PurposeThis is a foundational study in which multiorgan system point of care ultrasound (POCUS) and machine learning (ML) are used to mimic physician management decisions regarding the functional intravascular volume status (IVS) and need for diuretic therapy. We present this as an impactful use case of an application of ML in aided decision making for clinical practice. IVS represents complex physiologic interactions of the cardiac, renal, pulmonary, and other organ systems. In particular, we focus on vascular congestion and overload as an evolving concept in POCUS diagnosis and clinical relevance. It is critical for physicians to be able to evaluate IVS without disrupting workflow or exposing patients to unnecessary testing, radiation, or cost. This work utilized a small retrospective dataset as a feasibility test for ML binary classification of diuretic administration validated with clinical decision data. Future work will be directed toward artificial intelligence (AI) delivery at the bedside and assessment of the impact on patient-centered outcomes and physician workflow improvement.ApproachWe retrospectively reviewed and processed 1039 POCUS video clips, including cardiac, thoracic, and inferior vena cava (IVC) views. Multiorgan POCUS clips were correlated with clinical data extracted from the electronic health record and deidentified for algorithm training and validation. We implemented a two-stream three-dimensional (3D) deep learning approach that fuses heart and IVC data to perform binary classification of the need for diuretic use.ResultsOur proposed approach achieves high classification accuracy (84%) for the determination of diuretic use with 0.84 area under the receiver operating characteristic curve.ConclusionsOur two-stream 3D deep neural network is able to classify POCUS video clips that match physicians’ classification for or against diuretic use with high accuracy. This serves as a foundational step in the progress toward AI-aided diagnosis and AI implementation in the field of IVS evaluation by POCUS.
Cell phone usage while driving is common, but widely considered dangerous due to distraction to the driver. Because of the high number of accidents related to cell phone usage while driving, several states have enacted regulations that prohibit driver cell phone usage while driving. However, to enforce the regulation, current practice requires dispatching law enforcement officers at road side to visually examine incoming cars or having human operators manually examine image/video records to identify violators. Both of these practices are expensive, difficult, and ultimately ineffective. Therefore, there is a need for a semi-automatic or automatic solution to detect driver cell phone usage. In this paper, we propose a machine-learning-based method for detecting driver cell phone usage using a camera system directed at the vehicle’s front windshield. The developed method consists of two stages: first, the frontal windshield region localization using the deformable part model (DPM), next, we utilize Fisher vectors (FV) representation to classify the driver’s side of the windshield into cell phone usage violation and non-violation classes. The proposed method achieved about 95% accuracy with a data set of more than 100 images with drivers in a variety of challenging poses with or without cell phones.
It is of great value to be able to track image quality of a printing system and detect changes before/when it occurs. To do
that effectively, image quality data need to be constantly gathered and processed. A common approach is to print and
measure test-patterns over-time at a pre-determined schedule and then analyze the measured image quality data to
discover/detect changes. But due to the presence of other printer noise, such as page-to-page instability, mottle etc., it is
likely that the measured image quality data for a given image quality attribute of interest (e.g. streaks) at a given time is
governed by a statistical model rather than a deterministic one. This imposes difficulty for methods intended to detect
image quality changes reliably unless sufficient data of test samples are collected. However, these test samples are non-value-
add to the customers and should be minimized. An alternative is to directly measure and assess the image quality
attributes of interest from customer pages and post-processing them for detecting changes. In addition to the difficulty
caused by sources of other printer noise, variable image contents from customer pages further impose challenges in the
change detection. This paper addresses these issues and presents a feasible solution in which change points are detected
by statistical model-ranking.
Moiré in color printing is an undesirable visible artifact that can arise from overlaying multiple halftone color separations. Halftone geometric configurations designed to avoid moiré in the overlays strictly require that individual halftone color separations must possess a low degree of relative distortion. However, optical and mechanical errors of multiple imaging systems within a printer usually produce differences between the color planes in the trajectory and placement of the exposure spots. We study color halftone moiré due to these optical and mechanical errors for otherwise moiré-free halftone configurations. Distortions due to commonly used imaging systems in xerography (i.e., raster output scanners and image bars) are categorized into two classes that depend on the direction of the displacement errors [i.e., process direction distortions (such as shear, bow, and skew) and cross-process direction distortions (such as scanline magnification, magnification imbalance, and high-order scanline distortions)]. Using frequency vector representation of color halftones, we derive analytical expressions for acceptability bounds on these distortions. We evaluate the analytical expressions for a classical halftone screen configuration and a minimum rosette geometry to enable specification allocations for different imaging components in the design of an imaging system.
