1.A Novel Method for Hyperacuity Measurement
Jin Ha KIM ; Key Hwan LIM ; Yun Taek KIM
Journal of the Korean Ophthalmological Society 2020;61(2):175-182
PURPOSE: We developed a novel method for measurement of hyperacuity and verified the utility thereof.METHODS: We developed a three-dimensional (3D) hyperacuity test using a 3D liquid crystal flat screen, a left- and right-image polarized display, and liquid crystal shutter glasses. We tested the technique in three groups: normal (n = 48), with cataracts (n = 14), and with macular disease (n = 35). We used a chart consisting of five dots and a reference line. Of the five dots, one was variably shifted from the other dots. A chart was presented to one eye and the reference line or blank image to the other eye; a subject scored positive when the dot in the unusual position was recognized.RESULTS: Hyperacuity was measured in terms of the reference line seen by the reference eye (RR), a blank image seen by the reference eye (RB), the reference line seen by the contralateral eye (CR), and a blank image seen by the contralateral eye (CB). All test scores were significantly lower when the reference line was seen than not (RR vs. RB and CR vs. CB; p < 0.01, respectively). For the RR and CR tests, no significant difference was apparent between the normal and cataracts group (p = 0.553, p = 0.494) but such differences were evident between the normal and macular disease groups (p = 0.028, p = 0.002). Also, visualization of the reference line by the reference and contralateral eyes did not differ (p > 0.05).CONCLUSIONS: Measurement of hyperacuity using our new method was not affected by media opacity but was significantly affected by macular disease. Presentation of a reference line facilitated hyperacuity assessment.
Cataract
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Eyeglasses
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Glass
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Liquid Crystals
;
Methods
2.The Effects of Diffusive Blur on Snellen and Grating Acuity in Amblyopia.
Sueng Han HAN ; Sang Kyun KIM ; Jong Bok LEE
Journal of the Korean Ophthalmological Society 1996;37(11):1920-1924
Amblyopia is a disturbance of spatial or form vision that develops early in life, usually in association with strabismus, anisometropia, high refractive errors and so on. It was reported that the visual functions obtained from the foveal region of an amblyopic eye resembled those obtained from the peripheral retina rather than central retina of a normal eye. We designed this experiment which examines the effects of diffusion blur on grating and Snellen acuity in normal and amblyopic eyes, using a liquid crystal window. We obtained the value of diffusion blur in 26 amblyopic eyes and then compared the result with that of normal eyes. The diffusion blur had a strong negative effect on both the Snellen and grating acuity but it had a more potent effect on grating acuity. Because there is a significant difference in the diffusion blur produced by an amblyopic eye and a normal eye at the same vision, there is a difference between visual function of amblyopic eyes and that of normal central retina.
Amblyopia*
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Anisometropia
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Diffusion
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Liquid Crystals
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Refractive Errors
;
Retina
;
Strabismus
3.Study on the orientation of liquid crystals presented on the glass substrates spin-coated and functionalized with copper ions.
Shiming WANG ; Xingliang XIONG ; Yan ZHANG ; Guang LI ; Mengmeng CHEN
Journal of Biomedical Engineering 2013;30(3):464-468
A stable, uniform, easily implemented, LC-based chemical and biological sensor substrate for orientations of liquid crystals (LCs) for a long-term is urgently needed for medical applications of the sensors. We proposed a use of spin-coating of copper perchlorate (Cu(ClO4)2), with five different concentrations(0-100mmol/L), directly on glass slides for fabricating a layer of chemically-sensitive copper ions. Observing the transmitted light with a polarized microscope, we found the luminosity of the light propagated through sensors deposited with copper ions started to weaken gradually after a certain time. The higher was the concentration of copper ions covered on the glass substrates of the sensors, the faster the weakening occurred, and the less time was needed for transmitted light to turn completely dark. But there was no change in luminosity of the transmitted light for the sensors without Cu(ClO4)2 spin-coating even after stored at room temperature (25 degrees C) for a whole day. When the Cu(ClO4)2 deposited sensors were stored within a drying oven at room temperature (25 degrees C) for 2 months, it was found that there vas almost no change in luminosity of the transmitted lights. The results showed that all the thin films of LC on glass slides functionalized with Cu(ClO4)2 could keep homeotropic and stable orientation for a long time; the concentration of Cu (ClO4)2I has an influence on the orientation response speed of LC from planar to perpendicular orientation.
