Zooming Capabilities Research Articles

A dual-view multi-resolution laparoscope for safer and more efficient minimally invasive surgery

Minimally invasive surgery (MIS) is limited in safety and efficiency by the hand-held nature and narrow fields of view of traditional laparoscopes. A multi-resolution foveated laparoscope (MRFL) was invented to address these concerns. The MRFL is a stationary dual-view imaging device with optical panning and zooming capabilities. It is designed to simultaneously capture and display a zoomed view and supplemental wide view of the surgical field. Optical zooming and panning capabilities facilitate repositioning of the zoomed view without physically moving the system. Additional MRFL features designed to improve safety and efficiency include its snub-nosed endoscope, tool-tip auto tracking, programmable focus profiles, unique selectable display modalities, foot pedal controls, and independently controlled surgeon and assistant displays. An MRFL prototype was constructed to demonstrate and test these features. Testing of the prototype validates its design architecture and confirms the functionality of its features. The current MRFL prototype functions adequately as a proof of concept, but the system features and performance require further improvement to be practical for clinical use.

Enhancing electrocardiographic analysis by combining a high-resolution 12-lead ECG with novel software tools

IntroductionSignal-averaged electrocardiography is a non-invasive, computerized technique that amplifies, filters, and averages cardiac electrical signals reducing contaminating noise to obtain a high-resolution record. The most widely used signal averaging (SA) method involves a bipolar X, Y, and Z orthogonal lead system. Information is limited regarding its application in the standard resting 12-lead ECG. A novel system combining a high-resolution 12-lead ECG (HR-ECG) registered by SA with advanced analysis tools is presented. HistoryOriginal programming of a commercially available signal-averaged HR-ECG device was modified, introducing more exhaustive electrocardiographic assessment instruments. DescriptionUsing SA techniques and placing surface electrodes in the standard 12-lead ECG positions, a HR-ECG is acquired within a bandwidth of 0.25 to 262 Hz at a rate of 1000 samples per second. It is advisable to average at least 200 cycles, taking three to five minutes to record. The package includes different optional high-frequency filters, manual calipers, zoom/superimposing/amplification functions. Clinical roleThe main strength lies in obtaining a low noise HR-ECG with zooming capabilities without definition loss. Other potential advantages are the greater ease in performing high precision analysis and comparing different ECG leads simultaneously. Current problemsThe primary limitation is the inability to document intermittent or dynamic electrocardiographic disorders because of averaging similar electrical cardiac cycles. Future developmentsAdding artificial intelligence and further refinements in the averaging process could lead to software upgrades. ConclusionIntegrating HR-ECG, obtained through SA techniques, with novel advanced analysis tools can enhance the ability to detect electrocardiographic disorders of permanent expression expeditiously.

Strain-Multiplex Metalens Array for Tunable Focusing and Imaging.

Metalenses on a flexible template are engineered metal‐dielectric interfaces that improve conventional imaging system and offer dynamic focusing and zooming capabilities by controlling the focal length and bandwidth through a mechanical or external stretch. However, realizing large‐scale and cost‐effective flexible metalenses with high yields in a strain‐multiplex fashion remains as a great challenge. Here, single‐pulsed, maskless light interference and imprinting technique is utilized to fabricate reconfigurable, flexible metalenses on a large‐scale and demonstrate its strain‐multiplex tunable focusing. Experiments, in accordance with the theory, show that applied stretch on the flexible‐template reconfigurable diffractive metalenses (FDMLs) accurately mapped focused wavefront, bandwidth, and focal length. The surface relief metastructures consisted of metal‐coated hemispherical cavities in a hexagonal close‐packed arrangement to enhance tunable focal length, numerical aperture, and fill factor, FF ≈ 100% through normal and angular light illumination with external stretch. The strain‐multiplex of FDMLs approach lays the foundation of a new class of large‐scale, cost‐effective metalens offering tunable light focusing and imaging.

Improved multi-resolution foveated laparoscope with real-time digital transverse chromatic correction.

