scholarly journals Efficient Fiducial Point Detection of ECG QRS Complex Based on Polygonal Approximation

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4502 ◽  
Author(s):  
Seungmin Lee ◽  
Yoosoo Jeong ◽  
Daejin Park ◽  
Byoung-Ju Yun ◽  
Kil Park
Keyword(s):  
Morphological Changes ◽  
Polygonal Approximation ◽  
Qrs Complex ◽  
Fiducial Point ◽  
Change Rate ◽  
Practical Applications ◽  
Auxiliary Signal ◽  
Electrocardiogram Signal ◽  
Feature Values ◽  
Point Detection

Electrocardiogram signal analysis is based on detecting a fiducial point consisting of the onset, offset, and peak of each waveform. The accurate diagnosis of arrhythmias depends on the accuracy of fiducial point detection. Detecting the onset and offset fiducial points is ambiguous because the feature values are similar to those of the surrounding sample. To improve the accuracy of this paper’s fiducial point detection, the signal is represented by a small number of vertices through a curvature-based vertex selection technique using polygonal approximation. The proposed method minimizes the number of candidate samples for fiducial point detection and emphasizes these sample’s feature values to enable reliable detection. It is also sensitive to the morphological changes of various QRS complexes by generating an accumulated signal of the amplitude change rate between vertices as an auxiliary signal. To verify the superiority of the proposed algorithm, error distribution is measured through comparison with the QT-DB annotation provided by Physionet. The mean and standard deviation of the onset and the offset were stable as − 4.02 ± 7.99 ms and − 5.45 ± 8.04 ms, respectively. The results show that proposed method using small number of vertices is acceptable in practical applications. We also confirmed that the proposed method is effective through the clustering of the QRS complex. Experiments on the arrhythmia data of MIT-BIH ADB confirmed reliable fiducial point detection results for various types of QRS complexes.

Microscopic characteristic of biological iron sulfide composites during the generation process and the association with treatment effect on heavy metal wastewater

2014 ◽  
Vol 70 (7) ◽  
pp. 1292-1297 ◽  
Author(s):  
Yang Yang ◽  
Yifei Xie ◽  
Xudong Li ◽  
Jingchao Zhou ◽  
Jingwei Liu
Keyword(s):  
Heavy Metal ◽  
Stationary Phase ◽  
Iron Sulfide ◽  
Treatment Time ◽  
Environmental Concern ◽  
Morphological Changes ◽  
Generation Process ◽  
Toxic Heavy Metals ◽  
Practical Applications ◽  
Heavy Metal Wastewater

Heavy metal pollution is a serious environmental concern worldwide, resulting in both environmental and human harm. Recently, studies have shown that environmental biotechnologies based on sulfate reduction offer a potential for removal of toxic heavy metals. Biological iron sulfide composites are iron sulfide compounds generated in situ by sulfate-reducing bacteria. In this study, microscopic morphological changes during the composites' generation process were studied, and the effect of biological iron sulfide composites in different generation phases on treatment of heavy metal wastewater was investigated to establish the correlation between macro-effect and micro-properties. The results revealed that the generation process of biological iron sulfide composites occurs in three phases: the formation phase, stationary phase, and agglomeration phase. The stationary phase can be divided into a pre-stationary phase and post-stationary phase. It was found that the best treatment time for Cr6+ is in the pre-stationary phase, while the best treatment time for Cu2+and Cd2+ is in the post-stationary phase. The results of this study further prove the benefits of treatment of heavy metal wastewater using biological sulfide composites and provide theoretical guidance in practical applications.

scholarly journals PREDICTIVE EQUATIONS REGARDING COASTAL TRANSPORTS

1976 ◽  
Vol 1 (15) ◽  
pp. 65 ◽  
Author(s):  
D.H. Swart
Keyword(s):  
Sediment Transport ◽  
Morphological Changes ◽  
Predictive Equations ◽  
Practical Applications ◽  
Engineering Problems

Morphological changes are the result of gradients in longshore and onshore-offshore sediment transport. The coastal engineer is continually faced with engineering problems in which a quantitative knowledge of these morphological changes is required. For this purpose predictive equations have been developed for both longshore and onshore-offshore sediment transport, which are being used in practical applications. In this paper a few of these predictive techniques, as well as one of their typical applications, viz. to a beachfill problem, will be discussed.

scholarly journals Endothelin in the perinatal circulation

2003 ◽  
Vol 81 (6) ◽  
pp. 644-653 ◽  
Author(s):  
Thérèse Perreault ◽  
Flavio Coceani
Keyword(s):  
Pulmonary Hypertension ◽  
Transition Period ◽  
Morphological Changes ◽  
Ductus Arteriosus ◽  
Negative Inotropic Effect ◽  
Pulmonary Vasculature ◽  
Practical Applications ◽  
Neonatal Cardiomyocytes ◽  
Nitric Oxide Formation ◽  
Pulmonary Vasoconstriction

