Digital Zoom Research Articles

Shape and size of epididymal sperm from Gir bulls using atomic force microscopy: A nanoscale characterization of epididymal sperm

As epididymal sperm (EP) are not exposed to seminal plasma, they are physiologically different from ejaculated spermatozoa (EJ). Therefore, the aim of this study was to morphologically characterize the head of EP recovered from the epididymis tail, and to evaluate if the physiological differences between EP and EJ were also expressed in the head’s shape and size. EP and EJ were recovered from seven Gir bulls and were individually assessed. Sperm cells were washed, fixed, and 20 cells from each animal were analyzed by atomic force microscopy (AFM). The images were acquired through contact mode. Then, an off-line processing software was used and the images acquired were manually segmented using digital zoom of the original images. Twenty-four structural features were assessed including one, two, and three dimensional parameters, and also shape descriptors which were calculated based on the one and two dimensional parameters. Data were compared by t-test, then, a collective analysis was performed using principal component analysis (PCA). The EP group presented higher roughness and elongation (P ≤ 0.05), and smaller form factor and circularity rate than that of the EJ group (P ≤ 0.05). For the other parameters no differences (P ≥ 0.05) were observed. In addition, in the PCA analysis no differences among EP and EJ were observed either (P ≤ 0.05). This study showed that EP and EJ collected from the same sire presented similar characteristics in nineteen of the twenty-four parameters evaluated, indicating that absence of seminal plasma does not affect the morphology of EP.

Dual Fluoroscopy With Live-Image Zooming Significantly Reduces Patient and Operating Staff Radiation During Fenestrated-Branched Endovascular Aortic Aneurysm Repair

Fenestrated-branched endovascular aneurysm repair (F/BEVAR) is a complex procedure that generates high radiation dose. Use of magnification views aids in the success of vessel cannulation but increases the overall radiation dose. The aim of the study was to compare the radiation doses to patients and operating room staff from two fluoroscopy techniques, standard magnification vs dual fluoroscopy with live-image digital zooming during F/BEVAR.

Development of aluminum cone tip for fast ignition target

We have developed a novel method to fabricate an aluminum cone tip to attach the conventional gold cone for fast ignition. An aluminum cone tip is fabricated by laser thermal chemical vapor deposition. Trimethylaluminum (TMA) is used as a chemical precursor of aluminum. TMA is introduced into a vacuum chamber with argon gas and heated on a substrate by using a heater and a laser. Aluminum products are measured by using digital zoom microscope. It is found that the deposition rate is increased with the increase of the substrate temperature, argon gas flow, and the laser intensity. However, the increase of the laser intensity increases the temperature of the deposit, and also causes the melt of the deposit. Under suitable conditions, we succeeded in making desired aluminum conical shape with 32 μm height, whose size is difficult by conventional cutting technology. Therefore, this method will be important not only to the fusion experiments but also to many other industrial applications.

P2434Digital zoom decreases radiation exposure dose up to 30% in percutaneous coronary intervention

Abstract Background Interventional cardiology is gaining greater popularity worldwide with each passing year. Reduction of exposure dose is a very imminent and an important issue in cardiology procedure. Although a newer radiation reduction technique, device and procedure are very valuable and expected, we should consider about therapy technique, radiation technique, devices, and the way to protection. Digital zoom digitally enlarges images in real time by up to 2.5-fold at lower doses than those used with traditional field of view changes. In our phantom examination the average dose reduction of digital zoom was 27%. Methods and results This study is designated as single-center, retrospective, not-randomized, observation study. 2101 eligible cases were collected. We assigned the cases of PCI without the use of Digital zoom to the Conventional group and those involving the use of Digital zoom to the Digital zoom group. There were 806 patients in the Conventional group and 1195 in the Digital zoom group. Because we had begun using Digital zoom from January 2015 onwards, all patients in the Conventional group had undergone PCI from January 2013 to December 2014 and all patients in the Digital zoom group had undergone PCI from January 2015 to December 2016. In addition, we calculated the RAK/minute and DAP/minute for an accurate assessment. To minimize the difference of characteristics between two groups, propensity score including all baseline variables was performed. Furthermore, Predictors of radiation exposure were investigated using multivariable least square methods. Inter group differences were observed in DAP, RAK, DAP/min, and RAK/min (Digital zoom group vs conventional group: DAP, 16000 cGy cm2 [from 1st quartile to 3rd quartile; 10300–24400] vs 20700 [13400–29500], p<0.001; DAP/min, 557 cGy cm2/min [392–737] vs 782 [571–1010], p<0.01; RAK, 1590 Gy [990–2410] vs 1850 [1220–2720], p<0.01; RAK/min, 54.7 Gy/min [38.5–73.2] vs 71.2 [51.5–93.0], p<0.01). Even after propensity score matching, intergroup differences in DAP (810 cases), DAP/min (811 cases), RAK (746 cases), and RAK/min (744 cases) persisted. Furthermore, the least squares method showed that Digital zoom is an important predictor of DAP (β=0.17, p<0.01) and RAK (β=0.12, p<0.01). Conclusion Digital zoom is an old and cost-free technique, but one of most powerful reduction of exposure method. Propensity score adjustment and least square methods show that digital zoom is one of independent effective method.