Biosensing Techniques
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instrumentation
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Copper
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chemistry
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Glass
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chemistry
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Liquid Crystals
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chemistry
4.Digital Chest Radiography with an Amorphous Silicon Flat-Panel-Detector Versus a Storage-Phosphor System: Comparison of Soft-Copy Images.
Hyun Ju LEE ; Jung Gi IM ; Jin Mo GOO ; Chang Hyun LEE
Journal of the Korean Radiological Society 2006;54(5):353-360
PURPOSE: We compared the soft-copy images produced by an amorphous silicon flat-panel-detector system with the images produced by a storage-phosphor radiography system for their ability to visualize anatomic regions of the chest. MATERIALS AND METHODS: Two chest radiologists independently analyzed 234 posteroanterior chest radiographs obtained from 78 patients on high-resolution liquid crystal display monitors (2560x2048x8 bits). In each patient, one radiograph was obtained with a storage-phosphor system, and two radiographs were obtained via amorphous silicon flat-panel-detector radiography with and without spatial frequency filtering. After randomizing the 234 images, the interpreters rated the visibility and radiographic quality of 11 different anatomic regions. Each image was ranked on a five-point scale (1 = not visualized, 2 = poor visualization, 3 = fair visualization, 4 = good visualization, and 5 = excellent visualization). The statistical difference between each system was determined using the Wilcoxon's signed rank test. RESULTS: The visibility of three anatomic regions (hilum, heart border and ribs), as determined by the chest radiologist with 14 years experience (p<0.05) and the visibility of the thoracic spine, as determined by the chest radiologist with 8 years experience (p=0.036), on the amorphous silicon flat-panel-detector radiography prior to spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. The visibility of 11 anatomic regions, as determined by the chest radiologist with 14 years experience (p<0.0001) and the visibility of five anatomic regions (unobscured lung, rib, proximal airway, thoracic spine and overall appearance), as determined by the chest radiologist with 8 years experience (p<0.05), on the amorphous silicon flat-panel-detector radiography after spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. CONCLUSION: The amorphous silicon flat-panel-detector system depicted the anatomic structures on chest radiographs comparably or significantly better as compared to the storage-phosphor system. The superiority of the amorphous silicon flat-panel-detector system compared to the storage-phosphor system was more obvious after performing spatial frequency filtering.
Heart
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Humans
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Liquid Crystals
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Lung
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Radiographic Image Enhancement
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Radiography*
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Radiography, Thoracic
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Ribs
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Silicon*
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Spine
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Thorax*
5.Effect of LCD monitor type and observer experience on diagnostic performance in soft-copy interpretations of the maxillary sinus on panoramic radiographs.
Tae Young KIM ; Jin Woo CHOI ; Sam Sun LEE ; Kyung Hoe HUH ; Won Jin YI ; Min Suk HEO ; Soon Chul CHOI
Imaging Science in Dentistry 2011;41(1):11-16
PURPOSE: The aim of this study was to evaluate the effect of liquid crystal display (LCD) monitor type and observer experience on the diagnostic performance in soft-copy interpretations of maxillary sinus inflammatory lesions on panoramic radiographs. MATERIALS AND METHODS: Ninety maxillary sinuses on panoramic images were grouped into negative and positive groups according to the presence of inflammatory lesions, using CT for confirmation. Monochrome and color LCDs were used. Six observers participated and ROC analysis was performed to evaluate the diagnostic performance. The reading time, fatigue score, and inter-/intra-observer agreements were assessed. RESULTS: The interpretation of maxillary sinus inflammatory lesions was affected by the LCD monitor type used and by the experience of the observer. The reading time was not significantly different, however the fatigue score was significantly different between two LCD monitors. Inter-observer agreement was relatively good in experienced observers, while the intra-observer agreement for all observers was good with monochrome LCD but not with color LCD. CONCLUSION: The less experienced observers showed lowered diagnostic ability with a general color LCD.
