabricate and certify these optics commensurate with EUVL requirements. The goal of this paper is to demonstrate that procuring EUVL projection optical substrates is feasible

Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome

We studied 735 patients who activated “911” for chest pain and/or anginal equivalent symptoms and received 12-lead ECG monitoring with specialized ischemia monitoring software in the ambulance. Prehospital electrocardiograms (PH ECG) were analyzed to determine the proportion of patients who present with completely normal PH ECG findings (absence of ischemia/infarction, arrhythmia, or any other abnormality) and to compare outcomes amongst patients with and without any PH ECG abnormality

eXtreme Adaptive Optics Planet Imager: overview and status

As adaptive optics (AO) matures, it becomes possible to envision AO systems oriented towards specific important scientific goals rather than general-purpose systems. One such goal for the next decade is the direct imaging detection of extrasolar planets. An "extreme" adaptive optics (ExAO) system optimized for extrasolar planet detection will have very high actuator counts and rapid update rates - designed for observations of bright stars - and will require exquisite internal calibration at the nanometer level. In addition to extrasolar planet detection, such a system will be capable of characterizing dust disks around young or mature stars, outflows from evolved stars, and high Strehl ratio imaging even at visible wavelengths. The NSF Center for Adaptive Optics has carried out a detailed conceptual design study for such an instrument, dubbed the eXtreme Adaptive Optics Planet Imager or XAOPI. XAOPI is a 4096-actuator AO system, notionally for the Keck telescope, capable of achieving contrast ratios >10^7 at angular separations of 0.2-1". ExAO system performance analysis is quite different than conventional AO systems - the spatial and temporal frequency content of wavefront error sources is as critical as their magnitude. We present here an overview of the XAOPI project, and an error budget highlighting the key areas determining achievable contrast. The most challenging requirement is for residual static errors to be less than 2 nm over the controlled range of spatial frequencies. If this can be achieved, direct imaging of extrasolar planets will be feasible within this decade

Calibration of symmetric and non-symmetric errors for interferometry of ultra-precise imaging systems

The azimuthal Zernike coefficients for shells of Zernike functions with shell numbers n<N may be determined by making measurements at N equally spaced rotational positions. However, these measurements do not determine the coefficients of any of the purely radial Zernike functions. Label the circle that the azimuthal Zernikes are measured in as circle A. Suppose that the azimuthal Zernike coefficients for n<N are also measured in a smaller circle B which is inside circle A but offset so that it is tangent to circle A and so that it has the center of circle A just inside its circular boundary. The diameter of circle B is thus only slightly larger than half the diameter of circle A. From these two sets of measurements, all the Zernike coefficients may be determined for n<N. However, there are usually unknown small rigid body motions of the optic between measurements. Then all the Zernike coefficients for n<N except for piston, tilts, and focus may be determined. We describe the exact mathematical algorithm that does this and describe an interferometer which measures the complete wavefront from pinholes in pinhole aligners. These pinhole aligners are self-contained units which include a fiber optic, focusing optics, and a 'pinhole mirror'. These pinhole aligners can then be used in another interferometer so that its errors would then be known. Physically, the measurements in circles A and B are accomplished by rotating each pinhole aligner about an aligned axis, then about an oblique axis. Absolute measurement accuracies better than 0.2 nm were achieved

Construction and testing of wavefront reference sources for interferometry of ultra-precise imaging systems

We have built and calibrated a set of 532-nm wavelength wavefront reference sources that fill a numerical aperture of 0.3. Early data show that they have a measured departure from sphericity of less than 0.2 nm RMS (0.4 milliwaves) and a reproducibility of better than 0.05 nm rms. These devices are compact, portable, fiber-fed, and are intended as sources of measurement and reference waves in wavefront measuring interferometers used for metrology of EUVL optical elements and systems. Keys to wave front accuracy include fabrication of an 800-nm pinhole in a smooth reflecting surface as well as a calibration procedure capable of measuring axisymmetric and non-axisymmetric errors

Os saberes a ensinar e para ensinar matemática e suas relações com o ensino industrial brasileiro

Disponível em: http://revistas.upel.edu.ve/index.php/paradigma/article/view/6907/0Este trabalho é parte de uma pesquisa de doutorado que se preocupa em investigar o ensino de matemática no Liceu e na Escola Industrial de Florianópolis no período de 1937 a 1961. O objetivo é identificar os saberes a ensinar e para ensinar nos cursos do Liceu Industrial e da Escola Industrial de Florianópolis e quais as principais mudanças no ensino de Mat emática destas instituições de ensino industrial. Foram utilizados como referenciais teóricos Chervel (1990) sobre história das disciplinas escolares, Julia (2001) sobre cultura escolar , Hofstetter & Valente (2017) a respeito dos saberes a ensinar , Hofstet ter et al . (2017) na definição dos experts e Cellard (2008) para a análise documental . Percebeu - se que o ensino de Matemática era voltado para cálculos básicos, pois o enfoque era formar o aluno para a indústria, apesar de se intensificar o ensino de Álgeb ra e Trigonometria no início dos anos de 1940. Palavras - chave: Ensino Industrial. História da Educação Matemática. Experts . Saberes a ensinar. Saberes para ensinar