ECG beat classification based on discrete wavelet transformation and nearest neighbour classifier

Abstract

Myocardial infarction (MI) is a coronary artery disease acquired due to the lack of blood supply in one or more sections of the myocardium, resulting in necrosis in that region. It has different types based on the region of necrosis. In this paper, a statistical approach for classification of Anteroseptal MI (ASMI) is proposed. The first step of the method involves noise elimination and feature extraction from the Electrocardiogram (ECG) signals, using multi-resolution wavelet analysis and thresholding-based techniques. In the next step a classification scheme is developed using the nearest neighbour classification rule (NN rule). Both temporal and amplitude features relevant for automatic ASMI diagnosis are extracted from four chest leads v1–v4. The distance metric for NN classifier is calculated using both Euclidian distance and Mahalanobis distance. A relative comparison between these two techniques reveals that the later is superior to the former, as evident from the classification accuracy. The proposed method is tested and validated using the PTB diagnostic database. Classification accuracy for Mahalanobis distance and Euclidean distance-based NN rule are 95.14% and 81.83%, respectively.     

How does local government use the planning system to regulate hot food takeaway outlets? A census of current practice in England using document review

Takeaway food outlets typically sell hot food, ordered and paid for at the till, for consumption off the premises due to limited seating provision. Growing numbers of these outlets has raised concerns about their impact on diet and weight gain. This has led to proposals to regulate their proliferation through urban planning. We conducted a census of local government areas in England with planning power (n = 325) to identify planning policies specifically addressing takeaway food outlets, with a ‘health’, and ‘non-health’ focus. We reviewed planning policies using content analysis, and developed a typology. One hundred and sixty-four (50.5%) local government areas had a policy specifically targeting takeaway food outlets; of these, 56 (34.1%) focused on health. Our typology revealed two main foci: ‘Place’ with five targeted locations and ‘Strategy’ with four categories of approach. The most common health-focused approach was describing exclusion zones around places for children and families (n = 33). Non-health focused approaches primarily involved minimising negative impacts associated with takeaway food outlets within a local government area boundary (n = 146). To our knowledge, this is the first census of planning policies explicitly focused on takeaway food outlets in England. Further work is required to determine why different approaches are adopted in different places and their acceptability and impact.     

快速康复外科在腹腔镜胃癌根治术围手术期中的应用

目的探讨快速康复外科（fast track surgery，FTS）在腹腔镜胃癌根治术中的应用价值。方法对60例择期行腹腔镜胃癌根治术的患者，随机分为快速康复外科理念指导下的围手术期处理组为观察组（30例）和传统的围手术期处理组为对照组（30例），比较两组术后临床观察指标的差异。结果观察组术后进食时间、排便排气时间、下床活动时间、住院天数明显缩短，差异有显著意义（P〈0.05）。结论快速康复外科理念在腹腔镜胃癌根治术患者中应用安全有效，促进了患者术后康复，缩短了术后住院时间，具有较高的临床应用价值。     

Do regions of interest location and type influence liver stiffness measurement using magnetic resonance elastography?

PurposeTo assess the variability of liver stiffness measurements using magnetic resonance elastography (MRE) at 1.5 T, depending on different approaches of regions of interest (ROIs) drawing.Material and methodsFifty consecutive patients with successful liver MRE were included. There were 32 men and 18 women with a mean age of 52 ± 14 (SD) years (range: 20–85 years). MRE was acquired using a gradient recalled-echo MRE sequence. At the level of the portal bifurcation, one observer drawn in the right liver first 3 elliptical ROI and then one free-hand ROI, as large as possible based on the confidence map and the anatomy. Three additional elliptical ROIs were further drawn on the slice above and 3 other on the slice below, for a total of 9 elliptical ROIs. The average value of liver stiffness in the 3 elliptical ROIs of the central slice and the one from the 9 elliptical ROIs were computed. Three liver stiffness values were obtained for each patient from the 3 measurement methods (one free-hand ROI, 3 elliptical ROIs and 9 elliptical ROIs). Inter-method variability was assessed using the intra-class correlation coefficient (ICC) and Bland-Altman analysis.ResultsThe variability between the 3 methods was excellent with ICC > 0.978 (P < 0.0001). The Bland-Altman analysis revealed high agreement between the 3 methods with bias < 0.45 kPa and limits of agreement < ±1.13 kPa. The variability was lower when comparing a large free-hand ROI and the 3-elliptical ROIs, than when comparing the 9-elliptical ROIs to one of the other methods.ConclusionOur results show that the variability between the 3 methods of ROI drawing and placement is very low.     

