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Medical applications in which patient movements are tracked with 3-D surface imaging systems are becoming increasingly popular. The 3-D imaging systems used for such applications must be able to cope with controlled and uncontrolled motions of the human body. The key factors for producing a high-quality 3-D representation of the moving human body are the spatial resolution, accuracy, and precision of the 3-D imaging system. To our knowledge, no international standard yet exists to assess these parameters. In this article, we propose a phantom model, a method, and parameters for the assessment of spatial resolution, accuracy, and precision to evaluate systems for the 3-D imaging of moving objects. The proposed phantom model is an extension of the standard 1951 USAF resolution test chart to 3-D and consists of two parallel staircases with varying step heights. The phantom model is actuated with an industrial robot. The application of our method to the Photoneo MotionCam-3-D showed that their multishot structured-light mode has a higher accuracy for static and slowly moving objects (accuracy of 0.1 mm) than their single-shot structured-light mode (accuracy of 0.5 mm). However, the single-shot mode can capture fast-moving objects without much loss of accuracy and precision. This provides practical quantifications for the Photoneo MotionCam-3-D. Furthermore, this confirms that the proposed phantom model, method, and parameters can be used as part of a standard to assess the spatial resolution, accuracy, and precision of systems for the 3-D imaging of moving objects.

Binary patterns that utilize a diffusion kernel and a fixed quantization threshold to binarize 8-bit sinusoidal fringes are popular in 3-D imaging of dynamic objects by virtue of the fast-switching capability of digital mirror device projectors. Unfortunately, to remove the encoding noise and obtain approximate sinusoidal fringes, a large defocus is generally required for existing binarization methods. This behavior inevitably results in the adopted 3-D measurement system working under a discounted depth of field, while the low signal-to-noise ratio of captured images has an adverse influence on the phase extraction accuracy of commonly adopted high-frequency fringes for practical 3-D reconstruction. In this article, we present a spatial–temporal binary encoding method of jointly optimizing diffusion kernel and quantization threshold for 3-D surface measurement. Our method involves determining the quantization threshold by simulation, searching optimal diffusion kernels in both phase and intensity-domain via particle swarm optimization (PSO) algorithm, and implementing error diffusion (ED) encoding spatially and temporally using the optimized quantization threshold (OptQ) and diffusion kernel. Finally, one 8-bit sinusoidal fringe is temporally decomposed into multiple ( $K$ ) 1-bit binary patterns, which are nearly in-focus projected to yield approximate sinusoidal pattern in the manner of integral imaging strategy. Comparative experiments verify that the accuracy of our method outperforms the state-of-the-art methods in terms of phase and 3-D measurement accuracy. Additionally, the binary encoding fringe patterns are also to successfully implement dynamic 3-D imaging of a moving arm.

It has been shown that the detection of flat body surfaces (thorax, pelvis) using the three-dimensional optical surface imaging system (3D–OSIS) is less accurate than curved surfaces (head, neck). Here, we evaluated the applicability and technical performance of the 3D–OSIS for prone breast radiotherapy using silicon cup markers. Three silicon cups were attached on the dorsal surface of a female atom phantom. We evaluated the data reproducibility with these marker cups and compared the accuracy with or without their use. For the reproducibility test, we scanned an object 11 times every 15 s with the 3D–OSIS and registered the differences. For the accuracy test, we positioned the phantom on the table and manually moved it in the X, Y, and Z directions to predetermined values. These values were compared to those measured with the 3D–OSIS. This process was repeated 21 times and the differences of the measured values were compared according to the presence or absence of markers. In reproducibility test, the mean variations for the shifts in the lateral, longitudinal, and vertical directions were 0.15 ± 0.22 mm, 0.47 ± 0.13 mm, and 0.34 ± 0.19 mm, respectively. And the mean deviations elicited based on the accuracy test for the manually applied and the measured shifts in the lateral, longitudinal, and vertical directions were (a) 0.23 ± 0.1 mm, 0.044 ± 0.39 mm, and 0.18 ± 0.1 mm with the use of markers, and (b) 0.44 ± 0.33 mm, 0.97 ± 0.55 mm, and 0.63 ± 0.55 mm without the markers, respectively. The use of silicon cup markers yielded highly accurate results in the 3D–OSIS. The use of 3D–OSIS and silicon cups has potential in achieving precise patient setup and in reducing the CBCT frequency in prone breast radiotherapy.

