scholarly journals Automatic detection of the cornea location in video captures of fluorescence

2021 ◽  
Vol 3 (1) ◽  
pp. 55-70
Author(s):  
Tobin Driscoll ◽  
Richard J. Braun ◽  
Carolyn G. Begley
Keyword(s):  
Dry Eye ◽  
Open Source Software ◽  
Visual Inspection ◽  
Initial Conditions ◽  
Tear Film ◽  
Region Of Interest ◽  
Normal Subjects ◽  
Pixel Intensity ◽  
Wide Range ◽  
Corneal Radius

Purpose: Fluorescence imaging is a valuable tool for studying tear film dynamics andcorneal staining. Automating the quantification of fluorescence images is a challenging necessary step for making connections to mathematical models. A significant partof the challenge is identifying the region of interest, specifically the cornea, for collected data with widely varying characteristics. Methods: The gradient of pixel intensity at the cornea–sclera limbus is used as the objective of standard optimization to find a circle that best represents the cornea. Results of the optimization in one image are used as initial conditions in the next imageof a sequence. Additional initial conditions are chosen heuristically. The algorithm iscoded in open-source software. Results: The algorithm was first applied to 514 videos of 26 normal subjects, for a total of over 87,000 images. Only in 12 of the videos does the standard deviation in thedetected corneal radius exceed 1% of the image height, and only 3 exceeded 2%. The algorithm was applied to a sample of images from a second study with 142 dry-eye subjects. Significant staining was present in a substantial number of these images. Visual inspection and statistical analysis show good resuls for both normal and dry-eye images. Conclusion: The new algorithm is highly effective over a wide range of tear film andcorneal staining images collected at different times and locations.

scholarly journals Assessment of tear secretion and tear film instability in cases with pterygium and normal subjects

2013 ◽  
Vol 5 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Narayani Roka ◽  
SP Shrestha
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Strong Relationship ◽  
Normal Subjects ◽  
Controlled Study ◽  
Control Group ◽  
P Value ◽  
Tear Secretion ◽  
Schirmer’S Test ◽  
Significant Difference

Introduction: Dry eye is a common disorder affecting a significant percentage of the population. Materials and methods: This study is a prospective, hospital-based, case-controlled study conducted between January 2009 and May 2010. Seventy-six pterygium cases and 152 age-and- sex matched controls presenting to the OPD of Manipal Teaching Hospital were included. The TBUT Schirmer’s test and basal tear secretion were estimated in all patients. A TBUT of less than 10 seconds and a Schirmer’s test of less than 10 mm were considered abnormal. Results: Pterygium was bilateral in 15 (19.7 % ) and unilateral in 61 (80.3 %) patients. Ninety-two (92.1 %) pterygium patients reported either one or more of the six dry eye symptoms. Redness was the most common (67 %) symptom reported. The mean Schirmer’s test I, mean basal secretion and mean TBUT values were 16.19 mm, 10.01 mm and 10.56 seconds in pterygium cases and 20.22 mm,13.25 mm and 26.25 seconds in the control group respectively. There was a statistically significant difference in the dry eye results between the pterygium cases and the control group (p value < 0.05). The odds ratio between pterygium and dry eye was 3.28. Dry eye was present in 26 % of the normal patients and in 54 % of the pterygium cases. Conclusion: There is a strong relationship between dry eye and pterygium. Nepal J Ophthalmol 2013; 5(9):16-23 DOI: http://dx.doi.org/10.3126/nepjoph.v5i1.7816

scholarly journals Effects of Aerobic Exercise on Tear Secretion and Tear Film Stability in Dry Eye Patients

2021 ◽  
Author(s):  
Chao Sun ◽  
Xiaofan Chen ◽  
Yanming Huang ◽  
Huan Zou ◽  
Wei Fan ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Aerobic Exercise ◽  
Dry Eye ◽  
Tear Film ◽  
Normal Subjects ◽  
Oxidative Stress Marker ◽  
Film Stability ◽  
Tear Secretion ◽  
Tear Film Stability ◽  
Before And After

