west china medical publishers
Keyword
  • Title
  • Author
  • Keyword
  • Abstract
Advance search
Advance search

Search

find Keyword "感知" 23 results
  • Colorectal polyp segmentation method based on fusion of transformer and cross-level phase awareness

    In order to address the issues of spatial induction bias and lack of effective representation of global contextual information in colon polyp image segmentation, which lead to the loss of edge details and mis-segmentation of lesion areas, a colon polyp segmentation method that combines Transformer and cross-level phase-awareness is proposed. The method started from the perspective of global feature transformation, and used a hierarchical Transformer encoder to extract semantic information and spatial details of lesion areas layer by layer. Secondly, a phase-aware fusion module (PAFM) was designed to capture cross-level interaction information and effectively aggregate multi-scale contextual information. Thirdly, a position oriented functional module (POF) was designed to effectively integrate global and local feature information, fill in semantic gaps, and suppress background noise. Fourthly, a residual axis reverse attention module (RA-IA) was used to improve the network’s ability to recognize edge pixels. The proposed method was experimentally tested on public datasets CVC-ClinicDB, Kvasir, CVC-ColonDB, and EITS, with Dice similarity coefficients of 94.04%, 92.04%, 80.78%, and 76.80%, respectively, and mean intersection over union of 89.31%, 86.81%, 73.55%, and 69.10%, respectively. The simulation experimental results show that the proposed method can effectively segment colon polyp images, providing a new window for the diagnosis of colon polyps.

    Release date:2023-06-25 02:49 Export PDF Favorites Scan
  • High quality reconstruction algorithm for cardiac magnetic resonance images based on multiscale low rank modeling

    Taking advantages of the sparsity or compressibility inherent in real world signals, compressed sensing (CS) can collect compressed data at the sampling rate much lower than that needed in Shannon’s theorem. The combination of CS and low rank modeling is used to medical imaging techniques to increase the scanning speed of cardiac magnetic resonance (CMR), alleviate the patients’ suffering and improve the images quality. The alternating direction method of multipliers (ADMM) algorithm is proposed for multiscale low rank matrix decomposition of CMR images. The algorithm performance is evaluated quantitatively by the peak signal to noise ratio (PSNR) and relative l2 norm error (RLNE), with the human visual system and the local region magnification as the qualitative comparison. Compared to L + S, kt FOCUSS, k-t SPARSE SENSE algorithms, experimental results demonstrate that the proposed algorithm can achieve the best performance indices, and maintain the most detail features and edge contours. The proposed algorithm can encourage the development of fast imaging techniques, and improve the diagnoses values of CMR in clinical applications.

    Release date:2019-08-12 02:37 Export PDF Favorites Scan
  • 文献导读——肥胖对哮喘支气管收缩时患者症状感知与肺功能改变的影响( Effects of obesity on perceptual and mechanical responses to bronchoconstriction in asthma . )