2021 JUN 10 (NewsRx) -- By a News Reporter-Staff News Editor at Women's Health Weekly -- Investigators publish new report on mastectomy. According to news reporting from Stockholm, Sweden, by [...]

Accuracy of position setup and monitoring is a key element in the success of spinal stereotactic radiosurgery. We investigated the reposition and target accuracies of a proposed complementary surface imaging guided (SIG) application to infrared (IR) fiducial marker system for patient setup in the spinal radiosurgery. Among the iterative closest point (ICP) and normal distribution transformation (NDT) algorithm, the appropriate method for SIG system was selected by measuring the reposition accuracy. To evaluate the performance of SIG and marker systems, the reposition and target accuracies was measured by dividing into three groups; Group 1 (infrared (IR)-fiducial marker system alone), Group 2 (SIG alone), and Group 3 (combination of Group1 and 2). Overall, six degrees of freedom (DOF) and the root-mean-square (RMS) values were calculated to evaluate the performance of reposition and target accuracies. The RMS value of ICP and NDT was 3.18 ± 1.80 mm and 0.88 ± 0.71 mm, respectively. The real-time reposition accuracy using NDT algorithm were 0.29 ± 0.50 mm in Group 1, 0.79 ± 0.62 mm in Group 2 and 0.13 ± 0.05 mm in Group 3. Target accuracy of Group 3 (RMS of 0.90 ± 0.62 mm) was superior to that of Group 1and 2 (1.23 ± 0.81 mm and 1.93 ± 1.26 mm, respectively). The positioning and target accuracy were statistically significantly improved by implementing real-time SIG system complementary to conventional IR—fiducial marker-guided system in stereotactic body radiosurgery.

Obesity and overweight are commonplace, yet attrition rates in weight management clinics are high. Traditional methods of body measurement may be a deterrent due to invasive and time-consuming measurements and negative experiences of how data are presented back to individuals. Emerging new technologies, such as three-dimensional (3D) surface imaging technology, might provide a suitable alternative. This study aimed to understand acceptability of traditional and 3D surface imaging-based body measures, and whether perceptions differ between population groups.

2018 MAY 31 (NewsRx) -- By a News Reporter-Staff News Editor at Women's Health Weekly -- Investigators publish new report on Oncology - Breast Cancer. According to news originating from [...]

Implementing 3D surface imaging camera systems into miniaturized devices for a variety of 3D applications such as movement recognition, object sensing, and 3D endoscopy has received great attention over the past decade. Recently, various MEMS techniques enabled the fabrication of key optical elements for 3D surface imaging with compact size, reasonable cost, and high yield. This article will overview the principles of major categories of 3D surface imaging techniques and their applications using optical MEMS devices for compact 3D surface imaging camera.

Recent advancement of fabrication technologies enables nanoscale surface patterning on microstructures, which requires multi-scale measurements for the determination of their geometric dimensions and surface texture in the same coordinate system. Previously, we have developed a micro-coordinate measuring machine with a laser-trapped microprobe that uses an optically trapped microsphere as a surface detecting sensor. In this paper, we propose a surface imaging technique using the optically trapped microsphere as a micro-lens, i.e., the surface imaging system is integrated into the coordinate measuring system. The optically trapped microsphere with a diameter of 8 μm was brought close to a measured surface to image the surface underneath it. Because there is an unknown gap between the microsphere and surface, the focal plane of the imaging system had to be adjusted to the measured surface by the developed imaging lens system. With the microsphere-based imaging system, an optical diffractive grating of sub-micrometer periodic structure with 417 nm pitch and 50 nm depth was successfully imaged and the defect on the grating was detected. Thus, we verified that development of an imaging system based on the optically trapped microsphere for multi-scale evaluation systems can be accomplished.

In an optical lithography system, short wavelength (λ) sources and high numerical aperature (NA) lenses are desirable for fine feature printing, but can result in a depth of focus (DOF) […]

To understand the metal electrodeposition reaction, the data from a number of surface specific techniques were combined Production of metals constitutes a significant fraction of the Canadian economy. Production of [...]