Holographic measurement of surface acoustic wave parameters in crystals

The theoretical basis of a specialized technique for applying digital holographic interferometry to measure the parameters of surface acoustic waves is presented, a measuring system for visualization and quantitative analysis of the parameters of ultralow-amplitude high-frequency oscillations arising in electronic devices using surface acoustic waves is developed, and experimental results of the study of surface acoustic waves in crystals of lithium niobate are obtained. In this case, to ensure the possibility of recording precision double-exposure interferograms of high-frequency surface acoustic waves, a picosecond pulsed laser with two-stage frequency multiplication was used as a radiation source, and to increase the spatial resolution of the system with the possibility of observing a wide field of view, an adjustable optical zoom of the incoming image was applied to the matrix input (based on charge-coupled devices) of the recording camera and digital zoom was used for obtained interferogram. We achieved the measuring sensitivity of the surface acoustic waves amplitude and spatial-temporal resolution allowing visualization and measurement of surface acoustic waves with amplitudes of the order of 1 nm and frequencies of the order of 10 MHz, which is far beyond the capabilities of standard methods of holographic interferometry.

Initial Experience of ORBEYE™ Surgical Microscope for Carotid Endarterectomy.

Background:Carotid endarterectomy (CEA) is widely performed under operative microscopes. They provide magnified and stereoscopic vision of operative field suitable for precise maneuver. However, the microscope has some shortcomings, which are a narrow field-of-view, shallow depth-of-field, and the operator's fatigue due to fixed gaze posture through eyepieces. To overcome them, we introduced ORBEYE™ Surgical Microscope, which was 4K ultra high-definition three-dimensional (3D) system. We present our initial experience of the system for CEA and discuss its usefulness compared with the operating microscopes.Methods:A 66-year-old male presented to our department for the treatment of the left internal carotid artery severe stenosis. He underwent CEA using the ORBEYE™ Surgical Microscope.Results:The surgery was successfully completed only under the system without complication. The microscope was set over the operative field. Its wide field-of-view, deep depth of field, and smooth digital zooming allowed minimal repositioning of the microscope. The system provided high quality stereoscopic image of the surgical site, which enables us to perform precise surgery. The 55-inch 4K 3D monitor remarkably contributed to a reduction of the surgeons’ fatigue.Conclusions:The ORBEYE™ Surgical Microscope, incorporating 4K 3D video technology, has overcome shortcomings of the operative microscope. This system is highly feasible for CEA and has the certain possibility for other neurovascular surgeries.

Mass-Remainder Analysis (MARA): An Improved Method for Elemental Composition Assignment in Petroleomics.

Data processing and visualization methods have an important role in the mass spectrometric study of crude oils and other natural samples. The recently invented data mining procedure, Mass-Remainder Analysis (MARA), was further developed for use in petroleomics. MARA is based on the calculation of the remainder after dividing by the exact mass of a base unit, in petroleomics by the mass of the CH2 group. The two key steps in the MARA algorithm are the separation of the monoisotopic peaks from the other isotopic peaks and the subsequent intensity correction. The effectiveness of our MARA method was demonstrated on the analysis of lubricating mineral oil and crude oil samples by ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry experiments. MARA is able to handle a huge portion of the overlapped peaks even in a moderate resolution mass spectrum. With use of MARA, effective chemical composition assignment and visual representation were achieved for complex mass spectra recorded by a time-of-flight analyzer with a limited resolution of 40 000 at m/ z 400. In the absence of an ultra-high-resolution mass analyzer, MARA can provide a closer look on the mass spectral peaks, like a digital zoom in a simple camera.