A multi-resolution foveated laparoscope (MRFL) with autofocus and zooming capabilities was previously designed to address the limiting trade-off between spatial resolution and field of view during laparoscopic minimally invasive surgery. The MRFL splits incoming light into two paths enabling simultaneous capture of the full surgical field and a zoomed-in view of the local surgical site. A fully functional prototype was constructed to demonstrate and test the autofocus, zooming capabilities, and clinical utility of this new laparoscope. The test of the prototype in both dry lab and animal models was successful, but it also revealed several major limitations of the prototype. In this paper, we present a brief overview of the aforementioned MRFL prototype design and results, and the shortcomings associated with its optical and mechanical designs. We then present several methods to address the shortcomings of the existing prototype with a modified optical layout and redesigned mechanics. The performances of the new and old system prototypes are comparatively analyzed in accordance with the design goals of the new MRFL. Finally, we present and demonstrate a real-time digital method for correcting transverse chromatic aberration to further improve the overall image quality, which can be adapted to future MRFL systems.

Compact optical zoom camera module based on Alvarez elements

A compact optical zoom camera module with Alvarez freeform elements is reported. A 3 × magnification in the optical zoom system was achieved by means of lateral shifting two pairs of Alvarez lenses. The optical design performances, profiles of the freeform surfaces, tolerance analysis results, and Monte Carlo yield simulation for mass production of the optical zoom system are presented. The optomechanical structures of the whole camera module including the barrels, actuators, and the slide-guiding systems are also described. The Alvarez elements and aspheric lenses were fabricated by precise injection molding and the movable elements are actuated by voice coil motors with a stroke of 3 mm. A camera module was developed with a size of 25 mm (width) × 25 mm (length) × 6 mm (height). The zooming and imaging capabilities of this Alvarez zoom lens were demonstrated experimentally.

Ultra Slim Optical Zoom System Using Alvarez Freeform Lenses

In this paper, we proposed an ultra slim optical zoom system with Alvarez freeform lenses. A 3X optical zoom system with two pairs of Alvarez lenses was developed. Alvarez lenses are fabricated by precise injection molding and the movable elements are actuated by voice coil motors. A slim camera module was fabricated with a size of 25 mm(width)×25 mm(length)×6 mm(height). The zooming and imaging capabilities of this Alvarez zoom system are demonstrated experimentally. The prototype exhibits a promising future for space-constrained application such as mobile phone camera module, wearable imaging system and endoscopic system.

Zoomable telescope by rotation of toroidal lenses.

A novel type of a continuously zoomable telescope is based on two pairs of adjacent toroidal lenses ("saddle lenses") in combination with standard optical components. Its variable magnification is adjusted by a mere rotation of the four saddle lenses around the optical axis. This avoids the necessity of classical zoom systems to shift multiple lenses along the longitudinal axis of the setup. A rotationally tunable pair of saddle lenses consists of two individual saddle lenses (also known as quadrupole lenses, or biconic lenses), which are arranged directly behind each other, acting as a "combi-saddle lens." The transmission function of such a combi-saddle lens corresponds to that of a single saddle lens, but with an adjustable optical power which depends on the mutual rotation angle between its two components. The optical system contains two of these combi-saddle lenses, and acts as a cylindrical Kepler telescope in one plane, and as a cylindrical Galilei telescope in the orthogonal plane. The two orthogonal Kepler/Galilei telescopes stay aligned and change their magnification factors in the same way when the telescope is zoomed by adjusting the optical powers of the two combi-saddle lenses. Altogether this produces a sharp image, which is mirrored with respect to the axis of the Kepler telescope. Thus, in addition to the zooming capabilities of the telescope, it is also possible to rotate the resulting image by a rotation of the whole telescope, or of all included saddle lenses. The operation principle of the telescope will be explained in both a ray-optical and a wave-optical description.

An Image Analysis Environment for Species Identification of Food Contaminating Beetles

Food safety is vital to the well-being of society; therefore, it is important to inspect food products to ensure minimal health risks are present. The presence of certain species of insects, especially storage beetles, is a reliable indicator of possible contamination during storage and food processing. However, the current approach of identifying species by visual examination of insect fragments is rather subjective and time-consuming. To aid this inspection process, we have developed in collaboration with FDA food analysts some image analysis-based machine intelligence to achieve species identification with up to 90% accuracy. The current project is a continuation of this development effort. Here we present an image analysis environment that allows practical deployment of the machine intelligence on computers with limited processing power and memory. Using this environment, users can prepare input sets by selecting images for analysis, and inspect these images through the integrated panning and zooming capabilities. After species analysis, the results panel allows the user to compare the analyzed images with reference images of the proposed species. Further additions to this environment should include a log of previously analyzed images, and eventually extend to interaction with a central cloud repository of images through a web-based interface.