The use of three-dimensional (3D) surface imaging is becoming more popular and accepted in the fields of Medicine and Dentistry. The present study aims to develop a technique to automatically localise and quantify soft-tissue asymmetry in adults using 3D facial scans. This may be applied as a diagnostic tool to monitor growth and dynamic changes and to evaluate treatment outcomes. 3D facial surface data were captured from 55 adults comprising 28 symmetrical faces and 27 asymmetrical faces using a 3dMDface system. A landmark-independent method, which compared the original and the mirrored 3D facial data, was developed to quantify the asymmetry. A Weibull distribution-based probabilistic model was generated from the root-mean-square (RMS) error data for the symmetrical group to designate a level of asymmetry which represented a normal range. Statistically significant (p< 0.0001) differences in the RMS error values were found when comparing symmetrical with asymmetrical groups and a similarly significant difference was identified between the lower and the upper face of the asymmetrical group. The proposed 3D imaging-based method of identifying and quantifying facial soft-tissue asymmetry was fast and effective. The Weibull distribution-based comparison of a person’s asymmetry with respect to a large sample of symmetrical faces may also be used to evaluate growth, soft-tissue compensations and surgical outcomes.

The surge of ocular surface disease (OSD) management in Optometric practice has driven technology to the forefront. Now, it not only helps to diagnose and treat this disease state but [...]

OVERVIEW In a comparison to standard DUV lithography with bottom antireflection coatings, top surface imaging provides improved resolution in a via first, copper dual-damascene process. This technique effectively extends the […]

Near-infrared (NIR) optical imaging is a noninvasive and nonionizing modality that is emerging as a diagnostic tool for breast cancer. The handheld optical devices developed to date using the NIR technology are predominantly developed for spectroscopic applications. A novel handheld probe-based optical imaging device has been recently developed toward area imaging and tomography applications. The three-dimensional (3D) tomographic imaging capabilities of the device have been demonstrated from previous fluorescence studies on tissue phantoms. In the current work, fluorescence imaging studies are performed on tissue phantoms, in vitro, and in vivotissue models to demonstrate the fast two-dimensional (2D) surface imaging capabilities of this flexible handheld-based optical imaging device, toward clinical breast imaging studies. Preliminary experiments were performed using target(s) of varying volume (0.23 and 0.45 cm3) and depth (1–2 cm), using indocyanine green as the fluorescence contrast agent in liquid phantom, in vitro, and in vivotissue models. The feasibility of fast 2D surface imaging (∼5 seconds) over large surface areas of 36 cm2was demonstrated from various tissue models. The surface images could differentiate the target(s) from the background, allowing a rough estimate of the target's location before extensive 3D tomographic analysis (future studies).

ABSTRACTAccuracy, precision, quality, and simplicity are goals of diagnostic 3-D surface imaging of the face. The rewards include improved diagnosis, an ability to create a patient-specific model, simulate treatment, and improve treatment outcomes. This article discusses 3-D surface imaging of the face and selected clinical applications that add value to the image data.

We investigate capability of the stellar surface imaging technique for studying stellar non-radial pulsations on the basis of inversions of time series of variable line profiles without making assumptions on the specific shape of the pulsations. The inversion results in an image of the stellar surface in which sectoral and tesseral modes can be distinguished in many cases, and the pulsational degree $\ell$and the azimuthal order $|m|$can be determined. We find that sectoral and tesseral modes with $\ell-|m|=2$(or any even number) can be successfully restored under various conditions (different inclinations of the rotational axis, surface temperature or velocity fluctuations due to pulsations). Tesseral modes with $\ell-|m|=1$(or any odd number) do not show significant line profile variations at higher inclinations of the rotational axis, and, thus, no information can be recovered from line profiles. At lower inclinations, only the azimuthal order $|m|$of such modes can be recovered. We conclude that stellar surface imaging is a useful technique for pulsation-mode identification.

We demonstrate the capability of optical coherence tomography (OCT) to perform topography of metallic surfaces after being subjected to ductile or brittle fracturing. Two steel samples, OL 37 and OL 52, and an antifriction Sn–Sb–Cu alloy were analyzed. Using an in-house-built swept source OCT system, height profiles were generated for the surfaces of the two samples. Based on such profiles, it can be concluded that the first two samples were subjected to ductile fracture, while the third one was subjected to brittle fracture. The OCT potential for assessing the surface state of materials after fracture was evaluated by comparing OCT images with images generated using an established method for such investigations, scanning electron microscopy (SEM). Analysis of cause of fracture is essential in response to damage of machinery parts during various accidents. Currently the analysis is performed using SEM, on samples removed from the metallic parts, while OCT would allow in situ imaging using mobile units. To the best of our knowledge, this is the first time that the OCT capability to replace SEM has been demonstrated. SEM is a more costly and time-consuming method to use in the investigation of surfaces of microstructures of metallic materials.