An effective and practical diagnostic clinical method in primary scarring alopecia: Dermoscopy

Objective: There are several studies on the dermoscopy of the cicatricial alopecia. When the national literature is reviewed, however, only one original study focusing on the subject exists. Here, we aimed to investigate the dermoscopic features of the patients with primary cicatricial alopecia. Materials and Methods: In this study, dermoscopic findings of 40 patients with clinical and histopathological diagnosis of primary cicatricial alopecia were retrospectively reviewed. Dermoscopic examination was performed by a handheld dermoscope with 10-fold magnification. Photographing was performed using a dermoscope attached to a cell phone camera with 2-fold digital zoom. Results: Tubular perifollicular scale in lichen planopilaris (n = 12), cutaneous clefts with emerging hairs and three-dimensional yellow dots in dissecting cellulitis (n = 6), tufted hairs in folliculitis decalvans (n = 6), and follicular plugs and branching vessels in discoid lupus erythematosus (n = 6) were the main findings. No characteristic finding was found for pseudopelade of Brocq (n = 8) and frontal fibrosing alopecia (n = 2). Conclusion: Dermoscopy is a noninvasive, effective, and practical diagnostic tool for the differential diagnosis of primary cicatricial alopecia. The retrospective nature, lack of a control group, and relatively small number of the patients are the main limitations of our study.

Impact of onlay fusion and cone beam computed tomography on radiation exposure and technical assessment of fenestrated-branched endovascular aortic repair

ObjectiveThe objective of this study was to analyze the impact of advanced imaging applications and cone beam computed tomography (CBCT) on radiation exposure of the patient and operator and detection of technical problems during fenestrated-branched endovascular aortic repair (F-BEVAR) for treatment of pararenal aneurysms and thoracoabdominal aortic aneurysms (TAAAs). MethodsWe reviewed the clinical data of 386 consecutives patients (289 male; mean age, 75 ± 8 years) treated by F-BEVAR for 196 pararenal aneurysms and 190 TAAAs (mean, 3.4 ± 0.9 targeted vessels/patient) between 2007 and 2017. Radiation exposure (cumulative air kerma) was analyzed in three fixed imaging systems used between 2007 and 2011 (system 1), 2012 and 2016 (system 2), and 2016 and 2017 (system 3). Onlay fusion and CBCT were available with systems 2 and 3, whereas digital zoom with fusion overlay was used with system 3. Operator effective dose was measured per month using a radiation dosimeter badge. Computed tomography angiography and CBCT were analyzed for findings requiring immediate revision or secondary interventions. End points were patient radiation exposure; operator effective dose; procedure technical success; and 30-day rates of mortality, major adverse events, and secondary interventions. ResultsF-BEVAR was performed using system 1 in 98 patients, system 2 in 198 patients, and system 3 in 90 patients. Use of onlay fusion/CBCT was 0% with system 1, 42% with system 2, and 98% with system 3. Procedures performed with onlay fusion/CBCT had significantly (P < .05) higher technical success (99.4% vs 98.8%) and lower contrast material volume (155 ± 58 mL vs 172 ± 80 mL), fluoroscopy time (83 ± 34 minutes vs 94 ± 49 minutes), and cumulative air kerma (2561 ± 1920 mGy vs 3767 ± 2307 mGy). Despite higher case volume and increasing complexity during the experience, operator effective dose decreased to 9 ± 4 × 10−2 mSv/case with system 3 compared with 26 ± 3 × 10−2 mSv/case with system 1 and 20 ± 2 × 10−2 mSv/case with system 2 (P = .001). Among 219 patients who had no CBCT, 18 (8%) had computed tomography angiography findings that prompted secondary interventions before dismissal. Conversely, among 167 patients who had CBCT, 14 patients (8%) had intraoperative CBCT findings requiring immediate revision, with no additional secondary interventions. Patients treated with onlay fusion/CBCT had significantly (P < .05) lower mortality (4% vs 1%), major adverse events (43% vs 19%), and secondary interventions (10% vs 4%) at 30 days. ConclusionsRadiation exposure and operator effective dose significantly decreased with evolution of F-BEVAR experience and use of advanced imaging applications such as onlay fusion and CBCT. CBCT allowed immediate assessment and identified intraoperative technical problems, leading to immediate revision and avoiding early secondary interventions.

