scholarly journals Learning curve evaluation upskilling retinal imaging using smartphones

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Linus G. Jansen ◽  
Payal Shah ◽  
Bettina Wabbels ◽  
Frank G. Holz ◽  
Robert P. Finger ◽  
...  
Keyword(s):  
Image Quality ◽  
Low Cost ◽  
Field Studies ◽  
Field Of View ◽  
Retinal Images ◽  
Fundus Imaging ◽  
Resource Limited ◽  
Examination Time ◽  
Significant Difference

AbstractSmartphone-based fundus imaging (SBFI) is a low-cost approach for screening of various ophthalmic diseases and particularly suited to resource limited settings. Thus, we assessed how best to upskill alternative healthcare cadres in SBFI and whether quality of obtained images is comparable to ophthalmologists. Ophthalmic assistants and ophthalmologists received a standardized training to SBFI (Heine iC2 combined with an iPhone 6) and 10 training examinations for capturing central retinal images. Examination time, total number of images, image alignment, usable field-of-view, and image quality (sharpness/focus, reflex artifacts, contrast/illumination) were analyzed. Thirty examiners (14 ophthalmic assistants and 16 ophthalmologists) and 14 volunteer test subjects were included. Mean examination time (1st and 10th training, respectively: 2.17 ± 1.54 and 0.56 ± 0.51 min, p < .0001), usable field-of-view (92 ± 16% and 98 ± 6.0%, p = .003) and image quality in terms of sharpness/focus (p = .002) improved by the training. Examination time was significantly shorter for ophthalmologists compared to ophthalmic assistants (10th training: 0.35 ± 0.21 and 0.79 ± 0.65 min, p = .011), but there was no significant difference in usable field-of-view and image quality. This study demonstrates the high learnability of SBFI with a relatively short training and mostly comparable results across healthcare cadres. The results will aid implementing and planning further SBFI field studies.

scholarly journals Diagnostic Capabilities of a Smartphone- Based Low-Cost Microscope

2020 ◽  
Vol 6 (3) ◽  
pp. 522-525
Author(s):  
Dorina Hasselbeck ◽  
Max B. Schäfer ◽  
Kent W. Stewart ◽  
Peter P. Pott
Keyword(s):  
Low Cost ◽  
Field Of View ◽  
Parasitic Diseases ◽  
Optical Parameters ◽  
Trade Off ◽  
Resource Limited ◽  
Wide Range ◽  
Diagnostic Applications ◽  
Diagnostic Capabilities

AbstractMicroscopy enables fast and effective diagnostics. However, in resource-limited regions microscopy is not accessible to everyone. Smartphone-based low-cost microscopes could be a powerful tool for diagnostic and educational purposes. In this paper, the imaging quality of a smartphone-based microscope with four different optical parameters is presented and a systematic overview of the resulting diagnostic applications is given. With the chosen configuration, aiming for a reasonable trade-off, an average resolution of 1.23 μm and a field of view of 1.12 mm2 was achieved. This enables a wide range of diagnostic applications such as the diagnosis of Malaria and other parasitic diseases.

scholarly journals Non-contact smartphone-based fundus imaging compared to conventional fundus imaging: a low-cost alternative for retinopathy of prematurity screening and documentation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maximilian W. M. Wintergerst ◽  
Michael Petrak ◽  
Jeany Q. Li ◽  
Petra P. Larsen ◽  
Moritz Berger ◽  
...  
Keyword(s):  
Retinopathy Of Prematurity ◽  
Low Cost ◽  
Cost Effective ◽  
Field Of View ◽  
Fundus Examination ◽  
Fundus Imaging ◽  
Examination Time ◽  
Sensitivity Specificity ◽  
Rop Screening ◽  
Good Agreement

AbstractRetinopathy of prematurity (ROP) is a frequent cause of treatable childhood blindness. The current dependency of telemedicine-based ROP screening on cost-intensive equipment does not meet the needs in economically disadvantaged regions. Smartphone-based fundus imaging (SBFI) allows for affordable and mobile fundus examination and, therefore, could facilitate cost-effective telemedicine-based ROP screening in low-resources settings. We compared non-contact SBFI and conventional contact fundus imaging (CFI) in terms of feasibility for ROP screening and documentation. Twenty-six eyes were imaged with both SBFI and CFI. Field-of-view was smaller (ratio of diameters, 1:2.5), level of detail was equal, and examination time was longer for SBFI as compared to CFI (109.0 ± 57.8 vs. 75.9 ± 36.3 seconds, p < 0.01). Good agreement with clinical evaluation by indirect funduscopy was achieved for assessment of plus disease and ROP stage for both SBFI (squared Cohen’s kappa, 0.88 and 0.81, respectively) and CFI (0.86 and 0.93). Likewise, sensitivity/specificity for detection of plus disease and ROP was high for both SBFI (90%/100% and 88%/93%, respectively) and CFI (80%/100% and 100%/96%). SBFI is a non-contact and low-cost alternative to CFI for ROP screening and documentation that has the potential to considerably improve ROP care in middle- and low-resources settings.