Surface imaging of stars from the profiles of spectral lines, has become an important tool in modern astrophysics. It is presently used for mapping the distribution of chemical elements on Ap stars and the variation in temperature over the surface of late-type stars. Magnetic field maps will be produced as soon as high quality polarization observations are available. Recently imaging techniques have been developed for application to eclipsing binary stars. In this paper we review the improvements we have found to result in more reliable and detailed maps in all aspects of surface imaging.

Images from ordinary laparoscopes and endoscopes are two dimensional (2D), meaning the surgeon’s depth perception is hindered. The proposed method supplements the 2D image with an image of the depth profile of the surface. The depth profile is obtained in real time without surface contact. The profilometer uses the same principle for acquiring distance information as the divergence-ratio axi-vision camera. The profilometer was added to an ordinary laparoscope with minimal increase in the weight and diameter of the shaft. With the profilometer added, there was a significant improvement in the ability to detect minute protrusions.

We present a new Doppler-imaging inversion code that uses quasi-optimal filtering of the object's principal components of a Fisher information matrix. The new code allows one to perform the reconstruction of stellar surface temperature maps using molecular features like TiO, CO, OH, CN etc. which are numerous in spectra of late-type dwarfs. It is possible to use atomic and molecular features simultaneously in the restoration. Our tests verify the robustness of OPC but also emphasize its dependency on the various atomic and molecular line lists. Without inclusion of molecules, Doppler imaging of stars with photospheric temperatures below ≈4250 K (K7-M0) remains unreliable.

Rapidly rotating late-type stars typically display signs of magnetic activity that exceed those seen on the Sun by over two orders of magnitude. The techniques of Doppler imaging and Zeeman Doppler imaging have been instrumental in unveiling magnetic activity patterns at the photospheres of these active stars. Essentially, these techniques work by inverting time-series of high resolution spectra to produce temperature, brightness and/or magnetic field maps at the surfaces of stars. I will describe how these techniques work and review what they have taught us about the nature of magnetic activity in rapid rotators over the last 20 years. Finally, I will conclude by outlining the capabilities of these techniques in light of new instrumentation that is now becoming available. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We present surface temperature maps for the FK Comae-type star HD 199178(V1794 Cygni) calculated from high resolution spectra obtained in 1994 and 1995. The spot pattern evolves, but all maps reveal a large cool spot remaining nearly at the same high latitude. The main spot is 1200-1600 K cooler than the mean surface temperature. The observed slightly flat bottomed absorption lines would usually be interpreted as evidence for a large cool polar spot. We argue that antisolar surface differential rotation offers a better explanation for the box like shape of the line profiles. However, we do not find conclusive evidence for antisolar differential rotation and note that there are still other possible explanations for the slightly flat bottomed line profiles.

Bruker AXS GmbH (Karisruhe, Germany), developer and manufacturer of analytical X-ray systems and solutions for material analysis, has signed an agreement to acquire all of the equity of Surface Imaging [...]

Germany's Bruker AXS is acquiring domestic AFM supplier Surface Imaging […]

The standard ConfoMap ST package includes numerous analytical studies. Geometric studies calculate distances, angles, areas, volumes, and step heights on 2-D profiles and 3-D surfaces. Functional studies, including the bearing [...]

The Leica Map software, based on Digital Surf's Mountains technology, is used to visualize and quantify features of measured surfaces, characterize surface texture and geometry and generate visual surface metrology [...]

Abstract:  The paper describes a new technique for measuring surface slopes at the air–water interface. A microlens array is employed to optically sample the fluid surface at a large number of measurement points in parallel. The focal plane image of the lenslet array is recorded by a standard video camera, generating a data set of typically 4000 candidate samples for each video frame. The displacement of the focal spots is analyzed using a cross-correlation technique augmented by a topological identification algorithm which makes use of the hexagonal structure of the lenslet array. Surface height profiles are computed by integrating the surface slope field.

KARLSRUHE and HERZOGENRATH, GERMANY--Bruker AXS GmbH, developer and manufacturer of analytical X-ray systems and solutions for material analysis, has signed an agreement to acquire all of the equity of Surface [...]