Myelinated mouse nerves studied by X-ray phase contrast zoom tomography.

We have used X-ray phase contrast tomography to resolve the structure of uncut, entire myelinated optic, saphenous and sciatic mouse nerves. Intrinsic electron density contrast suffices to identify axonal structures. Specific myelin labeling by an osmium tetroxide stain enables distinction between axon and surrounding myelin sheath. Utilization of spherical wave illumination enables zooming capabilities which enable imaging of entire sciatic internodes as well as identification of sub-structures such as nodes of Ranvier and Schmidt-Lanterman incisures.

Quantitative interior x-ray nanotomography by a hybrid imaging technique

Hierarchical structures appear often in life and materials sciences, and their characterization profits greatly from imaging methods that allow seamless probing of various length scales without sacrificing image quality. X-ray tomography is particularly adept at probing 3D structures; however, zooming in on a region of interest results in a loss of quantitativeness of image contrast and suffers from artifacts unless a priori knowledge or assumptions about the sample are used. Here, we demonstrate a hybrid technique that exploits a micrometer-resolution overview to realize ab initio nanoscale interior tomography with quantitative contrast. In a study of avian eggshell, a model for bionanoporous materials, our approach reveals a complex arrangement of vesicles with sizes ranging from hundred nanometers to a few micrometers. We anticipate that such an approach can be widely adopted and benefited from at synchrotron and laboratory sources, for instance, where such zooming capabilities are already present or can be readily realized.

Scleral Buckling for Rhegmatogenous Retinal Detachment Using Vitrectomy-Based Visualization Systems and Chandelier Illumination.

The objective of this study was to evaluate an alternative approach to scleral buckling surgery using vitrectomy-based chandelier visualization systems instead of the indirect ophthalmoscope. This was a prospective case series. Ten eyes underwent scleral buckling under microscope using contact wide-angle lens with 25-gauge chandelier illumination and were followed up for 6 months. An encirclage was done in 8 eyes, and segmental buckle used in 2 eyes. Excellent intraoperative visualization was achieved, and all routine buckling steps were easily replicated with this approach. Using contact wide-angle lens along with chandelier illumination under microscope allows good visualization for scleral buckling procedure. This approach may allow excellent visibility with zooming capabilities for each step of the procedure as well as allows transmission to a monitor in the theater for teaching purposes apart from allowing better ergonomics for the surgeon.

In vessel characterization and first power tests on plasma of the Real-Time controllable EC launcher on FTU Tokamak

The Electron Cyclotron (EC) fast launcher for real time control experiments has been installed on FTU and characterized to be fully integrated in a real-time MHD control module under development. The launcher scheme is based on a two module sys- tem, symmetric with respect to the equatorial plane of FTU, with a front steering concept and the launched beams are real-time controllable both in poloidal and toroidal directions. Specific design parameters, defined by the FTU MHD dynamics (typically island size and q profile changes), are the beam dimensions with zooming capabilities, the steering range and mirror speed with the most demanding requirement on poloidal speed of the Steering Mirror (SM) = 1 in 10 ms. A set of tests has been done to verify the system perfor- mance. High power tests of the launcher have been done on a 500 kA, 0.5 10 20 m -3 and 5.3 T plasma with 2 300 kW of EC power delivered to the plasma. The steering mechanism was tested under the automatic control system and showed a dynamic response in line with the requirements. Results of these tests will be presented in the paper.