    免疫抑制治疗后的同种异体气管移植(Delaere P, Vranckx J, Verleden G, et al. Tracheal allotransplantation after withdrawal of immuno-suppressive therapy. N Engl JMed, 2010,362:138-145.) 【摘要翻译】 研究理由: 肥胖对哮喘患者感知急性支气管收缩导致的呼吸不适有何影响尚不清楚。目的: 我们假设体重指数( body mass index, BMI) 上升可导致呼吸功能损害, 并将在原有症状基础上加重哮喘急性支气管收缩过程中患者的主观症状。因此, 我们比较了肥胖和正常体重的轻到中度哮喘患者乙酰甲胆碱( methacholine, MCh) 激发过程中呼吸困难程度与肺功能改变的关系。方法: 患者年龄为20 ~60 岁。在51 例体重正常( BMI 为18. 5 ~24. 9 kg/m2 , 其中男性29% ) 和45 例肥胖( BMI 为30. 1 ~51. 4 kg/m2 , 其中男性33% ) 的哮喘患者中进行了高剂量MCh 激发试验, 激发后FEV1 下降最大达到50% 。在支气管激发过程中测定系列的肺功能、深吸气量( inspiratory capacity, IC) 、体描吸气末肺容积( end-expiratory lung volume, EELV) , 并以Borg 量表评定患者的呼吸困难程度。检测和主要结果: 两组肺功能及气道敏感性无明显差异; 与正常体重患者相比, 肥胖组EELV 较低而IC 较高( P 值分别为0. 0005 和0. 007) 。从基础值到PC20, 肥胖组EELV 增加较正常体重组明显( 分别增加20% 和13% , P = 0. 008) , 同时肥胖组IC 下降明显( P lt;0. 0005) 。两组患者在相同FEV1 或IC 时呼吸困难程度并无差异。通过混合效应回归分析发现, BMI、性别或两者一起均对激发诱导的呼吸困难与肺功能参数改变之间的关系并无影响。结论: 尽管哮喘患者基础肺容积不同, 但患者对MCh 激发导致的支气管收缩和肺过度充气的感知反应并无明显差异。 【述评】 哮喘和肥胖的发病率均有逐年增加的趋势。由于肥胖可以导致患者出现呼吸道症状, 因此, 研究如何正确评估肥胖哮喘患者症状具有临床价值。这项研究检测了MCh 激发过程中患者肺功能改变与临床症状之间的关系,结果发现BMI 对激发过程中患者呼吸困难程度及多数肺功能指标变化影响并不明显。本研究中肥胖组的咳嗽、夜间觉醒等症状较体重正常者严重, 作者认为可能与哮喘并不相关; 遗憾的是, 本研究并未评估两组的气道炎症的严重程度,而仅将基础症状及肺功能作为评定指标, 加上两组临床症状的差异, 尽管基础肺功能无差异, 其气道炎症严重程度是否一致尚无法确定。由于目前越来越多的研究表明肥胖往往伴有系统性炎症改变, 这种系统性炎症改变对哮喘气道炎症是否有影响也不清楚。另外, 作者在研究中很多肺功能指标用了实测值占预计值的百分比, 由于目前使用的肺功能预计值公式往往是基于正常人群, 是否适合肥胖患者值得商。

    Release date:2016-08-30 11:53 Export PDF Favorites Scan
  • Testing Method of Human Body's Current Threshold for Perception Based on EEG Analysis

    Electric and electronic products are required to pass through the certification on electrical safety performance before entering into the market in order to reduce electrical shock and electrical fire so as to protect the safety of people and property. The leakage current is the most important factor in testing the electrical safety performance and the test theory is based on the perception current effect and threshold. The traditional method testing the current threshold for perception only depends on the sensing of the human body and is affected by psychological factors. Some authors filter the effect of subjective sensation by using physiological and psychological statistical algorithm in recent years and the reliability and consistency of the experiment data are improved. We established an experiment system of testing the human body's current threshold for perception based on EEG feature analysis, and obtained 967 groups of data. We used wavelet packet analysis to detect α wave from EEG, and used FFT to do spectral analysis on α wave before and after the current flew through the human body. The study has shown that about 97.72% α wave energy changes significantly when electrical stimulation occurs. It is well proved that when the EEG feature identification is applied to test the human body current threshold for perception, and meanwhile α wave energy change and human body sensing are used together to confirm if the current flowing through the human body reaches the perception threshold, the measurement of the human body current threshold for perception could be carried out objectively and accurately.

    Release date: Export PDF Favorites Scan
  • Research on Reconstruction of Ultrasound Diffraction Tomography Based on Compressed Sensing

    Ultrasound diffraction tomography (UDT) possesses the characteristics of high resolution, sensitive to dense tissue, and has high application value in clinics. To suppress the artifact and improve the quality of reconstructed image, classical interpolation method needs to be improved by increasing the number of projections and channels, which will increase the scanning time and the complexity of the imaging system. In this study, we tried to accurately reconstruct the object from limited projection based on compressed sensing. Firstly, we illuminated the object from random angles with limited number of projections. Then we obtained spatial frequency samples through Fourier diffraction theory. Secondly, we formulated the inverse problem of UDT by exploring the sparsity of the object. Thirdly, we solved the inverse problem by conjugate gradient method to reconstruct the object. We accurately reconstructed the object using the proposed method. Not only can the proposed method save scanning time to reduce the distortion by respiratory movement, but also can reduce cost and complexity of the system. Compared to the interpolation method, our method can reduce the reconstruction error and improve the structural similarity.