Pico Image is a modular atomic force microscope (AFM) imaging and analysis software package designed for AFM users working in a wide range of research applications, including life sciences and […]

Pat. No. 6,495,833 B1 Long Island inventor Ping-Pei Ho of Great Neck along with Robert Alfano have invented a system for sub-surface imaging under paints or coatings. The system detects [...]

Surlinx Surlinx offers a new prefinished and recoatable line of 'exotic veneer' finished panels. The company says its imaging process offers a reasonable alternative to typically unattainable or unaffordable veneers [...]

Atomic-level information about the surfaces of small metal particles has been recorded directly in recent observations with a 600-kV high-resolution electron microscope. Here, we have studied small polycrystalline particles of silver and gold tilted to bring their surfaces parallel to the electron beam. However, unlike previous workers using this normal reflection electron microscopy (REM) configuration, we have used conventional bright field axial imaging thereby considerably facilitating image interpretation. As well as clean, sharp surface images, morphological details of catalytic significance, such as the distribution of surface steps, particle facetting and the nature of surface reconstructions, have been obtained. Moreover, detailed computer simulations confirmed that the electron micrographs can be interpreted in terms of atomic columns and, in particular, established that some micrographs showed, for the first time in a transmission electron microscope (TEM), direct atomic-scale imaging of a reconstructed metal surface.

Introduction The assessment of joints with active arthritis is a core component of widely used outcome measures. However, substantial variability exists within and across examiners in assessment of these active joint counts. Swelling and temperature changes, two qualities estimated during active joint counts, are amenable to quantification using noncontact digital imaging technologies. We sought to explore the ability of three dimensional (3D) and thermal imaging to reliably measure joint shape and temperature. Methods A Minolta 910 Vivid non-contact 3D laser scanner and a Meditherm med2000 Pro Infrared camera were used to create digital representations of wrist and metacarpalphalangeal (MCP) joints. Specialized software generated 3 quantitative measures for each joint region: 1) Volume; 2) Surface Distribution Index (SDI), a marker of joint shape representing the standard deviation of vertical distances from points on the skin surface to a fixed reference plane; 3) Heat Distribution Index (HDI), representing the standard error of temperatures. Seven wrists and 6 MCP regions from 5 subjects with arthritis were used to develop and validate 3D image acquisition and processing techniques. HDI values from 18 wrist and 9 MCP regions were obtained from 17 patients with active arthritis and compared to data from 10 wrist and MCP regions from 5 controls. Standard deviation (SD), coefficient of variation (CV), and intraclass correlation coefficients (ICC) were calculated for each quantitative measure to establish their reliability. CVs for volume and SDI were <1.3% and ICCs were greater than 0.99. Results Thermal measures were less reliable than 3D measures. However, significant differences were observed between control and arthritis HDI values. Two case studies of arthritic joints demonstrated quantifiable changes in swelling and temperature corresponding with changes in symptoms and physical exam findings. Conclusion 3D and thermal imaging provide reliable measures of joint volume, shape, and thermal patterns. Further refinement may lead to the use of these technologies to improve the assessment of disease activity in arthritis.

This work aims at detecting surface defects on reflecting industrial parts. A machine vision system, performing the detection of geometric aspect surface defects, is completely described. The revealing of defects is realized by a particular lighting device. It has been carefully designed to ensure the imaging of defects. The lighting system simplifies a lot the image processing for defect segmentation and so a real-time inspection of reflective products is possible. To bring help in the conception of imaging conditions, a complete simulation is proposed. The simulation, based on computer graphics, enables the rendering of realistic images. Simulation provides here a very efficient way to perform tests compared to the numerous attempts of manual experiments.

