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Handheld devices such as mobile phones and tablet computers have become widespread with thousands of available software applications. Recently, handhelds are being proposed as part of medical imaging solutions, especially in emergency medicine, where immediate consultation is required. However, handheld devices differ significantly from medical wor...
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Technological advances have led to the development of powerful yet portable tablet computers whose touch-screen resolutions now permit the presentation of targets small enough to test the limits of normal visual acuity. Such devices have become ubiquitous in daily life and are moving into the clinical space. However, in order to produce clinically...
Citations
... Both HHUS and HEUS produce digital images with a minimum resolution of 800 × 600 pixels after post-processing. Although there may be measurable differences in the quality of displays used for HHUS [52], the influence of display resolution on B-scan quality should be negligible, due to the considerably lower real spatial resolution of sonography devices [53,54]. ...
Background: the use of handheld ultrasonography (HHUS) devices is well established in prehospital emergency diagnostics, as well as in intensive care settings. This is based on several studies in which HHUS devices were compared to conventional high-end ultrasonography (HEUS) devices. Nonetheless, there is limited evidence regarding potential variations in B-scan quality among HHUS devices from various manufacturers, and regarding whether any such differences hold clinical significance in intensive care medicine settings. Methods: this study included the evaluation of eight HHUS devices sourced from diverse manufacturers. Ultrasound videos of five previously defined sonographic questions (volume status/inferior vena cava, pleural effusion, pulmonary B-lines, gallbladder, and needle tracking in situ) were recorded with all devices. The analogue recording of the same pathologies with a HEUS device served as gold standard. The corresponding findings (HHUS and HEUS) were then played side by side and evaluated by sixteen intensive care physicians experienced in sonography. The B-scan quality and the clinical significance of the HHUS were assessed using a five-point Likert scale (5 points = very good; 1 point = insufficient). Results: both in assessing the quality of B-scans and in their ability to answer clinical questions, the HHUS achieved convincing results—regardless of the manufacturer. For example, only 8.6% (B-scan quality) and 9.8% (clinical question) of all submitted assessments received an “insufficient” rating. One HHUS device showed a significantly higher (p < 0.01) average points score in the assessment of B-scan quality (3.9 ± 0.65 points) and in the evaluation of clinical significance (4.03 ± 0.73 points), compared to the other devices. Conclusions: HHUS systems are able to reliably answer various clinical intensive care questions and are—while bearing their limitations in mind—an acceptable alternative to conventional HEUS devices. Irrespective of this, the present study was able to demonstrate relevant differences in the B-scan quality of HHUS devices from different manufacturers.
... Devices can also differ in terms of ergonomics [33,36] and monitor quality [37]. The devices we used showed, without exception, a high and intuitive level of user-friendliness as well as appealing monitor quality. ...
Aims:
A meaningful sonographic examination is decisively dependent on the B-scan quality of the ultrasound device. When selecting a suitable ultrasound device, B-scan quality should be an important purchase criterion. Although there is no generally accepted method to measure B-scan quality, we tried to evaluate comparable sonography devices from different manufacturers regarding B-scan quality.
Material and methods:
We systematically assessed the B-scan quality in ultrasound devices of seven different manufacturers from the mid-price segment. All 7 ultrasound units tested had comparable equipment features and the purchase value of approximately $20,000. We recorded video sequences and compared B-mode image quality. We used both physiological sectional images and pathological findings from abdominal ultrasound.
Results:
We identified three ultrasound units that scored significantly better in measuring the B-scan quality than the other devices. The Canon Xario 200, the General Electric Logiq P7 and the Mindray DC70 (in alphabetical order) were the units that outperformed all others.The differences identified were found to be statistically significant. A subgroup analysis showed that the contrasts in quality were more pronounced in near-field examinations than in examinations with greater penetration depth.
Conclusions:
There are considerable qualitative discrepancies in B-scan ultrasound devices despite being similar in terms of equipment and price. Our findings show that these differences are statistically detectable and likely clinically relevant.