    Release date: Export PDF Favorites Scan
  • Investigation of Awareness and Requirements of Care in the Elderly with Chronic Diseases in Community

    目的 了解成都市社区老年慢性病患者对关爱的感知和需求,为更好地关爱老年慢性病患者提供依据。 方法 于2011年8月-10月采用随机抽样和问卷调查的方法,对成都市玉林社区、二仙桥社区、草堂街社区和驷马桥社区的180名老年慢性病患者的关爱感知和需求进行调查,并根据调查结果提出相应对策。 结果 180例老年慢性病患者中有98.89%能感受到关爱,1.11%自觉缺乏关爱;感知到的关爱主要来源于家庭成员,占91.01%,其次来源于亲戚朋友和邻居,占7.87%,最少来源于单位同事,占1.12%。关爱需求主要为家人团聚、关心体贴、尊重理解、日常照顾和心理情感支持、帮助解决困难、给予经济资助、提供情感支持等;护理关爱需求以尊重理解排在首位,其次是慢性病日常护理、慢性病的防治、老年保健和慢性病基本知识等。 结论 加强对社区卫生服务人员的能力培训,强化尊老爱老家庭氛围和社会风气,提高老年慢性病患者的关爱感知,有效地为老年慢性病患者提供关爱,更好地促进他们的健康。

    Release date: Export PDF Favorites Scan
  • A grid field calculation model based on perceived speed and perceived angle

    The method of directly using speed information and angle information to drive attractors model of grid cells to encode environment has poor anti-interference ability and is not bionic. In response to the problem, this paper proposes a grid field calculation model based on perceived speed and perceived angle. The model has the following characteristics. Firstly, visual stream is decoded to obtain visual speed, and speed cell is modeled and decoded to obtain body speed. Visual speed and body speed are integrated to obtain perceived speed information. Secondly, a one-dimensional circularly connected cell model with excitatory connection is used to simulate the firing mechanism of head direction cells, so that the robot obtains current perception angle information in a biomimetic manner. Finally, the two kinds of perceptual information of speed and angle are combined to realize the driving of grid cell attractors model. The proposed model was experimentally verified. The results showed that this model could realize periodic hexagonal firing field mode of grid cells and precise path integration function. The proposed algorithm may provide a foundation for the research on construction method of robot cognitive map based on hippocampal cognition mechanism.

    Release date:2020-12-14 05:08 Export PDF Favorites Scan
  • Impact of hospital staff’s risk perception on their emergency responses: taking coronavirus disease 2019 fixed-point treatment hospitals in first tier cities as an example

    Objective To explore the impact of hospital staff’s risk perception on their emergency responses, and provide reference for future responses to public health emergencies. Methods Based on participatory observation and in-depth interviews, the staff of the First Affiliated Hospital of Guangzhou Medical University who participated in the prevention and control of the coronavirus disease 2019 from April to September 2020 were selected. The information on risk perception and emergency responses of hospital staff was collected. Results A total of 61 hospital staff were included. The positions of hospital staff were involved including hospital leading group, hospital office, medical department, logistics support department and outpatient isolation area. The interview results showed that both individual and organizational factors of hospital staff would affect the risk perception of hospital staff, thus affecting the emergency responses of hospital staff, mainly reflected in the psychological and behavioral aspects. Among them, their psychological reactions were manifested as more confidence, sensitivity, and sense of responsibility and mission; The behavior aspects was mainly reflected in the initiation time, execution ability, and standardization level of emergency responses actions. Conclusion Therefore, relevant departments should pay attention to the risk perception of hospital staff, improve the risk perception and emergency responses of hospital staff by influencing the individual and organizational factors of hospital staff, so as to respond more effectively to future public health emergencies and reduce the adverse impact of public health emergencies on the work of hospital staff.