Photo-realistic continuous digital zooming for an asymmetrical dual camera system

Asymmetrical dual camera systems are becoming more and more popular among many commercial products and they are expected to provide digital zooming images. Existing related algorithms such as super-solution and image fusion fail to reconstruct photo-realistic results because of the sampling rate inconsistency, especially when the focal lengths of cameras vary largely. Nevertheless, magnification factor of super-resolution algorithms are fixed and inflexible as well. By looking into the inherent drawbacks of existing super-resolution algorithm, a new photo-realistic continuous digital zooming algorithm is then proposed in this paper on the basis of a novel super-resolution framework and a band-inpainting algorithm. Experiment result illustrates that proposed algorithm combines the advantages of both super-resolution algorithm and image inpainting algorithm: it reconstructs band information with super-resolution methods, and introduce image inpainting algorithm to reconstruct poorly super-resolved texture areas to produce state-of-the-art photo-realistic digital zooming images.

Adaptive variable order polynomial based digital zoom of images

Digital zoom is widely used in daily life from zooming a captured image to navigating through live maps. The applications are simple but application domains benefit large number of users. This manuscript proposes a novel approach to escalate zoom limits by modifying the zoom tolerance bound of an image. The approach focuses on preserving original information and transfer it to zoomed image. Digital zoom is achieved by first representing the original image as a set mathematical model representing underlying statistical parameters. The sets in model are further analyzed to calculate set variance; which in turn is used for localizing fluctuations and generate polynomial for each set. These polynomial are then used for implementing variable order interpolation scheme. Experimental results confirm that the present technique outperforms existing techniques in terms of image quality measurement parameters. The discussed approach can be implemented on RGB or grayscale images equivalently.

Angiographers no longer need to avoid digital zoom

AbstractThe physics of angiographic digital flat‐panel detectors suggests that no increase in dose is required for appropriate image quality in image‐magnified fields of view. This is contrary to current practice. A dose‐saving protocol decreased radiation dose by an average of 32% for these zoomed fields of view with no observable image quality degradation. This change in protocol may be applicable across all manufactures of flat‐panel angiographic systems. Angiographers may preferentially use reduced‐dose zoomed fields to minimize scatter radiation, assure anatomical conspicuity and reduce patient radiation burden.

Tunable‐focus negative poly(vinyl chloride) gel microlens driven by unilateral electrodes

ABSTRACTTunable‐focus microlenses are urgently required for compact optical products to replace digital zoom and obtain high‐quality images. An electrically controllable tunable‐focus negative microlens is proposed, which is based on an electroactive poly(vinyl chloride) gel plasticized by ecofriendly dioctyl terephthalate. The anode and cathode of the microlens are simply assembled on the same side of the electrorheological elastomer, which greatly saves space and allows the thickness of the proposed microlens to be less than 1 mm. By applying voltages ranging from 0 to 1000 V, the stable focus of the microlens is interestingly able to vary as wide as from –∞ to −21.3 mm correspondingly. The proposed microlens is simple and thin but is flexible and stable and has a wide range of the focus variation, showing promising applications in minielectric and optical devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46136.

Continuous digital zooming of asymmetric dual camera images using registration and variational image restoration

This paper presents a theoretical basis to realize a high-quality digital zooming using two camera modules with different focal lengths. First, we describe an image degradation model of the asymmet...

Continuous digital zooming using local self-similarity-based super-resolution for an asymmetric dual camera system.

This paper presents a digital zooming method using a super-resolution (SR) algorithm based on the local self-similarity between the wide- and tele-view images acquired by an asymmetric dual camera system. The proposed SR algorithm consists of four steps: (i)registration of an optically zoomed image to the wide-view image, (ii)restoration of the central region of the zoomed wide-view image, (iii)restoration of the boundary region of the zoomed wide-view image, and (iv)fusion of the results from steps (ii) and (iii). Since an asymmetric dual camera system acquires different-resolution images on the same scene due to the different optical specifications, the proposed method can restore the low-resolution wide-view image using the ideal high-frequency component estimated from the optically zoomed image. Experimental results demonstrate that the proposed method can provide significantly improved high-resolution wide-view images compared to existing single-image-based SR methods.

