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[IEEE 2018 International Conference on Information and Communication Technology Robotics (ICT-ROBOT) - Busan (2018.9.6-2018.9.8)] 2018 International Conference on Information and Communication Technology Robotics (ICT-ROBOT) - Hidden-Surface Processing for Interaction of Hand and Virtual Objects Using Leap Motion Controller
摘要： Recently augmented reality (AR) technology has attracted a lot of attention and is studied. Furthermore, it is applied to the interaction technology between human and virtual objects. In AR interaction technology, it is necessary for the user to be able to manipulate virtual objects intuitively, so it is required to manipulate the objects by their hand. However, in AR technology, since the 3-dimensional model is superimposed on the image of the real space afterwards, it is always displayed on the front side than the hand (occlusion problem). It is an unnatural scene in some cases. In this study, we utilized Leap Motion Controller to acquire the depth data of the user’s hand and fingers. We performed hidden-surface processing considering the depth and the color of the hand and fingers. Thus we enabled appropriate hidden-surface processing in the area of the user’s hand and fingers.
关键词： virtual objects,augmented reality,intuitive manipulation,occlusion problem
更新于2025-09-23 15:23:52
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Quantitative measurement of vascular density and flow using optical coherence tomography angiography (OCTA) in patients with central retinal vein occlusion: Can OCTA help in distinguishing ischemic from non-ischemic type?
摘要： Background: To evaluate microvascular changes and quantitative parameters in patients with central retinal vein occlusion (CRVO) by using optical coherence tomography angiography (OCTA) and finding difference between presumably ischemic and non ischemic CRVO. Methods: Patients with CRVO (31) and healthy control (20) were enrolled in this observational case control study. The OCTA was done for each patient and control subject. In macular area 2 images were taken for each eye (3 × 3 mm and 8 × 8 mm). The images were analyzed at three capillary plexuses (superficial and deep retinal capillary layers and choriocapillaris layer). Results: Thirty-one patients with CRVO (mean age 60.00 ± 13.72 years) and 20 healthy age/gender matched subjects (mean age 54.10 ± 12.33 years) were enrolled in this study (p = 0.095). The mean visual acuity of patients was 0.47 ± 0.54 LogMAR. Eyes with CRVO as compared with fellow eyes and control group showed significant reduction of flow in superficial (1.171 ± 0.262 vs. 1.362 ± 0.285 vs. 1.453 ± 0.105) and deep capillary plexus (1.042 ± 0.402 vs. 1.331 ± 0.315 vs. 1.526 ± 0.123) and choriocapillaris (1.206 ± 0.543 vs. 1.841 ± 0.308 vs. 1.966 ± 0.05) and vascular density in superficial (45.92 ± 4.2 vs. 50.99 ± 4.35 vs. 52.85 ± 2.99) and deep (48.03 ± 4.71 vs. 55.86 ± 3.81 vs. 58.2 ± 2.65) capillary plexuses. Some parameters (flow of both retinal capillary plexuses and parafoveal vascular density in deep plexus) showed significantly reduction in fellow eyes than control group. The parameters including flow [superficial (1.014 ± 0.264 vs. 1.279 ± 0.19) and deep (0.873 ± 0.442 vs. 1.152 ± 0.32) capillary plexuses and choriocapillaris (0.79 ± 0.327 vs. 1.424 ± 0.51)] and vascular density [superficial (44.24 ± 2.13 vs. 46.58 ± 4.13) and deep (45.28 ± 3.5 vs. 49.32 ± 3.94) capillary plexuses] were lower significantly in ischemic type than non ischemic CRVO. The most damaged parameter was flow in deep capillary plexus. The model with smallest Akaike information criterion and Bayesian information criterion was chosen as the best model. For easier calculation, we also calculated the reduced model. By choosing the threshold of 12.6, the formula [3.9 × F1S + 0.8 × F3S] can diagnose the presumably ischemic CRVO from non ischemic type with AUC of 0.84, sensitivity of 100% and specificity of 69%. (F1S: flow in the central 1 mm-radius-circle of superficial plexus and F3S: flow in the central 3 mm-radius-circle of superficial plexus). Conclusion and relevance: In CRVO patients, the OCTA can accurately evaluate changes in microvascular structures. It may help in differentiation ischemic CRVO from non-ischemic CRVO.
关键词： Ischemic,Non-ischemic,Central retinal vein occlusion,Optical coherence tomography angiography
更新于2025-09-23 15:23:52
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[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Image-Based 3D Model Retrieval for Indoor Scenes by Simulating Scene Context
摘要： We propose a single image-based 3D model retrieval method for indoor scenes. By simulating the scene context of the input image, our method is able to handle several challenging scenarios featuring cluttered backgrounds and severe occlusions. To use our system, the user only needs to drag a few semantic bounding boxes for the query objects. The proposed approach then retrieves the most similar 3D models from the ShapeNet model repository, and aligns them with the corresponding objects automatically. This requires that the 3D models are represented by calibrated view-dependent visual elements learned from the rendered views. With the estimated occlusion relationships, the rendered model images are stacked at the corresponding locations to simulate the scene context. By conducting matching between these synthesized scenes and the input image, the most similar 3D models under the approximate poses are retrieved. Moreover, we show that the retrieving time can be significantly reduced based on a novel greedy algorithm. Experimental results demonstrate the effectiveness of our proposed method.