Individual halftone color separations must possess a low degree of distortion to avoid undesirable moiré in the
overlays that produce the process colors. Achieving low relative distortion requires precise registration between
the exposure devices used to write the halftone separations. However, optical and mechanical errors within the
multiple Raster Output Scanners (ROS's) or image bars of a printer result in differences in the trajectory and
placement of the exposure spots among color planes. In this paper, color halftone moiré due to ROS errors is
analyzed using a frequency vector representation of color halftones. We analyze three forms of process-direction
distortion: skew, shear, and bow. Each distortion is inspired from a practical printing system (i.e. while shear
and bow are observed in ROS systems, skew is observed in image bar imaging systems). The frequency vector
formalism is used to derive bounds on distortion for a classical halftone screen configuration (square cell equal
frequency halftones at 15°, 45°, and 75°). The bounds are examined for distortion of one halftone screen and the
analysis can be readily applied to distortion of multiple screens. The bounds can be used to develop specifications
for imaging components in the design of a ROS or image bar imaging system.
We present a specialized form of error diffusion (ED) that addresses certain long-standing problems associated with operating on images possessing halftone structure and other local high-contrast structures. For instance, image-quality defects often occur when rendering a scanned halftone image to printable form via quantization reduction. Rendering the scanned halftone via conventional ED produces fragmented dots, which can appear grainy and be unstable in printed density. Rendering by thresholding or rehalftoning often produces moiré, and descreening blurs the image. Another difficulty arises in printers that utilize a binary image path, where an image is rasterized directly to halftone form. In that form it is difficult to perform basic image processing operations such as applying a digital tone reproduction curve. Rank-order error diffusion (ROED) has been developed to address these problems. ROED utilizes brightness ranking of pixels within a diffusion mask to diffuse quantization error at a pixel. This approach results in an image-structure-adaptive quantization with useful properties. We describe the basic methodology of ROED as well as several applications in processing halftone images.
We present a specialized form of error diffusion that addresses certain long-standing problems associated with operating
on images possessing halftone structure as well as other images with local high contrast. For instance, when rendering
an image to printable form via quantization reduction, image quality defects often result if that image is a scanned
halftone. Rendering such an image via conventional error diffusion typically produces fragmented dots, which can
appear grainy and be unstable in printed density. Rendering by simple thresholding or rehalftoning often produces
moire, and descreening blurs the image. Another difficulty arises in printers that utilize a binary image path, where an
image is rasterized directly to halftone form. In that form it is very difficult to perform basic image processing
operations such as applying a digital tone reproduction curve. The image processing operator introduced in this paper,
rank-order error diffusion (ROED), has been developed to address these problems. ROED utilizes brightness ranking of
pixels within a diffusion mask to diffuse quantization error at a pixel. This approach to diffusion results in an imagestructure-
adaptive quantization with many useful properties. The present paper describes the basic methodology of
ROED as well as several applications.
Glossmark technology is a halftone-based digital imaging process to embed visible watermarks into xerographic color prints. The gloss of a xerographic print depends not only on surface roughness of paper and toner, but also on the microscopic structure created by the halftone process. The surface relief of a halftone image can be treated as a two-dimensional phase grating. The shape, or profile, of the surface relief determines the reflected pattern of the illumination. A strong angular differential gloss can be obtained by employing two anisotropic halftone screens in the halftone process. A careful design of these screens enables embedding Glossmark images while maintaining the high quality of the color reproduction. The printing process, that simultaneously creates high quality primary and Glossmark images in a single step, requires neither special equipment nor special paper or toner. Glossmark images, shown in a high contrast of gloss, provide a perfect simulation of the traditional paper watermarks, while their digital implementation makes it easy to embed variable data as digital watermarks into individual documents.
We have developed a new algorithm for determining the cross- section range of the heart from a sequence of SPECT projection images. The new algorithm provides accurate estimation of the heart range for a fully automatic myocardial perfusion SPECT processing system. The limits of the heart range are used for reconstructing transverse images for the subsequent analysis. The basis of the approach is the 1D pseudo motion analysis which has three major components, spatial feature to position mapping, knowledge-driven analysis of heart region, and heart range determination. The main advantage of the algorithm is that the processing is fully automatic regarding no user intervention and is less sensitive to the image intensity distribution comparing to other existing methods.
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