Abstract Background: To study the effects of aerobic exercise (AE) on tear secretion and tear film stability in dry eye patients.Methods: Firstly we observed Schirmer Ⅰ test and 6 tear compositions detected by ELISA in 34 eyes of dry eye patients and 34 eyes of normal subjects before and after AE. Then we observed 30 eyes of dry eye patients and 30 eyes of normal subjects before and after AE, the evaluated variables included tear meniscus height (TMH), first and average non-invasive tear breakup time (F-NITBUT and A-NITBUT), lipid layer thickness (LLT), number of incomplete and complete blinks, partial blink rate (PBR) and visual acuity.Results: In dry eye group, compared with baseline, Schirmer Ⅰ test at 0 minutes after AE increased significantly (P < 0.001), F-NITBUT and A-NITBUT at every time point after AE prolonged significantly (P < 0.001, P = 0.007, P = 0.036; P < 0.001, P = 0.001, P = 0.044), number of incomplete blinks and PBR at 10 minutes after AE decreased significantly (P < 0.001; P < 0.001) while number of complete blinks increased significantly (P < 0.001), visual acuity at 10 and 20 minutes after AE improved significantly (P = 0.017, P = 0.021). The overall oxidative stress marker 8-hydroxy-2’-deoxyguanosine at 0 minutes after AE decreased significantly compared with baseline (P = 0.040).Conclusion: AE promotes tear secretion and improves tear film stability in dry eye patients. AE may be a potential treatment for dry eye.Trial registration: Chinese Clinical Trial Registry, ChiCTR2000038673. Registered 27 September 2020, http://www.chictr.org.cn/showproj.aspx?proj=57282

scholarly journals Effect of Airflow Exposure on the Tear Meniscus

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Shizuka Koh ◽  
Cynthia Tung ◽  
Ranjini Kottaiyan ◽  
James Zavislan ◽  
Geunyoung Yoon ◽  
...  
Keyword(s):  
Dry Eye ◽  
Anterior Segment ◽  
Tear Film ◽  
Normal Subjects ◽  
Dry Eyes ◽  
Before And After ◽  
Evaporative Dry Eye ◽  
Tear Meniscus ◽  
Tear Meniscus Height ◽  
Blink Frequency

Purpose. To compare the effect of airflow exposure on the tear meniscus and blink frequency in normal and evaporative dry eye subjects.Methods.In 9 normal subjects and 9 short tear breakup time (SBUT) dry eye subjects, lower tear meniscus height (TMH) and area (TMA) and blink frequency were measured with anterior segment optical coherence tomography (OCT) before and after 5 minutes of airflow exposure (1.5±0.5 m/s).Results.In SBUT dry eyes, both TMH and TMA decreased significantly (P=0.027,P=0.027) with a significant increase of blink frequency after airflow exposure, while significant increase in TMA was found in normal eyes.Conclusion. Measurement of the tear meniscus with anterior segment OCT seems to be useful as a noninvasive and objective method for evaluating the effect of airflow on tear film.

scholarly journals Tear Osmolarity in the Diagnosis of Systemic Dehydration and Dry Eye Disease

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 387
Author(s):  
Anthony J. Bron ◽  
Catherine Willshire
Keyword(s):  
Dry Eye ◽  
Point Of Care ◽  
Plasma Osmolality ◽  
Tear Film ◽  
The Elderly ◽  
Diagnostic Feature ◽  
High Morbidity ◽  
Point Of Care Test ◽  
Wide Range ◽  
At Risk Populations

Systemic dehydration due to inadequate water intake or excessive water loss, is common in the elderly and results in a high morbidity and significant mortality. Diagnosis is often overlooked and there is a need for a simple, bedside diagnostic test in at-risk populations. Body hydration is highly regulated with plasma osmolality (pOsm) being tightly controlled over a wide range of physiological conditions. By contrast, normal tear osmolarity (tOsm) is more variable since the tear film is exposed to evaporation from the open eye. While plasma hyperosmolality is a diagnostic feature of systemic dehydration, tear hyperosmolality, with other clinical features, is diagnostic of dry eye. Studies in young adults subjected to exercise and water-deprivation, have shown that tOsm may provide an index of pOsm, with the inference that it may provide a simple measure to diagnose systemic dehydration. However, since the prevalence of both dry eye and systemic dehydration increases with age, the finding of a raised tOsm in the elderly could imply the presence of either condition. This diagnostic difficulty can be overcome by measuring tear osmolality after a period of evaporative suppression (e.g., a 45 min period of lid closure) which drives tOsm osmolality down to a basal level, close to that of the pOsm. The arguments supporting the use of this basal tear osmolarity (BTO) in the diagnosis of systemic dehydration are reviewed here. Further studies are needed to confirm that the BTO can act as a surrogate for pOsm in both normally hydrated subjects and in patients with systemic dehydration and to determine the minimum period of lid closure required for a simple, “point-of-care” test.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