Within the article, a preeroded copper cathode was subjected to the impact of a series of high-voltage pulses with a duration of < 1 ns for surface conditioning. An effective cathode surface area was ~0.01 mm2. Preerosion of the cathode surface was performed using a series of vacuum arc discharges of microsecond duration. As a result, a well-pronounced microrelief with a typical dimension of ~5– $10~\mu \text{m}$ was formed at the cathode surface. Then, to smooth the microrelief, the cathode was placed into a vacuum setup based on a RADAN pulse generator with a pulse duration of < 1 ns and a pulse amplitude of up to −140 kV. About 900 discharges of a subnanosecond duration were initiated. To estimate the conditioning effectiveness, the state of the cathode surface was controlled by studying the cathode field-emission characteristics and cathode surface imaging by scanning electron microscopy (SEM). The field-emission characteristic study made it possible to estimate the electric field enhancement factor $\beta $ near the cathode surface before and after the conditioning. It was shown that the subnanosecond conditioning led to a decrease in $\beta $ by a factor of 6–8 from ~170 after eroding to ~20–30. Employing SEM investigation of the sample surface morphology, it was found that a typical microrelief dimension was decreased from ~5–10 to ~1– $2~\mu \text{m}$ or less. That is, a proposed conditioning technique allowed significant smoothing of the cathode surface.

The article focuses on captured image of surface of Mars by Colour and Stereo Surface Imaging System (CaSSIS) and mentions tracks of wispy blue threads caused by whirlwinds known as dust devils.

A report from the Medical University of Vienna discusses new findings on breast cancer treatment. The researchers investigated the feasibility of using a thermo-optical surface imaging system combined with stereoscopic X-ray image guidance in a dedicated breast deep inspiration breath-hold irradiation workflow. They analyzed data from 30 breast cancer patients who underwent treatment using this method and found that stereoscopic X-ray positioning was successfully verified by standard image-guided radiation therapy techniques. The study concludes that this approach is feasible for breast cancer patients. [Extracted from the article]

A novel scale space approach, SphereSiZer, is proposed for exploring structure in spherical data, that is, directional data on the unit sphere of the three-dimensional Euclidean space. The method finds statistically significant gradients of the smooths of the probability density function underlying the observed data. Bootstrap is used to establish significance and inference is summarized with planar maps of contour plots of smooths of the data, overlaid with arrows that indicate the directions and magnitudes of the significant gradients. An effective way to explore such maps is a movie where each frame corresponds to a fixed level of smoothing, that is, a particular spatial scale on the sphere. The SphereSiZer is demonstrated using simulated data as well as two real-data examples. The first example examines the distribution of infant head normal vector directions. The presence of local maxima in the normal vector distribution may indicate head deformity, such as severe flatness or asymmetry. The second example considers the distribution of earthquakes in the Northern Hemisphere. [ABSTRACT FROM AUTHOR]

Ultrasound imaging offers a noninvasive, radiation-free method for visualizing internal tissues and organs, with deep penetration capabilities. This has established it as a crucial tool for physicians in diagnosing internal tissue pathologies and monitoring human conditions. Nonetheless, conventional ultrasound probes are often characterized by their rigidity and bulkiness. Designing a transducer that can seamlessly adapt to the contours and dynamics of soft, curved human skin presents significant technical hurdles. We present a novel flexible and stretchable ultrasound transducer (FSUT) designed for adaptability to large-curvature surfaces while preserving superior imaging quality. Central to this breakthrough is the innovative use of screen-printed silver nanowires (AgNWs) coupled with a composite elastic substrate, together ensuring robust and stable electrical and mechanical connections. Standard tensile and fatigue tests verify its durability. The mechanical, electrical, and acoustic properties of FSUTs are characterized using standard methods, with large tensile strains (≥110%), high flexibility ( ${R} \ge1.4$ mm), and lightweight ( $\le 1.58$ g) to meet the needs of wearable devices. Center frequency and −6-dB bandwidth are approximately 5.3 MHz and 66.47%, respectively. Images of the commercial anechoic cyst phantom yielded an axial and lateral resolution (depths of 10–70 mm) of approximately 0.31 and 0.46, and 0.34 and 0.84 mm, respectively. The complex curved surface imaging capabilities of FSUT were tested on agar-gelatin-based breast cyst phantoms under different curvatures. Finally, ultrasound images of the thyroid, brachial, and carotid arteries were also obtained from volunteer wearing FSUT.