... zum Einsatz im abdominellen Ultraschall macht die Systeme auch zum Einsatz für komplexe Fragestellungen, wie zum Beispiel Dyspnoe wertvoll [47]. In vielen Anwendungsgebieten wird die Bildqualität von Handheld-Systemen als adäquat für die Fragestellungen bei POCUS eingeschätzt [48]. ...
Zusammenfassung
Es wird der Einsatz von Handheld-Ultraschallgeräten unter technischen und datenschutzrechtlichen Gesichtspunkten, Geräteeigenschaften, Funktionalität, Dokumentation, Indikationen, Delegation der Leistung, Anwendungen durch Ärzte, Studierende und nichtärztliches Personal beleuchtet und diskutiert.
... The display size of the SMDs ranged from 4.7 to 9.7 inches. The high spatial resolution, acceptable contrast ratios and brightness levels, provided good image quality for safe interpretation [15,16]. DICOM images were displayed in original quality without any pixel loss and image quality remained intact while zooming. ...
In emergency settings, fast access to medical imaging for diagnostic is pivotal for clinical decision making. Hence, a need has emerged for solutions that allow rapid access to images on small mobile devices (SMD) without local data storage. Our objective was to evaluate access times to full quality anonymized DICOM datasets, comparing standard access through an authorized hospital computer (AHC) to a zero-footprint teleradiology technology (ZTT) used on a personal computer (PC) or SMD using national and international networks at a regional neurosurgical center. Image datasets were sent to a senior neurosurgeon, outside the hospital network using either an AHC and a VPN connection or a ZTT (Image Over Globe (IOG)), on a PC or an SMD. Time to access DICOM images was measured using both solutions. The mean time using AHC and VPN was 250 ± 10 s (median 249 s (233–274)) while the same procedure using IOG took 50 ± 8 s (median 49 s (42–60)) on a PC and 47 ± 20 s (median 39 (33–88)) on a SMD. Similarly, an international consultation was performed requiring 23 ± 5 s (median 21 (16–33)) and 27 ± 1 s (median 27 (25–29)) for PC and SMD respectively. IOG is a secure, rapid and easy to use telemedicine technology facilitating efficient clinical decision making and remote consultations.
... For mobile displays, the glossy finish is effective in avoiding intense light sources (like the sun) by simply tilting the mirror-like specular reflections away from the viewer field of vision. While initial steps have been taken to develop these measurement methods for mobile medical devices [57], as discussed in the AAPM Task Group 260 report in 2018, the wide diversity in ambient environments present unresolved challenges [62]. In desktop applications, it is not always possible to avoid the specular reflections. ...
Visual information is a critical component in the evaluation and communication of patient medical information. As display technologies have evolved, the medical community has sought to take advantage of advances in wider color gamuts, greater display portability, and more immersive imagery. These image quality enhancements have shown improvements in the quality of healthcare through greater efficiency, higher diagnostic accuracy, added functionality, enhanced training, and better health records. However, the display technology advances typically introduce greater complexity in the image workflow and display evaluation. This paper highlights some of the optical measurement challenges created by these new display technologies and offers possible pathways to address them.
... It can be used for image classification and segmentation as an input to the classifier (Yogalakshmi & Rani, 2020;Nawzat Sadiq Ahmed & Sadiq, 2018). The purpose of feature extraction is to reduce the original data set by measuring certain properties, or features, that distinguish one input pattern from another (Martin & Tosunoglu, 2000;Yamazaki et al., 2013;N. A. Zebari et al., 2021;R. ...
Brain tumor is one of the commonest tumors. For the diagnosis of this disease, automated detection and classification are crucial. Magnetic resonance imaging (MRI) is a unique sort of imaging which is utilized for detecting these tumors and categorizing them as benign or malignant using special algorithms such as of K-Nearest Neighbors (K-NN) and Support Vector Machine (SVM). The classification of brain tumors through imaging can be divided into four phases: pre-processing, extraction, segmentation and classification. This paper reviews some recent studies that highlight the efficacy of K-NN and SVM accuracies in classifying brain MRI images as normal or abnormal, benign or malignant. IJSB Literature review
... Handheld display [32], [36] size, resolution, viewing distance, and even brightness are not significant problem for image presentation and viewing. Touch screen interfaces can be designed to leave an image area clear of fingerprints and have low diffusive reflection, but high specular reflections [37] may be the most significant issue causing disruptive glare. ...