Ayurvedic Management of Dry Eye Sydrome - A Case Study

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Hemalatha S. ◽  
Rati S.
Keyword(s):  
Dry Eye ◽  
Treatment Modality ◽  
Similar Condition ◽  
Symptomatic Relief ◽  
Tear Film ◽  
Modern Medicine ◽  
Common Condition ◽  
Dry Out ◽  
Tear Substitute

Dry eye syndrome is a common condition that results from reduced tear production or excessive tear evaporation or an abnormality in the production of mucus or lipids normally found in the tear layer or combination of these. If blinking is decreased or if the eyelids cannot be closed, they may dry out leading to dry eye. It is accompanied by increased osmolarity of the tear film and inflammation on the surface of the eye may occur of left untreated leading to pain, ulcers or scars on the cornea and loss of vision. Prevalence of dry eye range from 5% to 35% worldwide while in India it is 29.25%. Tear substitute are the only treatment modality with modern medicine, only providing symptomatic relief. Ayurveda describes similar condition called Sushkakshi Paka and this patient was treated with Tarpana and Nasya with Jeevantyadi Ghrita.

scholarly journals Automatic Hip Detection in Anteroposterior Pelvic Radiographs—A Labelless Practical Framework

2021 ◽  
Vol 11 (6) ◽  
pp. 522
Author(s):  
Feng-Yu Liu ◽  
Chih-Chi Chen ◽  
Chi-Tung Cheng ◽  
Cheng-Ta Wu ◽  
Chih-Po Hsu ◽  
...  
Keyword(s):  
Medical Image ◽  
Image Annotation ◽  
Region Of Interest ◽  
Confidence Score ◽  
Heterogeneous Data ◽  
Single Shot ◽  
Hip Joints ◽  
Pelvic Radiographs ◽  
Wide Range ◽  
Average Confidence

Automated detection of the region of interest (ROI) is a critical step in the two-step classification system in several medical image applications. However, key information such as model parameter selection, image annotation rules, and ROI confidence score are essential but usually not reported. In this study, we proposed a practical framework of ROI detection by analyzing hip joints seen on 7399 anteroposterior pelvic radiographs (PXR) from three diverse sources. We presented a deep learning-based ROI detection framework utilizing a single-shot multi-box detector with a customized head structure based on the characteristics of the obtained datasets. Our method achieved average intersection over union (IoU) = 0.8115, average confidence = 0.9812, and average precision with threshold IoU = 0.5 (AP50) = 0.9901 in the independent testing set, suggesting that the detected hip regions appropriately covered the main features of the hip joints. The proposed approach featured flexible loose-fitting labeling, customized model design, and heterogeneous data testing. We demonstrated the feasibility of training a robust hip region detector for PXRs. This practical framework has a promising potential for a wide range of medical image applications.

scholarly journals Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

2021 ◽  
Vol 22 (1) ◽  
pp. 422
Author(s):  
Ming-Tse Kuo ◽  
Po-Chiung Fang ◽  
Shu-Fang Kuo ◽  
Alexander Chen ◽  
Yu-Ting Huang
Keyword(s):  
Dry Eye ◽  
Ocular Surface ◽  
Tear Film ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Mechanistic Studies ◽  
Clinical Tests ◽  
Tear Proteins ◽  
Proteomic Data ◽  
Surface Performance

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye’s performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

scholarly journals On the generation of internal waves by river plumes in subcritical initial conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Mendes ◽  
J. C. B. da Silva ◽  
J. M. Magalhaes ◽  
B. St-Denis ◽  
D. Bourgault ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Internal Waves ◽  
Coastal Waters ◽  
Initial Conditions ◽  
Spatial Scales ◽  
River Plumes ◽  
Wide Range ◽  
Near Shore ◽  
Generation Mechanisms ◽  
Douro River

AbstractInternal waves (IWs) in the ocean span across a wide range of time and spatial scales and are now acknowledged as important sources of turbulence and mixing, with the largest observations having 200 m in amplitude and vertical velocities close to 0.5 m s−1. Their origin is mostly tidal, but an increasing number of non-tidal generation mechanisms have also been observed. For instance, river plumes provide horizontally propagating density fronts, which were observed to generate IWs when transitioning from supercritical to subcritical flow. In this study, satellite imagery and autonomous underwater measurements are combined with numerical modeling to investigate IW generation from an initial subcritical density front originating at the Douro River plume (western Iberian coast). These unprecedented results may have important implications in near-shore dynamics since that suggest that rivers of moderate flow may play an important role in IW generation between fresh riverine and coastal waters.

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