Low power tests on the new front steering EC launcher for FTU

Abstract A new electron cyclotron (EC) antenna for real time control experiments on FTU tokamak has been tested at IFP-CNR laboratory. mm-Wave characterization was performed at the operating frequency of 140 GHz with low power measurements, primarily to test the internal optics of the launcher in terms of focusing properties and beam directivity. The antenna is devoted to the injection of high power EC waves in different working configurations using a front steering setup. The beam direction is controlled with a fast mirror (steerable both toroidally and poloidally) and the available launching angles have been determined to fix the steering mirror working space. Beam dimension can also be controlled, using a sliding structure in the plug-in system, equipped with a focusing mirror that provides zooming capabilities. This paper contains results of low power tests performed on the antenna in order to characterize the launcher in its quasi-optical design. Beams are found to be slightly astigmatic (maximum ratio w y / w x = 1.1 ) and with an expected beam radius in the plasma ranging from 18.6 to 26.0 mm due to cited zooming effects. Additional beam patterns and linear scans of the launched mm-wave power for different injection angles have been measured, in some cases in realistic conditions (using a mock-up of the FTU port provided with metallic side-walls) to evaluate diffraction and beam truncation effects.

AN AUTOMATIC CALIBRATION METHOD BASED ON FEATURE POINT MATCHING FOR THE COOPERATION OF WIDE-ANGLE AND PAN-TILT-ZOOM CAMERAS

Wide-angle cameras are used to monitor large open areas, but moving objects on the image are often too small to view in detail. However, pan-tilt-zoom (PTZ) cameras have zooming capabilities that can be used to capture close-up images of a moving object. Therefore, the cooperation of these two types of cameras has been studied extensively in recent years. A calibration method is necessary to achieve the above cooperation. For any coordinate on the image plane of a wide-angle camera, this calibration method is needed to obtain the corresponding pan, tilt, and zoom values, known as the point correspondence of the PTZ camera. It is inconvenient to manually establish point correspondences, as shown in previous studies. Therefore, an automatic calibration method is proposed in this paper. The method is mainly based on the matching of feature points on the images of wide-angle and PTZ cameras. A feature point (FP) is extracted based on several edge operators derived from a 2D Gaussian smoothing function. A two-phase FP match is then designed to obtain the point correspondences. In the study of a prototype for capturing close-up images of moving objects, the calibration process took approximately 7 minutes for 44 FPs. The average successful rate of the capturing tasks was 82 percent. It shows that the automatic calibration method is feasible for the cooperation of wide-angle and PTZ cameras.http://dx.doi.org/10.5755/j01.itc.40.1.191

KinSNP software for homozygosity mapping of disease genes using SNP microarrays

Consanguineous families affected with a recessive genetic disease caused by homozygotisation of a mutation offer a unique advantage for positional cloning of rare diseases. Homozygosity mapping of patient genotypes is a powerful technique for the identification of the genomic locus harbouring the causing mutation. This strategy relies on the observation that in these patients a large region spanning the disease locus is also homozygous with high probability. The high marker density in single nucleotide polymorphism (SNP) arrays is extremely advantageous for homozygosity mapping.We present KinSNP, a user-friendly software tool for homozygosity mapping using SNP arrays. The software searches for stretches of SNPs which are homozygous to the same allele in all ascertained sick individuals. User-specified parameters control the number of allowed genotyping 'errors' within homozygous blocks. Candidate disease regions are then reported in a detailed, coloured Excel file, along with genotypes of family members and healthy controls. An interactive genome browser has been included which shows homozygous blocks, individual genotypes, genes and further annotations along the chromosomes, with zooming and scrolling capabilities. The software has been used to identify the location of a mutated gene causing insensitivity to pain in a large Bedouin family. KinSNP is freely available from http://bioinfo.bgu.ac.il/bsu/software/kinSNP.

Zooming and Scanning Gregorian Confocal Dual Reflector Antennas

The zooming and scanning capabilities of a Gregorian confocal dual reflector antenna are described. The basic antenna configuration consists of two oppositely facing paraboloidal reflectors sharing a common focal point. A planar feed array is used to illuminate the subreflector allowing the antenna to scan its beam. The resulting quadratic aberrations can be compensated by active mechanical deformation of the subreflector surface, which is based on translation, rotation and focal length adjustment. In order to reduce the complexity of the mechanical deformation, least squares fit paraboloids are defined to approximate the optimal correction surface. These best fit paraboloids considerably reduce scanning losses and pattern degradation. This work also introduces two different zooming techniques for the Gregorian confocal dual reflector antenna: the first consists of introducing a controlled quadratic path error to the main reflector aperture; and the second is based on reducing the size of the radiating aperture of the feeding array.