Distributed acoustic sensing (DAS) is a new technology for recording vibration signals using optical fibers, and is advantageous over traditional seismic geophones given high spatial sampling density, real-time monitoring capabilities, and relatively low cost for large-scale data acquisition. In recent years, progress in applications of the DAS technique has been achieved in near-surface imaging, earthquake detection, and urban traffic monitoring. In this study, we propose to apply a machine-learning (ML) method to recognize and extract vehicle signals from DAS data acquired in a typical urban environment in Hangzhou, China. To design an efficient ML framework, we apply a series of processing steps to eliminate noise and strengthen the vehicle signal, which is crucial for preparing high-quality labels. Initially, a total of 190 features (62 1-D features and 128 2-D features) are extracted from raw data, which are filtered down to 31 through univariate feature selection, random forest, and similarity analyses. These selected features are classified into (traffic) signal or (nontraffic) noise using the classic ML method of support vector machine (SVM). The resulting model enables robustly extracting vehicle signals with only a small (e.g., 10) training dataset and achieve an overall accuracy of about 80% on the test data. We further demonstrate the application of city traffic monitoring by considering the slope and coherence of the extracted vehicle signals. The isolation of car signals leads to a more accurate estimate of vehicle speed and volume. This study highlights the potential of real-time monitoring of speed and volume of traffic flow using existing city infrastructure and sheds light on the promising applications of the DAS technique in developing smart cities.

Objective: For tumor resections, margin status typically correlates with patient survival but positive margin rates are generally high (up to 45% for head and neck cancer). Frozen section analysis (FSA) is often used to intraoperatively assess the margins of excised tissue, but suffers from severe under-sampling of the actual margin surface, inferior image quality, slow turnaround, and tissue destructiveness. Methods: Here, we have developed an imaging workflow to generate en face histologic images of freshly excised surgical margin surfaces based on open-top light-sheet (OTLS) microscopy. Key innovations include (1) the ability to generate false-colored H&E-mimicking images of tissue surfaces stained for &lt; 1 min with a single fluorophore, (2) rapid OTLS surface imaging at a rate of 15 min/cm2 followed by real-time post-processing of datasets within RAM at a rate of 5 min/cm2, and (3) rapid digital surface extraction to account for topological irregularities at the tissue surface. Results: In addition to the performance metrics listed above, we show that the image quality generated by our rapid surface-histology method approaches that of gold-standard archival histology. Conclusion: OTLS microscopy has the feasibility to provide intraoperative guidance of surgical oncology procedures. Significance: The reported methods can potentially improve tumor-resection procedures, thereby improving patient outcomes and quality of life.

The South Polar Layered Deposits (SPLD) are the largest water ice reservoirs on Mars. Their accumulation is believed to result from climate oscillations that drive the movement of ice and dust on the surface. The High‐Resolution Imaging Science Experiment and the Colour and Stereo Surface Imaging System have imaged exposures of its internal structure in troughs and marginal scarps. Here we use the stereo imaging products of these instruments to extract stratigraphic profiles representative of various locations throughout the SPLD. Through wavelet and series‐matching analyses of these profiles, we reveal periodicities in the stratigraphy that correlate to the orbital oscillations that drive climate change on Mars and that have been observed to force the accumulation of the north polar cap. We infer that the water ice and dust of the SPLD were deposited at variable rates of 0.13–0.39 mm/year, taking a minimum of 10–30 Myr to accumulate. The single location on Mars with the most water ice is in the southern polar ice cap, in the so‐called South Polar Layered Deposits (SPLD). Changes in Martian climate through time affect the locations on Mars where ice is stable, and it is believed that these changes drove the accumulation of layers upon layers of ice and dust in the SPLD. The High‐Resolution Imaging Science Experiment and the Colour and Stereo Surface Imaging System are satellite cameras that have photographed troughs and scarps within the SPLD to produce 3‐D views of this layered internal structure. We analyzed this structure and found patterns in the layering related to variations of Mars' orbit and spin axis. These variations drive climate change on Mars, so our analysis confirms the connection between the SPLD and Mars' astronomical parameters. From this relationship, we inferred that the ice and dust of the SPLD took at least 10–30 Myr to accumulate. Patterns in the stratigraphy of Mars' south polar ice sheet are consistent with orbital climate forcingMars' south polar ice sheet accumulated nonuniformly at rates of 0.11–0.39 mm/yearSimilar orbital oscillations forced the accumulation of the northern and southern ice sheets

