An innovative model to quantify corneal transparency in donor corneal buttons

2017 ◽  
Vol 6 (6) ◽  
pp. 202-205
Author(s):  
Jeyanth Rose ◽  
Syrpailyne Wankhar ◽  
Aarwin Joshua ◽  
Sanita Korah ◽  
Thomas Kuriakose
Keyword(s):  
Anterior Chamber ◽  
Digital Camera ◽  
Laser Source ◽  
Corneal Transplant ◽  
Human Cornea ◽  
Proof Of Concept ◽  
Pixel Intensity ◽  
Corneal Transparency ◽  
Average Pixel Intensity ◽  
Corneal Button

Assessment of corneal transparency in donor corneal buttons has only been performed qualitatively. The quantification of corneal transparency has implications with respect to clinical suitability of the donor cornea and research involving corneal transparency as an outcome measure. In this study an artificial anterior chamber was modified to create a central transparent passage. This was made possible by replacing the base of the chamber with Perspex and a water  tight seal. An inlet and outlet tube was a ached to the sides of chamber. This was done to maintain a standardized pressure within the chamber when connected to an IV bo le. A corneal button rejected for corneal transplant was placed on the artificial anterior chamber and the chamber was  filled with normal saline. A digital camera and a laser source were placed on either side of the chamber at predetermined intervals. Alignment was achieved so that the laser light passed through the center of the cornea. The image of the laser spot was acquired and subjected to image analysis. To test this proof of concept, a human cornea rejected for human transplant was injected with intrastromal saline to create corneal haze. Pre and Post injection images were analyzed. The average pixel intensity that was calculated was found to be 111 pre-saline injury and 17.2 post-saline injection. Pre and Post-saline measurement showed a marked difference in average pixel intensity. This simple inexpensive setup and ease of analysis are advantages of this method of quantification.

A Comparison of Near-Infrared Imaging and Computerized Tomography Scan for Detecting Maxillary Sinusitis

2021 ◽  
pp. 000348942110606
Author(s):  
Mehdi Abouzari ◽  
Brooke Sarna ◽  
Joon You ◽  
Adwight Risbud ◽  
Kotaro Tsutsumi ◽  
...  
Keyword(s):  
Maxillary Sinus ◽  
Computerized Tomography ◽  
Sensitivity And Specificity ◽  
Near Infrared ◽  
Maxillary Sinusitis ◽  
Tertiary Care ◽  
Pixel Intensity ◽  
Sinus Disease ◽  
Nir Imaging ◽  
Average Pixel Intensity

Objective: To investigate the use of near-infrared (NIR) imaging as a tool for outpatient clinicians to quickly and accurately assess for maxillary sinusitis and to characterize its accuracy compared to computerized tomography (CT) scan. Methods: In a prospective investigational study, NIR and CT images from 65 patients who presented to a tertiary care rhinology clinic were compared to determine the sensitivity and specificity of NIR as an imaging modality. Results: The sensitivity and specificity of NIR imaging in distinguishing normal versus maxillary sinus disease was found to be 90% and 84%, normal versus mild maxillary sinus disease to be 76% and 91%, and mild versus severe maxillary sinus disease to be 96% and 81%, respectively. The average pixel intensity was also calculated and compared to the modified Lund-Mackay scores from CT scans to assess the ability of NIR imaging to stratify the severity of maxillary sinus disease. Average pixel intensity over a region of interest was significantly different ( P < .001) between normal, mild, and severe disease, as well as when comparing normal versus mild ( P < .001, 95% CI 42.22-105.39), normal versus severe ( P < .001, 95% CI 119.43-174.14), and mild versus severe ( P < .001, 95% CI 41.39-104.56) maxillary sinus disease. Conclusion: Based on this data, NIR shows promise as a tool for identifying patients with potential maxillary sinus disease as well as providing information on severity of disease that may guide administration of appropriate treatments.