Dynamic Map Labeling

We address the problem of filtering, selecting and placing labels on a dynamic map, which is characterized by continuous zooming and panning capabilities. This consists of two interrelated issues. The first is to avoid label popping and other artifacts that cause confusion and interrupt navigation, and the second is to label at interactive speed. In most formulations the static map labeling problem is NP-hard, and a fast approximation might have O(nlogn) complexity. Even this is too slow during interaction, when the number of labels shown can be several orders of magnitude less than the number in the map. In this paper we introduce a set of desiderata for "consistent" dynamic map labeling, which has qualities desirable for navigation. We develop a new framework for dynamic labeling that achieves the desiderata and allows for fast interactive display by moving all of the selection and placement decisions into the preprocessing phase. This framework is general enough to accommodate a variety of selection and placement algorithms. It does not appear possible to achieve our desiderata using previous frameworks. Prior to this paper, there were no formal models of dynamic maps or of dynamic labels; our paper introduces both. We formulate a general optimization problem for dynamic map labeling and give a solution to a simple version of the problem. The simple version is based on label priorities and a versatile and intuitive class of dynamic label placements we call "invariant point placements". Despite these restrictions, our approach gives a useful and practical solution. Our implementation is incorporated into the G-Vis system which is a full-detail dynamic map of the continental USA. This demo is available through any browser.

The Pathway Tools cellular overview diagram and Omics Viewer

The Pathway Tools cellular overview diagram is a visual representation of the biochemical network of an organism. The overview is automatically created from a Pathway/Genome Database describing that organism. The cellular overview includes metabolic, transport and signaling pathways, and other membrane and periplasmic proteins. Pathway Tools supports interrogation and exploration of cellular biochemical networks through the overview diagram. Furthermore, a software component called the Omics Viewer provides visual analysis of whole-organism datasets using the overview diagram as an organizing framework. For example, gene expression and metabolomics measurements, alone or in combination, can be painted onto the overview, as can computed whole-organism datasets, such as predicted reaction-flux values. The cellular overview and Omics Viewer provide a mechanism whereby biologists can apply the pattern-recognition capabilities of the human visual system to analyze large-scale datasets in a biologically meaningful context. SRI's BioCyc.org website provides overview diagrams for more than 200 organisms. This article describes enhancements to the overview made since a 1999 publication, including the automatic layout capability, expansion of the cellular machinery that it includes, new semantic zooming and poster-generating capabilities, and extension of the Omics Viewer to support painting of metabolites, animations and zooming to individual pathway diagrams.

The application of multidimensional wavelets to unveiling multi-phase diagrams and in situ physical properties of rocks

Calculation of phase diagrams for terrestrial and planetary materials exerts a growing impact in geosciences today. In this work, we demonstrate the feasibility of efficient delineation and visualization of complicated realistic multi-phase diagrams and related in situ physical properties of rocks by using discontinuous second generation wavelets, allowing a representation of both isotropic and anisotropic properties with arbitrary resolution. This is done by combining adaptive wavelet-based meshing technology with recently developed efficient “phase diagram function” designed as a Gibbs free energy minimization. The proposed automated strategy allows one to obtain an efficient delineation of physical properties using a uniform set of wavelet nodes regardless of whether these variables are continuous or discontinuous functions of pressure, temperature, or composition. The use of this strategy captures very small details of phase diagram morphology allowing both acceleration of the calculations and compression of results on the order of 10 2 by comparison to uniform grids of the same effective resolution. The web-based application of the proposed methodology for phase diagram visualization with interactive zooming capabilities is also discussed.

Digital camera zooming based on unified CFA image processing steps

A unified camera image processing system that performs zooming and full color image reconstruction for single-sensor digital cameras is introduced. Compact and low-cost single-sensor solutions often lack optical zooming capabilities and thus depend on digital techniques. However, the computational power required for high-quality output using traditional techniques is generally too prohibitive to implement in such devices. The proposed scheme employs a small number of reusable, low-complexity operations and a consistent color model throughout to achieve high-quality zoomed output that is practical for hardware implementation. The high-level system components are color filter array (CFA) zooming, CFA interpolation (demosaicking) and demosaicked image postprocessing. The resulting output is consistently superior to other methods.