The Influence of Alteration of kVp and mAs towards the Image Quality of Acrylic Using CBCT

2019 ◽  
Vol 829 ◽  
pp. 252-257
Author(s):  
Azhari ◽  
Yohanes Hutasoit ◽  
Freddy Haryanto
Keyword(s):  
Image Quality ◽  
Signal To Noise Ratio ◽  
Region Of Interest ◽  
Signal To Noise ◽  
Bite Block ◽  
Significant Difference ◽  
Noise Ratio ◽  
Post Hoc ◽  
Radiograph Image

CBCT is a modernized technology in producing radiograph image on dentistry. The image quality excellence is very important for clinicians to interpret the image, so the result of diagnosis produced becoming more accurate, appropriate, thus minimizing the working time. This research was aimed to assess the image quality using the blank acrylic phantom polymethylmethacrylate (PMMA) (C­5H8O2)n in the density of 1.185 g/cm3 for evaluating the homogeneity and uniformity of the image produced. Acrylic phantom was supported with a tripod and laid down on the chin rest of the CBCT device, then the phantom was fixed, and the edge of the phantom was touched by the bite block. Furthermore, the exposure of the X-ray was executed toward the acrylic phantom with various kVp and mAs, from 80 until 90, with the range of 5 kV and the variation of mA was 3, 5, and 7 mA respectively. The time exposure was kept constant for 25 seconds. The samples were taken from CBCT acrylic images, then as much as 5 ROIs (Region of Interest) was chosen to be analyzed. The ROIs determination was analyzed by using the ImageJ® software for recognizing the influence of kVp and mAs towards the image uniformity, noise and SNR. The lowest kVp and mAs had the result of uniformity value, homogeneity and signal to noise ratio of 11.22; 40.35; and 5.96 respectively. Meanwhile, the highest kVp and mAs had uniformity value, homogeneity and signal to noise ratio of 16.96; 26.20; and 5.95 respectively. There were significant differences between the image uniformity and homogeneity on the lowest kVp and mAs compared to the highest kVp and mAs, as analyzed with the ANOVA statistics analysis continued with the t-student post-hoc test with α = 0.05. However, there was no significant difference in SNR as analyzed with the ANOVA statistic analysis. The usage of the higher kVp and mAs caused the improvement of the image homogeneity and uniformity compared to the lower kVp and mAs.

scholarly journals A comparative study on image quality of two digital intraoral sensors

2019 ◽  
Vol 48 (7) ◽  
pp. 20190063 ◽  
Author(s):  
Cinar Aziman ◽  
Kristina Hellén-Halme ◽  
Xie-Qi Shi
Keyword(s):  
Image Quality ◽  
Observer Agreement ◽  
Visual Grading ◽  
Intra Class Correlation ◽  
Subjective Image Quality ◽  
Significant Difference ◽  
General Dentists ◽  
Parallel Technique ◽  
Specialist Group

Objectives The aims of this study were to evaluate the subjective image quality and reliability of two digital sensors. In addition, the image quality of the two sensors evaluated by specialists and general dentists were compared. Methods: 30 intraoral bitewings from five patients were included in the study, 15 were exposed with a Dixi sensor (CCD-based) and 15 with a ProSensor (CMOS-based) using modified parallel technique. Three radiologists and three general dentists evaluated the images in pair. A five-point scale was used to register the image quality. Visual grading characteristics (VGC) analysis was performed to compare the image quality and the observer agreement was assessed in terms of intra class correlation co-efficient. Results No statistically significant difference was found on image quality between the sensors. The average scores of the observer agreement were moderate with an average of 0.66 and an interval of 0.30 to 0.87, suggesting that there was a large variation on preference of image quality. However, there was a statistically significant difference in terms of the area under the VGC- curves between the specialist group and the general dentist group ( p = 0.043), in which the specialist group tended to favor the ProSensor. Conclusions Subjective image quality of the two intraoral sensors were comparable when evaluated by both general and oral radiologists. However, the radiologists seemed to prefer the ProSensor to the Dixi as compared to general dentists. Inter- observer conformance showed a large variation on the preference of the image quality.