Outcome of degenerative nonprolapse mitral regurgitation using the average pixel intensity method

2020 ◽  
Vol 37 (9) ◽  
pp. 1329-1335
Author(s):  
Victor Kamoen ◽  
Milad El Haddad ◽  
Tine De Backer ◽  
Marc De Buyzere ◽  
Frank Timmermans
Keyword(s):  
Mitral Regurgitation ◽  
Pixel Intensity ◽  
Average Pixel Intensity

Grading of mitral regurgitation in mitral valve prolapse using the average pixel intensity method

2018 ◽  
Vol 258 ◽  
pp. 305-312 ◽  
Author(s):  
Victor Kamoen ◽  
Milad El Haddad ◽  
Marc De Buyzere ◽  
Tine De Backer ◽  
Frank Timmermans
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Prolapse ◽  
Pixel Intensity ◽  
Average Pixel Intensity

scholarly journals Toxic Anterior Segment Syndrome following Phacoemulsification Secondary to Overdose of Intracameral Gentamicin

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Yaran Koban ◽  
Selim Genc ◽  
Gorkem Bilgin ◽  
Halil Huseyin Cagatay ◽  
Metin Ekinci ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Corneal Endothelium ◽  
Penetrating Keratoplasty ◽  
Histopathological Examination ◽  
Anterior Segment ◽  
High Dose ◽  
Bullous Keratopathy ◽  
Corneal Incision ◽  
Toxic Anterior Segment Syndrome ◽  
Corneal Button

Objective. To report a case of toxic anterior segment syndrome (TASS) that was caused by inadvertent anterior chamber and cornea stromal injection with high dose gentamicin following cataract surgery.Methods. Case report.Results. We report a 72-year-old female patient who developed TASS that was caused by high dose gentamicin (20 mg/0.5 mL), which was inadvertently used during the formation of the anterior chamber and hydration of the corneal incision. Unlike previous cases, hyphema and hemorrhagic fibrinous reaction were seen in the anterior chamber. Despite treatment, bullous keratopathy developed and penetrating keratoplasty was performed. The excised corneal button was sent for histopathological examination.Conclusions. Subconjunctival gentamicin is highly toxic to the corneal endothelium and anterior chamber structures. Including it on the surgical table carries a potentially serious risk for contamination of the anterior chamber.

scholarly journals Using a non-monochromatic microbeam for serial snapshot crystallography

2013 ◽  
Vol 46 (3) ◽  
pp. 791-794 ◽  
Author(s):  
Catherine Dejoie ◽  
Lynne B. McCusker ◽  
Christian Baerlocher ◽  
Rafael Abela ◽  
Bruce D. Patterson ◽  
...  
Keyword(s):  
Laser Source ◽  
Single Shot ◽  
Structural Studies ◽  
Proof Of Concept ◽  
Partial Reflection ◽  
Crystalline Materials ◽  
X Ray ◽  
Reflection Measurement ◽  
Type Zeolite ◽  
Diffraction Patterns

The new X-ray free-electron laser source (SwissFEL) that is currently being developed at PSI will provide a broad-bandpass mode with an energy bandwidth of about 4%. By using the full energy range, a new option for structural studies of crystalline materials may become possible. The proof of concept of broad-bandpass diffraction presented here is based on Laue single-crystal microdiffraction and the experimental setup on BL12.3.2 at the Advanced Light Source in Berkeley. Diffraction patterns for 100 randomly oriented stationary crystallites of theMFI-type zeolite ZSM-5 were simulated assuming several bandwidths, and the statistical and structural results are discussed. With a 4% energy bandwidth, the number of reflection intensities measured in a single shot is significantly higher than with monochromatic radiation. Furthermore, the problem of partial reflection measurement, which is inherent to the monochromatic mode with stationary crystals, can be overcome.

scholarly journals Color Restoration for Full-Waveform Multispectral LiDAR Data

2020 ◽  
Vol 12 (4) ◽  
pp. 593
Author(s):  
Binhui Wang ◽  
Shalei Song ◽  
Wei Gong ◽  
Xiong Cao ◽  
Dong He ◽  
...  
Keyword(s):  
Spatial Information ◽  
Digital Camera ◽  
Color Difference ◽  
Laser Source ◽  
Imaging Data ◽  
Waveform Data ◽  
Multispectral Data ◽  
Full Waveform ◽  
Relative Standard ◽  
Color Restoration