    Release date:2023-09-28 02:17 Export PDF Favorites Scan
  • Altered Perceptual Networks in Tuberous Sclerosis Complex Patients with Epilepsy Revealed by Resting Functional Magnetic Resonance Imaging

    ObjectiveTo reveal impairments in the perceptual networks in tuberous sclerosis complex (TSC) with epilepsy by functional connectivity MRI (fcMRI). MethodsThe fcMRI-based independent component analysis (ICA) was used to measure the resting state functional connectivity in nine TSC patients with epilepsy recruited from June 2010 to June 2012 and perceptual networks including the sensorimotor network (SMN), visual network (VN), and auditory network (AN) were investigated. The correlation between Z values in regions of interest (ROIs) and age of seizure onset or duration of epilepsy were analyzed. ResultsCompared with the controls, the TSC patients with epilepsy presented decreased functional connectivity in primary visual cortex within the VN networks and there were no increased connectivity. Increased connectivity in left middle temporal gyrus and inferior temporal gyrus was found and decreased connectivity was detected in right inferior frontal gyrus within AN networks. Decreased connectivity was detected at the right inferior frontal gyrus and the increase in connectivity was found in right thalamus within SMN netwoks. No significant correlations were found between Z values in ROIs including the primary visual cortex within the VN, right thalamus and inferior frontal gyrus within SMN, left temporal lobe and right inferior frontal gyrus within AN and the duration of the disease or the age of onset. ConclusionFhere is altered (both increased and decreased) functional connectivity in the perceptual networks of TSC patients with epilepsy. The decreased functional connectivity may reflect the dysfunction of correlative perceptual networks in TSC patients, and the increased functional connectivity may indicate the compensatory mechanism or reorganization of cortical networks. Our fcMRI study may contribute to the understanding of neuropathophysiological mechanisms underlying perceptual impairments in TSC patients with epilepsy.

    Release date: Export PDF Favorites Scan
  • The Differences in Self-perception Level of Asthma Control and Related Influencing Factors in Asthmatic Patients

    ObjectiveTo investigate the differences in self-perception level of asthma control and the factors affecting the ability of self-perception in patients with bronchial asthma. MethodsA total of 322 patients who were diagnosed with bronchial asthma at the First Affiliated Hospital of Harbin Medical University from March 2013 to February 2015 were recruited in the study. The clinical data were collected, including the demographic characteristics of the patients, the Asthma Control Test (ACT) and results of routine blood test and pulmonary function test on the same day that they were required to fill out the ACT. Then they were followed up at the 1st, 3rd, 6th, 12th months, and required to fill out the ACT again, and underwent the blood routine test and lung function test. In addition, health education about asthma was offered regularly during these visits. ResultsA total of 226 patients met the inclusion criteria of the study. The patients with asthma had significant differences between self-perception control level and real symptoms control level (P<0.05). The patients who were 65 years old or older perceived their symptoms of bronchial asthma rather poorly (P=0.000). The patients who received senior high school or higher education had a higher ability of self-perceived asthma control (P=0.005). The patients with allergic rhinitis combined were less likely to correctly perceive their illness compared with those who did not suffered from allergic rhinitis, and the difference was statistically significant (P=0.001). In addition, for those diagnosed with allergic rhinitis combined with bronchial asthma, regular treatment also made difference--longer treatment for rhinitis means a higher ability of self-perceived asthma control (P=0.000). The health education did play a constructive role in helping patients correctly perceive their illness (P=0.000). There was no correlation between the absolute value of peripheral blood eosinophils and the accuracy of self-perceived asthma control. Nevertheless,there was a noticeable correlation between the ability of peripheral blood eosinophils of patients with asthma and acute attack of bronchial asthma (P=0.003),which was a meaningful finding in assessing the risk of future acute attack of bronchial asthma (P=0.469). ConclusionsThere is a significant difference between self-perception control level and symptom control level in patients with asthma. The self-perception control level of asthma patients who are elderly, the low degree of educational level, merged allergic rhinitis, and lack of health education are associated with lower accuracy of self-perception control level. The absolute value of peripheral blood eosinophils of the patients with asthma can be used to assess the risk of asthma acute attack in the future, but has no significant correlation with the accuracy of self-perception control level.

    Release date: Export PDF Favorites Scan
3 pages Previous 1 2 3 Next

Format

Content