scholarly journals Quality of eyeglass prescriptions from a low-cost wavefront autorefractor evaluated in rural India: results of a 708-participant field study

2019 ◽  
Vol 4 (1) ◽  
pp. e000225 ◽  
Author(s):  
Nicholas J Durr ◽  
Shivang R Dave ◽  
Daryl Lim ◽  
Sanil Joseph ◽  
Thulasiraj D Ravilla ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Form Factor ◽  
Low Cost ◽  
Rural India ◽  
Resource Setting ◽  
Low Resource Setting ◽  
Significant Difference ◽  
Minimum Angle ◽  
The Mean

ObjectiveTo assess the quality of eyeglass prescriptions provided by an affordable wavefront autorefractor operated by a minimally trained technician in a low-resource setting.Methods and Analysis708 participants were recruited from consecutive patients registered for routine eye examinations at Aravind Eye Hospital in Madurai, India, or an affiliated rural satellite vision centre. Visual acuity (VA) and patient preference were compared between trial lenses set to two eyeglass prescriptions from (1) a novel wavefront autorefractor and (2) subjective refraction by an experienced refractionist.ResultsThe mean±SD VA was 0.30±0.37, –0.02±0.14 and −0.04±0.11 logarithm of the minimum angle of resolution units before correction, with autorefractor correction and with subjective refraction correction, respectively (all differences p<0.01). Overall, 25% of participants had no preference, 33% preferred eyeglass prescriptions from autorefraction, and 42% preferred eyeglass prescriptions from subjective refraction (p<0.01). Of the 438 patients 40 years old and younger, 96 had no preference and the remainder had no statistically significant difference in preference for subjective refraction prescriptions (51%) versus autorefractor prescriptions (49%) (p=0.52).ConclusionAverage VAs from autorefractor-prescribed eyeglasses were one letter worse than those from subjective refraction. More than half of all participants either had no preference or preferred eyeglasses prescribed by the autorefractor. This marginal difference in quality may warrant autorefractor-based prescriptions, given the portable form factor, short measurement time, low cost and minimal training required to use the autorefractor evaluated here.

Yoga in women undergoing treatment for breast cancer: Impact on quality of life in a randomized controlled trial.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 527-527
Author(s):  
Nita S. Nair ◽  
Nishu Singh Goel ◽  
Rohini W Hawaldar ◽  
Shabina Siddique ◽  
Vani Parmar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Adjuvant Therapy ◽  
Low Cost ◽  
Controlled Trial ◽  
Statistical Significance ◽  
Disease Free Survival ◽  
Complementary Therapy ◽  
Significant Difference

527 Background: Yoga has been tested in multiple small-randomized studies for its impact on quality of life (QOL) on breast cancer (BC). We propose to study the effect of yoga on disease free survival as the primary endpoint in women with operable breast cancer. (Study methodology details refer to NCT02161900). Methods: Women with non-metastatic BC were randomized to yoga and conventional exercise (YCE) versus conventional exercise only (CE) in addition to standard therapy. Over and above documentation of recurrence and death, QOL was assessed in these women using the EORTC QLQC30, BR23, Brief fatigue inventory (BFI), Visual pain scores (VPS) and a spirituality questionnaire (SQ). EORTC QLQ was assessed at baseline (BL), 6-9 months (mo), 18-21 mo. BFI and VPS at BL, 6-8 mo and 12-15 mo and SQ at BL and 12-15 mo. We report the first interim analysis of QOL in 605 patients randomized to the study with atleast 1 year of follow up. The groups were balanced in both arms with respect to clinico-pathological factors. Results: At 6-9 mo (completion of adjuvant therapy), there was no significant difference in global QOL scores (p = 0.08), however 52% women on YCE showed an improvement from baseline compared to 42% in CE. At 18-21 mo emotional function scores were better in YCE (p = 0.002); with lesser systemic side effects in YCE arm (44% vs 56% p = NS). The median score of fatigue after adjuvant therapy measured by QLQ C30 was lower in YCE (17.37vs22.22, p = 0.003) which was similar to that observed by BFI at 12-15 mo (1.6vs 2, p = 0.04). Also in YCE there was lower reporting of detriment in general activity (41%vs 59%) and mood (34%vs66%) (p = NS). In VPS at 12-15mo, the median scores for pain intensity (p = 0.042), pain on movement (p = 0.038), pain on mobilization (p = 0.008) were lower in YCE. Lastly SQ assessed spirituality and showed no difference, but less deterioration compared to baseline scores in YCE. Conclusions: Yoga did not show a significant difference in global QOL but had a major benefit reaching statistical significance in fatigue, emotional score and pain. Yoga is a low-risk, low-cost complementary therapy that may improve compliance to therapy by improving parameters that can affect day-to-day activity in women with breast cancer. Clinical trial information: NCT02161900.