The current full-waveform data at a single wavelength can mainly retrieve the geometric attributes of targets along the light path by detecting waveform components, resulting in the lack of spectral or color attribute information. This kind of device relies on a digital camera for acquiring the color information, however, which is inevitably limited by the lighting conditions and geometric registration errors. With the development of multispectral light detection and ranging (LiDAR) or even hyperspectral LiDAR that often utilize a supercontinuum laser source covering the whole visible light band, including red, green and blue bands, the simultaneous acquisition of color and spatial information becomes possible and makes passive imaging data no longer necessary. In this study, we propose a color restoration method for a full-waveform multispectral LiDAR (FWMSL) system. Additionally, we develop a multispectral lognormal function to fit the tailing echoes measured by FWMSL further accurately. Experimental data from our FWMSL system are used to evaluate the performance of the proposed method. The relative standard deviation, correlation coefficient (R2) and color difference ( Δ E ) metrics suggest that the color restoration for the full-waveform multispectral data is feasible.

Impaired Intracellular Ca2+Dynamics in Live Cardiomyocytes Revealed by Rapid Line Scan Confocal Microscopy

2005 ◽  
Vol 11 (3) ◽  
pp. 235-243 ◽  
Author(s):  
David M. Plank ◽  
Mark A. Sussman
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Intensity ◽  
Linear Regression Analysis ◽  
Data Interpretation ◽  
Live Cells ◽  
Correction Factors ◽  
Pixel Intensity ◽  
Scanning Confocal Microscopy ◽  
Intracellular Ca ◽  
Average Pixel Intensity

Altered intracellular Ca2+dynamics are characteristically observed in cardiomyocytes from failing hearts. Studies of Ca2+handling in myocytes predominantly use Fluo-3 AM, a visible light excitable Ca2+chelating fluorescent dye in conjunction with rapid line-scanning confocal microscopy. However, Fluo-3 AM does not allow for traditional ratiometric determination of intracellular Ca2+concentration and has required the use of mathematic correction factors with values obtained from separate procedures to convert Fluo-3 AM fluorescence to appropriate Ca2+concentrations. This study describes methodology to directly measure intracellular Ca2+levels using inactivated, Fluo-3-AM-loaded cardiomyocytes equilibrated with Ca2+concentration standards. Titration of Ca2+concentration exhibits a linear relationship to increasing Fluo-3 AM fluorescence intensity. Images obtained from individual myocyte confocal scans were recorded, average pixel intensity values were calculated, and a plot is generated relating the average pixel intensity to known Ca2+concentrations. These standard plots can be used to convert transient Ca2+fluorescence obtained with experimental cells to Ca2+concentrations by linear regression analysis. Standards are determined on the same microscope used for acquisition of unknown Ca2+concentrations, simplifying data interpretation and assuring accuracy of conversion values. This procedure eliminates additional equipment, ratiometric imaging, and mathematic correction factors and should be useful to investigators requiring a straightforward method for measuring Ca2+concentrations in live cells using Ca2+-chelating dyes exhibiting variable fluorescence intensity.

P3372Prediction of outcome in functional mitral regurgitation using the average pixel intensity method

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
V Kamoen ◽  
M El Haddad ◽  
M De Buyzere ◽  
T De Backer ◽  
F Timmermans
Keyword(s):  
Heart Failure ◽  
Multivariate Analysis ◽  
Mitral Valve ◽  
Mitral Valve Surgery ◽  
Valve Surgery ◽  
Functional Mitral Regurgitation ◽  
Heart Failure Hospitalization ◽  
Pixel Intensity ◽  
Clinical Events ◽  
Average Pixel Intensity