During the fetal period, blood is oxygenated through the placenta, and most of the cardiac output bypasses the lung through the ductus arteriosus. At birth, pulmonary vascular resistance falls with the initiation of ventilation. Coincidentally, the ductus arteriosus constricts. Endothelin-1 (ET-1) appears to play an important role during that transition period and postnatally. ET-1 can dramatically increase resistance in the placental microcirculation and may be involved in blood flow redistribution with hypoxia. At birth, the increase in oxygen tension is important in triggering ductus vasoconstriction. It is proposed that oxygen triggers closure of the ductus arteriosus by activating a specific, cytochrome P450-linked reaction, which in turn stimulates the synthesis of ET-1. On the neonatal heart, ET-1 has a positive chronotropic but negative inotropic effect. In the newborn piglet and the fetal lamb, both term and preterm, ET-1 causes a potent, long-lasting pulmonary vasoconstriction. Furthermore, a transient dilator response has been identified, and it is ascribed to nitric oxide formation. ET receptors are abundant in the piglet pulmonary vasculature. They are predominantly of the ETA constrictor subtype, though ETB2 constrictor receptors may also be present in certain species. The dilator response is linked to the ETB1 receptor, and the number of ETB1 receptors is reduced in hypoxia-induced pulmonary hypertension. ET-1 appears to be a causative agent in the pathogenesis of hypoxia- and hyperoxia-induced pulmonary hypertension as demonstrated by reversal of hemodynamic and morphological changes with treatment with an ETA receptor antagonist. Findings are amenable to practical applications in the management of infants with pulmonary hypertension or requiring persistent patency of the ductus arteriosus.Key words: ductus arteriosus, neonatal pulmonary circulation, neonatal pulmonary hypertension, neonatal cardiomyocytes, fetus.

scholarly journals On-line detection algorithm of ore grade change in grinding grading system

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 701-709
Author(s):  
Jianjun Zhao ◽  
Junwu Zhou
Keyword(s):  
Detection Method ◽  
Control Process ◽  
Detection Algorithm ◽  
Operating Conditions ◽  
Grading System ◽  
Process Data ◽  
Practical Applications ◽  
Grade Change ◽  
On Line ◽  
Point Detection

AbstractIn process industry control, process data is critical for both control and fault diagnosis. Timely detection of outliers and mutation point in process data can quickly adjust control parameters or discover potential failures throughout the system. Aiming at the shortcomings of the traditional mutation point detection method, such as the detection time delay and not being suitable for the process industrial data that mixed outliers, this paper proposes a mutation point and outliers detection method that is suitable for the grinding grading system using the wavelet method to analyze the “Efficient Scoring Vector.” In this algorithm, to distinguish between outliers and mutation points in the detection process, we propose a detection framework based on the relationship between Lipschitz index and wavelet coefficients. Under this framework, the detection algorithm proposed in this paper can detect outliers and mutation points simultaneously. The advantage of this is that the accuracy of the mutation point detection is not affected by the outliers. This means that the method can process grinding grading system process data containing outliers and mutation points under actual operating conditions and is more suitable for practical applications. Finally, the effectiveness and practicability of the proposed detection method are proved by simulation results.

Robot-handling fabrics with curved edges based on visual servoing and polygonal approximation

2008 ◽  
Vol 222 (10) ◽  
pp. 1263-1274 ◽  
Author(s):  
P Zacharia ◽  
I G Mariolis ◽  
N Aspragathos ◽  
E S Dermatas
Keyword(s):  
Visual Servoing ◽  
Detection Method ◽  
Experimental Tests ◽  
Polygonal Approximation ◽  
Curve Section ◽  
Robot Controller ◽  
Straight Line ◽  
Dominant Point ◽  
Point Detection ◽  
Work Table

The main scope of this work is the development of a robot controller for the manipulation of fabrics lying on a work table towards the sewing process. A fuzzy visual servoing manipulator controller is developed to guide the fabric along the sewing line. The paper focuses on handling fabrics with curved edges by locally approximating the curve section with straight-line segments. An innovative algorithm based on the dominant point detection method and the genetic-based method is incorporated in the robot visual servoing system to achieve sewing of the curved edges. Simulation and experimental tests are conducted to evaluate the performance of the proposed algorithm. The results demonstrate that this approach is efficient and effective for the polygonal approximation, and the proposed robotic system is proved to be robust and efficient, achieving acceptable seam accuracy in the minimum time.

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