Distributed Acoustic Sensing (DAS) is an emerging technique for ultra-dense seismic observation, which provides a new method for high-resolution sub-surface seismic imaging. Recently a large number of linear DAS arrays have been used for two-dimensional S-wave near-surface imaging in urban areas. In order to explore the feasibility of three-dimensional (3D) structure imaging using a DAS array, we carried out an active source experiment at the Beijing National Earth Observatory. We deployed a 1 ​km optical cable in a rectangular shape, and the optical cable was recast into 250 sensors with a channel spacing of 4 ​m. The DAS array clearly recorded the P, S and surface waves generated by a hammer source. The first-arrival P wave travel times were first picked with a Short-Term Average/Long-Term Average (STA/LTA) method and further manually checked. The P-wave signals recorded by the DAS are consistent with those recorded by the horizontal components of short-period seismometers. At shorter source-receiver distances, the picked P-wave arrivals from the DAS recording are consistent with vertical component recordings of seismometers, but they clearly lag behind the latter at greater distances. This is likely due to a combination of the signal-to-noise ratio and the polarization of the incoming wave. Then, we used the TomoDD software to invert the 3D P-wave velocity structure for the uppermost 50 ​m with a resolution of 10 ​m. The inverted P-wave velocity structures agree well with the S-wave velocity structure previously obtained through ambient noise tomography. Our study indicates the feasibility of 3D near-surface imaging with the active source and DAS array. However, the inverted absolute velocity values at large depths may be biased due to potential time shifts between the DAS recording and seismometer at large source-receiver distances.

A report from Leiden University Medical Center in the Netherlands discusses the use of computed tomography (CT) imaging for motion management and surface guidance in radiation therapy. The report presents the results of a survey conducted among medical physics experts at radiotherapy institutions in Belgium and the Netherlands. The survey found that respiratory management is standard practice in most institutions, and surface imaging during CT-simulation is used in some institutions. The report emphasizes the need for clear guidelines for quality assurance procedures and highlights the importance of implementing surface guidance techniques in clinical radiotherapy simulation workflows. [Extracted from the article]

A recent image taken by the ExoMars Trace Gas Orbiter reveals a massive impact crater in Mars' Utopia Planitia. The crater, with a diameter of approximately 3,300 kilometers, is the largest known impact basin in the Solar System. The image shows ice-related features on and below the surface of the crater, indicating Mars' watery past. The crater also exhibits signs of material ejected in a way that suggests the presence of water ice during the ancient asteroid impact. The smooth appearance of the crater and other features in the region further support the hypothesis of a water-ice history on Mars. [Extracted from the article]

Purpose To improve the setup reproducibility of neck curvature using real-time optical surface imaging (OSI) guidance on 2 regions of interest (ROIs) to infer cervical spine (c-spine) curvature for surface-guided radiotherapy (SGRT) of head-and-neck (HN) and c-spine cancer.Methods A novel SGRT setup approach was designed to reproduce neck curvature with 2 ROIs: upper-chest ROI and open-face ROI. It was hypothesized that the neck curvature could be reproduced if both ROIs were aligned within ±3 mm/2˚ tolerance. This was tested prospectively in 7 volunteers using real-time 3D-OSI guidance and lateral 2D-photography verification after the 3D and 2D references were captured from the initial conventional setup. Real-time SGRT was performed to align chest-ROI and face-ROI, and the longitudinal distance between them was adjustable using a head-support slider. Verification of neck curvature anteriorly and posteriorly was achieved by overlaying edge-extracted lateral pictures. Retrospectively, the relationship between anterior surface and spinal canal alignment was checked in 11 patients using their simulation CT (simCT) and setup cone-beam CT (CBCT). After the anterior surface was rigidly aligned, the spinal canal alignment was checked and quantified using the mean-distance-to-agreement (MDA) and DICE similarity index, and surface-to-spine correlation was calculated.Results The reproducibility of neck curvatures using the 2xROI SGRT setup is verified and the mean neck-outline-matching difference is within ±2 mm in lateral photographic overlays. The chest-ROI alignment takes 110 ± 58 s and the face-ROI takes 60 ± 35 s. When the anterior body surface is aligned (MDA = 1.1 ± 0.6 mm, DICE = 0.96 ± 0.02,) the internal spinal canal is also aligned (MDA = 1.0 ± 0.3 mm, DICE = 0.84 ± 0.04) in 11 patients. The surface-to-spine correlation is c = 0.90 (MDA) and c = 0.85 (DICE).Conclusion This study demonstrates the feasibility of the novel 2-ROI SGRT setup technique to achieve reproducible neck and c-spine curvature regardless of neck visibility and availability as ROI. Staff training is needed to adopt this unconventional SGRT technique to improve patient setup.