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

Search

find Keyword "视觉" 118 results
  • Experience on Endoscopic Thyriodectomy by Via-Breast Approach Under Local Anaesthesia

    目的 探讨局麻下经胸前入路行腔镜甲状腺手术的体会。方法 对2009年3月至2010年3月期间四川省南充市中心医院普外科收治的28例在局麻下行腔镜甲状腺手术患者术中及术后情况进行回顾性分析。结果 1例因术中冰冻检查发现为甲状腺癌而转开放性手术未纳入分析。视觉模拟镇痛评分(VAS): 术中评分结果为0~5分,平均2.2分; 术后评分结果为0~3分,仅2例口服布洛芬缓释胶囊镇痛,其余25例未使用镇痛药物。手术时间为95~215 min,平均117 min; 术中出血量为50~150 ml,平均84 ml。术后引流量为25~70 ml,平均34 ml; 引流管放置时间为2~4 d。住院时间平均4.5 d。术后颈部及胸壁皮下无瘀血、肿胀,无声嘶、呛咳。经随访2~10个月(平均8个月),未见切口处明显瘢痕。结论 局麻下经胸前入路行腔镜甲状腺手术切实可行,并具有良好的美容效果。

    Release date:2016-09-08 10:54 Export PDF Favorites Scan
  • 混合脑机接口技术用于痉挛性偏瘫手功能训练两例

    Release date: Export PDF Favorites Scan
  • A Wireless Smart Home System Based on Brain-computer Interface of Steady State Visual Evoked Potential

    Brain-computer interface (BCI) system is a system that achieves communication and control among humans and computers and other electronic equipment with the electroencephalogram (EEG) signals. This paper describes the working theory of the wireless smart home system based on the BCI technology. We started to get the steady-state visual evoked potential (SSVEP) using the single chip microcomputer and the visual stimulation which composed by LED lamp to stimulate human eyes. Then, through building the power spectral transformation on the LabVIEW platform, we processed timely those EEG signals under different frequency stimulation so as to transfer them to different instructions. Those instructions could be received by the wireless transceiver equipment to control the household appliances and to achieve the intelligent control towards the specified devices. The experimental results showed that the correct rate for the 10 subjects reached 100%, and the control time of average single device was 4 seconds, thus this design could totally achieve the original purpose of smart home system.

    Release date: Export PDF Favorites Scan
  • 光相干断层扫描检查在多发性硬化视觉系统损伤及发病机制研究中的应用

    多发性硬化(MS)是一种中枢神经系统(CNS)的炎性脱髓鞘性疾病。视觉传导通路是CNS的重要组成部分, MS发生于CNS的病理损伤同样累及视觉系统。光相干断层扫描(OCT)检查不仅可以直观反映视网膜形态改变, 还能定量测量视网膜各层厚度及容积。以视网膜作为窗口, 通过OCT检查, 评估MS导致的视觉系统结构与功能损伤, 进而探讨MS的病理机制、神经损伤与修复, 减轻MS视觉系统损伤的危害及评估CNS预后具有重要的临床应用和基础研究价值。

    Release date: Export PDF Favorites Scan
  • Seize the opportunity to raise the eye health to a new level in China

    The great progress achieved in eye health in the recent forty years laid the foundation for further promoting the eye health in China. China is a developing country and is facing some challenges in eye health, including: with the huge population and aging, the number of age-related eye disease is increasing; China is still a country with the most blindness and moderated and severe visual impairment; the resource of the ophthalmic service is insufficient and maldistributed. The " Thirteenth Five-Year Plan” period is a key period and an opportunity period for the eye health. The central government pays more attention to the national health, including eye health, and proposes the goal of building a healthy China. That is a great opportunity for further promoting eye health. We should get to the points in promoting the eye health: people aged fifty or above are the priority population, rural and poverty areas and the mid and west regions are the priority areas, and cataract and uncorrected refractive error are the priority eye diseases.

    Release date:2018-11-22 04:28 Export PDF Favorites Scan
  • Visual object detection system based on augmented reality and steady-state visual evoked potential

    This study investigates a brain-computer interface (BCI) system based on an augmented reality (AR) environment and steady-state visual evoked potentials (SSVEP). The system is designed to facilitate the selection of real-world objects through visual gaze in real-life scenarios. By integrating object detection technology and AR technology, the system augmented real objects with visual enhancements, providing users with visual stimuli that induced corresponding brain signals. SSVEP technology was then utilized to interpret these brain signals and identify the objects that users focused on. Additionally, an adaptive dynamic time-window-based filter bank canonical correlation analysis was employed to rapidly parse the subjects’ brain signals. Experimental results indicated that the system could effectively recognize SSVEP signals, achieving an average accuracy rate of 90.6% in visual target identification. This system extends the application of SSVEP signals to real-life scenarios, demonstrating feasibility and efficacy in assisting individuals with mobility impairments and physical disabilities in object selection tasks.