Fatigue
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Liquid Crystals
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Maxillary Sinus
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Organothiophosphorus Compounds
;
ROC Curve
;
Task Performance and Analysis
6.Varicocele in Children and Low Teenagers: Studies on Prevalence. Scrotal Temperature and Testicular Volume.
Korean Journal of Urology 1989;30(4):518-525
Studies on the prevalence of varicocele and the relation of varicocele to scrotal temperature and testicular volume were performed on 986 healthy Korean boys 6 to 15 years of age for 5 months from the May, 1988 to September, 1988. We examined the subjects in standing position with Valsalva maneuver for detecting varicocele and classified the varicocele as grade I, grade II, or grade III according to the system proposed by Dubin and Amelar in 1970. Scrotal temperatures were measured in standing position by contact scrotal thermography using Varicoscreen, a flexible screen covered with thermosensitive liquid crystals reflecting color from brown (at 31.8 degrees C) to blue (at 34.5 degrees C). Testicular volume was measured by indirect method using series of graduated plastic models (Prade orchidometer). Following results were obtained. The overall prevalence rate of varicocele aged 6 to 15 years was 8.8%. No case of varicocele was encountered in 303 boys aged 6 to 8 years, while the incidence in the 683 subjects 9 to 15 years was 12.8% with an increase from 2.9% in 9-year-olds to 18.8% in 14-year-olds. Among 87 varicocele subjects, varicocele accounted for 75.9% in the left side, 5.7% in the right and 18.4% in both sides. And of 103 varicocele testes 51.5% were classified as grade I, 29.1 % as grade II and 19.4% as grade III. The scrotal temperature exceeded 31.8 degrees C in their contralateral normal testes. Varicocele increased scrotal temperatures not only in the affected side, but also in the other side. Scrotal temperature in varicocele testes was revealed significantly higher than that in normal (p<0.01). The degree Of varicocele bears relation to scrotal temperatures (p<0.01). In healthy Korean boys in 6-year-olds, the mean testicular volume was 1.1+/-0.4 ml. The testicular growth rapidly increased in 11-year-olds and in 15 years of age testis was 14 times larger than that of 6-year-olds. There was no volume differential between both testes in normal subjects. In the subjects with unilateral left varicocele, the testicular volume was decreased in both sides than in the normal subjects. Ipsilateral and contralateral testicular volume was most prominently decreased in grade III varicocele.
Adolescent*
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Child*
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Humans
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Incidence
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Liquid Crystals
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Plastics
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Prevalence*
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Testis
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Thermography
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Valsalva Maneuver
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Varicocele*
7.The Effect of Diffusion Blur on Central and Peripheral Vision in Normal Adults.
Sueng Han HAN ; Gang Wook CHUNG ; Jong Bok LEE ; Young Ghee LEE
Journal of the Korean Ophthalmological Society 1996;37(5):818-822
Diffusion blur, caused by liquid crystal windows, reduces contrast sensitivity and luminance, so visual acuity is decreased. Moreover, the windows' optical characteristics are similar to those of the cataractous lens. We measured the effect of liquid crystal window on central and peripheral visual acuity using Snellen and grating visual acuity charts. The subjects were 10 normal adults, therefore 20 eyes. We measured the voltage of the liquid crystal window at which the subjects could read the visual acuity chart through the liquid crystal window. In central vision, visual acuity was overestimated according to the Snellen chart, when compared to the results measured by those grating chart. But in peripheral vision, there were no differences between the two visual acuity charts. These results suggested that grating acuity has some limitations when used as a visual acuity test for cataractous patient. The ability of liquid crystal windows to cause diffusion blur suggests they could be used for foUowup observation in treatment of amblyopia or macular diseases.