关键词： 3D model retrieval,cluttered background,scene context,occlusion relationship
更新于2025-09-23 15:23:52
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Baseline characteristics associated with early visual acuity gains after ranibizumab treatment for retinal vein occlusion
摘要： Background: To identify baseline patient characteristics associated with early clinically significant visual acuity (VA) improvements within 3 months of treatment initiation in ranibizumab-treated patients with retinal vein occlusion (RVO) in the SHORE study. Methods: Post hoc analysis of baseline patient characteristics in the randomized, open-label, vision examiner–masked SHORE phase 4 study that compared monthly versus pro re nata dosing of ranibizumab in patients with branch and central RVO. Patients who enrolled in SHORE fulfilled eligibility criteria per protocol (N = 202). SHORE data were retrospectively analyzed to identify baseline patient characteristics associated with early clinically significant improvements in VA, defined as improvement to a Snellen equivalent of 20/40 or better vision (≥ 69 Early Treatment Diabetic Retinopathy Study [ETDRS] letters) or an increase in best-corrected VA (BCVA) of 15 or more ETDRS letters from baseline within 3 months of treatment initiation. Main outcome measures were BCVA gain of 15 or more ETDRS letters from baseline, Snellen equivalent of 20/40 or better vision, and baseline factors associated with early clinically significant improvement in BCVA. Results: The median time for patients to achieve a BCVA of 20/40 or better was 59 days and the median time for patients to gain 15 or more ETDRS letters was 63 days. Better baseline BCVA (> 50 ETDRS letters/Snellen equivalent ≥ 20/100), greater baseline total macular volume (> 9.99 mm3), and presence of subretinal fluid at baseline were all associated with early improvement to 20/40 or better vision (ETDRS equivalent ≥ 69 letters; P < .0001, P = .02, and P = .03, respectively). Conclusions: This retrospective analysis found that better BCVA, greater total macular volume, and presence of subretinal fluid at baseline were associated with more rapid vision gains. Clinicians may find these helpful when considering the likelihood of achieving early clinically significant VA improvements with ranibizumab in patients with RVO.
关键词： Ranibizumab,Branch retinal vein occlusion,Central retinal vein occlusion,CRVO,BRVO,Retinal vein occlusion,Anti-VEGF,RVO
更新于2025-09-23 15:22:29
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3-D People Counting with a Stereo Camera on GPU Embedded Board
摘要： People counting in surveillance cameras is a key technology for understanding the flow population and generating heat maps. In recent years, people detection performance has been greatly improved with the development of object detection algorithms using deep learning. However, in places where people are crowded, the detection rate is low as people are often occluded by other people. We proposed a people-counting method using a stereo camera to resolve the non-detection problem due to the occlusion. We applied stereo matching to extract the depth image and convert the camera view to top view using depth information. People were detected using a height map and an occupancy map, and people were tracked and counted using a Kalman filter-based tracker. We operated the proposed method on the NVIDIA Jetson TX2 to check the real-time operation possibility on the embedded board. Experimental results showed that the proposed method had higher accuracy than the existing methods and that real-time processing is possible.
关键词： NVIDIA Jetson TX2,occlusion,view projection,stereo matching,Kalman filter tracker,3-D people counting
更新于2025-09-23 15:22:29
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Is there still a role for abdominal plain X-ray in acute abdomen?
摘要： The imaging workup of patients with acute abdominal pain still starts with abdominal X-ray in several clinical settings and facilities. Unfortunately, conventional plain film is of limited utility if performed as a routine investigation. Abdominal radiography is valuable only in patients with suspected perforated viscus and large bowel obstruction. Ultrasound is mostly valuable in the vast majority of abdominal pain presentations, whereas computed tomography scan should be considered as second level test.
