There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Summary Background Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics of patients with COVID-19 have been reported but risk factors for mortality and a detailed clinical course of illness, including viral shedding, have not been well described. Methods In this retrospective, multicentre cohort study, we included all adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Jinyintan Hospital and Wuhan Pulmonary Hospital (Wuhan, China) who had been discharged or had died by Jan 31, 2020. Demographic, clinical, treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Findings 191 patients (135 from Jinyintan Hospital and 56 from Wuhan Pulmonary Hospital) were included in this study, of whom 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients). Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p Interpretation The potential risk factors of older age, high SOFA score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage. Prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future. Funding Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences; National Science Grant for Distinguished Young Scholars; National Key Research and Development Program of China; The Beijing Science and Technology Project; and Major Projects of National Science and Technology on New Drug Creation and Development.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study

With digital equipment becoming increasingly networked, either on wired or wireless networks, for personal and professional use alike, distributed software systems have become a crucial element in information and communications technologies. The study of these systems forms the core of the ARLES' work, which is specifically concerned with defining new system software architectures, based on the use of emerging networking technologies. In this context, we concentrate on the study of distributed systems which bring to life the vision of ubiquitous computing systems, also known as ambient intelligence.

반도체 공정 overview

Background: About a third of home-dwelling older people fall each year, and institutionalized older people even report a two- or threefold higher rate for falling

Sensitivity and false alarm rate of a fall sensor in long-term fall detection in the elderly

Mobile devices are becoming increasingly sophisticated and the latest generation of smart cell phones now incorporates many diverse and powerful sensors These sensors include GPS sensors, vision sensors (ie, cameras), audio sensors (ie, microphones), light sensors, temperature sensors, direction sensors (ie, magnetic compasses), and acceleration sensors (ie, accelerometers) The availability of these sensors in mass-marketed communication devices creates exciting new opportunities for data mining and data mining applications In this paper we describe and evaluate a system that uses phone-based accelerometers to perform activity recognition, a task which involves identifying the physical activity a user is performing To implement our system we collected labeled accelerometer data from twenty-nine users as they performed daily activities such as walking, jogging, climbing stairs, sitting, and standing, and then aggregated this time series data into examples that summarize the user activity over 10- second intervals We then used the resulting training data to induce a predictive model for activity recognition This work is significant because the activity recognition model permits us to gain useful knowledge about the habits of millions of users passively---just by having them carry cell phones in their pockets Our work has a wide range of applications, including automatic customization of the mobile device's behavior based upon a user's activity (eg, sending calls directly to voicemail if a user is jogging) and generating a daily/weekly activity profile to determine if a user (perhaps an obese child) is performing a healthy amount of exercise

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Activity recognition using cell phone accelerometers

The application of transparent conductive films to flexible biomedical optoelectronics is limited by stringent requirements on the candidate materials' electromechanical and optical properties as well as their biological performance. Thin films of graphene and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) are sought as mechanically flexible alternatives to traditional indium tin oxide (ITO). However, they require more understanding of their suitability for biomedical optoelectronic devices in terms of transmission behavior and electromechanical stability. This study shows that the relative increase in sheet resistance under cyclic loading for ITO, graphene, and PEDOT:PSS was $3546\pm3908\%,12\pm2.7\%$, and $62\pm 68\%$, respectively. Moreover, graphene and PEDOT:PSS showed a transmission uniformity of 9.3% and 36.3% (380–2000 nm), respectively, compared with ITO film (61%). Understanding the optical, electrical, and mechanical limits of the transparent conductive films facilitates the optimization of flexible optoelectronic designs to fit multiple biomedical research and clinical applications.

Electromechanical Stability and Transmission Behavior of Transparent Conductive Films for Biomedical Optoelectronic Devices

Active lumbar spine movement was acquired and analyzed using a computer controlled data acquisition and analysis system. A 3Space Isotrak was used to record rotational displacement and velocity in three dimensions. The Isotrak was interfaced to a Macintosh computer running LabVIEW software to display real-time kinematic parameters. Results from five subjects showed ranges of motion in the sagittal plane to be in accordance with previous literature reports. This paper is one of the first to analyze the parameter of velocity as a component of lumbar spine motion.

A system for kinematic analysis of lumbar spine motion

Fall events and their severe consequences represent not only a threatening problem for the affected individual, but also cause a significant burden for health care systems. Our research work aims to elucidate some of the prospects and problems of current sensor-based fall risk assessment approaches. Selected results of a questionnaire-based survey given to experts during topical workshops at international conferences are presented. The majority of domain experts confirmed that fall risk assessment could potentially be valuable for the community and that prediction is deemed possible, though limited. We conclude with a discussion of practical issues concerning adequate outcome parameters for clinical studies and data sharing within the research community. All participants agreed that sensor-based fall risk assessment is a promising and valuable approach, but that more prospective clinical studies with clearly defined outcome measures are necessary.

/pdf/sensor-based-fall-risk-assessment-dagger-of-the-mind-4uh3q8osru.pdf

Sensor-based fall risk assessment - dagger of the mind?

Atrial fibrillation (AF) is mostly treated via robotic catheter-based cardiac ablation procedures. Over the last few decades, cables or tendon mechanisms are at the core of available cardiac catheters. Despite advances, the use of cables often results in considerable force loss, nonlinear hysteresis, and control challenges. Most catheters are not equipped with force sensing, which increases the risk of the ablation process and decreases their efficacy in clinical settings. In addition, current catheters have a poor user interface and therefore the ablation process requires skilled or trained surgeons to steer the complex motion of the catheter tip within the heart chambers. To improve the cardiac ablation procedure, a new robotic catheter that has the ability to extend its working space without moving its flexible body and a real-time force sensor for safe operation is highly desired. In this work, a new handheld and soft robotic catheter for AF ablation is introduced. The new device consists of several improved components such as a soft manipulator for navigation and bending motion, an ergonomic handheld controller, and a soft force sensor for monitoring tool-tissue contact. The design, modeling, and fabrication of the device are presented and followed by experimental characterizations and ex-vivo validation.

A Handheld Hydraulic Cardiac Catheter with Omnidirectional Manipulator and Touch Sensing

Initial studies in five conscious dogs with their baroreceptors either intact or surgically isolated, demonstrate that deterministic chaos is likely to exist In both heart interval and mean arterial blood pressure. The nature of this chaotic activity is not qualitatively different between the intact and open loop preparations. To assess nonlinear dynamical behavior, the authors constructed phase space trajectories from the time series data. The fractal dimension of the reconstructed trajectories was measured using the Grassberger-Procaccia algorithm. In four out of five dogs the fractal dimension of the reconstructed trajectory did not clearly converge for embedding dimensions up to 5. In one dog the fractal dimension of the attractor converged to a value between 2 and 3 for both heart interval and blood pressure in open and closed loop cases. Further evidence for deterministic chaos was provided by the reliability of data forecasts based on the fractal attractor.

Nigel H. Lovell

Papers

Electromechanical Stability and Transmission Behavior of Transparent Conductive Films for Biomedical Optoelectronic Devices

A system for kinematic analysis of lumbar spine motion

Sensor-based fall risk assessment - dagger of the mind?

A Handheld Hydraulic Cardiac Catheter with Omnidirectional Manipulator and Touch Sensing

Chaotic behavior of blood pressure and heart rate in the conscious dog