Designing computer-based learning contents: influence of digital zoom on attention

In the present study, we investigated the role of digital zoom as a tool for directing attention while looking at visual learning material. In particular, we analyzed whether minimal digital zoom functions similarly to a rhetorical device by cueing mental zooming of attention accordingly. Participants were presented either static film clips, film clips with minimal zoom-ins, or film clips with minimal zoom-outs while eye movements were recorded. We hypothesized that minimal zoom-ins should lead to more gaze coherence, to longer dwell times as an indicator of more elaborative processing, and to fewer transitions as an indicator of less mental integration. Zoom-outs, on the other hand, were expected to have opposite effects. Results showed that zoom-ins increase gaze coherence and dwell times on the center parts of the depictions while decreasing transitions of pictorial elements from the center and the context areas. In contrast, patterns of results from zoom-outs and static presentations were similar to a large degree, indicating that zoom-ins and zoom-outs do not operate in a complementary fashion. Theoretical and practical implications of the present results are discussed.

Comparison between image quality in electronic zoom and geometric magnification in digital mammography.

Magnification mammography is performed to enhance the visibility of small structures at the expense of relatively high radiation dose as a complementary examination to standard mammography. The introduction of post-processing capabilities and the widespread use of digital mammography has promoted some controversy in the last decade on whether similar visibility can be achieved using electronic zoom. The aim of this study is to compare the visibility of small structures in images obtained by the two techniques stated above for different exposure conditions. Images of a Fluke Biomedical Model 18-220 Mammography Accreditation Phantom were obtained using standard techniques and geometric magnification, using a digital mammography unit, with different exposure factors. Three different target/filter combinations (Mo/Mo,Mo/Rh,Rh/Rh), variable kVp (26-32), and automatic exposure control were used. Images obtained using standard technique were electronically zoomed and compared to the corresponding magnification mammograms. Comparisons were based on the visibility of structures evaluated by five senior technologist with extensive experience in mammography. Statistical analysis was performed using non-parametric tests. Visibility of structures was not affected by the kV used for a given target/filter combination for both techniques (p > 0.065). Target/filter combination of Mo/Mo provided better visibility of micro-calcification and fibers (p < 0.026) in geometric magnification technique and Mo/Rh in the digital zoom technique. No significant differences were observed in the visibility of simulated breast masses. The overall image score was significantly higher (p < 0.001) for geometric magnification over the digital zoom for Mo/Mo & Rh/Rh combinations. Although sufficient image quality was maintained in electronically zoomed images, geometric magnification provided better overall visualization of structures in the phantom.

Comment on "'Tape dermatoscopy': constructing a low-cost dermatoscope using a mobile phone, immersion fluid and transparent adhesive tape".