Cortical mechanisms underlying variability in intermittent theta-burst stimulation-induced plasticity: A TMS-EEG study

ObjectiveTo test the hypothesis that intermittent theta burst stimulation (iTBS) variability depends on the ability to engage specific neurons in the primary motor cortex (M1).MethodsIn a sham-controlled interventional study on 31 healthy volunteers, we used concomitant transcranial magnetic stimulation (TMS) and electroencephalography (EEG). We compared baseline motor evoked potentials (MEPs), M1 iTBS-evoked EEG oscillations, and resting-state EEG (rsEEG) between subjects who did and did not show MEP facilitation following iTBS. We also investigated whether baseline MEP and iTBS-evoked EEG oscillations could explain inter and intraindividual variability in iTBS aftereffects.ResultsThe facilitation group had smaller baseline MEPs than the no-facilitation group and showed more iTBS-evoked EEG oscillation synchronization in the alpha and beta frequency bands. Resting-state EEG power was similar between groups and iTBS had a similar non-significant effect on rsEEG in both groups. Baseline MEP amplitude and beta iTBS-evoked EEG oscillation power explained both inter and intraindividual variability in MEP modulation following iTBS.ConclusionsThe results show that variability in iTBS-associated plasticity depends on baseline corticospinal excitability and on the ability of iTBS to engage M1 beta oscillations.SignificanceThese observations can be used to optimize iTBS investigational and therapeutic applications.     

快速康复外科在食管癌治疗中的应用

过去的10年间，快速康复外科治疗在很多外科领域都得到了应用。快速康复外科的应用可以使患者更快地恢复从而缩短住院时间，在增加患者满意度的同时减少了治疗费用。本文通过相关文献复习并结合我们的临床实践，探讨食管癌快速康复外科的具体措施及其临床应用价值。     

快速康复外科理念在普外科围术期健康教育中的应用

目的 探讨在快速康复外科理念下围术期健康教育内容改变后的效果。方法 选取2012年10月~2013年4月湖北省宜昌市中心人民医院普外3科住院并手术治疗的乳腺癌、直肠癌、结肠癌、甲状腺癌4种疾病的患者120例,采用随机平行对照的方法将其分为观察组和对照组各60例,观察两组患者对疾病相关知识的了解程度、术后下床活动时间、平均住院天数、并发症、患者满意率。结果 观察组对疾病相关知识的了解率为86.7%,术后下床活动时间为（1.65±0.50）d,平均住院天数为（5.8±1.5）d,无并发静脉血栓患者,并发肺部感染1例,并发症总发生率为1.7%,患者满意率为100.0%;对照组对疾病相关知识的了解率为33.3%,术后下床活动时间为（4.50±2.50）d,平均住院天数为（10.0±2.2）d,并发静脉血栓为2例,并发肺部感染为4例,并发症总发生率为10.0%,患者满意率为89.5%。两组患者对疾病相关知识了解率、患者满意率、并发症发生率、平均住院天数、术后下床活动时间比较,差异均有统计学意义（P〈0.05）。结论 快速康复外科理念指导下的健康教育更有利于患者术后康复,从护士、患者两方面改变观念,并建立完善的随诊机制,才能使快速康复外科更好地发挥其作用。全面优质的健康教育会取得护患双赢的效果。     

The Fast Alcohol Screening Test (FAST) is as Good as the AUDIT to Screen Alcohol Use Disorders

This study was aimed at assessing the psychometric qualities of the fast alcohol screening test (FAST), and at comparing these qualities to those of the alcohol use disorders identification test (AUDIT) in three samples of Brazilian adults: (i) subjects attended at an emergency department (530); (ii) patients from a psychosocial care center (40); and (iii) university students (429). The structured clinical interview for diagnosis (SCID)-IV was used as gold standard. The FAST demonstrated high test–retest and interrater reliability coefficients, as well as high predictive and concurrent validity values. The results attest the validity and reliability of the Brazilian version of the FAST for the screening of indicators of alcohol abuse and dependence.     

Effects of old age on vascular complexity and dispersion of the hepatic sinusoidal network

OBJECTIVES: In old age, there are marked changes in both the structure of the liver sinusoidal endothelial cell and liver perfusion. The objective of this study was to determine whether there are also aging changes in the microvascular architecture and vascular dispersion of the liver that might influence liver function. METHODS: Vascular corrosion casts and light micrographs of young (4 months) and old (24 months) rat livers were compared. Fractal and Fourier analyses and micro-computed tomography were used. Vascular dispersion was determined from the dispersion number for sucrose and 100-nm microspheres in impulse response experiments. RESULTS: Age did not affect sinusoidal dimensions, sinusoidal density, or dispersion number. There were changes in the geometry and complexity of the sinusoidal network as determined by fractal dimension and degree of anisotropy. CONCLUSIONS: There are small, age-related changes in the architecture of the liver sinusoidal network, which may influence hepatic function and reflect broader aging changes in the microcirculation. However, sinusoidal dimensions and hepatic vascular dispersion are not markedly influenced by old age.