Accuracy and predictability of novel MS Excel-based surgically induced astigmatism calculator

Study of steepening, flattening, clockwise, and counter-clockwise torque effect is indispensable to understand and design surgical induced astigmatism calculator. Hence, in this study by constructing a novel Microsoft Office Excel 2007 based astigmatic calculator following cataract surgery, analysis on the accuracy and predictability evaluated for the performance. Post-cataract surgery patients from May 2019 to January 2020 at a tertiary medical institution recruited for this present study. Based on Pythagoras principle, MS Excel calculator designed and the law of cousins for calculating the vector magnitude and axis respectively. Manual keratometry measurements for pre and postoperative horizontal (Kh) and vertical (Kv) curvatures established, and statistical analysis for the resultant SIA magnitude and axis deduced with Medcalc software comparing with the existing SIA 2.1 version calculator. A total of 29 eyes of 25 patients studied with a mean age of 62.55 (±8.08) years, males contributing to 14 (56%), and right laterally in 17 (58%) eyes. MS Excel and SIA 2.1 versions calculated a mean SIA magnitude of 0.66 (±0.47) D and 0.64 (±0.55) D respectively. Pearson coefficient correlation (r=-0.16, p=0.40), paired-two sample test (t value= 0.11, p= 0.91) and ROC curve analysis (AUC = 0.75, p= 0.34, 95% CI= 0.25 to 0.99) calculated. Regression equation (y = 0.75 + -0.14 x) and limits of agreements (95% CI -0.29 to 0.31) analyzed, and, 95% of data points distributed within ±1.96 SD of the line of equality on Bland-Altman difference plots.The present calculator proclaimed an acceptable accuracy and agreement with a prediction of 0.61 Diopter for every unit change in the magnitude of SIA 2.1 software in addition to consideration of interchangeability.

Real & Simulated QPSK Up-Converted Signals by a Sampling Method Using a Cascaded MZMs Link

This study focuses on a novel concept of transmitting of a quadrature phase shift keying (QPSK) modulation by an electro-optical frequency up-conversion using a cascaded Mach–Zehnder modulators (MZMs) link. Furthermore, we conduct and compare the results obtained by simulations using the Virtual Photonics Inc. (VPI) (Berlin, Germany) simulator and real-world experiments. The design and operating regime peculiarities of the MZM used as a sampling up-converter mixer in a radio over fiber (RoF) system are also analyzed. Besides, the simulation and experimental results of static and dynamic characteristics of the MZM have approximately the same behavior. The conversion gain of the cascaded MZMs link is simulated over many mixing frequencies and it can decrease from 17.5 dB at 8.3 GHz to −4.5 dB at 39.5 GHz. However, in real world settings, it may decrease from 15.5 dB at 8.3 GHz to −6 dB at 39.5 GHz. The maximum frequency range is attained at 78.5 GHz for up-conversion through simulations. Error vector magnitude (EVM) values have been done to evaluate the performance of our system. An EVM of 16% at a mixing frequency of 39.5 GHz with a bit rate of 12.5 Gbit/s was observed with the considering sampling technique, while it reached 19% in real-world settings with a sampling frequency of 39.5 GHz and a bit rate of 12.5 Gbit/s.

Noise resistance territorial intensity-based optical flow using inverse confidential technique on bilateral function

This paper presents the use of the inverse confidential technique on bilateral function with the territorial intensity-based optical flow to prove the effectiveness in noise resistance environment. In general, the image’s motion vector is coded by the technique called optical flow where the sequences of the image are used to determine the motion vector. But, the accuracy rate of the motion vector is reduced when the source of image sequences is interfered by noises. This work proved that the inverse confidential technique on bilateral function can increase the percentage of accuracy in the motion vector determination by the territorial intensity-based optical flow under the noisy environment. We performed the testing with several kinds of non-Gaussian noises at several patterns of standard image sequences by analyzing the result of the motion vector in a form of the error vector magnitude (EVM) and compared it with several noise resistance techniques in territorial intensity-based optical flow method.

BrainWear: Longitudinal, objective assessment of physical activity in 42 High Grade Glioma (HGG) patients