关键词： Bowel occlusion,Plain radiography,Abdominal X ray,Pneumoperitoneum,Acute abdomen
更新于2025-09-23 15:22:29
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Bevacizumab versus bevacizumab and macular grid photocoagulation for macular edema in eyes with non-ischemic branch retinal vein occlusion: results from a prospective randomized study
摘要： Background The objective of the study was the investigation of the effects of intravitreal bevacizumab (BEV) with or without additional macular grid laser photocoagulation (GRID) for macular edema (ME) secondary to branch retinal vein occlusion (BRVO). Methods Prospective, randomized, monocentric study. Thirty-two patients were included. Initially, all eyes in both groups received three monthly injections of BEV, followed by additional injections if re-treatment criteria were met. In the BEV + GRID group, photocoagulation was performed 2 weeks after the first BEV injection and laser re-treatment was allowed. The follow-up was 38 weeks. Main outcome measures were best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Changes of foveal avascular zone (FAZ) and of retinal ischemia, as well as the number of injections were also evaluated. Results Sixteen eyes were randomized into each group. At baseline, BCVA was similar in both groups (BEV + GRID: 20/71; BEV: 20/60; P = 0.51). At 38 weeks, BCVA significantly improved in the two groups (BEV + GRID gain of 9 ± 11.2 letters and 16.25 ± 10.08 letters in the BEV) with no difference between them (P < 0.06). With regard to anatomical findings, initial CRT in BEV + GRID was 496.2 μm ± 138.4 μm and 538.9 μm ± 156.9 μm in BEV (P < 0.1697). At 38 weeks, CRT decreased in both groups significantly, 98.2 μm in the BEV + GRID (P = 0.02) and 141.7 μm in the BEV group (P = 0.01), with no significant difference between groups (P < 0.17). The area of FAZ a significantly increased in both groups (41% (P = 0.04) in BEV + GRID; 35% (P = 0.03) in BEV) during the study and the grade of peripheral ischemia remained unchanged. The mean number of injections was 3.8 (range 3–6) with no significant difference between groups. Conclusions Our data demonstrate a beneficial effect of bevacizumab in ME in eyes with BRVO. A loading phase of three injections led to a significant improvement in vision in both groups, which persisted at week 38. Additional grid laser photocoagulation exhibited no beneficial functional or anatomical effect during the study, nor did it reduce the number of injections. The FAZ area increased significantly in both groups, but overall retinal ischemia did not. Further studies investigating more numerous eyes and longer follow-up are needed to confirm these data.
关键词： Anti-VEGF,Grid laser photocoagulation,Macular edema,Branch retinal vein occlusion,Bevacizumab
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference of the Biometrics Special Interest Group (BIOSIG) - Darmstadt (2018.9.26-2018.9.28)] 2018 International Conference of the Biometrics Special Interest Group (BIOSIG) - A benchmark database of visible and thermal paired face images across multiple variations
摘要： Although visible face recognition systems have grown as a major area of research, they are still facing serious challenges when operating in uncontrolled environments. In attempt to overcome these limitations, thermal imagery has been investigated as a promising direction to extend face recognition technology. However, the reduced number of databases acquired in thermal spectrum limits its exploration. In this paper, we introduce a database of face images acquired simultaneously in visible and thermal spectra under various variations: illumination, expression, pose and occlusion. Then, we present a comparative study of face recognition performances on both modalities against each variation and the impact of bimodal fusion. We prove that thermal spectrum rivals with the visible spectrum not only in the presence of illumination changes, but also in case of expression and poses changes.
关键词： visible spectrum,thermal spectrum,pose,score-level fusion,sensor-level fusion,occlusion,expression,illumination,face database
更新于2025-09-23 15:22:29
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3D tracking of multiple onsite workers based on stereo vision
摘要： Varied sensing technologies have been delved in for positioning workers and equipment in construction sites. Vision-based technology has been received growing attentions by the virtue of its tag-free and inexpensive con?guration. One of the core research works in this area was the use of stereo camera system for tracking 3D locations of construction resources. However, the previous work was limited to tracking of a single entity. To overcome the limitation, this paper presents a new framework for tracking multiple workers. The proposed framework supplements the previous work by embedding an additional step, entity matching, which ?nds corresponding matches of tracked workers across two camera views. Entity matching takes advantage of the epipolar geometry and workers' motion directions for ?nding correct pairs of a worker's projections on two image planes. This paper also presents an e?ective approach of camera calibration for positioning entities located a few tens of meters away from the cameras. The proposed framework is evaluated based on completeness, continuity, and localization accuracy of the generated trajectories. The evaluation results have shown its capability of retrieving 96% of actual movements, within localization errors of 0.821 m with 99.7% con?dence.
关键词： Occlusion,Computer vision,Entity matching,Tracking,Construction worker,Site monitoring,Camera calibration
更新于2025-09-23 15:21:01
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Evaluation of a Force-Sensing Handheld Robot for Assisted Retinal Vein Cannulation*
摘要： Approximately 16.4 million people are affected by retinal vein occlusion (RVO) resulting from hyper-coagulability, low blood flow or thrombosis in the central or the branched retinal veins. Most common current treatments for RVO aim to limit the damage. In recent years, an experimental procedure, retinal vein cannulation (RVC) has been studied in animal models as well as human eye models. RVC is a procedure for targeted delivery of a therapeutic agent into the occluded retinal vein for dissolving the thrombi. Although effective treatment has been demonstrated via RVC, performing this procedure manually still remains at the limits of human skills. RVC requires to precisely insert a thin cannula into a delicate thin retinal vein, and to maintain it inside the vein throughout the infusion. The needle-vein interaction forces are too small to sense even by an expert surgeon. In this work, we present an evaluation study of a handheld robotic assistant with a force-sensing microneedle for RVC. The system actively cancels hand tremor, detects venous puncture based on detected tool-tissue forces, and stabilizes the needle after venous puncture for reduced trauma and prolonged infusion. Experiments are performed cannulating the vasculature in fertilized chicken eggs. Results show 100% success in venous puncture detection and significantly reduced cannula position drift via the stabilization aid of the robotic system.
关键词： handheld robotic assistant,retinal vein cannulation,force-sensing microneedle,cannula stabilization,Retinal vein occlusion,venous puncture detection
更新于2025-09-23 15:21:01