Digital medical imaging technology is developing rapidly in the last few decades and widely used as medical diagnostic tool. Medical image visual content analysis and interpretation is the most often method applied in detection and tracking of the pathogen behaviour of the imaged tissue. The human visual perception of the displayed image is limited by human visual system properties, display device characteristics and illumination environment influences during observation. In this review article we are analyzing how medical image specificities, human eye visual properties and display technology ultimate performances could be used to define medical image monitor technical requirements according to named application. We are focused on the analysis of the physical processes involved and technical aspects leading to optimization of the medical display requirements definition. This will help engineering and medical specialists to understand better medical display properties and provide more objective assessment of the display diagnostic suitability.
... 17 The computer screen's spatial resolution was lower than that of the handheld devices and this may be one of the reasons why it received a lower quality rating. However, spatial resolution is just one of the technical features that come into play when looking at display quality 18 and its importance may depend on the type of image. 19 The large variations found within each image category and more so between the clinical photographs of the type not studied thus far (burns and dermatological) might enhance the importance of protocols for image capture in those specialties. ...
... The experiment was also conducted in realistic lightning conditions so as to represent an environment as similar as possible to what experts experience in real-life consultation. Further, as the display characteristics (spatial resolution, noise and reflectance) of handheld devices have already been assessed technically, 18 the subjective user approach we adopted felt most relevant. ...
Background
Mobile health has promising potential in improving healthcare delivery by facilitating access to expert advice. Enabling experts to review images on their smartphone or tablet may save valuable time. This study aims at assessing whether images viewed by medical specialists on handheld devices such as smartphones and tablets are perceived to be of comparable quality as when viewed on a computer screen.
Methods
This was a prospective study comparing the perceived quality of 18 images on three different display devices (smartphone, tablet and computer) by 27 participants (4 burn surgeons and 23 emergency medicine specialists). The images, presented in random order, covered clinical (dermatological conditions, burns, ECGs and X-rays) and non-clinical subjects and their perceived quality was assessed using a 7-point Likert scale. Differences in devices' quality ratings were analysed using linear regression models for clustered data adjusting for image type and participants’ characteristics (age, gender and medical specialty).
Results
Overall, the images were rated good or very good in most instances and more so for the smartphone (83.1%, mean score 5.7) and tablet (78.2%, mean 5.5) than for a standard computer (70.6%, mean 5.2). Both handheld devices had significantly higher ratings than the computer screen, even after controlling for image type and participants' characteristics. Nearly all experts expressed that they would be comfortable using smartphones (n=25) or tablets (n=26) for image-based teleconsultation.
Conclusion
This study suggests that handheld devices could be a substitute for computer screens for teleconsultation by physicians working in emergency settings.
... 9 The display characteristics of the iPad have been previously reported. 10 However, there has been no evaluation of the effect of time in use on the display performance of the iPad. The aim of this study was to evaluate changes to the display characteristic of the lu- minance, luminance uniformity and conformance to the DICOM greyscale display function (GSDF) as a function of time in use for the iPad. ...
... Deviation from the DICOM GSDF has been previously reported in tablet displays. 10 The contrast response is particularly notable at the lower range of JND indices. ...
... This study did not measure the interdevice variability of the iPad display charac- teristics. Variability has been previously reported 10 and emphasizes the need to undertake conformance checks on devices used to display medical images. ...
Objectives:
The aim of this study was to evaluate changes to luminance, luminance uniformity and conformance to the DICOM grayscale standard display function (GSDF) as a function of time in use for the iPad.