Aims In patients with HGG, we know that QoL and physical function decline with progressive disease (PD) and fatigue is a strong predictor of survival in recurrent disease. Despite notable technical advances in therapy for in the past decade, survival has not improved. The role of physical function as a predictor of QoL, treatment tolerance and as an early indicator of worsening morbidity (e.g. tumour recurrence) is an area of growing importance. Recent advancements in wearable technology allow us the opportunity to gather high-quality, continuous and objective data BrainWear is a feasibility study collecting longitudinal physical activity (PA) data from patients with primary and secondary brain tumours and we hypothesise changes in PA over time, are a potentially sensitive biomarker for PD both at diagnosis and relapse. Method Here we show early analysis of this novel dataset of 42 HGG patients and will present: 1) feasibility and acceptability 2) how digitally captured PA changes through treatment and at PD/hospitalization 3) the correlation between patient reported outcomes (PRO) and PA data 4) how PA in HGG patients compares with healthy UK Biobank participants. PA data is collected via a wrist-worn accelerometer. Raw accelerometer data is processed using the UK Biobank Accelerometer Analysis pipeline in python 3.7, and evaluated for good quality wear-time. Overall activity is represented as vector magnitude in milligravity units(mg) and a machine-learning classifier classifies daily activity into 5 separate groups (walking, tasks-light, moderate, sedentary and sleep). Descriptive statistics summarise baseline characteristics and unadjusted mean used to present vector magnitude and accelerometer-predicted functional behaviours (in h/day) by age, sex, radiotherapy and weekend days. Mixed effect models for repeated measures are used for longitudinal data evaluation of PA. Results Between October 2018 and March 2021, 42 patients with a suspected HGG were recruited; 16 females and 26 males with a median age of 59. 40 patients had surgery and 35 patients had adjuvant primary radiotherapy, 23 of whom had a 6-week course. They have provided 3458 days of accelerometer data, 80% of which has been classified as good quality wear-time. There are no statistical differences in mean activity between gender, patients >60 years show statistical difference in time spent doing moderate activity compared to those <60 years, and there are significant differences in mean vector magnitude and walking between radiotherapy and non-radiotherapy days. In patients having a 6-week RT course, time spent in daily moderate activity falls 4-fold between week 1 and the second week following RT completion (70 minutes to 16 minutes). HGG versus healthy UK Biobank participants shows significant differences in all measures of PA. Conclusion Here we present preliminary analysis of this highly novel dataset in adult high grade glioma patients, and show digital remote health monitoring is feasible and acceptable with 80% of data classified as high quality wear-time suggesting good patient adherence. We are able to objectively describe how PA changes through standard treatments and understand the inter and intra-patient variation in PA, and whether there are correlates with patient-centred measures, clinical measures and early indicators of worsening disease. We will present further data on changes in PA prior to hospitalisation and at disease progression, and discuss some of the challenges of running a digital health trial. The passive and objective nature of wearable activity monitors gives clinicians the opportunity to evaluate and monitor the patient in motion, rather than the episodic snapshot we currently see, and in turn has the potential to improve our clinical decision making and potentially outcomes.

Reproducibility of global electrical heterogeneity measurements on 12-lead ECG: The Multi-Ethnic Study of Atherosclerosis.

Objective: Vectorcardiographic (VCG) global electrical heterogeneity (GEH) metrics showed clinical usefulness. We aimed to assess the reproducibility of GEH metrics. Methods: GEH was measured on two 10-second 12-lead ECGs recorded on the same day in 4,316 participants of the Multi-Ethnic Study of Atherosclerosis (age 69.4 ± 9.4 y; 2317(54%) female, 1728 (40%) white, 1138(26%) African-American, 519(12%) Asian-American, 931(22%) Hispanic-American). GEH was measured on a median beat, comprised of the normal sinus (N), atrial fibrillation/flutter (S), and ventricular-paced (VP) beats. Spatial ventricular gradient's (SVG's) scalar was measured as sum absolute QRST integral (SAIQRST) and vector magnitude QT integral (VMQTi). Results: Two N ECGs with heart rate (HR) bias of -0.64 (95% limits of agreement [LOA] -5.68 to 5.21) showed spatial area QRS-T angle (aQRST) bias of -0.12 (95%LOA -14.8 to 14.5). Two S ECGs with HR bias of 0.20 (95%LOA -15.8 to 16.2) showed aQRST bias of 1.37 (95%LOA -33.2 to 35.9). Two VP ECGs with HR bias of 0.25 (95%LOA -3.0 to 3.5) showed aQRST bias of -1.03 (95%LOA -11.9 to 9.9). After excluding premature atrial or ventricular beat and two additional beats (before and after extrasystole), the number of cardiac beats included in a median beat did not affect the GEH reproducibility. Mean-centered log-transformed values of SAIQRST and VMQTi demonstrated perfect agreement (Bias 0; 95%LOA -0.092 to 0.092). Conclusion: GEH measurements on N, S, and VP median beats are reproducible. SVG's scalar can be measured as either SAIQRST or VMQTi. Significance: Satisfactory reproducibility of GEH metrics supports their implementation.

Detection of Constellation-Modulated Wireless Covert Channel Based on Adjusted CNN Model

With the development of wireless communication technology, more and more information leakage is realized through a wireless covert channel, which brings great challenges to the security of wireless communication. Compared with the wireless covert channel on the upper layer, the wireless covert channel based on the physical layer (WCC-P) has better concealment and greater capacity. As the most widely used scheme of WCC-P, the wireless covert channel with the modulation of the constellation point (WCC-MC) has attracted more and more attention. In this paper, a deep learning scheme based on amplitude-phase characteristics is proposed to detect and classify the WCC-MC scheme. We first extract the amplitude and phase characteristic of error vector magnitude (EVM) and constellation points and then map the amplitude and phase characteristic to the grayscale image, respectively. Finally, the generated feature images are trained, detected, and classified with the adjusted convolution neural network. The experimental results show that the detection accuracy of our proposed scheme can reach 98.5%, and the classification accuracy can reach 81.7%.