    Release date:2024-10-22 02:33 Export PDF Favorites Scan
  • Visual function before and after photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration

    Objective To evaluate the visual function before and after photodynamic therapy(PDT) in patients with subfoveal choroidal neovascularization ( CNV) caused by age-related macular degeneration (AMD). Methods Twenty-five consecutive patients (34 eyes) treated with PDT (verteporfin) for subfoveal CNV in age-related macular degeneration diagnosed by fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT). Visual function including best corrected visual acuity, contrast sensitivity frequency, binocular function, confusion, stereo-vision, color vision, metamorphopsis and central scotoma were examed before photodynamic therapy and 1 week, 1 month, 3 month after photodynamic therapy. The follow-up time varied from 3 months to 2 years (mean 7.6 months). Results The changes of visual function at the 3rd month after photodynamic therapy revealed improving in 13 eyes (38.24%), without any change in 17 eyes (50.00%), and decreasing in 6 eyes (17.65%). Visual acuity with logMRA improved after photodynamic therapy, but without statistic difference. All spatial contrast sensitivity improved. Contrast sensitivity for spatial frequencies 5 cycles per degree (cpd) was better after photodynamic therapy with significant difference (P=0.045).Binocular function, fusion function, stereo function and color vision were slightly improved without statistic difference. Conclusion Damage of visual function in macular degeneration is many-sided. The treatment of PDT for exudative AMD can improve part visual function. (Chin J Ocul Fundus Dis,2004,20:289-291)

    Release date:2016-09-02 05:58 Export PDF Favorites Scan
  • A review of researches on decoding algorithms of steady-state visual evoked potentials

    Brain-computer interface (BCI) systems based on steady-state visual evoked potential (SSVEP) have become one of the major paradigms in BCI research due to their high signal-to-noise ratio and short training time required by users. Fast and accurate decoding of SSVEP features is a crucial step in SSVEP-BCI research. However, the current researches lack a systematic overview of SSVEP decoding algorithms and analyses of the connections and differences between them, so it is difficult for researchers to choose the optimum algorithm under different situations. To address this problem, this paper focuses on the progress of SSVEP decoding algorithms in recent years and divides them into two categories—trained and non-trained—based on whether training data are needed. This paper also explains the fundamental theories and application scopes of decoding algorithms such as canonical correlation analysis (CCA), task-related component analysis (TRCA) and the extended algorithms, concludes the commonly used strategies for processing decoding algorithms, and discusses the challenges and opportunities in this field in the end.

    Release date:2022-06-28 04:35 Export PDF Favorites Scan
  • Clinical features and visual function of recurrent neuromyelitis optica

    Objective To observe the clinical features and visual function of recurrent neuromyelitis optica (NMO). Methods Thirty-four patients with NMO were enrolled in this retrospective case series study. The patients included two males and 32 females. The average first onset age was (35.03plusmn;14.56) years old and the average recurrent rate were (4.24plusmn;2.45) times. The recurrent rate of optic neuritis (ON) ranged from two to 12 times. The recurrent rate of ON was two times in 15 eyes of 10 patients, ge;three times in 37 eyes of 24 patients. Vision acuity, direct ophthalmoscope, fundus pre-set lens examination, visual field and visual evoked potential (VEP) were evaluated. Clinical features were observed. The abnormal rate of optic nerve including optic edema and atrophy; abnormal rate of visual field including decreasing retinal sensitivity, central and paracentral scotoma, ring scotoma, half field defects, tunnel visual field, visual field centrality constriction; abnormal rate of VEP including Prolonged latent phase and/or decreasing amplitude of P100 wave from patients of first episode or recurrence was analyzed. Serum NMO-IgG was detected from 28 patients by indirect immunofluorescence technique to observe its positive rate. Results All patients were characterized by repeated episodes of ON and myelitis. The main clinical feature of ON was visual loss, and the main clinical features of myelitis included sensory disability, dyskinesia and vesicorectal disorder. Blindness rate was 41.67% after the first attack of ON, 33.33% after two relapses, and 64.86% after ge; three relapses. The difference of blindness rate between first attack and two episodes was not significant (chi;2=0.270,P=0.603). However, the blindness rate in patients having ge; three episodes was significantly higher than those having two episodes (chi;2=4.300,P=0.038). With recurrence rate increasing, the abnormal rate of the optic nerve (chi;2=6.750,P=0.034)and VEP(chi;2=6.990,P=0.030)increased. But the abnormal rate of visual field did not increase along with recurrent rate (chi;2=0.660,P=0.718). Seropositive rate of NMO-IgG did not differ significantly between patients with first attack ON and that with recurrent ON (chi;2=1.510,P=0.470). But the seropositive patients had significantly higher bilateral blindness rate than seronegative patients (chi;2=5.063,P=0.027). Conclusions NMO are characterized by recurrent ON and myelitis. Visual loss, sensory disability, dyskinesia and vesicorectal disorder are the main clinical features. With recurrence rate increasing, the blindness rate, abnormalities the optic nerve and the abnormity rate of VEP increase. Seropositive recurrent NMO patients have higher bilateral blindness rate than seronegative patients.

    Release date:2016-09-02 05:22 Export PDF Favorites Scan
  • Research progress of brain-computer interface application paradigms based on rapid serial visual presentation

    Rapid serial visual presentation (RSVP) is a type of psychological visual stimulation experimental paradigm that requires participants to identify target stimuli presented continuously in a stream of stimuli composed of numbers, letters, words, images, and so on at the same spatial location, allowing them to discern a large amount of information in a short period of time. The RSVP-based brain-computer interface (BCI) can not only be widely used in scenarios such as assistive interaction and information reading, but also has the advantages of stability and high efficiency, which has become one of the common techniques for human-machine intelligence fusion. In recent years, brain-controlled spellers, image recognition and mind games are the most popular fields of RSVP-BCI research. Therefore, aiming to provide reference and new ideas for RSVP-BCI related research, this paper reviewed the paradigm design and system performance optimization of RSVP-BCI in these three fields. It also looks ahead to its potential applications in cutting-edge fields such as entertainment, clinical medicine, and special military operations.

    Release date:2023-12-21 03:53 Export PDF Favorites Scan
12 pages Previous 1 2 3 ... 12 Next

Format

Content