Methods:
Luminance measurements of the AAPM TG18 test patterns (TG18-UNL and TG18-LN8) were performed using a calibrated near-range luminance meter. Nine sets of measurements were taken where the time in use of the iPad ranged from 0 to 2500 hours.
Results:
The maximum luminance of the display decreased (367 to 338 cdm(-2)) as a function of time. The minimum luminance remained constant. The maximum non-uniformity coefficient was 11%. Luminance uniformity decreased slightly as a function of time in use. The conformance of the iPad deviated from the GSDF curve at commencement of use. Deviation did not increase as a function of time in use.
Conclusion:
This study has demonstrated that the iPad display exhibits luminance degradation typical of LCD displays. The maximum luminance of the iPad fell below the ACR-AAPM-SIIM recommendations for primary displays (greater than 350 cdm(-2)) at approximately 1000 hours in use. The maximum luminance recommendation for secondary displays (greater than 250 cdm(-2)) was exceeded during the entire study. The maximum non-uniformity coefficient did not exceed the recommendations for either primary or secondary displays. The deviation from the GSDF exceeded the recommendations of the TG18 for use as either a primary or secondary display. Advances in Knowledge: The brightness, uniformity and contrast response are reasonably stable over the useful lifetime of the device however the device fails to meet the contrast response standard for either a primary or secondary display.
... 1 Evaluation of LCDs in terms of the MTF and WS requires an image-capture device such as a scientific-grade digital camera for high-precision evaluation or a high-resolution photographic-grade digital camera for simple evaluation. 1 With the rapid development of the display devices, the evaluation of the display performance is necessary to appropriately select a LCD in clinical situations, e.g., monochrome or color, resolution, maximum brightness, cold-cathode fluorescent lamp or LED backlight, handheld display, and display system for stereoscopic device. [10][11][12][13][14][15] In this paper, we focus on developing an evaluation method for LCDs by using a widely available single-lens reflex digital color camera (hereafter referred to as color camera) instead of a photometric camera. ...
... Recently, Yamazaki et al. reported MTFs and WS of color displays including LCDs and handheld devices, such as mobile phones and tablet computers, by using a photometric charge-coupled device camera. 13 The signal intensity of unprocessed data acquired by any camera, except for photometric cameras, depends on the spectral sensitivity of the image sensor regardless of whether the camera operates in color or monochrome. Such cameras cannot be directly used to quantitatively assess LCDs without prior calibration. ...
The aim of this study is to propose a method for the quantitative evaluation of image quality of both monochrome and color liquid-crystal displays (LCDs) using a commercially available color digital camera.
The intensities of the unprocessed red (R), green (G), and blue (B) signals of a camera vary depending on the spectral sensitivity of the image sensor used in the camera. For consistent evaluation of image quality for both monochrome and color LCDs, the unprocessed RGB signals of the camera were converted into gray scale signals that corresponded to the luminance of the LCD. Gray scale signals for the monochrome LCD were evaluated by using only the green channel signals of the camera. For the color LCD, the RGB signals of the camera were converted into gray scale signals by employing weighting factors (WFs) for each RGB channel. A line image displayed on the color LCD was simulated on the monochrome LCD by using a software application for subpixel driving in order to verify the WF-based conversion method. Furthermore, the results obtained by different types of commercially available color cameras and a photometric camera were compared to examine the consistency of the authors' method. Finally, image quality for both the monochrome and color LCDs was assessed by measuring modulation transfer functions (MTFs) and Wiener spectra (WS).
The authors' results demonstrated that the proposed method for calibrating the spectral sensitivity of the camera resulted in a consistent and reliable evaluation of the luminance of monochrome and color LCDs. The MTFs and WS showed different characteristics for the two LCD types owing to difference in the subpixel structure. The MTF in the vertical direction of the color LCD was superior to that of the monochrome LCD, although the WS in the vertical direction of the color LCD was inferior to that of the monochrome LCD as a result of luminance fluctuations in RGB subpixels.
The authors' method based on the use of a commercially available color camera is useful to evaluate and understand the display performances of both monochrome and color LCDs in radiology departments.