The use of vector electrocardiography for pulmonary hypertension screening in patients with atrial septal defects

Funding Acknowledgements Type of funding sources: None. Background Patients with unrepaired atrial septal defects accumulate yearly risk of developing pulmonary arterial hypertension due to vascular remodeling in response to chronically increased pulmonary circulation. Electrocardiography, though readily available, has so far been of limited screening utility in this population. We hypothesize that vectorcardiographic parameters will aid in identifying increased ventricular afterload and thus provide an additional screening tool for pulmonary hypertension in this patient population. Purpose To establish whether vector electrocardiography can be used as a non-invasive screening tool for pulmonary hypertension screening in patients with atrial septal defects. Methods Retrospective chart review of patients with the diagnosis of secundum atrial septal defect who underwent cardiac catheterization at the University of Minnesota from January 2012 to September 2020. We excluded patients with other congenital heart diagnoses, insufficient hemodynamic data, or no sinus rhythm electrocardiogram. An electrocardiogram prior to or on the day of the intervention was assessed. Parameters analyzed include: Sokolow-Lion right ventricular hypertrophy criteria, PR duration, QRS duration, corrected QT intervals, QRS and Twave frontal plane axes, rSR’, rSR’ with the R’ of 5mm or more, as well as vectorcardiographic parameters (Kohr’s regression-related method) the QRS vector magnitude, T wave vector magnitude, and spatial QRS-T angle. These results were then used to compare those with and without pulmonary hypertension (diagnosed by mean pulmonary artery pressure of 25mmHg or more along with body surface area-indexed pulmonary vascular resistance of 3 Woods units/meter squared with normal left atrial/pulmonary vein wedge pressure). Mann-Whitney U-testing was used for non-parametric testing for significance within the dataset. Results Three hundred and five patients were identified with secundum atrial septal defects, but after exclusion, there were a total of 122 patients meeting criteria for assessment. Eight ASD patients had pulmonary hypertension (37% male, median age 7.5 years, interquartile range 0.4 to 23 years) while 114 patients did not (31% male, median age 5 years, interquartile range 3 to 13 years, p-value 0.68). Only the spatial QRS-T angle significantly differentiated pulmonary hypertension (median 104 degrees, interquartile range 55 to 137 degrees) from those ASD patients without pulmonary hypertension (median 37 degrees, interquartile range 21 to 63 degrees) with a p-value of 0.002. At a cut-off of 124 degrees, the positive and negative predictive values for identification of pulmonary hypertension was 36.4% and 96.4%, respectively, with an odds ratio of 13.4 (95% confidence interval of 2.9 to 63.7). Conclusions The spatial QRS-T angle may be a useful, non-invasive screening tool for pulmonary hypertension in patients with secundum atrial septal defects.

Research of the Influence of the Quadrature Components Mismatch on the Noise Immunity of OFDM and UFMC Signals

Метод непосредственной модуляции с использованием комплексных сигналов применяется при реализации сигнальных трактов передатчиков в базовых станциях систем сотовой связи. В процессе модуляции возникают рассогласования коэффициента усиления и фазы квадратурных составляющих сигнала. Рассогласование ухудшает модуль вектора ошибки (Error Vector Magnitude, EVM) в приемнике, что, в свою очередь, приводит к повышению частоты появления ошибочных битов (Bit Error Rate, BER). Качество принимаемого сигнала выражается в частоте появления битовых ошибок. Рассогласование амплитуды и фазы квадратурных составляющих является одним из важнейших факторов, вносящих наибольший вклад в амплитуду вектора ошибки, который необходимо исследовать.В статье приведено исследование влияния рассогласования квадратурных составляющих сигналов технологий OFDM (Orthogonal frequency-division multiplexing) и UFMC (universal filtered multi-carrier). Разработана модель передатчика, канала связи и приемника для сигналов OFDM и UFMC. Модель построена в програм­мной среде MatLab при помощи языка MatLab и представляет собой программную модель m-script.В ходе работы путем исследования имитационной модели изучена зависимость помехоустойчивости технологий путем изменения параметров канала связи, таких как амплитудное и фазовое рассогласование квадратурных составляющих сигнала, а также отношение сигнал/шум. Проведен сравнительный анализ таких параметров сигналов, как занимаемая полоса частот, пик-фактор, частота появления битов с ошибкой. По результатам исследования получены графики зависимости вероятности ошибки и пик-фактора сигнала от рассогласования квадратурных составляющих для двух технологий – OFDM и UFMC. Проведенное исследование позволяет выделить преимущества технологии UFMC, которые выражаются в спектральной эффективности, помехоустойчивости и уровне пик-фактора сигнала.