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find Keyword "视觉" 118 results
  • Recent advance on photosensitive occipital lobe epilepsy

    Photosensitive occipital lobe epilepsy (POLE) is a rare idiopathic reflex focal epilepsy that can occur in all age groups. It is characterized by occipital lobe seizures induced by flashing stimuli (flashing sunlight, video games, TV commercials and programs, etc.). Photoparoxysmal response on EEG is induced by intermittent photic stimulation; Ictal EEG shows rapid spike rhythms are originated from the occipital region. There are no obvious abnormalities in brain image. POLE responds well to anti-seizure medications and has a good prognosis. This article reviews the research progress on POLE in order to improve the clinician’s understanding and reduce the rates of missed diagnosis and misdiagnosis.

    Release date:2024-07-03 08:46 Export PDF Favorites Scan
  • 以眼部病变为首发症状的脑肿瘤二例

    Release date:2016-09-02 06:07 Export PDF Favorites Scan
  • 二价锰离子增强磁共振视神经活体示踪的实验研究

    Release date:2016-09-02 05:41 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
  • 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
  • Expression of alternatively spliced mRNA isoforms of the NMDA-R1 in the visual cortex of strabismic amblyopic cats

    Purpose To identify the expression of alternatively spliced mRNA isoforms of the NMDA-R1 in the visual cortex of strabismic cats. Methods Two pai rs of normal and strabismic cats were used.The amblyopic cats had been made monocularly esotropic (by tenotomy) at the age of weeks,resulting in behavioral am blyopia.Animals were sacrificed about 6 months by intraperitoneal administration of Nembutal.Cryostat sections of fresh,frozen central visual cortex of the ats were cut to 20 micron thickness.A series of digoxygenin-labelled oligonucle otide probes basing on the human gene sequence were used for ISH.Control probes included sense oligonucleotides and short segment probes which were adjacent to ,but did not,span the splice junctions.A computer-assisted systematic morphometric ounting procedure was used to enumerate hybridising cells. Results The number of positive cells expressing NMDA-R1 mRNA in t he strabismic amblyopic cats was decreased,notably in layer IV of visual cortex (P<0.0001).The pattern of isoform expression varied between normal and strabismic amblyopic cats with decreased numbers of 1-a,1- b and 1-1 isoforms and apparently increased expression of 1-3 P <0.0001),whereas no significant difference was found for the 1-2 and 1-4 isoforms (P>0.05). Conclusion Transcriptional inhibition of NMDA-R1 mRNA and of specifie isoforms may underlie the change in receptor expression.Alternatively,preferentialloss of neurones bearing particular NMDA-R1 isoforms and compensation with a proportional increase in cells expressing other isoforms may occurr during the critical period of visual plasticity. (Chin J Ocul Fundus Dis,2000,16:71-138)

    Release date:2016-09-02 06:05 Export PDF Favorites Scan
  • Application of a parallel branches network based on Transformer for skin melanoma segmentation

    Cutaneous malignant melanoma is a common malignant tumor. Accurate segmentation of the lesion area is extremely important for early diagnosis of the disease. In order to achieve more effective and accurate segmentation of skin lesions, a parallel network architecture based on Transformer is proposed in this paper. This network is composed of two parallel branches: the former is the newly constructed multiple residual frequency channel attention network (MFC), and the latter is the visual transformer network (ViT). First, in the MFC network branch, the multiple residual module and the frequency channel attention module (FCA) module are fused to improve the robustness of the network and enhance the capability of extracting image detailed features. Second, in the ViT network branch, multiple head self-attention (MSA) in Transformer is used to preserve the global features of the image. Finally, the feature information extracted from the two branches are combined in parallel to realize image segmentation more effectively. To verify the proposed algorithm, we conducted experiments on the dermoscopy image dataset published by the International Skin Imaging Collaboration (ISIC) in 2018. The results show that the intersection-over-union (IoU) and Dice coefficients of the proposed algorithm achieve 90.15% and 94.82%, respectively, which are better than the latest skin melanoma segmentation networks. Therefore, the proposed network can better segment the lesion area and provide dermatologists with more accurate lesion data.

    Release date:2022-12-28 01:34 Export PDF Favorites Scan
  • Full-field flash electroretinogram following up for children with history of pre-threshold or threshold retinopathy of prematurity

    ObjectiveTo evaluate the characteristics of electroretinagram (EGR) in children with history of pre-threshold or threshold retinopathy of prematurity (ROP). MethodsA total of 24 children (48 eyes) with history of pre-threshold ROP or threshold ROP received F-ERG examination.Ten age and body weight-matched children with a history of premature birth (20 eyes) but without ROP were recruited as control group. The rod response, maximal rod-cone response and cone response of F-ERG were recorded respectively following the International Standard Protocal of ISCEV (2000 version).The latency and amplitude of a-wave and b-wave of various responses were analyzed. The trial was approved by the Ethic Committee of Hunan Children's Hospital and informed consent was obtained from the parents of patients prior to any medical procedure. ResultsThere was significant difference between ROP and control group in rod response,the latency was longer (t=5.643,P<0.05) and the amplitude was lower in ROP group(t=7.068,P<0.05).In maximal rod-cone response both in a and b wave, the latency wave was longer(t=3.099, 2.886;P<0.05) and the amplitude was lower(t=5.614, 2.850;P<0.05) in ROP group. But there is no difference between ROP and control group in cone response latency(t=0.819, 0.948)and amplitude(t=0.904, 0.850). ConclusionERG in ROP children with history of pre-threshold or threshold ROP is abnormal, which mainly in rod response,but the cone response remains normal.

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  • A portable steady-state visual evoked potential brain-computer interface system for smart healthcare

    This paper realized a portable brain-computer interface (BCI) system tailored for smart healthcare. Through the decoding of steady-state visual evoked potential (SSVEP), this system can rapidly and accurately identify the intentions of subjects, thereby meeting the practical demands of daily medical scenarios. Firstly, an SSVEP stimulation interface and an electroencephalogram (EEG) signal acquisition software were designed, which enable the system to execute multi-target and multi-task operations while also incorporating data visualization functionality. Secondly, the EEG signals recorded from the occipital region were decomposed into eight sub-frequency bands using filter bank canonical correlation analysis (FBCCA). Subsequently, the similarity between each sub-band signal and the reference signals was computed to achieve efficient SSVEP decoding. Finally, 15 subjects were recruited to participate in the online evaluation of the system. The experimental results indicated that in real-world scenarios, the system achieved an average accuracy of 85.19% in identifying the intentions of the subjects, and an information transfer rate (ITR) of 37.52 bit/min. This system was awarded third prize in the Visual BCI Innovation Application Development competition at the 2024 World Robot Contest, validating its effectiveness. In conclusion, this study has developed a portable, multifunctional SSVEP online decoding system, providing an effective approach for human-computer interaction in smart healthcare.

    Release date:2025-06-23 04:09 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
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