Digital Luminescence Radiography Using a Chest Phantom

1993 ◽  
Vol 34 (5) ◽  
pp. 440-444 ◽  
Author(s):  
K. Lyttkens ◽  
M. Kehler ◽  
B. Andersson ◽  
S. Carlsen ◽  
A. Ebbesen ◽  
...  
Keyword(s):  
Image Quality ◽  
Operating Characteristic ◽  
Roc Curves ◽  
Diagnostic Image Quality ◽  
Diagnostic Image ◽  
Digital Radiographs ◽  
Significant Difference ◽  
Digital Luminescence Radiography ◽  
Optical Discs

With the introduction of picture and archiving communicating systems an alternative image display for the wards might be a personal computer (PC). The intention with this study was to evaluate the diagnostic image quality of the monitor of a PC compared to that of a workstation. Eighty-five digital radiographs of a chest phantom with simulated tumors in the mediastinum and right lung were saved on optical discs. The examinations were reviewed by 4 radiologists on a monitor at a workstation and at a PC, and receiver operating characteristic (ROC) curves were constructed. No significant difference was found between performance of the PC and the workstation.

scholarly journals A Novel Device for Smartphone-Based Fundus Imaging and Documentation in Clinical Practice: Comparative Image Analysis Study

10.2196/17480 ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. e17480
Author(s):  
Maximilian W M Wintergerst ◽  
Linus G Jansen ◽  
Frank G Holz ◽  
Robert P Finger
Keyword(s):  
Clinical Practice ◽  
Image Quality ◽  
Image Acquisition ◽  
Posterior Pole ◽  
Image Resolution ◽  
Imaging Device ◽  
Video Mode ◽  
Novel Device ◽  
Fundus Imaging ◽  
Significant Difference

Background Smartphone-based fundus imaging allows for mobile and inexpensive fundus examination with the potential to revolutionize eye care, particularly in lower-resource settings. However, most smartphone-based fundus imaging adapters convey image quality not comparable to conventional fundus imaging. Objective The purpose of this study was to evaluate a novel smartphone-based fundus imaging device for documentation of a variety of retinal/vitreous pathologies in a patient sample with wide refraction and age ranges. Methods Participants’ eyes were dilated and imaged with the iC2 funduscope (HEINE Optotechnik) using an Apple iPhone 6 in single-image acquisition (image resolution of 2448 × 3264 pixels) or video mode (1248 × 1664 pixels) and a subgroup of participants was also examined by conventional fundus imaging (Zeiss VISUCAM 500). Smartphone-based image quality was compared to conventional fundus imaging in terms of sharpness (focus), reflex artifacts, contrast, and illumination on semiquantitative scales. Results A total of 47 eyes from 32 participants (age: mean 62.3, SD 19.8 years; range 7-93; spherical equivalent: mean –0.78, SD 3.21 D; range: –7.88 to +7.0 D) were included in the study. Mean (SD) visual acuity (logMAR) was 0.48 (0.66; range 0-2.3); 30% (14/47) of the eyes were pseudophakic. Image quality was sufficient in all eyes irrespective of refraction. Images acquired with conventional fundus imaging were sharper and had less reflex artifacts, and there was no significant difference in contrast and illumination (P<.001, P=.03, and P=.10, respectively). When comparing image quality at the posterior pole, the mid periphery, and the far periphery, glare increased as images were acquired from a more peripheral part of the retina. Reflex artifacts were more frequent in pseudophakic eyes. Image acquisition was also possible in children. Documentation of deep optic nerve cups in video mode conveyed a mock 3D impression. Conclusions Image quality of conventional fundus imaging was superior to that of smartphone-based fundus imaging, although this novel smartphone-based fundus imaging device achieved image quality high enough to document various fundus pathologies including only subtle findings. High-quality smartphone-based fundus imaging might represent a mobile alternative for fundus documentation in clinical practice.

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