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find Keyword "感知" 22 results
  • An antennal electric signal detection system based on template matching

    As the most efficient perception system in nature, the perception mechanism of the insect (such as honeybee) antennae is the key to imitating the high-performance sensor technology. An automated experimental device suitable for collecting electrical signals (including antenna reaction time information) of antennae was developed, in response to the problems of the non-standardized experimental process, interference of manual operation, and low efficiency in the study of antenna perception mechanism. Firstly, aiming at the automatic identification and location of insect heads in experiments, the image templates of insect head contour features were established. Insect heads were template-matched based on the Hausdorff method. Then, for the angle deviation of the insect heads relative to the standard detection position, a method that calculates the angle of the insect head mid-axis based on the minimum external rectangle of the long axis was proposed. Eventually, the electrical signals generated by the antennae in contact with the reagents were collected by the electrical signal acquisition device. Honeybees were used as the research object in this study. The experimental results showed that the accuracy of template matching could reach 95.3% to locate the bee head quickly, and the deviation angle of the bee head was less than 1°. The distance between antennae and experimental reagents could meet the requirements of antennae perception experiments. The parameters, such as the contact reaction time of honeybee antennae to sucrose solution, were consistent with the results of the manual experiment. The system collects effectively antenna contact signals in an undisturbed state and realizes the standardization of experiments on antenna perception mechanisms, which provides an experimental method and device for studying and analyzing the reaction time of the antenna involved in biological antenna perception mechanisms.

    Release date:2022-10-25 01:09 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.

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  • 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
  • A review on depth perception techniques in organoid images

    Organoids are an in vitro model that can simulate the complex structure and function of tissues in vivo. Functions such as classification, screening and trajectory recognition have been realized through organoid image analysis, but there are still problems such as low accuracy in recognition classification and cell tracking. Deep learning algorithm and organoid image fusion analysis are the most advanced organoid image analysis methods. In this paper, the organoid image depth perception technology is investigated and sorted out, the organoid culture mechanism and its application concept in depth perception are introduced, and the key progress of four depth perception algorithms such as organoid image and classification recognition, pattern detection, image segmentation and dynamic tracking are reviewed respectively, and the performance advantages of different depth models are compared and analyzed. In addition, this paper also summarizes the depth perception technology of various organ images from the aspects of depth perception feature learning, model generalization and multiple evaluation parameters, and prospects the development trend of organoids based on deep learning methods in the future, so as to promote the application of depth perception technology in organoid images. It provides an important reference for the academic research and practical application in this field.

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  • 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.

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  • Research progress on perception and feedback technology in artificial prosthesis

    Artificial prosthesis is an important tool to help amputees to gain or partially obtain abled human limb functions. Compared with traditional prosthesis which is only for decoration or merely has feedforward control channel, the perception and feedback function of prosthesis is an important guarantee for its normal use and self-safety. And this includes the information of position, force, texture, roughness, temperature and so on. This paper mainly summarizes the development and current status of artificial prostheses in the field of perception and feedback technology in recent years, which is derived from two aspects: the recognition way of perception signals and the feedback way of perception signals. Among the part of recognition way of perception signals, the current commonly adopted sensors related to perception information acquisition and their application status in prosthesis are overviewed. Additionally, from the aspects of force feedback stimulation, invasive/non-invasive electrical stimulation, and vibration stimulation, the feedback methods of perception signals are summarized and analyzed. Finally, some problems existing in the perception and feedback technology of artificial prosthesis are proposed, and their development trends are also prospected.

    Release date:2020-02-18 09:21 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
  • Image-aware generative medical visual question answering based on image caption prompts

    Medical visual question answering (MVQA) plays a crucial role in the fields of computer-aided diagnosis and telemedicine. Due to the limited size and uneven annotation quality of the MVQA datasets, most existing methods rely on additional datasets for pre-training and use discriminant formulas to predict answers from a predefined set of labels. This approach makes the model prone to overfitting in low resource domains. To cope with the above problems, we propose an image-aware generative MVQA method based on image caption prompts. Firstly, we combine a dual visual feature extractor with a progressive bilinear attention interaction module to extract multi-level image features. Secondly, we propose an image caption prompt method to guide the model to better understand the image information. Finally, the image-aware generative model is used to generate answers. Experimental results show that our proposed method outperforms existing models on the MVQA task, realizing efficient visual feature extraction, as well as flexible and accurate answer outputs with small computational costs in low-resource domains. It is of great significance for achieving personalized precision medicine, reducing medical burden, and improving medical diagnosis efficiency.

    Release date:2025-06-23 04:09 Export PDF Favorites Scan
  • 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
  • Cascaded multi-level medical image registration method based on transformer

    In deep learning-based image registration, the deformable region with complex anatomical structures is an important factor affecting the accuracy of network registration. However, it is difficult for existing methods to pay attention to complex anatomical regions of images. At the same time, the receptive field of the convolutional neural network is limited by the size of its convolution kernel, and it is difficult to learn the relationship between the voxels with far spatial location, making it difficult to deal with the large region deformation problem. Aiming at the above two problems, this paper proposes a cascaded multi-level registration network model based on transformer, and equipped it with a difficult deformable region perceptron based on mean square error. The difficult deformation perceptron uses sliding window and floating window techniques to retrieve the registered images, obtain the difficult deformation coefficient of each voxel, and identify the regions with the worst registration effect. In this study, the cascaded multi-level registration network model adopts the difficult deformation perceptron for hierarchical connection, and the self-attention mechanism is used to extract global features in the basic registration network to optimize the registration results of different scales. The experimental results show that the method proposed in this paper can perform progressive registration of complex deformation regions, thereby optimizing the registration results of brain medical images, which has a good auxiliary effect on the clinical diagnosis of doctors.

    Release date:2022-12-28 01:34 Export PDF Favorites Scan
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