We read with interest the article published by Blum and Giacomel, describing the low-cost dermatoscope designed using a mobile phone, immersion fluid and transparent adhesive tape. The method described by the authors has the advantage that it does not require any magnifying device [1]. We earlier described a technique where a low-cost jeweler’s loupe can be used as a dermoscopy device [2], and a modification of this where the loupe can be attached to any mobile phone and be used for mobile dermatoscopic imaging [3]. We used a jeweler’s loupe with an inbuilt LED lighting system (Figure 1), and we used alcohol gel as the fluid, which is used to reduce the reflection from the stratum corneum. In our apparatus, too, the imaging is done from a distance without actual contact with the fluid. The loupe is held at a distance of about 5 cm from the skin after a sufficiently thick layer of alcohol gel is applied over the skin (Figure 2). The technique is not “true” dermoscopy as such, but helps to visualize basic dermoscopic features. Compared to the technique described by Blum and Giacomel [1], we feel that the magnification actually adds to the quality of the image (and here it is true magnification, not digital zoom). The inbuilt lighting also makes it convenient, as we do not need to be dependent on an external light source or ambient lighting. Jeweler’s loupes with inbuilt lights are easily available on online shopping platforms; these devices are quite cheap and it is very easy to assemble this apparatus using just simple adhesive tape. However, our method also has the same disadvantages as in the method described by Blum and Giacomel—focusing the camera is not very easy and there are limitations in analyzing finer details, especially vascular patterns (Figure 3). Better quality of lighting and adjusting the angle of the light in a jeweler’s loupe might further improve the quality of the imaging. Figure 1. Jeweller’s loupe with inbuilt LED lighting attached to the camera of a Samsung Note 3® mobile phone. [Copyright: ©2016 Kaliyadan et al.] Figure 2. Imaging of the lesion with the mobile phone. [Copyright: ©2016 Kaliyadan et al.] Figure 3. Melanocytic nevus dermoscopy. Contact fluid used was alcohol gel: (A) with a jeweler’s loupe attached to a Samsung Galaxy Note 3 mobile phone camera and (B) standard dermoscopy (Derm-Lite Foto II Pro, 3 Gen Inc, San Juan Capistrano, CA). [Copyright: ... We would like to emphasize that these low-cost techniques are in no way a substitute for standard dermoscopy. All the same, these devices can definitely be used as a cost-effective means for understanding the basics of dermoscopy, especially for trainee dermatologists and medical students. There are probably two main factors which limit the regular use of dermoscopy as a diagnostic tool in many developing countries—one is a relatively lower incidence of skin cancers, specifically melanoma, and the other is the cost. Most standard dermoscopes are not easily affordable for medical students or residents. At the same time, dermoscopy is increasingly being used to aid in the diagnosis in general dermatology, especially trichology. Low-cost techniques, like the one described by us, can help in giving an initial hands-on exposure to residents and medical students regarding the basic physics of dermoscopy and also to understand the dermoscopic patterns of normal skin. More studies with a larger sample size are required to validate the actual effectiveness of these low-cost dermatoscopes vis-a-vis standard devices in the context of actual skin pathology. It would obviously not be prudent to use such a method for triaging in the context of conditions like melanoma.

Best practices to optimize intraoperative photography

BackgroundIntraoperative photography is used extensively for communication, research, or teaching. The objective of the present work was to define, using a standardized methodology and literature review, the best technical conditions for intraoperative photography. Materials and methodsUsing either a smartphone camera, a bridge camera, or a single-lens reflex (SLR) camera, photographs were taken under various standard conditions by a professional photographer. All images were independently assessed blinded to technical conditions to define the best shooting conditions and methods. ResultsFor better photographs, an SLR camera with manual settings should be used. Photographs should be centered and taken vertically and orthogonal to the surgical field with a linear scale to avoid error in perspective. The shooting distance should be about 75 cm using an 80–100-mm focal lens. Flash should be avoided and scialytic low-powered light should be used without focus. The operative field should be clean, wet surfaces should be avoided, and metal instruments should be hidden to avoid reflections. For SLR camera, International Organization for Standardization speed should be as low as possible, autofocus area selection mode should be on single point AF, shutter speed should be above 1/100 second, and aperture should be as narrow as possible, above f/8. For smartphone, use high dynamic range setting if available, use of flash, digital filter, effect apps, and digital zoom is not recommended. ConclusionsIf a few basic technical rules are known and applied, high-quality photographs can be taken by amateur photographers and fit the standards accepted in clinical practice, academic communication, and publications.

Fast digital zooming system using directionally adaptive image interpolation and restoration.

This paper presents a fast digital zooming system for mobile consumer cameras using directionally adaptive image interpolation and restoration methods. The proposed interpolation algorithm performs edge refinement along the initially estimated edge orientation using directionally steerable filters. Either the directionally weighted linear or adaptive cubic-spline interpolation filter is then selectively used according to the refined edge orientation for removing jagged artifacts in the slanted edge region. A novel image restoration algorithm is also presented for removing blurring artifacts caused by the linear or cubic-spline interpolation using the directionally adaptive truncated constrained least squares (TCLS) filter. Both proposed steerable filter-based interpolation and the TCLS-based restoration filters have a finite impulse response (FIR) structure for real time processing in an image signal processing (ISP) chain. Experimental results show that the proposed digital zooming system provides high-quality magnified images with FIR filter-based fast computational structure.