Adult*
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Amblyopia
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Cataract
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Contrast Sensitivity
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Diffusion*
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Humans
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Liquid Crystals
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Visual Acuity
8.Mobile phone based liquid crystal thermal imaging method and its medical implementation.
Chinese Journal of Medical Instrumentation 2010;34(5):317-322
In this paper, a new medical imaging strategy based on mobile phone is developed to obtain the quantitative temperature mappings of human skin. The visual images reflected by the TLC pre-painted on human skin are captured by the camera of mobile phone and transformed to the thermographies of human skin through digital image processing method according to the Temperature-Hue curve pre-established in the calibration experiment. The mobile phone acquired imaging is then applied to reconstruct the temperature distribution of dorsal hand and for thermodynamic check. Additional thermal parameters related to body health status are calculated based on the bioheat transfer model of human body. The present method is expected to be developed as a pervasive and low cost way to map the skin temperature imaging of human body.
Cell Phone
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Humans
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Image Processing, Computer-Assisted
;
Liquid Crystals
;
Skin Temperature
9.Advances in the study of lipid-based cubic liquid crystalline nanoparticles as drug delivery system.
Hong-Bing WU ; Dong-Feng HUO ; Xin-Guo JIANG
Acta Pharmaceutica Sinica 2008;43(5):450-455
Various geometric shapes and structures self-assembled of amphiphilic lipids when present in an aqueous environment, as active delivery vehicles, are becoming one of focuses of drug delivery system. Lipid-based cubic liquid crystalline nanoparticles (or Cubosomes) consisting of "honeycombed (cavernous)" structure spontaneously formed when a certain concentration of amphiphilic lipids dispersed in aqueous solution has curved bicontinuous lipid bilayer in three dimensions, separating two congruent networks of water channels. Its unique structure consists of internal double water channels and large interfacial areas, which reveal great flexibility in encapsulation efficiency of various polarities and amount of drugs, and has variegated range of drugs encapsulated. As a drug delivery vehicle, high drug payloads, stabilization of peptides or proteins and simple preparation process are also its advantages. The ability of cubic phase to incorporate and control release of drugs of varying size and polar characteristics, and biodegradability of lipids make it an interesting drug delivery system for various routes of administration, including oral, topical (or mucosal) and intravenous administrations, with extensive application in a multitude of dosage forms. Furthermore, a number of different proteins in cubic phase appear to retain their native conformation and bioactivity, and are protected against chemical and physical inactivation. In this paper, investigations of lipid-based cubic liquid crystalline nanoparticles are reviewed and summarized, with a hope to provide a reference for its in-depth study. At the end, the authors made a development prospect of this novel excellent candidate for active ingredients delivery vehicle.
Drug Carriers
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chemistry
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Drug Delivery Systems
;
methods
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Lipids
;
administration & dosage
;
chemistry
;
Liquid Crystals
;
chemistry
;
Nanoparticles
10.The development and transplantation of LCD module-based interface for medical diagnosis instrument.
Huisheng ZHANG ; Xinyu LIU ; Qiaoliang LI ; Jie RAO ; Xiaofei ZHANG ; Xiaoxuan WANG ; Shumei LIN ; Li YIN ; Siping CHEN ; Tianfu WANG
Chinese Journal of Medical Instrumentation 2012;36(6):400-406
Based on LCD Module and Visual C++ development environment, this paper proposes a new method which can quickly develop the human-machine interface .We define a LCD module programming interface by designing Serial Communication Class(SCS). On this basis,we achieve the transplantation on an Embedded ARM Platform to fulfil the requirements of Medical Diagnostic Instruments (MDI). Experimental results show that this method has advantages of short development cycle and high level transplantation which has broad application prospects in the field of Medical Diagnosis Instrument.
Diagnosis, Computer-Assisted
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instrumentation
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Equipment Design
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Liquid Crystals
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Robotics
;
instrumentation
;
methods
;
Software
;
User-Computer Interface