Abstract Background Functional mitral regurgitation (FMR) is a frequent finding in patients with systolic heart failure. However, the echocardiographic grading of MR is challenging and different severity cut-offs are recommended by international guidelines. We developed and validated a novel echocardiographic parameter to grade MR, the average pixel intensity (API) method, based on pixel intensity analysis of the continuous wave Doppler signal. Purpose In this study, we assessed the long-term predictive value of the API method on clinical endpoints in FMR. Methods Transthoracic echocardiography was performed in consecutive heart failure patients with reduced EF (HF-REF) (n=221). MR was assessed using the API method, vena contracta width (VCW), effective regurgitant orifice area (PISA-EROA) and regurgitant volume (PISA-RV). The primary clinical events were major adverse cardiac events (MACE: cardiovascular mortality, mitral valve surgery, percutaneous mitral intervention or heart failure hospitalization). Results The API method was feasible in 97% of all FMR patients, which was significantly higher than parameters such as VCW, PISA-EROA and PISA-RV. 84 patients (37%) had one or more clinical events during the follow-up period (cardiovascular mortality (20%), mitral valve surgery (5%), percutaneous mitral intervention (5%), heart failure hospitalization (16%) or heart transplantation (2%)). Based on ROC curves, an API cut-off of 121 au was defined as “severe” MVP-MR with an overall better sensitivity and specificity than current guideline-recommended parameters. On multivariate analysis, MR graded with API was independently predictive for clinical events, whereas PISA-based methods were not independent. In addition, pulmonary pressures and NYHA class were powerful independent predictors of clinical outcome in FMR on multivariate analysis. Conclusions The API method better predicts clinical events and outcome in FMR compared to established grading methods. Therefore, the API method may be considered for grading FMR severity in clinical practice.

scholarly journals Anatomical Outcome of Vitreoretinal Surgery Using Temporary Keratoprosthesis and Replacement of the Trephined Corneal Button for Severe Open Globe Injuries: One-Year Result

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hui-Jin Chen ◽  
Chang-Guan Wang ◽  
Hong-Liang Dou ◽  
Xue-Feng Feng ◽  
Kang Feng ◽  
...  
Keyword(s):  
Silicone Oil ◽  
Case Series ◽  
Vitreoretinal Surgery ◽  
Corneal Transplant ◽  
Open Globe ◽  
Temporary Keratoprosthesis ◽  
Pars Plana ◽  
One Year ◽  
Anatomical Outcome ◽  
Corneal Button

In this case series of 74 patients with coexisting vitreoretinal injury and severe corneal opacification, after temporary keratoprosthesis (TKP) assisted pars plana vitrectomy (PPV), an allograft corneal transplant was not performed at the same time; instead, the patient’s trephined corneal button was sutured back. One year after the surgery, if intraocular pressure of the injured eyes was above 8 mmHg, removing silicone oil was attempted, and penetrating keratoplasty could be performed. Finally, 10 eyes (13.5%) were enucleated due to atrophia bulbi; 46 eyes (62.2%) were silicone-oil sustained; 15 eyes (20.3%) were anatomically restored; and 3 eyes (4.0%) experienced recurrent retinal detachment. These figures only demonstrate a small percentage of the injured eyes in our series, which have PKP indications. It is a practical option to suture back the patient’s trephined cornea following a TKP assisted PPV; keratoplasty was reserved for selected cases.

The evolving temperature field in a 1-m methanol pool fire

2021 ◽  
pp. 073490412110196
Author(s):  
Jian Chen ◽  
Kunhyuk Sung ◽  
Zhigang Wang ◽  
Wai Cheong Tam ◽  
Ki Yong Lee ◽  
...  
Keyword(s):  
Time Series ◽  
Temperature Field ◽  
Digital Camera ◽  
Thermal Inertia ◽  
Dynamic Structure ◽  
Optical Filters ◽  
Pool Fire ◽  
Pixel Intensity ◽  
Inertia Effects ◽  
Local Probability

Thin filament pyrometry is used to measure the time-varying temperature field in a 1-m methanol pool fire. A digital camera with optical filters and zoom lens recorded the emission intensity of an array of 12-µm silicon–carbide filaments oriented horizontally at various heights across the steadily burning pool fire. A 50-µm-diameter thermocouple measured the temperature at locations corresponding to the filament positions. A correlation was developed between the local probability density functions of the thermocouple time-series measurements corrected for radiation and thermal inertia effects and the camera grayscale pixel intensity of the filaments. A regression analysis yields the local mean temperature and its variance. The time series of the temperature field is transformed into average values during consecutive phases of the fire’s puffing cycle, providing quantitative insight into the complex and dynamic structure of a turbulent fire.

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